Inclusion Criteria:  50Kg< body weight < 116Kg Cognitive ability to understand all instructions and questionnaires in the study; Higher active unilateral trans-femoral amputees Allows for 37mm knee center height to dome of pyramid alignment to allow for symmetrical knee height to sound side Willing and able to participate in the study and follow the protocol Comfortable and stable socket fit No socket issues/changes in the last 6 weeks No residual limb pain affecting functional ability Users with at least 6 months experience on a prosthesis  Exclusion Criteria:  Hip disarticulation amputees Bilateral amputees Users with Osseointegrated prosthesis Users with co-morbidities in the contra-lateral limb, which significantly affect their functional mobility Users taking beta-adrenergic blocking agents (beta blockers) or other medication for heart rate control e.g. Verapamil & Digoxin.