National Physical Therapy Examination (NPTE) Practice Exam

In a patient with a transfemoral prosthesis, what factor could contribute to abnormal hip abduction during the stance phase of gait?

1. Weak gluteus medius

2. High lateral prosthetic wall

3. High medial prosthetic wall

4. Tight adductor magnus muscle

The correct answer is: High lateral prosthetic wall

In analyzing the factors that contribute to abnormal hip abduction during the stance phase of gait for a patient with a transfemoral prosthesis, the configuration of the prosthesis plays a significant role. A high lateral prosthetic wall can impair the natural function of the residual limb by limiting the movement and support required during the stance phase. When the lateral wall of the prosthesis is excessively high, it can restrict hip motion, specifically impacting abduction. Proper alignment and fit of the prosthesis are crucial for optimal biomechanics; an inappropriate height of the lateral wall can lead to compensatory movements, such as increased hip abduction or lateral trunk bending, to maintain balance and weight bearing on that side. This can result in ineffective gait mechanics and possible strain on other muscles and joints. In contrast, the other options, like weak gluteus medius, a high medial wall, or a tight adductor magnus muscle, could also theoretically impact gait mechanics, but do not specifically point to the direct influence of prosthetic design in altering hip abduction during the stance phase as evidently as the high lateral prosthetic wall does. Thus, the configuration of the prosthesis is a critical determinant in this context, where a high lateral wall contributes directly to the observed