Radial Tunnel Syndrome (Elbow) Rehabilitation Protocol

This rehabilitation protocol provides a guideline for the physical therapy management of Radial Tunnel Syndrome (RTS). Treatment should be individualized based on the patient's specific presentation, symptom severity, and functional goals. Progression through the phases is dependent on pain levels, functional ability, and absence of provocative signs.

Pathophysiology

Radial Tunnel Syndrome is a compression neuropathy of the radial nerve in the proximal forearm. The radial nerve passes through a "tunnel" formed by various anatomical structures including:

• Fibrous bands connecting the radial head to the ECRB
• The ECRB muscle
• The arcade of Frohse (origin of the supinator muscle) – most common site
• Vascular leash of Henry (radial recurrent vessels)
• The supinator muscle itself

Compression can lead to pain, tenderness, and potential weakness in the radial nerve distribution, specifically affecting muscles innervated distal to the compression site. Unlike posterior interosseous nerve (PIN) syndrome, pure RTS presents without motor weakness initially, primarily with pain. Differential diagnosis is crucial to rule out lateral epicondylalgia.

Common Special Tests

• Resisted Supination Test: With the elbow extended and forearm pronated, the patient is asked to supinate against resistance. A positive test reproduces pain in the proximal forearm near the radial head.
• Middle Finger Extension Test: Resisted extension of the middle finger (ECRB) with the elbow extended often elicits pain.
• Pronation Test: The therapist passively pronates the forearm with the elbow extended. This stretches the structures of the radial tunnel and may reproduce pain.
• Tinel's Sign: Tapping along the course of the radial nerve in the radial tunnel may produce paresthesia distal to the site.
• Elbow Flexion Test: Sustained elbow flexion with pronation and wrist extension might reproduce symptoms.

Phase I: Protection (Acute Phase - Pain Control & Inflammation Reduction)

Goals: Reduce pain and inflammation, protect the injured tissues, prevent further irritation.

• Duration: Typically 1-2 weeks, or until pain is well-controlled.
• Activity Modification: Avoid aggravating activities, especially repetitive pronation/supination, forceful wrist extension, and prolonged elbow extension. Ergonomic assessment and modifications at work or home may be necessary.
• Immobilization: A wrist splint in slight extension may be used to decrease tension on the radial nerve. An elbow sleeve may also provide support and proprioceptive feedback.
• Pain Management:
  • Ice/Cryotherapy: Apply ice packs to the lateral elbow for 15-20 minutes, several times a day.
  • Modalities: Consider the use of modalities such as TENS (Transcutaneous Electrical Nerve Stimulation) or ultrasound for pain relief.
  • Medications: Physician may prescribe NSAIDs or other pain relievers.
• Gentle Range of Motion (ROM):
  • Wrist ROM: Pain-free wrist flexion/extension and radial/ulnar deviation.
  • Elbow ROM: Gentle elbow flexion/extension within a pain-free range.
  • Forearm ROM: Gentle pronation/supination within a pain-free range.
• Nerve Glides: Initiate gentle radial nerve glides (see example below) if tolerated. These should be pain-free and performed with caution.
  • Elbow extended, forearm pronated, wrist flexed, ulnar deviated. Slowly move into elbow flexion, forearm supination, wrist extended, radial deviation. Hold briefly, then return to the starting position.

Phase II: Loading (Subacute Phase - Restoring Strength & Function)

Goals: Improve strength and endurance of wrist and elbow musculature, restore functional ROM, normalize nerve mobility.

• Duration: Typically 2-4 weeks, dependent on pain levels and progress.
• Criteria for Progression: Decreased pain at rest and with activity, improved ROM, tolerance of gentle strengthening exercises.
• Strengthening Exercises: Progress from isometric to isotonic exercises.
  • Wrist Extension/Flexion: Start with light resistance bands or dumbbells, gradually increasing the weight as tolerated.
  • Forearm Pronation/Supination: Use a light dumbbell or resistance band.
  • Grip Strengthening: Use a hand gripper or putty.
  • Biceps and Triceps Strengthening: Light dumbbell exercises, focusing on controlled movements.
  • ECRB strengthening: Focus on isolated exercises with careful monitoring of symptoms.
• Stretching: Continue with gentle stretching exercises for the wrist extensors and supinator, holding each stretch for 30 seconds.
• Nerve Glides: Progress radial nerve glides, increasing the amplitude and frequency as tolerated. Monitor for any increase in symptoms.
• Soft Tissue Mobilization: Address any muscle tightness or trigger points in the forearm and elbow region with manual therapy techniques.
• Joint Mobilization: If joint restrictions are present in the elbow or wrist, gentle joint mobilization techniques may be used to restore normal joint mechanics.
• Proprioceptive Exercises: Begin incorporating proprioceptive exercises to improve coordination and joint stability, such as wrist wobble board exercises or weight shifting activities.

Phase III: Return to Function (Advanced Strengthening & Functional Activities)

Goals: Achieve full, pain-free ROM and strength, return to pre-injury activity level, prevent recurrence.

• Duration: Typically 2-4 weeks, or until functional goals are achieved.
• Criteria for Progression: Full pain-free ROM, good strength and endurance, ability to perform functional activities without pain.
• Advanced Strengthening:
  • Progress strengthening exercises to higher resistance levels and more functional movement patterns.
  • Incorporate plyometric exercises for power development if appropriate for the patient's activity level (e.g., medicine ball throws).
  • Simulate work or sport-specific activities to prepare for return to full participation.
• Endurance Training: Implement endurance exercises to improve the ability to sustain activity over prolonged periods. Examples include repetitive gripping exercises or simulated work tasks.
• Functional Activities: Gradually reintroduce activities that were previously limited due to pain.
• Return to Sport/Work Specific Training: Specific drills and exercises should be incorporated to mimic the movements and demands of the patient's sport or occupation.
• Education: Educate the patient on proper body mechanics, ergonomic principles, and activity modification strategies to prevent recurrence.
• Maintenance Program: Develop a home exercise program to maintain strength, flexibility, and nerve mobility.