Individuals with above-knee amputations utilize compensatory mechanisms to walk due to the functional loss of muscles spanning the knee and ankle joints and the use of mechanically-passive prostheses. Clinical classifications of an individual’s mobility (i.e. their k-level) are coarsely defined based on whether an individual can walk at multiple cadences and dependent or independent of a walking aide. However, it is unclear what biomechanical mechanisms they use to both walk and modulate their walking speed. The objective of this study was to investigate the kinematic and kinetic trajectories of the amputated and non-amputated limbs during walking at widely-varying speeds, as well as overall joint mechanical work computed over subjects’ gait cycles in individuals with differing clinical classifications of mobility. We hypothesized individuals with a higher k-level would walk with more symmetry due to having better strength, control over their residual limb, and use of their prosthesis, and thus be less reliant on the contralateral leg to walk at faster speeds. Not only was our hypothesis not supported, our data analysis supports the opposite notion – that higher k-level individuals walk with greater asymmetry of joint mechanics than lower k-level individuals. The development of active prostheses controllers has been a focus of rehabilitation research through the use of microprocessors and motors to restore the functional performance of individuals with amputation. The asymmetric joint trajectories used to walk with passive prostheses motivate a need to design adaptive protheses controllers than can be personalized for an individual’s baseline ability, especially at faster speeds.