If a BK prosthesis has an excessively firm heel wedge, the patient is MOST likely to walk with:

If a BK prosthesis has an excessively firm heel wedge, the patient is MOST likely to walk with:

• A. excessive knee flexion in early stance
• B. premature knee flexion in late stance
• C. insufficient knee flexion in early stance
• D. excessive knee flexion in late stance

Answer: (A)

The main idea is how the stiffness of the heel in a transtibial (BK) prosthesis affects knee motion during early stance. A excessively firm heel wedge reduces the heel’s ability to compress and absorb shock at heel strike, so the tibia advances over the foot more quickly. To control this rapid tibial progression and absorb the impact, the knee must flex more in the loading response, leading to excessive knee flexion in early stance. If the heel were softer, there would be more gradual plantarflexion and a smoother knee extension during early stance, so excessive knee flexion in that phase wouldn’t occur. Problems in late stance or other phases would show up as excessive knee motion later or insufficient motion earlier, but the firm heel specifically pushes the knee into greater flexion early on.

The main idea is how the stiffness of the heel in a transtibial (BK) prosthesis affects knee motion during early stance. A excessively firm heel wedge reduces the heel’s ability to compress and absorb shock at heel strike, so the tibia advances over the foot more quickly. To control this rapid tibial progression and absorb the impact, the knee must flex more in the loading response, leading to excessive knee flexion in early stance.

If the heel were softer, there would be more gradual plantarflexion and a smoother knee extension during early stance, so excessive knee flexion in that phase wouldn’t occur. Problems in late stance or other phases would show up as excessive knee motion later or insufficient motion earlier, but the firm heel specifically pushes the knee into greater flexion early on.