A patient wearing a KAFO reports anterior thigh pressure while sitting. What might be the cause?

The correct response indicates that the mechanical knee joint being too distal is causing anterior thigh pressure for the patient. When a KAFO (Knee-Ankle-Foot Orthosis) is designed, the alignment of the knee joint is critical for proper distribution of forces throughout the orthosis. If the knee joint is positioned too far down on the limb, it can create a situation where the orthosis does not adequately support the thigh. This misalignment often leads to concentrated pressure in the thigh area when the patient is seated.

In this scenario, the anterior thigh pressure arises because the distal placement of the knee joint alters how weight is distributed through the orthosis, specifically when the patient transitions into a seated position. Inadequate support from the KAFO in this orientation can cause the thigh to be forced against the orthosis, creating discomfort and pressure points.

Other considerations, such as the calf section being improperly fitted or excessive flexibility in the KAFO, would not directly cause the specific described symptom of anterior thigh pressure while sitting. The positioning of the mechanical knee joint plays a pivotal role in maintaining proper alignment and comfort, thus making the distal positioning the primary concern in this case.