Preliminary evaluation of an automatically stance-phase controlled pediatric prosthetic knee joint using quantitative gait analysis.

OBJECTIVES

To evaluate the effects on gait of a new pediatric prosthetic knee joint using an automatic stance-phase lock (ASPL), shown previously to help prevent falls, and to propose future design considerations and prosthetic alignments.

DESIGN

Case series and crossover trial.

SETTING

Human movement laboratory.

PARTICIPANTS

Three children with unilateral above-knee amputations and 3 children with bilateral above-knee or below-knee amputations.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Spatiotemporal, kinematic, and kinetic gait parameters.

RESULTS

Spatiotemporal parameters indicated higher gait velocities with the ASPL knee joint for the children with unilateral amputations. The increased speed, as expected, was associated with increased temporal interlimb asymmetry, joint moments and powers, and excessive prosthetic knee range of motion in swing. A trend toward increased pelvic motions was observed with ASPL knee when compared with conventional knees.

CONCLUSIONS

The biomechanic performance of the single-axis ASPL knee joint was shown to be comparable with more complex polycentric pediatric prosthetic knee joint technologies worn by the children in this study.