Arm Sling Use for Radial Nerve Injury Recovery
A full arm sling should be avoided for radial nerve injury recovery, as immobilization can lead to joint stiffness and does not enhance functional recovery—instead, use a dynamic wrist and finger extension splint to maintain joint mobility while supporting lost motor function. 1, 2, 3
Why Immobilization is Contraindicated
The available evidence strongly argues against prolonged immobilization for radial nerve injuries:
Light immobilization (sling use for 4 days) after upper extremity injury showed no benefit for enhancing recovery of muscle function or reducing delayed-onset muscle soreness, and may actually impair recovery by promoting stiffness 4
Early exercise is preferred over immobilization to prevent frozen shoulder and maintain joint range of motion—shoulder immobilization with arm slings should be explicitly avoided even in post-surgical contexts 5
The American Society of Anesthesiologists emphasizes that the primary concern with radial nerve injury is avoiding prolonged pressure on the spiral groove of the humerus, not immobilization of the entire limb 5, 6, 7
The Correct Approach: Dynamic Splinting
Dynamic splinting provides superior functional outcomes compared to static immobilization or no splint:
Dynamic splints improve manual dexterity significantly (9-hole peg test times: 25.7±3.5 seconds with dynamic splint vs 33.5±4.5 seconds with static splint vs 36.4±4.8 seconds without splint, P<0.01) 3
Dynamic tenodesis splints allow finger and thumb extension through wrist positioning, maximizing functional use during the lengthy nerve regeneration process 8
Low-profile dynamic splints using elastic cords can provide power to wrist, fingers, and thumb without bulky outriggers, promoting patient compliance and functional independence 1
Specific Splinting Algorithm
Follow this progression based on recovery stage:
Initial phase (complete wrist drop): Use a forearm-based dynamic splint that provides wrist extension support plus dynamic finger and thumb extension 1
Intermediate phase (partial wrist extension recovery): Transition to a hand-based dynamic splint once wrist extensor power returns 1
Late phase (near-complete recovery): Use a circumferential hand-based thumb-stabilizing splint for remaining deficits 1
Critical Positioning Principles
When positioning the affected arm (not immobilizing it):
Maintain neutral forearm position when the arm is at the patient's side to avoid concurrent ulnar nerve compression 7
Avoid elbow flexion beyond 90° to prevent additional ulnar neuropathy risk 5, 7
Prevent direct pressure on the spiral groove of the humerus during rest or sleep positioning 5, 6
Common Pitfalls to Avoid
Do not use static wrist cock-up splints alone—they provide inferior functional outcomes compared to dynamic designs and patients may not complete all functional tasks 2
Do not immobilize the shoulder or elbow joints—this leads to contractures and frozen shoulder without providing any benefit to nerve recovery 5, 4
Do not assume all splints are equally effective—only dynamic splints that allow tenodesis-driven finger extension have demonstrated statistically and clinically significant functional improvements 2, 3