RecruitingBehavioural interventionMental Imagery to Improve Quadriceps Strength Post Anterior Cruciate Ligament Reconstruction: a Feasibility StudyThe goal of this clinical trial is to understand if people recovering from anterior cruciate ligament reconstruction (ACLR) surgery will complete mental imagery training and if this will improve their injured leg's strength. The main questions are: * Will people complete a five-day mental imagery exercise schedule while in physical therapy for ACLR? * Does mental imagery exercise help raise leg strength during ACLR recovery? Researchers will also compare if different mental imagery exercises involving leg extension or squats will change leg strength. Participants will be asked to: * Participate in two testing sessions to make measurements of leg function * Complete about 10 minutes of mental imagery exercises once per day for five days at home and write down whether they complete the exercises.