National Physical Therapy Examination (NPTE) Practice Exam

What is a likely cause for circumduction compensation in gait with a transfemoral prosthesis?

1. Prosthesis is too short.

2. Weakness in the anterior tibialis.

3. Extension aid is loose.

4. Prosthesis is too loose.

The correct answer is: Prosthesis is too loose.

Circumduction during gait with a transfemoral prosthesis commonly occurs as a compensatory mechanism when the prosthesis does not fit properly or is not secured well to the residual limb. When the prosthesis is too loose, it can lead to instability and a lack of proper control over the limb. As a result, the individual may adopt a circumduction pattern to ensure that the foot of the prosthesis clears the ground during the swing phase of gait. This compensatory strategy allows for a smoother gait cycle, as the individual seeks to avoid tripping or falling due to the prosthesis shifting or moving unpredictably. Proper fitting and security of the prosthesis are crucial for optimal gait mechanics, and any looseness in the device can significantly alter the way a person moves. Other options, while they may seem plausible, do not directly lead to circumduction in the same way. For example, if the prosthesis is too short, it may lead to other compensatory mechanisms rather than circumduction. Similarly, weakness in the anterior tibialis would typically affect dorsiflexion control but wouldn't primarily contribute to circumscribing the prosthetic foot. Finally, if the extension aid is loose, it primarily affects knee stability rather than causing a circumductory movement