In an open-chain movement, which statement is true?

• A. The distal end remains fixed to a surface
• B. Movement involves only one joint
• C. The distal end moves freely in space (Correct)
• D. It cannot involve the limbs

Answer: (C)

In an open-chain movement, the distal end of the limb moves freely in space and is not fixed to a surface. This is what allows the hand or foot to travel through space while the rest of the limb isn’t anchored. The opposite idea is closed-chain movement, where the distal end is fixed to the ground or another surface.

Because the distal end is free, you can have movement at the target joint with or without involvement of adjacent joints, and it doesn’t have to involve only one joint. Limbs performing actions like a biceps curl demonstrate this, with the hand moving through space as the elbow and shoulder work. Statements that describe the end being fixed to a surface, or that limit movement to a single joint, or that exclude limb involvement, don’t fit open-chain movement.