Individuals with lower-limb amputations tend to have asymmetrical gait characteristics which can cause poor balance and asymmetrical joint loading. Poor balance increases an individual’s risk of falls, and asymmetrical loading can lead to secondary conditions such as contralateral knee and hip osteoarthritis. The prescription of a well fitted socket which is both comfortable and functional is key in addressing these issues. However, the process of optimizing socket fit is iterative, and success is dependent upon patient feedback and clinician experience.

Quantitative data is needed to expedite the socket fitting process and to optimize gait, balance, and loading in individuals with transfemoral amputations. As such, the objective of this dissertation is to evaluate the relationship between socket design and clinically relevant gait biomechanics for individuals with transfemoral amputations. These findings can be used to streamline the socket fitting process for individuals with lower extremity amputations and to provide evidence which can assist clinicians in justifying services provided to third party payers.

Individuals with unilateral transfemoral amputations donned up to seven sockets which varied in geometry, pliability, volume, and brim height. Gait, dynamic balance, and loading metrics were compared based on socket type during gait. Additionally, residual femur motion relative to the socket was evaluated during gait using a previously validated volumetric tracking process and correlated with dynamic balance metrics.

Sockets adjustments which reduced rigid stability, such as altered brim height or pliability, were associated with an increase in gait deviations, dynamic balance asymmetry, and frontal plane moments in the contralateral hip and knee in individuals with transfemoral amputations. Additionally, greater residual femur pistoning during stance phase of gait was associated with poorer balance in individuals with transfemoral amputations.

These findings provide insights into the influence of socket design adjustments on gait, balance, and loading in individuals with transfemoral amputations and support the theory that a socket which reduces residual femur motion may improve functional mobility in individuals with transfemoral amputations. This study lays the foundation for future work to assess the long term implications of socket design on physical function and fall risk in lower functioning individuals with transfemoral amputations.