The purpose of this study is to determine the effect of two different types of running shoes on lower extremity kinematics, kinetic, and in-shoe pressure while subjects run at different speeds. This study focuses specifically on hip, knee, and ankle kinematics and kinetics as well as plantar pressure during the stance phase at different running speeds. The

goal of this study is to determine whether certain types of running shoes allow players to decrease plantar pressure and maintain more desirable positioning of the hip, knee, and ankle while running. These factors have been linked to reducing lower leg injuries.

 

This study will compare athletic training shoes and racing flats. A total of 40 subjects, 20 male and 20 female subjects, will be tested. Subjects will range in age from 18-30 years and will be recruited by word of mouth and posted fliers. Subjects will have no history of lower extremity injuries in the past six months, no history of foot surgery within the

past 3 years, will be physically active and run at least 10 miles per week. Subjects who participate in some form of physical activity at least three times a week for approximately an hour each time will be considered to be physically active. After signing the informed consent, height, weight, foot length, and foot width will be recorded, to be used during data reduction. A total of eight infrared cameras (Motion Analysis, Inc, Santa Rosa, CA) will be positioned around the testing area and will be used to record the trajectories of the retro-reflective markers, which will be placed on the subjects. A total of 30 markers will be placed on each subject at the following anatomic landmarks: joint space between the fourth and fifth lumbar vertebrae (L4-L5), lateral epicondyle, iliac crest, posterior superior iliac spine (PSIS), anterior superior iliac spine (ASIS), greater trochanter, lateral thigh, lateral femoral condyle, medial femoral condyle, anterior lower leg over the tibial ridge, lateral malleolus, medial malleolus, toe, and posterior, superior, and lateral heel.

Following the placement of all of the markers, subjects will be asked to stand within the view of the cameras facing the direction they will be moving and a static standing trial will be recorded. Following the collection of the static standing trail, the four medial markers (medial femoral condyle, medial malleoli), and the iliac crest markers will be removed and the subject will be ready for the running trials. Participants will be asked to complete 7 acceptable trials at each speed for each shoe. Subjects will be asked to complete trials at 3.35m/s (8min/mile) as well as a comfortable running speed for each shoe condition. The running speed for each trial will be monitored using infrared photocells positioned approximately 6 meters apart. The standard speed will be useful for the direct comparison of the two shoe conditions; however, the self-selected speeds will allow for an examination of the effect of shoes on running speed as well as kinematics and kinetics. An acceptable trial will be defined as a trial in which the subject completes the indicated task and all of the markers are seen and the subject lands on the force plates as indicted. Subjects will be given a 30 second rest between each trial and a five minute rest between each shoe condition. The testing order for both shoes and running speeds will be randomized for each subject. After the first shoe condition is completed the shoes will be changed, the standing trial markers and shoe markers will be placed on the subject again and another static standing trial will be recorded. Following the static standing trial the testing will be repeated in a randomized order. Testing should take approximately 1 hour per subject.