Therapy Considerations for the Radial Nerve

1. Therapy Considerations for the Radial Nerve Sybil Hedrick, OTR/L, CHT, CSCS August 23, 2014 sybil.hedrick@providence.org

2. Radial Nerve Innervation

3. Etiology The regional anatomy of the nerve and its adjacent structures, as well as the nerve’s proximity to underlying bone and unyielding fascial bands, must be considered.

4. Muscle Loss:Axilla or Proximal Humerus • Weakness/paralysis of: • Tricep • Aconeous • Brachioradialis • All the muscles distal to brachioradialis

5. “Wrist Drop” Muscle Loss: Distal Humerus • Rests in a position of: • Forearm pronation • Wrist flexion • Thumb flexion & abduction • Slight MCP flexion • IP extension (some flexion if flexors are tight) • Unable to: • Extend wrist/fingers • Abduct/extend thumb

6. Muscle Loss:Forearm: Posterior Interosseous Nerve • Isolated involvement of the deep motor branch of the radial nerve • Present with strong radial deviation with extension of the wrist • Lack MP extension • Splinting is similar as for radial nerve palsy

7. Sensory Loss Sensory loss in Radial Nerve Palsy is not as much of a concern as compared to median/ulnar, address as applicable

8. Functional Loss • Cannot reach out with open hand to obtain objects • No stability at wrist for stable prehension • Difficult to write, type

9. Objectives Pre-Operative TherapyAnd/Or Conservative Management • Prevent deformity • Maintain tissue pliability • Promote neural regeneration and reorganization • Maintain function Radial Nerve Palsy often recovers spontaneously and will often not be rushed into tendon/nerve transfers so conservative management is key

10. Pre-Operative TherapyAnd/Or Conservative Management Evaluation • History • Sympathetic Function • Sensibility (tho not of a huge concern with radial nerve) • Motor Function • ROM: active and passive • Manual Muscle Testing • Be aware of substitution patterns • Dexterity

11. Splinting for Function • Goal to maximize current functional use of the hand/UE • Goal to harness wrist motion while allowing full finger flexion/extension • Try to recreate natural tenodesis motion to allow normal grasp/release of the hand * Note: a static wrist immobilization orthosis does not allow for functional grasp/release, covers palmar sensation and in the end, is not functional for the patient.

12. Splinting for Function

13. Splinting for Function

14. VanLede Radial Nerve Palsy Splint • Improved functional dexterity • Lower profile • Easier to get on/off for patient • Can use Delta Cast or Thermoplastic • Instructions for thermoplastic version can be found @ pattersonmedical.com search for Extension Assist Splint

15. Splinting to Prevent or Correct Deformity • Keep deneravated muscles from resting in an overstretched position • Prevent joint contractures • Enhance returning muscle function instead of allowing substitution patterns

16. Adaptations/Modifications • Cold intolerance frequently accompanies peripheral nerve injuries (PNI): neoprene mittens, gloves

17. Interventions: After Splinting • Modalities: • Heat • NMES • Nerve glides • Manual work • Home program • Repeated assessment to assist tracking of nerve recovery • Strengthening • Gravity eliminated • Aquatic therapy • Progressive resistance (PRE)

18. Preparationfor Tendon Transfer • Ideal, full if possible, PROM at joints which will be involved • Idea, full if possible, AROM as well • Proximal muscle strength should be at least 4/5 or better • The muscle to be transferred should have strength at least 4/5 or better

19. Motor Learning & Cortical Re-Mapping Motor Learning Cortical Re-Mapping • Motor Leaning aptitude should be assessed on the non-involved limb • Acquisition • Retention (consistency) • Transfer (flexibility) • Efficiency

20. Post-Operative TherapyRadial Nerve Tendon Transfer • Psychosocial Issues: client roles, motivation and compliance, cognition, past and current abilities/interests • Diminished success from transfer surgery can result with: • Denial • Frustration • Lack of trust in therapy program • Finances • Time • Must work closely with patient and Physician to eliminate and/or minimize or ease these factors

21. Post-Operative TherapyRadial Nerve Tendon Transfers • Pronator Teres to the ECRB for wrist extension • Palmaris Longus to rerouted EPL for thumb extension (if no PL, FDS (IV)) • FCR to EDC for finger extension (sometimes FCU is used) ‪emedicine.medscape.com

22. Tendon Transfer Precautions • Common complications from tendon transfer include: • Excessive radial deviation at the wrist • Bowstringing of transferred tendons (EPL in particular) • Incomplete extension of 1 or more fingers • Incomplete finger flexion with simultaneous wrist flexion • Complete Rupture • Tendon adhesion • Therapist can play a key role in preventing some of these issues: • Careful monitoring of active motion, retrain movement patterns • Gradual progression out of splint • Ensure tendon gliding • Education, education, education every visit on stage of healing, phase of rehab

23. Post-Operative TherapyRadial Nerve Tendon Transfers

24. Post-Operative TherapyRadial Nerve Tendon Transfers • Splint picture • Splint out of surgery: ultimately depends on your surgeon! Sources vary between surgical and therapy resources. Usually 2-3 weeks • Elbow included, held in a position of pronation • wrist 30-50 deg of extension and 10-15 deg of UD • MCP’s at 0deg or 0-15 deg of flexion, finger IP’s free • Thumb fully abducted with IP in full extension

25. Post-Operative TherapyRadial Nerve Tendon Transfers

26. Motor Re-Education • Start with both the original motion combined with new motion • Start in gravity eliminated position and/or place and hold • Some resources say to use the opposite limb, however the wiring is now different?? • Slow, short session at a non-extreme force • Tips for specifics: • Wrist extension • Resist pronation to help facilitate wrist ext • Finger extension • Resist wrist flexion to help facilitate finger ext • Caution to NOT flex forcefully past neutral as this can stress the repair site • Thumb abduction/extension

27. Post-Operative TherapyRadial Nerve Tendon Transfers

28. Ther Ex Pearls Hammer Dynaflex

29. The Cube

30. Post-Operative TherapyNerve Transfer for Radial Nerve Paralysis • Pre-operatively: Therapist should work on motor retraining using contralateral arm and normal movement patterns • Radial Nerve specific? Typing, reaching and grasping, playing instrument, etc. Tasks for wrist/finger extension, thumb abd/ex

31. Post-Operative TherapyNerve Transfer for Radial Nerve Paralysis • Post-operative pain management • Edema control • Immobilization • 7-10 days • Early ROM • Shoulder, trunk • 3-4 weeks: elbow, forearm, wrist and hand

32. MotorRe-Education • Must learn to coordinate new pathways for target muscle activation • Cortical command is now different and new • 1st: wrist/finger extension and thumb abduction muscle “contraction” combined with contraction from donor nerve: • FDS, FCR, PL • Want most synergistic action based on original motor pattern • Bimanual tasks • Motor reeducation with tasks that are normal for elbow flexion are instituted to relearn: • normal movement patterns • muscle recruitment • reestablish muscle balance

33. Strengthening • Utilize reinnervated muscle physiology and biomechanics • 1) short duration exercise sessions (<5-10min) • Slow onset contractions • begin in mid-range (place and hold) or gravity eliminated • 2) Multi-angle isometrics • 3) Concentric strengthening • 4) Eccentric strengthening