College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which hand deformity is characterized by MCP hyper-extension, PIP flexion, and DIP flexion?

1. Claw Fingers

2. Bishop's Hand

3. Ape Hand

4. Trigger Finger

The correct answer is: Claw Fingers

The hand deformity characterized by metacarpophalangeal (MCP) hyper-extension, proximal interphalangeal (PIP) flexion, and distal interphalangeal (DIP) flexion is known as Claw Fingers. This condition typically results from an imbalance in the intrinsic and extrinsic muscles of the hand, often due to ulnar nerve palsy. In this situation, the intrinsic muscles are weakened, allowing the fingers to extend at the MCP joints while the PIP and DIP joints flex due to the unopposed action of the flexor tendons. The specific configuration of this deformity is important for understanding hand function and rehabilitation strategies. Individuals with Claw Fingers often struggle with grasping objects due to their inability to fully extend the fingers into a functional position. Recognizing this deformity can guide effective treatment and management, including exercises to improve function and reduce the extent of contractures. Other hand deformities mentioned do not present with this specific pattern of joint involvement. Bishop's Hand, for example, involves a different set of muscle imbalances primarily affecting the ring and little fingers due to median nerve damage. Ape Hand also relates to the median nerve and results in a loss of the ability to oppose