Sensor Ankle Brace for Special Operations Rehabilitation

Inclusion Criteria for both cohorts: * Healthy adults: ages 18 - 40 years * considered "healthy to exercise" as determined by the physical activity readiness questionnaire (PAR-Q) Additional Inclusion Criteria specific to cohort 2 only: * Classified as "moderate" or "high" activity level as defined by the scoring criteria of the International Physical Activity Questionnaire - Short Form (IPAQ) * Comfortably fit into combat boots provided by the laboratory (Men's sizes 8, 9, 10, 11, 12 and Women's sizes 6, 7, 8, 9, 10 will be purchased, and so participants with foot lengths of 22.54-29.27.8 cm are expected to fit in the boots provided). Exclusion Criteria for both cohorts: * 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. Additional Exclusion Criteria specific to cohort 2 only: * Identification of Functional Ankle Instability (IDFAI) score of \<11. * unable to comfortably perform the drop landing condition. * Feet are too large or too small to fit comfortably in the combat boots provided.