Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee: Not Provided (Other) Subjects: Engineering

Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Engineering, Cleveland State University, 2015, Washkewicz College of Engineering

The combined defects of the glenoid and humeral head defects are often associated with recurrent anterior instability. Past studies have only investigated the effects of isolated humeral head or glenoid defects. A cadaveric model was developed to investigate the effect of combined defects. Moreover, two different finite element models were developed to validate against the experimental data. It was hypothesized that combination of smaller sizes of the two defects would reduce the glenohumeral joint's stability. Furthermore, it was hypothesized that the instability due to humeral head defect will be dependent on the arm position but this won't be the case for the glenoid defect. Also, it was believed that both specimen-specific and population-based models will validate against the experimental data. Different sets of simulation were run with both isolated and combined defects to analyze the reaction forces and calculate distance to dislocation. The experiments were performed with displacement control under a 50N compressive load. The results from the study predicted a statistical model that explained the direct correlation between the anterior stability of glenohumeral joint and the size of the defect. It was found that with the increase in size of the defect, the distance to dislocation decreased. It was determined that a combination of 10% glenoid defect with a 19% humeral head defect resulted in lower stability (p<0.05) than that of an isolated 20% glenoid defect. Results from finite element analysis showed that both specimen-specific and population-based models were similar to cadaveric model.

Committee: Stephen Fening Ph.D. (Committee Chair); Antonie van den Bogert Ph.D. (Advisor); Anthony Miniaci M.D., F.R.C.S.C. (Committee Member); Morgan Jones M.D., M.P.H (Committee Member); Ahmet Erdemir Ph.D. (Committee Member); Brian Davis Ph.D. (Committee Member) Subjects: Biomechanics; Biomedical Engineering; Biomedical Research; Design; Engineering; Experiments; Mathematics; Pathology; Sports Medicine

MS, University of Cincinnati, 2005, Engineering : Mechanical Engineering

Objective: The objective of this research work is to develop a biomechanical model of the upper extremities and perform its kinematic analysis, concentrating mainly on the geometry and motion at the shoulder joint. Rationale for the Research: The prediction of the location of shoulder joint center plays a key role in the analysis of upper extremity movement especially with respect to the shoulder joint. Methods: Various methods for determining the shoulder joint center have been examined along with different methods to procure the joint angles. Based on this research, the prediction of the shoulder joint center has been done using two landmarks on the scapula and the Joint Coordinate System (JCS) method has been used define the angles especially at the shoulder. Procuring angles through methods utilizing direction cosines and Euler parameters have also been considered. In addition to this, defining the coordinate system for Thorax in five different ways and its effect on the joint angles has been examined. The coordinate system where one of the axes passes through the Sternum was finally adopted. These parameters were tested in a pilot study based on plyometrics, conducted at the Human Performance Laboratory at Cincinnati Children's Sports Medicine Biodynamics Center. Results: The results of the current pilot study indicate that the shoulder angles procured through the predicted shoulder center represented the motion that took place to a good extent. Differences exist for the angles obtained through the JCS method and other methods. Usage of a particular coordinate system for thorax also played a role in the angles outputted. Conclusion: The major emphasis of the current study is to have an upper extremity model, tested and tried, with different means of defining the shoulder center, coordinate system for thorax and procuring of joint angles. Validation of this model is essential to make further improvements and tender its usage for clinical purposes.

Committee: Dr. Ronald Huston (Advisor) Subjects: Engineering, Mechanical