When fabricating a forearm based orthotic it should always be ________ of the forearm.

• A. 1/2 the length
• B. Full length
• C. 2/3 the length
• D. 3/4 the length

Answer: (C)

A forearm-based orthosis should be long enough to stabilize the wrist and forearm while keeping the elbow free to move. About two-thirds of the forearm length achieves that balance. It starts just distal to the elbow and extends roughly two-thirds down the forearm, giving a solid proximal anchor to control wrist motion without immobilizing the elbow. If it were full length, the elbow would be immobilized and movement would be restricted; if it were too short, there wouldn’t be enough proximal support to maintain stability and control. Hence, two-thirds of the forearm length is the best choice.