In a fixed flexion contracture of the proximal interphalangeal (PIP) joint, the structure that is contributing most to the rigid flexion is:
A. The collateral ligamentThe contracted proximal part of the volar plate. When the PIP joint flexes, the flexible proximal part of the volar plate (the check reins) folds back on itself to permit flexion. Left in this position, the folded portions adhere to each other and contract. This is the articular element that contracts and rigidly prevents extension.,