Impact of 'Recovery' Footwear on Lower Extremity Comfort and Biomechanics

Participants will be asked to make 2 visits, 6 weeks apart, to the Umass Biomechanics Lab in the Totman Building at UMass Amherst for gait analysis and biomechanical performance testing.

At the first study visit, participants will be randomly assigned to one of two groups. Participants assigned to the control group will be asked to continue wearing their typical shoes and to complete every two weeks the footwear and injury log provided. Individuals assigned to the intervention group will be provided with 2 styles of the OOFOS recovery shoes, and will be asked to wear the OOFOS slide, sandal and/or closed toe shoes as their primary footwear outside training and competition for the 6 weeks between study visits. Intervention participants will also be asked to complete a daily shoe wear log and a shoe comfort assessment survey every other week.

At each study visit, subjects will be asked to read and sign an Informed Consent Form, and will also be asked questions about their health, exercise, and injury history. To prepare for the data collection, participants will be asked to change into a pair of shorts and tight shirt that will be provided. Anatomic measurements will then be made with a measuring tape, and ankle flexibility will be assessed by manually moving the participant's ankle into the most flexed and most extended position.

Reflective markers will then be placed on subject's feet/shoes, legs, thighs, hips, shoulders, and arms to record 3-D limb kinematics. To place the markers, we will put little circles of double-sided tape on skin or clothing, with reflective balls on the outer side. The position of the reflective markers will be recorded by high-speed infrared cameras surrounding the data collection space. Subjects will also be instrumented with electromyography (EMG) sensors on the skin over muscles of the leg, to measure the activity of those muscles. Before placing the EMG sensors, a small patch of skin will be shaved to ensure the sensor stays in place and captures the signals needed.

Once markers have been placed, subjects will stand in the data collection space to record a standing calibration trial of the markers. The standing calibration trial will be used to create a computer model on which data analysis will be performed. Subjects will then walk on a long walkway with the cameras surrounding it at a both self-selected and a set speed of 1.4 m/s. This will be repeated several times until at least 5 successful trials have been recorded. A successful trial means that the walking speed varies by no more than 5 % from the previous trial. Subjects will perform the walking trials barefoot and in the OOFOS sandal and closed toe shoes.