Effectiveness of force production in persons with unilateral transtibial amputation during cycling.

BACKGROUND

Few published reports exist regarding the control of the human/prosthesis interface in persons with unilateral transtibial amputation.

OBJECTIVE

To investigate strategies employed by prosthetic users in controlling the human/prosthesis interface to highlight challenges associated with either the amputation or the design of the prosthesis.

STUDY DESIGN

Randomized controlled trial.

METHODS

Cycling was used as the locomotor task to allow for better control of task mechanics compared to walking. A group of nine cyclists with intact limbs were compared to eight cyclists with transtibial amputation (CTA) during a simulated cycling time trial. The CTA group pedaled with a stiff and flexible prosthetic foot. Reaction forces between the foot and the pedal were measured using an instrumented pedal system. The force effectiveness (FE) ratio was used as the measure of task performance. The FE ratio is the force component normal to the bicycle crank arm divided by the resultant force for both limbs and is commonly used to analyze pedaling technique.

RESULTS

The CTA group was equally as effective at applying forces as the intact group.

CONCLUSIONS

These data suggest that individuals with lower limb loss are able to compensate for their amputation to utilize a similar pedaling technique for locomotor performance. As global strategies, e.g. force effectiveness, appear similar between groups future research should focus on local strategies, e.g. individual joint kinematics and kinetics.