Which of the following is a significant drawback of the weight activated stance control knee?

The significant drawback of the weight activated stance control knee is related to its delayed swing phase. This design feature ensures that the knee remains stable during weight-bearing activities, providing safety for the user when standing or walking. However, this stability comes at a cost: the mechanism may not allow for quick transitions between stance and swing phases. As a result, users may experience delays when they attempt to initiate movement, which can hinder smooth gait patterns and make ambulation feel less fluid.

In contrast, the other choices highlight different aspects of the weight activated stance control knee. For instance, while such devices may benefit active patients by providing stability during movement (the first option), it does not mitigate the inherent delay in the swing phase. Additionally, requiring strong muscle mass underlines the need for the user to have good muscular control, but this doesn’t confirm the delay component. Lastly, the implication that the device is designed for long residual limbs pertains to fit and function rather than directly addressing the drawbacks or performance of the knee during use.