Clinical Outcomes With Non-Powered vs. Powered Prosthetic Knees by K2-level Amputees

Inclusion Criteria: * Are at least 18 years old * Transfemoral prosthesis user (limb absence between the knee and hip) * Current user of a mechanical knee * Regularly wears prosthesis at least 5 days per week * Have adequate clearance between distal end and ground for necessary knee and foot components * Current Medicare Functional Classification Level (K-Level) of 2 as determined by the healthcare team * Socket-Comfort Score: 6 or above to ensure adequate socket fit * Six months or more experience on a prosthesis * Body weight between 50kg and 116kg (110lbs - 256lbs) * Height between 1.2m and 1.95m (47.2in and 76.8in) * Has a phone to answer periodic study calls Exclusion Criteria: * Present injuries to residual limb or contralateral leg affecting functional ability * Contralateral amputation proximal to MTP (metatarsophalangeal) joint * Socket issues/changes in the last 6 weeks * Users with bone-anchored implants * Health or medical condition, diagnosis, or other cause that would prevent participant from effectively following study protocol, performing required outcome measures, and/or completing the study Subjects can be excluded at the discretion of the investigator for other unforeseen disqualifying criteria (such as specific cognitive issues, etc.). If subjects experience a health or medical condition that leaves them immobile for more than 2 weeks, they may be given the option to restart the study condition upon recovery, as long as eligibility criteria is still met, and comparable baseline functionality is demonstrated with outcomes measures. Using a knee that the subject is unfamiliar with may increase the risk of falling. Therefore, pregnant women should not participate in the study and will be screened by self-disclosure.