Which device assists knee extension during the latter part of the swing phase?

Which device assists knee extension during the latter part of the swing phase?

• A. Quadriceps contraction
• B. Hamstring activation
• C. Extension aid
• D. Ankle dorsiflexion aid

Answer: (C)

In gait, the knee should reach full extension as the leg finishes its swing so the foot can land in a stable, aligned position for heel strike. An extension aid is a device designed to provide the extra extending torque at the knee during this late swing, helping to bring the knee into full extension just before contact. This is particularly helpful when quadriceps strength or control isn’t enough to guarantee proper knee alignment on initial contact, improving stability and efficiency of the step. The other concepts aren’t supplying a knee-extension assist: quadriceps contraction is the muscular action that can achieve knee extension, not a device; hamstring activation promotes knee flexion and would oppose extension in late swing; and an ankle dorsiflexion aid focuses on lifting the foot and clearing it, not extending the knee.

In gait, the knee should reach full extension as the leg finishes its swing so the foot can land in a stable, aligned position for heel strike. An extension aid is a device designed to provide the extra extending torque at the knee during this late swing, helping to bring the knee into full extension just before contact. This is particularly helpful when quadriceps strength or control isn’t enough to guarantee proper knee alignment on initial contact, improving stability and efficiency of the step.

The other concepts aren’t supplying a knee-extension assist: quadriceps contraction is the muscular action that can achieve knee extension, not a device; hamstring activation promotes knee flexion and would oppose extension in late swing; and an ankle dorsiflexion aid focuses on lifting the foot and clearing it, not extending the knee.