 Therapy Considerations for the Radial Nerve Sybil Hedrick, OTR/L, CHT, CSCS August 23, 2014

Radial Nerve Innervation

Etiology TraumaInternal ForcesExternal ForcesOther LacerationRadial Tunnel Syndrome *b/t head of radius and supinator Wartenberg Syndrome TourniquetIschemia Gunshot WoundSynovitis“Crutch Palsy”Traction Fracture/Disloc ation *mid/distal 1/3 of humerus Tumor Callus Saturday Night Palsy X-radiation Electrical InjuryInjection 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.

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

 “Wrist Drop”  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 Muscle Loss: Distal Humerus

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

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

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

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

Pre-Operative Therapy And/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

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.

Splinting for Function

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 pattersonmedical.com search for Extension Assist Splint

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

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

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)

Preparation for 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

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

Post-Operative Therapy Radial 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

Post-Operative Therapy Radial 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

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

Post-Operative Therapy Radial Nerve Tendon Transfers PhaseGoalMethod 1 (weeks 0-3) Immobilization Protect repair siteGood fitting orthosis positioned per physician/therapist to minimize tension at wrist, fingers, thumb Ensure freedom of motion of joints allowed to move Manage Edema & incision/scar care Elevation (overhead hook fisting) Compression (coban, Game ready) Wound care, silicone gel Active motion of non- involved joints Shoulder PIP and DIP of fingers Legs/core

Post-Operative Therapy Radial 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 deg of extension and 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

Post-Operative Therapy Radial Nerve Tendon Transfers PhaseGoalMethod 2 Weeks 3-6 Activation Of the transfer Regain AROM & maintain PROM Elbow extension and flexion Protected: supination, wrist flexion, finger flexion, thumb adduction/flexion Pronation, wrist extension, finger extension, thumb abduction/extension PROM, myofascial release, scar massage Activation of tendon transfer Muscle retraining: Pronation for wrist extension Wrist flexion for finger extension Palm contraction for thumb abd/ext Enhance sensorimotor control Grasping lightweight objects of various shapes, sizes, manipulation Enhance function while maintaining good biomechanics Ensure normal movement patterns as much as possible using verbal/nonverbal feedback In clinic and with basic ADL tasks at home

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

Post-Operative Therapy Radial Nerve Tendon Transfers PhaseGoalMethod 3 Weeks 6-12 Improve strengthUsual suspects: weights, theraband Hammer, Dynaflex* Strengthening & return to prior function Enhance aerobic capacity UBE, aquatic, general conditioning Return to prior level of function Work hardening, sport specific training, don’t forget leisure! Ongoing assessmentCapacity for continuing improvement Needs for further surgical consult/issues Long-term adaptive equipment/techniques

Ther Ex Pearls HammerDynaflex

The Cube

Post-Operative Therapy Nerve 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

Post-Operative Therapy Nerve 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

Motor Re-Education  Must learn to coordinate new pathways for target muscle activation  Cortical command is now different and new  Motor reeducation with tasks that are normal for elbow flexion are instituted to relearn:  normal movement patterns  muscle recruitment  reestablish muscle balance  1 st : 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

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