The purpose of this study is to compare balance control during a single leg squat with and without a cognitive task between individuals with a history of concussion and individuals with a history of concussion and ankle sprain. Adults with a history of concussion, history of ankle sprain, history of both, or no history of ankle sprain or concussion will be enrolled. Participants will perform twelve trials of a single leg squat, half of which include listening to and recalling a series of words. This study will allow for possible avenues of improved evaluation and rehabilitation of individuals with a history of concussion and/or ankle sprain for healthcare professionals.