Which upper limb orthosis is the wrist-driven prehension orthosis, also known as a flexor hinge orthosis, that assists a patient in using wrist extensors to produce a grip in the absence of active flexion (e.g., tenodesis grasp in quadriplegia)?

Which upper limb orthosis is the wrist-driven prehension orthosis, also known as a flexor hinge orthosis, that assists a patient in using wrist extensors to produce a grip in the absence of active flexion (e.g., tenodesis grasp in quadriplegia)?

• A. Wrist-driven prehension orthosis
• B. Palmar splint
• C. Dorsal wrist splint
• D. Airplane splint

Answer: (A)

The key idea here is using the tenodesis principle to create a functional grip without active finger flexion. The wrist-driven prehension orthosis is designed with a hinge mechanism that links wrist movement to finger flexion. When the user extends the wrist, the mechanism translates that motion into finger flexion, allowing a grip to form even if the fingers can’t actively flex. This is especially helpful in quadriplegia, where wrist extensors are often preserved but finger flexors are weak or absent—the device lets the person use wrist extension to drive a grasp and release. Other splints don’t use this linkage to produce a tenodesis grasp. A palmar splint supports the palm without converting wrist movement into finger flexion. A dorsal wrist splint keeps the wrist in a fixed position, typically for protection or stabilization rather than generating a functional grip. The airplane splint is a different dynamic option for other conditions and does not provide the specific flexor-hinge mechanism that enables tenodesis-driven grasp.

The key idea here is using the tenodesis principle to create a functional grip without active finger flexion. The wrist-driven prehension orthosis is designed with a hinge mechanism that links wrist movement to finger flexion. When the user extends the wrist, the mechanism translates that motion into finger flexion, allowing a grip to form even if the fingers can’t actively flex. This is especially helpful in quadriplegia, where wrist extensors are often preserved but finger flexors are weak or absent—the device lets the person use wrist extension to drive a grasp and release.

Other splints don’t use this linkage to produce a tenodesis grasp. A palmar splint supports the palm without converting wrist movement into finger flexion. A dorsal wrist splint keeps the wrist in a fixed position, typically for protection or stabilization rather than generating a functional grip. The airplane splint is a different dynamic option for other conditions and does not provide the specific flexor-hinge mechanism that enables tenodesis-driven grasp.