Master of Science, The Ohio State University, 2024, Vision Science

The task of predicting the vertical location of an object when it arrives to an observer may be based on a combination of visual ball-flight cues and internal models of projectile motion, incorporating gravity, advance cues, and kinematic cues associated with a thrower's motion. The time required to efficiently process these visual cues to predict the ball's trajectory is unknown. The purpose of this experiment was to determine whether viewing an approaching ball for a longer period of time can improve estimates of the passing height of this ball when only visual cues from ball-flight are provided. A second goal was to determine whether heuristic information predominates over visual cues to object trajectory in estimating the passing height of approaching objects, and whether heuristic information is more likely to be used early in the ball's flight. Twenty subjects (12 males and 8 females, mean age 23.7±1.69) who had played baseball or softball at the high school level or above within the past 10 years participated. Subjects stood 40 feet from a pneumatic pitching machine that propelled tennis balls toward them at 3 speeds (76mph, 61mph, and 52mph). The subjects' vision was blocked with occluding spectacles at 100ms (duration 1) or 250ms (duration 2) after pitch release. Each combination of speed and viewing duration was randomly used 10 times. Subjects then indicated on a 2-meter ruler the height they expected the ball to arrive had they been able to view the entire duration of the ball's trajectory. The balls arrived at heights of about 99cm (fast speed), 59cm (medium speed), and 21cm (slow speed). The mean height responses at the fastest speed were 109cm (duration 1) and 100cm (duration 2). At the medium speed the mean responses were 98cm (duration 1) and 80cm (duration 2). At the slowest speed the mean responses were 88cm (duration 1) and 65cm (duration 2). Paired t-tests between the mean responses for the two viewing durations at each speed all showed s (open full item for complete abstract)

Committee: Nicklaus Fogt OD, PhD (Advisor); Andrew Toole OD, PhD (Advisor); Jennifer Fogt OD, MS (Committee Member); Teng Leng Ooi PhD (Committee Member) Subjects: Optics; Sports Medicine

Master of Science, The Ohio State University, 2017, Vision Science

Purpose. Record head and eye movements and analyze horizontal gaze tracking of novice subjects (no intercollegiate or professional baseball experience) as they viewed pitched balls. Compare these novice data to a group of Division 1 intercollegiate baseball players. Methods. Novice subjects with no prior intercollegiate or professional baseball experience viewed tennis balls projected from a pneumatic pitching machine in a simulated batting set up, but were not allowed to swing. Subjects were asked to call out numbers and the color of these numbers (red or black) printed on the balls. Eye movements were monitored with a video eye tracker, while the head was monitored with an inertial sensor. The eye and head movement data were synchronized with ball position using an analog recording device. Data were analyzed for 14 subjects. These data were then compared to data recorded in a similar manner for Division 1 intercollegiate baseball players. Results. Eye rotation, head rotation, and gaze errors (signed and unsigned) were calculated at various elapsed times. Overall, novice subjects tracked the ball with the head throughout the pitch trajectory, while the eye remained stable until very late in the pitch flight. Despite significant differences between subjects for the mean amplitudes of head and eye movements, a common tracking strategy emerged (partial rotational vestibulo-ocular reflex suppression) for all subjects. Anticipatory saccades were not visually detected for any subject based upon the mean amplitudes of gaze errors. When the novice subjects were compared to the intercollegiate subject data, significant differences emerged in the mean amplitudes of head and eye movements, along with gaze error differences especially very late in the pitch trajectory. Overall however, the novice subjects performed relatively similar to the intercollegiate subjects. Conclusions. On average, novice subjects tracked the pitched ball primarily with (open full item for complete abstract)

Committee: Aaron Zimmerman O.D., M.S. (Advisor); Nicklaus Fogt O.D., Ph.D. (Committee Member); Andrew Toole O.D., Ph.D. (Committee Member) Subjects: Ophthalmology

Master of Science in Mechanical Engineering, Cleveland State University, 2016, Washkewicz College of Engineering

Long term exposure to microgravity environment in spaceflight causes some health issues such as space motion sickness, shift in body fluids, muscle atrophy and bone demineralization. Studies have shown that aerobics, and resistive exercise could help astronauts to deal with the issues. Rowing exercise can provide both resistive and aerobic exercise. A rowing exercise machine has mechanical parameters which affect the user's movement and the loads on the user's tissues. If these effects can be predicted, exercise results can be improved. However, human testing is only possible on Earth during the development, and also the absence of gravity may affect the task execution in the space. Therefore, computational modeling is necessary. In this thesis, a computational model of an arm based on human musculoskeletal simulation and optimal control was used to investigate the effects of mechanical properties of the exercise machine on predicted human performance. Moreover, the other goal was to study the effects of the exercise on arm motion and tissue loads during the exercise. To explore this concept, we have modeled a scaled down rowing exercise machine and a biceps mus- cle. A system identification has been done on the Concept2 rowing machine to determine baseline machine parameters. In order to solve the problem, different methods in trajectory optimization were evaluated to choose the reliable one. Then, a linear muscle force generator was coupled to the rowing machine to examine how it performs the task. The design parameters were changed to investigate their effects on the movement. Finally, the simple muscle force generator was replaced by a brachii muscle model to study how it executes the exercise. Effects of the design elements were also studied.

Committee: Antonie van den Bogert Ph.D. (Advisor); Hanz Richter Ph.D. (Committee Member); Jason Halloran Ph.D. (Committee Member) Subjects: Biomechanics; Mechanical Engineering

Bachelor of Science, Wittenberg University, 2016, Biology

The advent of third-generation artificial turf in the 1990s has sparked much controversy over an increased risk of injury associated with synthetic surfaces. Some studies suggest no statistically significant difference in injury incidences between artificial turf and natural grass, whereas other studies have found increased risk of non-contact injury to the ACL in the knee. Studies have noted significant biomechanical differences between cleat interactions with artificial turf and natural grass; however, none have looked solely at the risk associated with foot and ankle injuries. This study analyzes 60 foot/ankle injuries documented by the Wittenberg University Athletic Training Department over the course of three years for differences in frequency and chance of injury across 3 male and 3 female field-related sports. Frequency of total foot/ankle injuries was no different between artificial turf and natural grass, as wells as between genders across all surfaces. Natural grass was noted to have a higher frequency of male foot/ankle injuries than females (χ2df=1=4.55, P=0.03). Field surface type does not have an effect on foot/ankle injury frequency.

Committee: Richard Phillips Dr. (Advisor); Schneider Greg Mr. (Committee Member); Cathy Pederson Dr. (Committee Member) Subjects: Biology; Sports Medicine

Master of Science, The Ohio State University, 2013, Vision Science

The purpose of this experiment was to observe and classify the head and eye movements of experienced baseball players when they are trying to hit a baseball. More specifically, it was designed to determine if players track deep into the pitch trajectory when attempting to hit, and if they use a similar tracking strategy when taking a pitch. We hypothesized that the batsmen would utilize two separate tracking methods, one for taking and another for swinging. Subjects were tested using a pitching machine called the Flamethrower under two separate conditions, in one condition they were instructed to “track the ball like you are taking a pitch”, and in the second condition they were instructed to “swing at the pitches like you would in batting practice”. Tennis balls were pitched from a distance of 56.3 feet from the batter at a measured velocity of approximately 75 miles per hour. Eye movements were recorded with the ISCAN infrared eye tracker and horizontal head rotations were recorded with the 3DM-GX1 head tracker and the Flock of Birds head tracker. All head and eye recordings were temporally synchronized with each other and with ball position using software. Two subjects were enrolled in the study. Each subject viewed 50 pitches under the “take” condition and 40 pitches under the “swing” condition. A total of 180 pitches were successfully recorded and both subjects were able to track a tennis ball in both testing conditions. Thus, 180 pitches were analyzed. Mean gaze errors for both trials indicated that the subjects were able to accurately track the pitched tennis balls for a majority of the ball's flight path under each testing condition. Inter-subject comparison revealed the subjects exhibited similar tracking strategies in each condition, although one subject appeared to have less variability with his head and eye movements. Both subjects utilized different tracking strategies for taking versus swinging. In the “take” condition, the subjects u (open full item for complete abstract)

Committee: Nicklaus Fogt O.D., Ph.D. (Advisor); Andrew Hartwick O.D., Ph.D. (Committee Member); Heather Chandler Ph. D. (Committee Member) Subjects: Kinesiology; Ophthalmology