Impact testing of the residual limb: System response to changes in prosthetic stiffness.

Currently, it is unknown whether changing prosthetic limb stiffness affects the total limb stiffness and influences the shock absorption of an individual with transtibial amputation. The hypotheses tested within this study are that a decrease in longitudinal prosthetic stiffness will produce (1) a reduced total limb stiffness, and (2) reduced magnitude of peak impact forces and increased time delay to peak force. Fourteen subjects with a transtibial amputation participated in this study.

Shock absorption during transtibial amputee gait: Does longitudinal prosthetic stiffness play a role?

Background: Reduced-stiffness components are often prescribed in lower-limb prostheses, but their efficacy in augmenting shock absorption has been inconclusive.

Objectives: To perform a systematic variation of longitudinal prosthetic stiffness over a wide range of values and to evaluate its effect on shock absorption during gait.

Study Design: Repeated-measures crossover experiment.

A novel in vivo impact device for evaluation of sudden limb loading response.

The lower limbs are subjected to large impact forces on a daily basis during gait, and ambulators rely on various mechanisms to protect the musculoskeletal system from these potentially damaging shocks. However, it is difficult to assess the efficacy of anatomical mechanisms and potential clinical interventions on impact forces because of limitations of the testing environment. The current paper describes a new in vivo measurement device (sudden loading evaluation device, or SLED) designed to address shortcomings of previous loading protocols.

Effect of prosthetic gel liner thickness on gait biomechanics and pressure distribution within the transtibial socket.

Prosthetic gel liners are often prescribed for persons with lower-limb amputations to make the prosthetic socket more comfortable. However, their effects on residual limb pressures and gait characteristics have not been thoroughly explored. This study investigated the effects of gel liner thickness on peak socket pressures and gait patterns of persons with unilateral transtibial amputations.