The Shoulder Repair Study was the thesis for two graduate students in Grand Valley State Universitys physical therapy program. For this study several people from 60-70 years old were recruited. In this group, about half of the subjects were recovering from rotator cuff surgery and their arm was required to be immobilized for some period of time. Each subject was asked to lean as far as possible forward, backward, to the left, and to the right without taking a step or leaving both feet. The task was then repeated with their arm in a sling. Force plates were used to measure the forces and moments of each foot. The center of pressure and center of reaction was then calculated. The results are not yet finished, but there is expected a difference in maximum leans and the favoring of one foot over the other. Assuming the results show this, the patients may need to undergo balance therapy due to their damaged shoulder.

The second Study was a bit more complex. The study was a continuation and development from previous studies. In the study the responses of a group of young women were compared to an older group of women. Each subject was subjected to a disturbance in their balance, which was a small tug at their waist. The subjects were asked to respond naturally, whether they needed to take a step, use the grab bar, or use a combination of both. The subjects were then asked to respond with their arms only or legs only. Many things were being monitored during this experiment, such as reaction times, balance recovery strategies, step lengths, their fear of falling, etc. Many times the older subject only preferred one type of strategy. However, in the case were the persons feet are caught up, that person has no choice but to use their upper body. As a result of the experiment, our hope is to lessen the likelihood of our elders falling by encouraging them to acknowledge, learn, and develop the many different balance recovery techniques.

After the experiments were completed, I had the opportunity to conclude my research agreement working with Darryl Thelen in his area of biomechanics. Under Darryl, I extensively explored MATLABs optimization tool. A program was then implemented to minimize the error of in offsets and missing angles of a raw data set that has already been collected. The data will eventually be fed into Working Model to drive his model of the lower extremities.