What is the ideal placement of a metacarpophalangeal (MP) extension stop?

The ideal placement of a metacarpophalangeal (MCP) extension stop is just proximal to the proximal interphalangeal (PIP) joint. This positioning allows for controlled extension of the MCP joint while preventing hyperextension.

When the extension stop is placed just proximal to the PIP joint, it serves to limit the motion of the fingers effectively, stabilizing the PIP joint during activities such as grasping or pinching. This setup ensures that the intrinsic muscles can function properly, maintaining a natural and effective range of motion while providing the necessary support to the hand and fingers.

Placing the stop at the MCP joint level may not provide adequate control over the extension of the PIP joint and could lead to undesired hyperextension or instability. If positioned at the distal phalanx, it would not effectively limit movement at the MCP joint where control is most needed. A placement just distal to the wrist joint would be inappropriate since it does not adequately address the specific movements of the fingers or allow for the intricate adjustments required at the MCP joint level. Therefore, the placement just proximal to the PIP joint strikes the best balance between control and function in the hand.