What are the correct joint positions when casting for a wrist-hand orthosis (WHO)?

When casting for a wrist-hand orthosis (WHO), the correct joint positions are crucial to ensure optimal functionality and comfort for the patient. The chosen option specifies that the wrist should be extended to 20 degrees and the metacarpophalangeal joints (MCPs) should be flexed between 35-40 degrees. This positioning strikes an important balance between stability, function, and prevention of contractures.

An extension of the wrist at this angle allows for effective use of the digits while also facilitating activities of daily living. The MCP joints being flexed at 35-40 degrees provides enough flexion to maintain finger functional grasp while avoiding excessive tightening of the tendons and muscles, which could lead to stiffness and reduced mobility.

This specific positioning helps to maximize both comfort during wear and functional use, allowing individuals to engage in necessary activities without being hindered by their orthotic device. Achieving the proper positioning is central to the design and effectiveness of wrist-hand orthoses, as it impacts the overall rehabilitation process and quality of life for the patient.