Sensor Ankle Brace for Special Operations Rehabilitation - Phase 1

Sensor Ankle Brace for Special Operations Rehabilitation - Phase 1

The primary purpose of this study overall is to validate a modified version of a commercially available ankle brace. Inertial measurement unit sensors incorporated into an existing ankle brace ("sXAB") by TayCo Brace, Inc. In two consecutive studies, gait metrics data collected from the sensor enabled ankle brace will be compared to data collected by the gold-standard equipment that is used in research and clinical settings to determine whether the sXAB performs adequately in terms of measurement or technical feasibility prior to further clinical evaluation. In the Phase 1 protocol, the sXAB will be validated in the lab on healthy subjects walking in standard tennis shoes/sneakers. All participants experience both conditions: with an ankle brace and without an ankle brace. Comparisons are made within-subject between brace and no-brace conditions. It is hypothesized that the sensor-enabled ankle brace will measure gait metrics with a high degree of accuracy (within 5%) when compared against the gold-standard lab equipment (i.e., motion capture and research-grade inertial measurement units).

All human subjects activities are taking place at the Indiana University Bloomington (IUB) campus. Potential participants for the Phase 1 study protocol will be recruited from the community and the IUB campus. Potential participants will either contact the research team to complete the initial screening or respond to the flyer via a QR code that takes them directly to the online version of the screening form. The screening form asks yes/no questions from the Physical Activity Readiness Questionnaire (PARQ+) and additional questions about the individuals health history, musculoskeletal injury history, and current physical activity levels. After initial screening to determine eligibility, provisionally eligible participants will come to the laboratory on the IUB campus to complete enrollment and study procedures.

At the in-person visit, participants will read the informed consent document and, after all questions have been answered, sign the informed consent document if they agree to participate in the study. Next, participants will complete a health history questionnaire which repeats the PARQ+ questions and additional health history questions presented in the initial screening to confirm eligibility. After eligibility is confirmed, foot length measurements and additional surveys will be completed [i.e., the Identification of Functional Ankle Instability (IDFAI), the International Physical Activity Questionnaire - Short Form (IPAQ), and the past-year physical activity questionnaire (PYPAQ)].

Following the surveys, height and weight will be measured then the dominant limb test and the preferred speed test will be performed. The dominant limb test determines whether the right or left lower limb is the dominant limb by observing which limb participants use to kick a ball. The preferred speed test involves the participant walking or running at or near their reported preferred speed (or 2.9 mph for walking and 4.5 mph for running if preferred speed is unknown). The speed will be blinded to the participant. The researcher will increase or decrease the speed in 0.5-1.0 mph increments until the participant identifies the same speed as their preferred speed three times.

Next, the participant will be prepared for data collection. Participants will be asked to change into form fitting clothing (provided by the laboratory, if needed) and the shoes they prefer to wear during exercise or physical activity. Reflective markers and the lab's research-grade inertial measurement units (IMUs) will be placed on anatomical landmarks of both feet, lower-legs, thighs, and pelvis, and the sensor-enabled ankle brace ("sXAB") will be secured on the dominant limb, if the first randomized condition is the brace condition. Participants will warm-up by walking on a treadmill before completing each of the brace conditions (brace and no-brace) to acclimate wearing the brace and/or the reflective markers and lab IMUs. Participants will then be asked to complete the movement tests specific to each protocol (Phase 1: standing balance, walking at preferred speed, walking at a standardized speed of 2.9 mph) while wearing the sXAB and without wearing the brace ("no brace" condition) as three-dimensional motion capture data, force plate data, IMU data, and data from the sXAB (if worn) are recorded. The order of the bracing conditions will be presented in a random order. The brace will be worn on the dominant limb. Within each brace condition, the standing balance test will be performed first then the remaining movements will be presented in a random order. After the first brace condition is complete, the participant will be prepared to complete the second brace condition then repeat the warm-up, standing balance test, and the movement tests.

Participants are expected to complete Phase 1 activities during a single study visit.

Inclusion Criteria:

• Healthy adults: ages 18 - 40 years
• considered "healthy to exercise" as determined by the physical activity readiness questionnaire (PAR-Q)

Exclusion Criteria:

• Smoking tobacco on a regular basis
• Previous lower back or lower limb surgery (including the joints of the pelvis and lower limbs)
• Musculoskeletal injury sustained within the 12-weeks prior to enrollment . A musculoskeletal injury is defined as musculoskeletal pain causing a reduction or stoppage of normal physical activity for at least 3 days within a 7-day period, and have not returned to their normal physical activity and exercise without pain for at least the last 6-weeks.
• Pregnant (women only)
• Current or history of an unresolved musculoskeletal, neurological, cardiovascular, pulmonary/respiratory, metabolic, renal condition, disease, or problem.
• Torn anterior or posterior cruciate ligament (ACL or PCL).
• Any other disease or problems that may affect movement or the ability to exercise even at a low intensity.