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C5 Neurologic Level: (C4-C5 Disk)


- Muscle Testing:
    - deltoid & biceps  are two muscles w/ C5 innervation that are easily tested;
    - while deltoid is innervated almost entirely by C5, biceps  has dual innervation, from both C5 and C6, and therefore, evaluation
            of C5 neurologic level thru biceps testing alone becomes less accurate;

- Reflex Testing:
    - inverted radial reflex may be present when cord & root compression are present at the C5 level;
         - this reflex is demonstrated by tapping the brachioradialis tendon;
         - a diminished reflex is noted along with a reflex contraction of spastic finger flexors;
    - biceps  reflex primarily indicates neurologic integrity of C5;
    - reflex also has a C6 component;

- Sensation: superior aspect of shoulder and lateral arm:


- C5 Quadriplegic Considerations:  (care of the spine injured patient)
    - pt w/ C5 quadriplegia will demonstrate voluntary shoulder abduction & elbow flexion;
          - the only muscle that is functioning at the forearm, and wrist is BR;
          - pt will be unable to move wrist or hand and will be dependent for transfers, feeding, and hygiene;
          - pt may use arm control electric wheelchair and will require mobile arm supports & externally powered hand splint for prehension;
    - in partial/incomplete quadriplegia spacity should be considered;
    - lesions at the level of C5 save the diaphram, levator scapulae and rhomboideus muscles, while deltoid, biceps
          & supra & infraspinatus muscles are partially impaired;
    - splints for C5 escape:
          - proximal stability present
          - no wrist extensors  available to power the orthosis;
          - may use external power system, usually electric power w/ switch control;
    - treatment:
          - as general rule surgery should follow a year of observation;
          - steindler flexorplasty;
          - transfer of BR to wrist extensors (Moberg);
          - restoration of key pinch (BR to FPL) and elbow extension (deltoid to triceps):
                 - may restore 0.9 pounds at the C5 level;
                 - technique:
                        - involves detachment of the BR from the distal radius and from the surrounding fascia;
                        - BR tendon is then sutured into the FPL using end to side weave;
                        - tenodesis of the EPL and EPB to the dorsal metacarpal is performed to prevent excessive flexion;
                        - the thumb IP joint is fused