▼ Context: Chronic ankle instability (CAI) is associated with altered lower extremity kinematics and deficits in dynamic postural control in tasks such as the star excursion balance test (SEBT). Relative phase analysis (RP), using segment displacement and velocity, can be used to describe the coordination strategies between segments; but has had limited application to understanding CAI deficits. Objective: The purpose of this study was to analyze coordination of the limb segments of the lower extremity using RP during dynamic postural control assessment with the SEBT in subjects with and without CAI. Design: A one between (Group), one within (Side) repeated measures design. Setting: Athletic Training Research Laboratory. Participants: Fourteen subjects with unilateral CAI (5 male, 9 female; age 19.6±1.45years; height: 174.72cm; mass: 70.79 kg) and fourteen healthy subjects (5 male, 9 female; age 21.2±3.1years; height 173.08cm; mass: 70.95kg) volunteered for this study. Interventions: Subjects had their leg lengths measured and electromagnetic sensors placed on their first stance leg at the dorsum of the foot, lateral shank, lateral thigh, and the sacrum. Reaching distance was recorded and the kinematic data was sampled at 100hz using MotionMonitor software during five successful trials of the posteriormedial direction of the SEBT. The procedure was then repeated on the other limb, with the order of limbs being counterbalanced. The mean of the reaching distances, normalized to stance limb leg length (MAXD), were used. A cubic spline equation was applied to the kinematic data so that trials of different lengths could be compared to one another. Using Microsoft Excel, mean absolute RP (MARP) was calculated for the Ankle-Knee (AKMARP), Knee-Hip (KHMARP), and Ankle-Hip (AHMARP) segments. For the MARP comparisons, the SEBT task was divided into 4 equal quarters to examine specific portions of the task. Main Outcome Measure(s): MAXD, AKMARP, KHMARP, AHMARP. Results: There was a statistically significant Group by Side interaction (F1,26=4.702; p=0.039) for the normalized reaching distance. Post-hoc analysis revealed that the Injured side of the CAI group(82.2±8.29%) produced significantly less reaching distance than the Non-injured side(85.6±7.89%). For the Ankle-Knee relationship during the first quarter of the SEBT task, there was a nearly statistically significant Group-by-Side Interaction (F1,26=3.88; p=0.059). When comparing the first quarter AKMARP of the Injured Side of the CAI group (49.23±14.90) to the Non-injured Side (32.44±18.75), a large effect size was observed (d=1.00). There were no significant influences of Group or Side on the AHMARP or the KHMARP relationships. Conclusions: Deficits in dynamic postural control in CAI subjects were observed. While not statistically significant, a large effect size suggests that an ankle-knee coordination during the task existed in the CAI group. Further research should examine intralimb coordination patterns during dynamic tasks as a source for developing more efficient interventions for CAI. Advisors/Committee Members: Gribble, Phillip.

▼ The focus of injury prevention generally lies within recognizing muscular strength and flexibility imbalances. One method of detecting muscular strength and flexibility imbalances is the Functional Movement ScreenTM (FMSTM). The purpose of this study is to investigate the reliability of the FMSTM since only one previous study has investigated the reliability of this screening tool. Three subjects were recruited and were videotaped performing the FMSTM test. Thirty seven evaluators were divided into one of four groups, based on level of experience. The evaluators watched each video-subject perform each exercise three times. The evaluators then came back a week later and watched the video-subjects again, but in a different order. The results demonstrated significant Group by Time differences (F3,33 = 3.67; p= .022). The main effect for Time also was significant (1,33=4.55; p=0.041). Overall, the raters scored the video-subjects higher on Day 2 (13.77±0.98) than they did on Day 1 (13.46±0.92). As hypothesized, the individuals who were classified as being FMSTM experts had the highest rate of reliability (ICC = .946). Therefore, reliability of using the FMSTM, increases as clinical and FMSTM experience increases. These results indicate that the FMSTM has high reliability and can be confidently used by trained individuals. Advisors/Committee Members: Gribble, Phillip.

▼ Objective: To examine how sex, sport, bracing, taping, and session (competition/practice) influence the injury rates of the ankle among high school athletes in the Toledo, OH area. Design and Setting: The Athletic Trainers at each high school was contacted every week and asked to report the data from the previous week. The information collected was transferred to a data collection form by the principal investigator and then entered into Excel spreadsheet for processing. The number of the total injuries for each injury category listed on the questionnaire served as the dependant variables, and the independent variables were sport, sex, protection, and session. For each independent variable, we used pure descriptives, and reported the number of injuries for each dependant variable/injury category from the survey. Data Source: Athletes ranging from 14-18 years old participating in the sports of volleyball, football, men’s and women’s soccer, and men’s and women’s basketball. Measurements: The following injuries were monitored: Grade I lateral and medial ankle sprain, Grade II lateral and medial ankle sprain, Grade III lateral and medial ankle sprain, dislocation, Achilles tendon Grade I, Grade II, and Grade III or rupture, peroneal tendon injuries Grade I, Grade II, and Grade II, and fracture, and graded by a certified Athletic Trainer. Results: Football and basketball had higher incidences of lateral ankle sprains grade I than volleyball and soccer, and basketball had more injuries than football. When the total number of ankle/foot injuries was considered for each sport, football had the most injuries. Basketball was next, and then there was a large drop off in the number of injuries in volleyball and soccer. Overall, males had four times more injuries than females when all ankle/foot injuries were combined. There were higher numbers of ankle/foot injuries in practice than in competition when all injuries were combined. There was a higher amount of injuries to the foot/ankle in athletes with no protection. Bracing had the next highest amount of injuries, and tape was only slightly lower than bracing. Conclusions: The evidence suggests that football and basketball have higher amounts of injuries, males are injured more than females, competition injuries are more severe than practice injuries, and taping and bracing were better than no protection with taping being slightly better than bracing. Advisors/Committee Members: Gribble, Phillip.

▼ Pre-participation screening is a critical part of preventing injury in an athletic population. It helps clinicians determine if athletes are physically fit for participation or if they are at serious risk for health complications as a result of participation. The Functional Movement Screen (FMSTM) is a tool that has been suggested could help clinicians evaluate the normal movement patterns that athletes use during athletic performance and daily living. Determine if the FMS is a reliable measure of injury differences suffered during a competitive season in intercollegiate basketball athletes. This will be important for clinicians in applying and utilizing the information from that FMS if it is verified that the test can be used to predict injury, and become a test that clinicians can use to quickly and cost effectively screen their athletes for injury risk. Advisors/Committee Members: Gribble, Phillip.

▼ Background and Purpose. The purpose of this study was to investigate the effects of a ten-week hippotherapy (HPOT) program on several temporal-spatial variables of gait as well as range of motion (ROM) at the trunk, pelvis, and hip joints in all three planes of motion over the stance phase of the gait cycle. Hippotherapy has been used as a tool by therapists for several decades to address functional limitations in patients with neuromusculoskeletal diagnoses, however, more objective measurements and data supporting HPOT as a therapeutic tool to help improve ambulation are needed. Subjects. Eleven children (6 males, 5 females; 7.9 ± 2.7 years) with neurological disorders resulting in impairments in ambulation and gross motor control in standing participated in this study. Methods. All subjects were receiving weekly traditional land-based physical or occupational therapy and elected to participate in HPOT for ten weekly sessions instead. Three-dimensional (3-D) gait analyses were performed with each child prior to the first session of HPOT. Data on cadence, velocity, stride length and step width were collected along with data regarding trunk, pelvis, and hip joint ROM. Subjects then participated in ten weekly sessions of HPOT and a second gait analysis was completed for each subject after completion of the sessions. A series of paired t-tests was performed on the temporal-spatial and kinematic data for each segment. Families of pairwise comparisons were used with the family-wise error rate set at 0.25. Results. Although no statistically significant differences were found from pre to post test for temporal-spatial data, trends in improved cadence, velocity, and stride length were seen. Significant improvements in sagittal plane pelvic and hip joint positions at initial contact (IC) and toe off (TO) phases of the gait cycle were found, and each demonstrated large effect sizes as determined via Cohen’s d. No differences in trunk ROM were determined, although trends towards more normal values were observed in all three planes at IC and TO. Discussion and Conclusion. The group’s improvement in sagittal plane pelvic and hip joint positioning and trends for improvement in trunk position, cadence, velocity, and stride length during ambulation may indicate increased postural control during the stance phase of gait after ten sessions of HPOT. Advisors/Committee Members: Armstrong, Charles.

▼ Women are capable of longer endurance time compared with men for contractions performed at low intensities. The purpose of the study was to compare endurance time, EMG characteristics, muscle blood flow (MBF) and recovery time between men (n =10) and women (n =10) at 20%, 50% and 80% MVC using handgrip dynamometer while performing continuous fatigue protocol. The absolute forces for men was significantly greater then women (389.9 ± 10.11 vs. 215.83 ± 5.6, F=53.420, p<0.001, ηp2= 0.748). However, there was no significant difference in the endurance time between men and women at 20% (262.80 ± 100.89 vs. 336 ± 159.03, p= 0.235); 50% (63.80 ± 23.3 vs. 64.4 ± 29.97, p =0.961) and 80% MVC (14.30 ± 7.36 vs. 13.10 ± 7.25, p= 0.718). Normalized IEMG between men and women increased in a similar non-linear fashion over time during all the three intensities, with the magnitude of NIEMG being proportional to the intensity of contraction. MBF increased from the onset of contraction to fatigue in both men and women (19.629-66.313 ± 2.135 ml/min, p<0.05). At exercise times ≥ 60% of total time to exhaustion, MBF was higher (p<0.05) in men compared to women. However when MBF was expressed relative to muscle mass, there was no difference between men and women at any time point examined. Also after reaching exhaustion, the percent decrease in MVC force (N) was significantly greater following the 20% MVC (mean ± SD, 34.97% ± 10.84%) and 50% MVC (mean ± SD, 33.01% ± 7.59%), than the 80% MVC (mean ± SD, 23.55% ± 4.35%). The time course of MVC force recovery was significantly greater following the 20% MVC and 50% MVC, than the 80% MVC. The percent MVC force decrease at 45 min was not observed to be significantly different between the three different contraction intensities (mean ± SD, 20% MVC: 8.53% ± 4.52%; 50% MVC: 6.56% ± 13.80%; 80% MVC: 6.10% ± 8.49%). In conclusion, considerable inter-subject variability resulted in a similar endurance time between genders at low intensity. However, the results of this study indicate that gender difference in muscle fatigue as reported in previous studies may not be related to absolute and relative force or relative muscle blood flow. The difference in absolute muscle blood with men requiring higher blood flow to maintain the same relative force as women may be related to gender differences in muscle fatigue. Also, the related increase in IEMG and decrease in force after the exhaustion is related to the intensity of the effort. Advisors/Committee Members: Pincivero, Danny.

▼ This dissertation examined the effect of different exercise-induced blood flow patterns on endothelial function in humans. Young and older subjects performed dynamic muscle contractions to modulate blood flow patterns during exercise. Conduit artery mean blood flow was measured during exercise using ultrasound Doppler. Antegrade blood flow, retrograde blood flow, and shear stress were computed. Endothelial-dependent vasodilation was assessed by measuring brachial artery flow-mediated vasodilation (FMD) and peak reactive hyperemia using ultrasound Doppler and venous strain-gauge plethysmography, respectively. Venous blood samples were collected by venipuncture and analyzed for plasma levels of von Willebrand Factor (vWF), protein carbonyls, and thiobarbituric acid reactive substances (TBARS).Shear stress showed a negative curvilinear relationship with vascular resistance during exercise. Retrograde blood flow was positively correlated with shear stress and negatively correlated with vascular resistance during exercise. The incorporation of retrograde blood flow in the exercise blood flow pattern was correlated to the oscillatory behavior of flow, and increased the amplitude of blood flow pulsatility. These results suggest that the pattern of blood flow is associated with endothelial function and demonstrated by changes in vascular resistance during exercise. Endothelial activation, as assessed by changes in plasma levels of vWF, was not related to different exercise-induced blood flow patterns during dynamic exercise. However, exercise-induced shear stress was positively correlated to plasma levels of vWF in older but not young subjects. Acute dynamic exercise resulted in a decrease in FMD and reactive hyperemia. The decrease in endothelial-dependent vasodilation was not correlated to exercise-blood flow patterns, but was negatively correlated with contractile work. In addition, plasma levels of protein carbonyls (biomarker of protein oxidation) were increased following dynamic exercise and were positively correlated with contractile work. These results demonstrate that endothelial dysfunction can be induced following acute dynamic exercise, and suggests that the decrease may be mediated by oxidative stress. Dynamic forearm exercise training for six weeks at different contraction velocities producing varying blood flow patterns did not differentially improve endothelial function in older subjects. Rather, forearm training increased the peak diameter in response to FMD, decreased basal levels of shear stress, lowered the cardiovascular response to submaximal exercise, and lowered basal plasma levels of TBARS, and increased basal plasma levels of protein carbonyls. In summary, these observations demonstrate the influence of exercise-induced blood flow patterns on endothelial function in humans. Advisors/Committee Members: Scheuermann, Barry W.

▼ Context: Patellofemoral pain syndrome (PFPS) is a maltifactorial knee condition. It has been suggested that alteration in hip musculature activation and excessive knee valgus are two of the major contributions to PFPS. However, the influence of hip muscle activation and knee kinematics during dynamic activity has not been explored fully. Objective: The primary purpose of this study was to compare hip and knee muscle activities and frontal plane knee kinematics during the anterior direction of the Star Excursion Balance Test (SEBT) between a PFPS group and a healthy group. The secondary purpose was to determine whether pain level and performance as measured by the reach distance of the dynamic postural control task may be associated with PFPS. Design: Case-controlled cohort study with repeated measures for the VAS. Setting: Athletic training research laboratory. Patients or Other Participants: Twenty eight subjects participated in this study and completed the test (14 PFPS: Age= 21.07±3.27yrs, Ht= 172.09±10.26cm, Mass= 69.96±9.05kg; 14 Control: Age= 20.93±3.00yrs, Ht= 170.18 ±8.94cm, Mass= 70.25 ±8.57kg) Subjects with PFPS reported minimal 2 months of anterior or lateral knee pain with walking, running, ascent and descent of stair climbing, kneeling, squatting, and sitting for long periods of time. Interventions: Participants performed 3 maximal voluntary isometric contractions (MVIC) in hip abduction, extension, external rotation, and knee extension and 5 anterior reaches of the SEBT. Main Outcome Measures: Frontal plane knee kinematics, anterior reach distance during the SEBT, and normalized average electromyography (Norm Avg EMG (%MVIC)) of the gluteus maximus (GMax), gluteus medius (GMed), and the vastus medialis (VM) were measured. In addition, knee pain was assessed with the Visual Analog Scale (VAS) before, during and after the task. Results: Comparing to the control group, PFPS group demonstrated increased knee valgus angle at touchdown, the point of the maximum reach (p=0.047), and significantly less varus displacement during the SEBT (p=.011). When observing the anterior-direction SEBT, reach distances were significantly shorter in PFPS group compared to the healthy group (p=.014). For pain on the visual analogue scale (VAS), there was a statistically significant group by time interaction for VAS (F2,52=4.70, p<.001). PFPS group demonstrated significantly increased pain at pre, during, and post tasks. In addition, subjects with PFPS demonstrated significantly increased pain during and post tests compared to pre test, and increased pain during test compared to post test. There was a statistically increased VM normalized average EMG in the PFPS group compared to the control group while there was no statistically significant difference in the iEMG of the gluteus medius and gluteus maximus between groups. Conclusion: The results derived from our study indicate that PFPS subjects demonstrate increased knee valgus angle in the anterior reach task on the SEBT. In addition, the PFPS group demonstrated shorter reach distance on the SEBT, along with increased pain on the VAS. On the contrary to our hypothesis, subjects with PFPS demonstrated greater VM activities than healthy subjects. In the sagittal plane movement, VM may play an important role to maintain the balance, while GMed and GMax may not be the primary muscle for the postural control during the task. During a common sagittal plane rehabilitation activity, it may be important for clinicians to observe differences in frontal plane positioning at the knee with PFPS. Advisors/Committee Members: Gribble, Philip.

▼ An Abstract of Hip Rotation Range of Motion Asymmetry in Elite Female Golfers Heather R. Gulgin Submitted as partial fulfillment of the requirements for the Doctor of Philosophy in Exercise Science The University of Toledo May 2005 The purpose of this study was to examine hip rotation ROM in elite female golfers and age-matched controls. Previous studies have shown that glenohumeral joint ER increases in the dominant arm (relative to the non-dominant arm) when participating in sports that require repetitive unilateral overhead throwing/serving motions. However, it is unknown if the lower extremities accommodate in the same way when individuals participate in repetitive motions for a particular sport skill. The current study examined hip rotation ROM anatomical limits in a passive and WB condition. Furthermore, the golfer’s hip ROM and velocities during the golf swing were analyzed. Subjects included 15 collegiate golfers (19.6 ± 1.4 yrs.) and 15 age-matched controls (20.5 ± 1.7 yrs.). Each subject was tested for passive (prone) and WB hip rotation ROM. Three trials for each measurement were made bilaterally in both internal rotation (IR) and external rotation (ER), with the mean used for analysis. Kinematic data for the WB ROM and golf swing were collected using an eight camera Motion Analysis System. Separate two-way repeated measures analysis of variance were used to compare group and side for IR and ER (significance at alpha = 0.05). The results indicated that, in general, both golfers and controls have similar hip rotation ROM. However, the golfer’s demonstrated a significant decrease in left hip passive IR relative to their right hip. Previous literature has indicated a link with side-to-side hip rotation asymmetry and low back pain. Furthermore, low back pain is the leading injury complaint among golfers, and thus the hip rotation asymmetry may be considered as a contributing factor in low back pain. Advisors/Committee Members: Armstrong, Charles.

▼ Context: Lateral ankle sprain is the most common lower extremity injury in sport. It is well documented that previous ankle sprains can predispose an individual to future injuries and is hypothesized that altered input from the damaged ligaments may inhibit motor neuron pool excitability and lead to diminished muscle activation and chronic weakness of surrounding muscles. This phenomenon, known as arthrogenic muscle inhibition (AMI), can be a limiting factor in rehabilitation and the pathways involved with these neuromuscular deficits are not completely understood. Objective: Determine the effect of acute LAS on reflex excitability of lower leg musculature over a 14 day period compared to healthy matched controls. Additionally, to determine the relationship between H-reflex and dynamic postural control, self-reported measures of function and pain in individuals with LAS within 36 hours of injury. Design: Case-Control. Setting: Clinical Laboratory. Participants: Eight patients with acute lateral ankle sprain (3 males, 5 females; age= 21±1.85 years, height=174.63±9.77 cm, mass=73.81±19.56 kg) and eight healthy participants (3 males, 5 females: age=20.38±1.60 years, height=173.99±9.21 cm, mass=73.98±17.87 kg) volunteered to participate in this study. All participants were individuals from the University community. Interventions: All participants reported for a total of 5 test sessions at 36 hours, 5, 7, 10, and 14 days following the initial ankle sprain; or from the day of enrollment as a healthy control. Spinal reflexive excitability of the lower leg musculature was assessed bilaterally in each participant as well as self-reported function and pain, and dynamic balance. Main Outcomes: For each lower leg muscle’s spinal reflex excitability, a repeated measures 2x5 ANOVA was used to determine if differences existed between groups over time. Spearman’s rho correlation coefficients were calculated in the injured group between measures of lower leg spinal reflex excitability and self-reported disability, pain, function, and dynamic stability, at 36 hours following the initial injury. Alpha levels were set a priori at P<.05 Results: A significant main effect for group was found in Soleus spinal reflexive excitability (F(1,13)=.182, p=0.011). ). A significant correlation was found between FL and function at 36 hours (r=.733, r2=.545, p=.025). Conclusion: Our results were similar to previous studies investigating differences in lower leg excitability in individuals with functional ankle instability. We found a significant correlation between function and FL only; however, because spinal reflex excitability is not the only factor associated with determining function, future studies should consider other factors such as ankle range of motion and girth measurements to quantify swelling. Those who suffer an acute LAS exhibit decreased spinal reflex excitability compared to healthy counterparts within two-weeks of the initial injury. While studies investigating the acute alterations in spinal reflexes of the lower leg muscles are limited, these results should be taken into consideration in ongoing treatment of acute lateral ankle sprains. Advisors/Committee Members: Pietrosimone, Brian.

▼ Objective: To examine the potential hormone contributions to ankle laxity, with an instrumented ankle arthrometer, and dynamic postural control with the Star Excursion Balance Test. These measures were performed on females in their pre-ovulatory and post-ovulatory phases of their menstrual cycle with a cohort group of male matched control subjects tested at similar times of the month. Design and Setting: Three separate ANOVAs were performed for the dependant variables of medial/lateral ankle laxity, anterior/posterior ankle laxity and maximum normalized reaching distance in the Star Excursion Balance Test (SEBT). Significance was set at p<0.05. All data were collected in a research laboratory. Subjects: 14 healthy females (29±7.05 yrs; 172.32±7.91cm; 68.05±9.27 kg) and 27 healthy males (23.22±4.06 yrs; 180.34±6.98 cm; 81.72±11.19 kg) participated in this study. Measurements: Female subjects used ovulation kits for three months to determine the time of ovulation and were tested in the lab with the ankle arthrometer and SEBT corresponding to their pre-ovulatory and post-ovulatory time periods. Males were tested at similar times and used as a control. To assess ankle stability a portable ankle arthrometer (Blue Bay Medical, Inc, Navarre, FL) was used. Anterior/posterior loading was performed first following by medial/lateral loading. Three trials were done in each direction on each ankle. For dynamic postural control, a custom made mat with eight measuring tapes rigidly fixed at 45° angles to each other was used to assess reaching distance in the SEBT. Only the posterior medial reaching distance was used and four practice trials were completed followed by five actual trials. The reaching test was performed on each leg and leg length was also measured. Results: For ML laxity there was a statistically significant sex main effect (F1,39=7.238; p=0.01). There was no statistically significant Time main effect or Side main effect for ML laxity. There were also no statistically significant interactions for Time by Sex, Side by Sex, Time by Side or Time by Side by Sex for ML laxity. For AP laxity there was no statistically significant Sex main effect or Time main effect. There was a statistically significant Side main effect for AP laxity (F1=5.280; p=0.027). There were no statistically significant interactions for Time by Sex, Side by Sex, Time by Side or Time by Side by Sex. For maximum normalized reaching distance in the SEBT there was a statistically significant Sex main effect (F1=5.093; p=0.030). There was no statistically Time main effect or Side main effect for the average normalized reaching distance. There were also no statistically significant interactions found for Time by Sex, Side by Sex, Time by Side or Time by Side by Sex. Conclusions: The results from this study suggest that hormone fluctuation during the menstrual cycle (pre-ovulatory compared to post-ovulatory) does not have an effect on ankle laxity in the medial/lateral and anterior/posterior directions or dynamic postural control. This was evidenced through the use of the ankle arthrometer and the results of the Star Excursion Balance Test. There have been few studies that have considered the impact of hormone fluctuation on ankle instability. Further research should aim to strengthen the finding of this study by conducting similar projects looking at more subjects, looking at different points in the menstrual cycle and perhaps looking at different areas of the body to rule out systemic ligament laxity due to hormone influence. Advisors/Committee Members: Gribble, Phillip.

▼ Objective: The objective of this study was to determine the efficacy of a posterior talar joint mobilization at altering both spinal reflexive and corticomotor neural excitability in patients with chronic ankle instability (CAI). Design and Setting: A single blinded, randomized control trial was conducted in a laboratory setting. Subjects: Sixteen patients with CAI were randomly assigned to an experimental group who received a joint mobilization treatment (4 males, 4 females; 22.63±4.21 years; 1.72±5.40 m; 73.01±12.11 kg), or to a control group (2 males, 6 females; 20.63±1.77 years; 164.94±8.20 m; 63.99±12.91 kg). Procedure: Experimental measures were measured pre- and post-intervention period. Patients were positioned in a Biodex System II Pro dynamometer during excitability testing. The Hoffmann reflex (H-reflex) of the tibialis anterior, fibularis longus, and soleus muscles were measured to estimate spinal reflex excitability using a BIOPAC MP150. Maximal H-reflexes were normalized to the maximal muscle response to create an H:M ratio used for analysis. A Magstim Rapid was utilized to administer the transcranial magnetic stimulation to the motor cortex during corticomotor testing. The Biodex dynomometer was used to collect maximal voluntary isometric torques for each muscle. Submaximal contractions at five percent of this maximal contraction were used to standardize voluntary contraction during corticomotor testing. Active motor threshold (AMT) was established as the lowest intensity required to elicit a motor evoked potential (MEP) of 100 µV amplitude in at least 5 of 10 trials. Five MEPs were collected at 120% of AMT then normalized to the M-wave for analysis. After the pre-test, a Certified Athletic Trainer administered three 60 second grade IV posterior talar mobilizations to participants in the experimental group. Participants in the control group sat quietly for the same duration needed to perform the joint mobilization. Significance was detemined using dependent t-tests between pre and post values (p<0.05). Cohen’s d effect sizes with corresponding 95% confidence intervals were calculated. Results: No significant differences were found for spinal reflex excitability in all muscles and effect sizes were small with wide confidence intervals. Although not significant (p=0.20), soleus AMT decreased following the mobilization producing an effect size of d=-0.71. Corticomotor excitability at 120% of AMT for all muscles were not significant and the effects sizes were small. Conclusion: This study provides limited support that a posterior talar joint mobilization has the potential to restore corticomotor excitability of the lower leg musculature in people with chronic ankle instability. Restoration of neural excitability is an imperative step in rehabilitation that will allow for greater rehabilitation gains which may result in quicker return to functional activities. Advisors/Committee Members: Pietrosimone, Brian.

▼ The purpose of this dissertation was to determine if limb blood flow was sufficient for the performance of handgrip exercise utilizing a variety of muscle contraction patterns, exercise intensities, and exercise durations. Subjects first performed heavy intensity intermittent isometric and dynamic handgrip exercise to examine the effect of muscle contraction pattern on mean blood flow and exercise tolerance. Brachial artery mean blood flow was measured throughout exercise using Doppler ultrasound. Electromyography (EMG) of the forearm muscles was also measured, and the time-tension integral was calculated to assure a similar work rate between protocols. The Time to task failure was significantly greater in intermittent isometric than dynamic exercise. However, there were no differences in mean blood flow following the first minute of exercise or in the normalized iEMG/time-tension integral ratio. These results indicate that motor unit recruitment patterns, mean blood flow and presumably oxygen delivery to the working muscles were similar between conditions, and therefore may not be a primary determinant of exercise tolerance during handgrip exercise.Compared to the mean blood flow response during dynamic handgrip exercise, there is a transient overshoot in muscle blood flow early in recovery which has been used as evidence to suggest that blood flow is inadequate for the metabolic requirements of the exercise. If muscle blood flow is limited during handgrip exercise, one might reason that progressive increases in exercise duration would lead to greater increases in post-exercise blood flow, consistent with the results of post-occlusive studies. In a subsequent study, subjects performed four bouts each moderate and heavy intensity dynamic handgrip exercise to examine the effect of progressively increasing exercise duration on exercise and recovery blood flow responses. Brachial artery blood flow was measured during exercise and 5 min of recovery using Doppler ultrasound. Peak blood flow was calculated for both end-exercise and early recovery periods. The area under the recovery blood flow curve (5 min) was determined and used as an index of total post-exercise hyperemia. Within each exercise intensity, peak blood flow during exercise exceeded peak recovery blood flow but was independent of exercise duration. Similarly, the area under the recovery curve was greater for heavy than moderate exercise but was not associated with exercise duration. These observations suggest that the transient overshoot in blood flow during early recovery does not reflect a blood flow limitation during exercise. Therefore, neither protocol provided evidence that brachial artery blood flow was inadequate to meet metabolic requirements. Advisors/Committee Members: Scheuermann, Barry W.

▼ Objective: To determine the intrarater reliability of transcranial magnetic stimulation (TMS) in both the quadriceps muscles and the fibularis longus muscles. Long term assessment of reliability and agreement between measures was conducted through two separate testing sessions with four weeks from baseline to follow-up. Design and Setting: Interclass Correlation Coefficients (ICCs) and Bland-Altman plots were created to assess the reliability of the dependent variables of Active Motor Threshold (AMT) and Motor Evoked Potential (MEP) wave size normalized to the M-wave. All data were collected in a research laboratory. Subjects: Twenty participants were initially included in this study; however two were deemed to be outliers and were removed during data analysis. Eighteen healthy subjects (8 male, 10 female; 22.35 + 2.3yrs; 1.71 + 0.11m; 73.61 + 16.77kg ) were included in the final analysis. Measurements: The MEPs were elicited using the Magstim Rapid (Magstim Company, Wales, UK) via a double cone coil (Magstim Company, Wales, UK). AMT was defined as the lowest output required to elicit 5 positive waves > 0.1µV, with 6 negative waves < 100 µV recorded at the output 1% less. After threshold was found, 5 MEPs were recorded at both 120 and 140% of AMT. The average of these 5 MEPs was calculated then divided by the maximal muscle output, which was found through stimulating the mixed nerve controlling the muscles being examined and increasing the stimulus until a maximal muscle reflex was achieved. Results: For AMT, the dominant and nondominant quadriceps showed good reliability (ICC3,1 = 0.873 and 0.828, respectively), but showed a lesser degree of agreement through Bland-Altman plot analysis. Conversely, MEP measurements at both 120 and 140% of AMT showed excellent reliability (ICC3,5 = 0.917 and 0.975, respectively) for the dominant quadriceps and also acceptable agreement between sessions. The nondominant quadriceps showed excellent reliability at both 120% (ICC3,5 = 0.954) and 140% (ICC3,5 = 0.982) of AMT. Nondominant quadriceps also showed strong agreement between sessions. For the AMT of the dominant fibularis reliability was poor (ICC3,1 = 0.522) but agreement was good. Nondominant fibularis AMT has good reliability (ICC3,5 = 0.763) and also good agreement. While all MEP measurements for the fibularis longus showed good or excellent reliability (Dominant 120% = 0.863; Dominant 140% = 0.939; Nondominant 120% = 0.919; Nondominant 140% = 0.726) Bland-Altman plot analysis showed poor agreement between the two sessions. Conclusions: TMS is a reliable tool for measuring levels of cortical excitability in the quadriceps and fibularis longus muscles over time. However, not all outcome measures are reliable for all four muscles that were studied. When looking at the quadriceps muscles, AMT should not be used as the outcome measure to be studied. MEP amplitude at 120 or 140% of AMT should be used for comparisons. Conversely AMT should be used when assessing cortical excitability in the fibularis longus muscles, not MEP at either 120 or 140% of AMT. Advisors/Committee Members: Pietrosimone, Brian.

▼ Objective: To examine acute lower extremity injury rates of the secondary school athlete; specifically considering what age group is more inclined to injury, and at what time during competition the athlete is more at risk. Design, Setting, and Data Source: Data on high school age athletes were collected from eleven Toledo Ohio and Southern Michigan area high schools in the sports of football, volleyball, boy’s and girl’s soccer, and boy’s and girl’s basketball. Middle school age data were collected from Toledo area youth leagues in the sports of girls and boys basketball, football, and girls and boys soccer. Athletes’ ages ranged from 10-19 years of age. All data were collected by certified Athletic Trainers and provided to the primary investigator. The number of each type of injury served as the dependant variables. The independent variables were age (middle school age, high school age), timing of injury, (1st quarter, 2nd quarter, 3rd quarter, 4th quarter) sex, and competition/ practice. For each dependant variable, frequency descriptives are represented according to each independent variable. Measurements: An exposure was defined by any player that participated on each day. The following injuries were tracked: lateral and medial ankle sprains, peroneal tendon sprains, achilles tendon strains, fracture or dislocation of the ankle and knee joint, hamstring and quadriceps strains, anterior and posterior cruciate ligament injuries, medial and lateral collateral ligament injuries, patellar dislocation, and medial and lateral meniscus injuries. Results: Middle school age athletes had a higher injury rate (4.03 injuries per 1000 exposures) compared to high school age athletes. Overall, in the breakdown of a competition, athletes were most likely to get injured during the 3rd quarter. Middle school age and high school age athletes recorded 0.51 injuries per 1000 in the 1st quarter, 1.22 injuries per 1000 in the 2nd quarter, 2.08 injuries per 1000 in the 3rd quarter, and 1.28 injuries per 1000 in the 4th quarter. When comparing practice injuries versus competition injuries, there were more injuries in practice. There were 1.70 injuries recorded for every 1000 practice exposures; while there were 1.50 injuries for every 1000 games exposures. When comparing males versus female injury rates, males overall had a larger injury rate (5.82 injuries/1000 exposures) compared with females (1.34 injuries/1000). Conclusions: On the whole middle school aged males in the 3rd quarter are the most at risk group, with high school males closely behind. Advisors/Committee Members: Gribble, Phillip.

▼ The purpose of this study was to examine the effect of changing the midsole density of athletic shoes on impact forces upon landing during a non-rhythmic athletic activity. Previous studies showed that changing the density of the midsole had neither a positive or negative effect on running, which is a repetitive rhythmic athletic activity. This investigation examined the influence of variations in athletic shoe midsole density on vertical ground reaction forces, loading rates, peak joint moments, and examined which specific kinematic variables were affected upon landing after a non-rhythmic vertical jump. Subjects included 20 female, NCAA volleyball athletes (mean=21.1; sd=2.84 years). Each subject was tested in three different athletic shoe conditions: control midsole, soft midsole, and hard midsole. For each of the athletic shoe midsole conditions, the subjects performed 10 volleyball approaches and spike jumps; landing onto two force platforms to measure impact forces. Kinematic data was collected simultaneously with the kinetic data using a six camera Motion Analysis system. Data was collected for each subject for a total of 30 trials (10 trials X 3 midsole conditions). A one-way repeated measures analysis of variance was used to compare the three different shoe conditions (significance; p = .05). Results indicated that variations in midsole density do not significantly affect impact forces or loading rates upon landing. Kinematic variables failed to sufficiently explain this result. It is possible that athletes may use neuromuscular adaptations to account for changes in midsole density during impact. More research is needed to determine if changes in muscle activity are used as a possible strategy during landing to affect impact forces. Further research is needed on the effects of athletic shoe midsole density during landings from non-rhythmic athletic activities. Advisors/Committee Members: Armstrong, Charles W.

▼ The effects of practice and chronic ankle instability (CAI) on movement economy andcoordination were investigated in order to determine if those with CAI demonstrate the same level of metabolic and neuromuscular adaptability as those without structural and functional deficits. Two groups of 10 participants (CAI and HEA) were matched according to gender, age, height, weight, and had a designated “injured” and “uninjured” leg. Participants completed three, six minute sessions of an alternating-side posterior lunge exercise on non-consecutive days during which oxygen consumption, heart rate, perceived exertion, and three-dimensional biomechanical data was collected. Intralimb coordination was determined through relative phase analysis of the shank-thigh, foot-shank, and foot-thigh relationships during support and nonsupport and by calculating mean absolute relative phase (MARP) and the standard deviation of mean absolute relative phase (MARP-SD). Metabolic data were analyzed with two-way ANOVAs (group x day) and relative phase data were analyzed with three-way ANOVAs (group x side x day). Oxygen consumption, heart rate, and perceived exertion demonstrated main effects for “day”. Tukey’s post hoc analysis indicated significant decreases in oxygen consumption, heart rate, and perceived exertion. Perceived exertion also demonstrated a main effect for “group” with a significantly higher rating for CAI. Five of the intralimb coordination variables demonstrated significant group or group x side differences in MARP, five demonstrated significant group or side differences in MARP-SD, and eleven exhibited qualitative differences in continuous relative phase curves. Although CAI demonstrated differences in perceived exertion, intralimb coordination patterns, and the variability of intralimb coordination patterns, there were no differences in the adaptive responses of the metabolic and neuromuscular systems. Advisors/Committee Members: Armstrong, Charles.

▼ Objective: To determine the effects of knee flexion and extension torque productions in the concentric and eccentric manners on the amount of time needed to stabilize following a jump landing task. Design and Setting: Two step-wise regression analysis were performed for time to stabilization in the anterior/posterior (APTTS) and medial/lateral (MLTTS) directions. Also performed wer 6 independent t-tests comparing soccer to volleyball athletes. Significance was set at p<0.05. All data was collected in a research laboratory. Subjects: Eleven healthy female athletes participated in this study. Six of these athletes were from the soccer team and five from the volleyball team at the University of Toledo. Measurements: Subjects participated in two separate testing sessions. Session 1 was used to take a medical history to ensure that all subjects met the inclusion criteria as well as collection of TTS data. Five successful trials of a jump landing task were performed on the dominant extremity. The jump landing task consisted of a single leg landing from a jump height equivalent to 50% of the subject’s maximum jump height (50% Vertmax). Subjects stood 70 cm from the center of the forceplate (Bertec Corp; Columbus, OH) then jumped with two feet, reached up and touched the indicated marker, and landed on the dominant extremity on the forceplate. During session 2 subjects were asked to perform isokinetic testing on a Biodex System 2 (Biodex Medical Systems Inc., Shirley NY). Isokinetic testing was performed on the dominant extremity at 120 degrees per second in knee flexion and extension in the concentric and eccentric manners. Results: For APTTS and MLTTS there was no statistical significance with none of the predictors significantly predicting variance in TTS. All four knee torque production variables were not statistically significant difference between volleyball and soccer players. For eccentric knee flexion, there were notable differences with soccer players producing more normalized average peak torque production (0.68 ± 0.089 Nm/kg) compared to volleyball players (0.59 ±0.06 Nm/kg) (t= 1.904; p=.089). APTTS (t= -1.987; p= 0.078) and MLTTS (t= -1.005; p=0.341) were not statistically different when compared between soccer and volleyball. APTTS was observed to be longer in volleyball athletes (2.74±0.88 sec) when compared to the APTTS of soccer athletes (1.99±0.28 sec). Conclusions: Variances in torque productions did not statistically predict variances in APTTS and MLTTS. Torque productions and sport may not be significant contributors in time needed to stabilize. The women’s soccer athletes used within this study participate in an ACL prevention program. Due to this limitation we concluded that the decreased TTS in the soccer athletes may be attributed to this program. Repetitive concentration on proper landings may be the greatest factor in reducing Advisors/Committee Members: Gribble, Phillip.

▼ Stretching routines are typically integrated into exercise programs to improve flexibility and performance. Static stretching has been promoted as the safest and best method of stretching whereas the very different ballistic method of stretching has been virtually abandoned due to its associated risk of injury. The purpose of the current investigation was to examine the biomechanics and muscle activity associated with static and ballistic stretching of the hamstring muscles in order to compare the assets and liabilities of each technique. In a randomized cross-over design, 16 men and 13 women (22.5 ± 4.5 yrs) participated in both static (STA) and ballistic (BAL) conditions. Each condition required the subject to perform a pre-maximum stretch, a series of three 30-second static or ballistic stretches, and a post-maximum stretch. Electromyography (EMG) of the gluteus maximus, hamstrings, gastrocnemius, and rectus femoris muscles as well as joint kinematics were measured during all procedures. Data regarding maximum stretch distance and hip angle were recorded. Measurements of perceived soreness were made before and after the stretching exercise as well as at 24, 48 and 72 hours after stretching. A two-way repeated measures ANOVA was used for statistical analysis of perceived soreness, maximum stretched distance, and hip angle and t-tests were used for analysis of muscle activity. Significance was determined at the p < 0.05 level. Stretching exercise significantly increased maximum distance stretched and hip flexion (p < 0.05), however there was no difference between the stretching techniques. No significant effects for muscle activity or soreness were found between the static and ballistic conditions. In conclusion, static and ballistic stretching influence range of motion, hip angle, muscle activity, and soreness similarly and, thus, contraindications towards ballistic stretching may be unwarranted. Future research should investigate whether differences exist in the kinematics and muscle activity patterns of the actual static and ballistic stretching maneuvers. Advisors/Committee Members: Armstrong, Charles W.

▼ The purpose of this dissertation was to examine the effect of eccentric exercise-induced muscle injury on local vascular function and muscle blood flow in humans. Healthy, male subjects performed maximal eccentric contractions to induce muscle injury to the forearm flexor muscles, with subsequent changes in maximal isometric strength and vascular responses assessed at one, 24, 48, and 96 hours post-injury. Endothelial-dependent and-independent vasodilation was measured using brachial artery flow-mediated dilation (FMD) and sublingual nitroglycerin administration, respectively. Mean blood velocities were measured by Doppler ultrasound and later used for the calculation of blood flow and the shear stress area under the curve (SSAUC). Subjects performed sub-maximal handgrip exercise 48 hours following injury and muscle blood flow was assessed via Doppler ultrasound. Eccentric exercise resulted in significant decreases in maximal isometric strength for up to 96 hours. Endothelial-dependent and –independent vasodilation was also significantly impaired for up to 96 hours following eccentric-induced injury. The shear stress stimulus (SSAUC) responsible for the FMD response was significantly reduced from one to 48 hours post-injury. However, resting blood pressure and blood flow remained the same throughout the duration of the study despite an increase in brachial artery diameter at one and 48 hours following eccentric exercise. Additionally, the muscle blood flow response to dynamic sub-maximal handgrip exercise was not significantly different 48 hours post-injury. In summary, these results suggest that skeletal muscle injury results in prolonged impairment of local vascular function without influencing subsequent muscle blood flow at rest or during sub-maximal exercise. Advisors/Committee Members: Scheuermann, Barry.

▼ Rehabilitation of the shoulder can be a complex process with an approach that is constantly changing. In order to be successful in the rehabilitation process, a complete understanding of the cause of injury and an accurate diagnosis is required2. Researchers are constantly testing new ideas and working to improve the current protocols. Knowing and understanding the movements of the shoulder complex and being aware of the muscles involved in this movement is vital to producing a solid rehabilitation protocol. Finding exercises that patients can perform on their own can be beneficial as well, especially when working with busy athletes or patients that may not have regular access to the clinician. One specific exercise, the push-up plus, is a great scapular stabilizing exercise that has been used clinically. Various hand placements during the push-up plus, however have not been thoroughly researched. The purpose of this study was to compare three different hand placements (normal, narrow, and wide) in a push-up plus to determine the average EMG activity in each using healthy female subjects. The female subjects’ results will be compared to a previous study which looked at the EMG activity in male subjects only for future investigations. A better understanding of the muscle activation involved in this exercise will allow clinicians to apply the correct techniques to the corresponding population they are working with. Twenty female subjects were recruited from a university setting and were tested performing the push-up plus in different hand positions (normal, narrow, and wide) while electromyography (EMG) of the serratus anterior (SA), middle (MT) and lower trapezius (LT) was assessed. Five trials for each hand placement were performed in a randomized order. The exercises were divided into three phases: 1) push-up phase, 2) plus phase 3) push-up plus phase. Each EMG signal collected during the push-up plus was normalized using the MVC average EMG signals. This allowed the trials to be expressed in percentages of each subject’s MVC trials. The data for each muscle was processed in SPSS v14.0 (SPSS Inc. Chicago, IL) for Windows statistical program. The independent variables were hand placement (Normal, Narrow, and Wide) and Exercise (Push-Up, Plus, and Push-Up Plus). The dependant variables were the average peak EMG activation of the three muscles (middle trapezius, lower trapezius, and serratus anterior). For each dependent variable, a separate two-within factor (Exercise and Hand Placement) repeated measures analysis of variance was performed. Significance was set a priori at p<0.05. For the trials showing statistical significance, a Scheffe’s post-hoc testing was applied. The findings of this study showed that there was marked muscle activation in the Serratus Anterior during all three phases of the exercise with the push-up portion of the exercise being the highest. For the hand position, there was marked activity for all hand placements with the Wide hand placement being the highest. The other two muscles, middle and lower trapezius showed moderate but not significant results for position and for exercise. This study suggests that the push-up plus is a good exercise if the clinician is focusing on the Serratus Anterior, but other exercises may be more well suited for the athlete if the goal is to strengthen the Middle or Lower Trapezius. Future studies may include a comparison between males and females during the push-up plus, and a comparison of the push-up plus to other upper body exercises. Advisors/Committee Members: Gribble, Phillip.

▼ Objective: To examine neuromuscular measures of the gluteus medius and gluteus maximus in healthy females, specifically strength and cortical excitability through measures of maximal isometric voluntary contraction (MVIC) and AMT respectively. It is of interest to identify if a relationship exists between these measures of neuromuscular function and lower extremity dynamic jump-landing mechanics as scored by the Landing Error Scoring System (LESS). Design and Setting: Pearson Product Moment correlation matrixes were performed for the predictor dependent variables, active motor threshold (AMT), motor evoked potentials (MEP), maximal voluntary isometric contractions (MVIC) and the criterion dependent variable, Landing Error Scoring System (LESS) scores. Significance was set as P<.05. All data was collected in a research laboratory. Subjects: 40 healthy females (21.08±2.15 yrs; 164.8±5.9 cm; 65.4±12.0 kg) participated in this study. Measurements: To assess MVIC, a Biodex System 2 Pro inclinometer was used. AMT measurements were taken with a Magstim Rapid. Dynamic Jump-landing was recorded using two video cameras, sampling at 60 Hz, and placed 136 inches away from a force plate with one in the frontal plane and one in the sagittal plane. Results: A moderate, positive correlation was found between dominate gluteus maximus MEP and LESS scores (r = 0.666, p=0.007). No other significant correlations were obtained for MVIC, AMT, or MEP for the gluteus maximus and gluteus medius, regardless of limb. Conclusions: No substantial relationship was found between gluteal MVIC and measures of cortical excitability with a clinical measure of jump-landing biomechanics. Future research is needed to understand the effect cortical level pathways have on neuromuscular control and jump-landing biomechanics. Advisors/Committee Members: Pietrosimone, Brian.

▼ Objective: The purpose of this study was to compare a lace-up ankle brace with a no-brace condition on the ability to return an athlete with CAI to a stable state by measuring the TTS following a jump-landing task. Design: Repeated measures within-subject design. Setting: Athletic Training Research Laboratory. Patients or Participants: Ten subjects, five males and five females (18.5625±.814yr; 174.0963±7.191cm; 69.2937±8.277kg) that fit the criteria for chronic ankle instability participated in this study. Measurements: Subjects participated in two separate testing sessions during which a jump-landing task was performed with one of two conditions: lace-up ankle brace or no ankle brace. The brace condition was randomized. During each session, five trials of a jump-landing task were performed on each leg. The jump-landing task consisted of a single-leg landing from a double-leg jump height equivalent to 50% of the subject’s maximum jump height. Subjects jumped off of both feet from a distance 70cm away from the center of the force plate, reached up and touched the indicated marker, and landed on the force plate on a single test limb. The landing leg was randomized. Ground reaction forces were used to calculate TTS in the medial/lateral (MLTTS) and anterior/posterior (APTTS) directions. The independent variables were Condition (brace, no brace) and Side (injured, non-injured). A separate two-within (Condition, Side) repeated measures ANOVA was performed for APTTS and MLTTS. Main Outcome Measure(s): APTTS and MLTTS. Results: For APTTS, the Side by Condition interaction was not statistically significant (F1,9 = .004; p=.952). For MLTTS, the Side by Condition interaction was not statistically significant (F1,9 = .023; p= .884). No measurements were found to be statistically significant in either direction. Conclusion: This study was designed to show if the use of an ankle brace, like the Swede-O Universal would assist those subjects with CAI in reducing the amount of time it takes for them to stabilize after a jump landing task. Although the results of this study do not support these conclusions with statistical significance, it may provide an important direction in examining the connection between TTS, ankle bracing, and those with CAI. There is a definite need for further testing on more subjects with CAI so we can make a better conclusion about the use of the Swede-O Universal and its ability to reduce time to stabilization after a jump-landing task. Advisors/Committee Members: Gribble, Phillip.

▼ This dissertation examined the effects of a chronic acidosis on vascular function during dynamic handgrip exercise and following post-occlusive reactive hyperemia. Seven males performed hand-grip exercise corresponding to 5% (moderate) and 10% (heavy) of maximal forearm strength during control (CON) and acidosis (acetazolamide 500 mg/d 3 d; AC) conditions. Flow-mediated dilation (FMD) was also measured on these subjects following a post-occlusive reactive hyperemia. Brachial artery diameters and velocities (MBV) were measured continuously during FMD and exercise using Doppler ultrasound. Muscle blood flow, shear rate, shear stress, mean arterial pressure, and vascular conductance were all computed. Muscle activity of the forearm flexors were measured using non-invasive electromyography. Arterialized venous blood was collected by catheter and analyzed for blood gases and ions. Plasma [H+] were significantly higher during AC compared to CON for both moderate and heavy exercise as well as during FMD. Blood [HCO3-] and blood gas PCO2 were significantly decreased during AC compared to control for both moderate and heavy exercise as well as during FMD. Hematocrit was unchanged between rest and exercise for both conditions. As well, no differences in hematocrit were present between AC and CON conditions. No difference in MBF or arterial diameters were detected between CON and AC conditions at rest or during moderate intensity exercise. As well, no significant difference was observed for MBF between CON and AC during heavy intensity exercise. However, heavy intensity exercise resulted in an increase in arterial diameter compared to rest for CON (p<0.05) but, no difference in arterial diameter was observed for AC. When expressed as a percent change from rest to heavy intensity exercise, the increase in diameter was greater (p<0.05) during CON compared to AC. FMD resulted in an increase in brachial artery diameter compared to rest (p<0.05). When expressed as %FMD, ACZ was significantly reduced compared to CON (p<0.05). In fact, the comparison resulted in a 48.5% difference in response between CON and ACZ conditions. Shear rate (SR) and Shear stress (SS) values were well matched between conditions during both moderate and heavy exercise. Peak values for SR and SS were not significantly different between conditions during FMD. However, when FMD was normalized relative to shear rate (%FMD/SR), the ratio for ACZ was significantly lower (p<0.05) compared to CON. Together these findings suggest that prior metabolic acidosis may alter vascular tone at rest and during heavy exercise but that MBF is unaltered between conditions during moderate and heavy exercise. As well, these results indicate that the endothelial-dependent FMD response is attenuated following chronic AC even after normalizing for changes in shear stress. Advisors/Committee Members: Scheuermann, Barry.

▼ Physical activity can prevent atherosclerotic progression which is characterized by an impaired flow-mediated dilation (FMD) response. Using the postprandial state as a surrogate, some of the mechanisms associated with endothelial dysfunction and physical activity are becoming better understood. PURPOSE: To determine the endothelium-dependent response (FMD) to a high fat meal (HFM) prior to a bout of moderate exercise and to see if the shear stress stimulus is appropriate for the FMD response. METHODS: 9 healthy men [32±8 yrs, 80.5±21.8 kg, 178.4±9.6 cm, 25.3±4.9 kg•m-2 (means±SD)] completed 4 randomized experimental conditions: 1) Control, 2) Meal only, 3) Exercise only, 4) Meal and Exercise combined. FMD was measured with B-Mode ultrasonography and mean blood velocity with Doppler velocimetry both in the left brachial artery at baseline, 2 hrs, 3hrs, and 4hrs post-baseline measurement. RESULTS: Baseline brachial artery diameter was not different between the 4 experimental conditions. The percent change in FMD2, FMD3, and FMD4 (4.6±2.0%, 3.9±1.6%, 4.0±2.0%, respectively) were significantly lower (P<0.05) compared to FMD1 (6.4±2.0%) in the Meal only condition. When expressed as the percent change from FMD1 in Meal and Exercise, a decrease in endothelial function following the meal (-29±26%) was attenuated by the bout of moderate exercise (+22±67%, P<0.05). There were no main effects or condition-by-time interactions for shear stress in any of the experimental conditions. CONCLUSION: These results indicate that the consumption of a high fat meal significantly impairs endothelial function and that a bout of moderate exercise performed after the meal can counteract these negative effects. In addition, it appears that the FMD response is independent of the shear stress stimulus suggesting the presence of another mechanism which impairs endothelial function. Advisors/Committee Members: Scheuermann, Barry.

▼ Objective: To establish a standard protocol for the number of practice and test trials needed for testing TTS. Design and Setting: Separate trial (1-20) by side dominant,non-dominant) repeated measures ANOVA was performed for APTTS and MLTTS. A paired samples t-test was performed to determine the number of failed trials between the dominant and non-dominant sides. A Scheffe’s post-hoc test was applied. Significance was set at p<0.05. Subjects: Thirty-one healthy subjects participated in this study. Measurements: Subjects participated in one testing session. Twenty trials of a jumplanding task were performed on each leg. The jump-landing task consisted of a single leg landing from a double leg jump height equivalent to 50% of the subject’s maximum jump height. Subjects started 70cm away from the center of the forceplate (Bertec, Corp; Columbus, OH). Subjects jumped off of both feet, reached up and touched the indicated marker, and landed on the forceplate with one foot. The landing leg was randomized. Results: For MLTTS, no significant interaction between side and time existed (F19,570=.078, p =.667; power = 0.64). A significant main effect for trial existed (F19, 570= 2.901, p< .001; power = 0.99). There was no significant main effect for Side dominant (1.61± .03)non-dominant(1.63 ± .03)(F1, 30= 6.17, p = .438; power = 0.12). For APTTS, there was no significant interaction between Side and Time. (F19, 570= .973, p = .492; power = 0.73) There was no significant main effect for trial (F19, 570= 1.34, p = .153; power = 0.89) or side (dominate (1.18 ± .02) vs. non-dominate (1.19 ± .02)) (F1, 30= .081, p = .778; power = 0.06). For failed trials, there was no significant difference between the dominant (5.90±0.84 trials) and non-dominant (6.00±1.06 trials) (t=-0.97, p = .924). Conclusion: This study attempted to determine how many practice and test trials are needed to achieve consistency. It appears that either leg can be used during TTS calculations which will help clinicians trying to find a base comparison for the injury leg. However, the primary purpose of this study, which was to determine the number of trials needed to overcome a learning effect, was not realized fully. We can cautiously conclude that three practice trials would allow a healthy subject to become familiar with the task. However, this study brings up the question if there really is a learning effect that is quantifiable associated with TTS assessment in healthy subjects. Advisors/Committee Members: Gribble, Phillip.

▼ Although much research has been conducted on those with chronic ankle instability (CAI), more research is necessary in understanding how activation of both proximal and distal lower extremity muscles influence the positioning of the ankle during a functional task. This study measured peak pressures on the plantar foot and the influences of fatigue on four lower extremity muscles during a lateral hop in those with and without CAI. The results revealed no significant differences in peak pressure between groups for the plantar pressure areas. The muscle measurements demonstrated higher peroneus longus and gluteus maximus activity just prior to landing the lateral hop. There were no statistically significant outcomes for fatigue. Both the muscle activation and the plantar pressure results suggest a pre programmed, feed-forward mechanism adapted by those with CAI. Altered neuromuscular activity in those with CAI has been documented in previous research. These results continue to support this theory, now demonstrated during a functional task which indicates those with CAI are finding methods to land a jump without injury in controlled situations. Advisors/Committee Members: Gribble, Phillip.

▼ Objective: To determine if there is a significant difference in FMSTM scores between athletes that were injured and athletes that were not injured during the high school basketball season. A cut-off score that maximizes specificity and sensitivity of the FMSTM will also be determined. Design, Setting, and Data Source: Testing and data collection was performed at local Toledo area high schools. The testing included the girls’ and boys’ junior varsity and varsity teams with the ages of the athletes ranging from 14-18 years old. Before testing, each subject completed a questionnaire providing demographics such as age, gender, previous/current injuries, brace/tape use, and participation in conditioning programs. The data collected was separated into three groups: all subjects, subjects with previous history of lower extremity injury, and subjects without previous history of lower extremity injury. To determine if there is a significant difference in FMSTM scores between athletes that were injured and athletes that were not injured during the high school basketball season, a dependent t-test was performed on each group with significance set at the P< .05 level. To determine cut-off scores, a receiver-operator characteristic (ROC) curve was used for each group to plot sensitivity (true positives) versus 1-specificty (false positives) for the screening test. A 2x2 contingency table was produced to dichotomize the athletes that suffered an injury and those who did not as well as those who were above or below the cut-off score. From the table, odds ratios, likelihood ratios, sensitivity and specificity were calculated. To estimate the amount of influence an athlete’s FMSTM score has on the probability of suffering an injury, post-test odds and probability were calculated. Results: A total of 82 athletes that completed the 2009-2010 basketball season who participated in the pre-season FMSTM screening met our inclusion criteria. Of the 82 subjects, 20 of them suffered an injury that caused them to be removed from participation during the season. For subjects without a previous history of lower extremity injury, a t-test revealed a significant difference between the means scores of those injured (14.2±1.8) and those who were not injured (15.6±2.0) (t = 2.2; df = 52; p = .034). Analysis of the ROC curve showed that a cut-off score of 14.5 maximized the sensitivity and specificity of this group’s data. The odds ratio for this group showed that athletes are almost 6 times more likely to get injured during the season if they score 14 or below on the FMSTM. The post-test probability for subjects with no previous history of lower extremity injury was calculated to be 34%, an increase of 19% from pre-test probability. Conclusion: This study demonstrated that high school basketball athletes who do not have previous history of injury and score a 14 or below on the FMSTM have a higher chance of suffering an injury over the period of the high school basketball season. However, the FMSTM did not have the ability to predict injury to high school basketball athletes with prior history of lower extremity injury. Clinicians should consider implementing the FMSTM to screen for first time lower extremity injury as a low cost, reliable tool when used by trained individuals. Advisors/Committee Members: Gribble, Phillip.