During terminal stance and pre-swing, internal muscle action at the knee is minimal because the knee does what?

During terminal stance and pre-swing, internal muscle action at the knee is minimal because the knee does what?

• A. Locks into hyperextension
• B. Dorsiflexes
• C. Unlocks naturally to prepare for swing
• D. Abducts strongly

Answer: (C)

In terminal stance and pre-swing the knee acts as a stable, extended lever. It is effectively locked in extension to provide a solid base for propulsion. To move into the swing phase, the knee must flex, and this unlocking happens largely automatically—the screw-home mechanism allows the knee to unlock with very little muscular effort, primarily through small action from the popliteus and the joint’s passive mechanics. That’s why internal knee muscle activity is minimal at this time: the knee naturally unlocks to prepare for swing. The other possibilities aren’t fitting because they describe motions that aren’t driving this transition: the knee isn’t actively locking into hyperextension, the primary preparatory movement isn’t knee dorsiflexion (that’s an ankle action), and strong knee abduction isn’t a hallmark of this phase.

In terminal stance and pre-swing the knee acts as a stable, extended lever. It is effectively locked in extension to provide a solid base for propulsion. To move into the swing phase, the knee must flex, and this unlocking happens largely automatically—the screw-home mechanism allows the knee to unlock with very little muscular effort, primarily through small action from the popliteus and the joint’s passive mechanics. That’s why internal knee muscle activity is minimal at this time: the knee naturally unlocks to prepare for swing.

The other possibilities aren’t fitting because they describe motions that aren’t driving this transition: the knee isn’t actively locking into hyperextension, the primary preparatory movement isn’t knee dorsiflexion (that’s an ankle action), and strong knee abduction isn’t a hallmark of this phase.