Brachial Plexus Examination

Inspection

  • Posture: Observe for any abnormal postures or deformities of the shoulder, arm, or hand.
  • Muscle Wasting: Assess for any visible muscle atrophy, particularly in the shoulder, arm, forearm, and hand muscles.
  • Fasciculations: Look for involuntary muscle twitching, which may indicate nerve irritation.
  • Scars: Note any surgical scars, especially in the neck, shoulder, axilla, or arm.
  • Horner’s Syndrome: Check for ptosis, miosis, and anhidrosis, which may indicate sympathetic nerve damage.

Palpation

  • Bony Landmarks: Palpate the clavicle, scapula, and humerus for any tenderness, deformity, or crepitus.
  • Muscle Tone: Assess muscle tone and bulk by palpation.

Sensation

  • Dermatomes: Test sensory function in the following dermatomes:
    • C4: Shoulder
    • C5: Lateral upper arm
    • C6: Lateral forearm and thumb
    • C7: Middle finger
    • C8: Medial forearm and little finger
    • T1: Medial upper arm

Motor Function

  • Root Level:
    • Dorsal Scapular Nerve: Test rhomboid muscle function by asking the patient to retract the scapula.
    • Long Thoracic Nerve: Test serratus anterior muscle function by asking the patient to push against a wall with outstretched arms.
  • Trunk Level:
    • Suprascapular Nerve: Test supraspinatus and infraspinatus muscle function by assessing shoulder abduction and external rotation.
  • Cords and Branches:
    • Axillary Nerve: Test deltoid muscle function by assessing shoulder abduction.
    • Musculocutaneous Nerve: Test biceps muscle function by assessing elbow flexion.
    • Radial Nerve: Test triceps, brachioradialis, and wrist extensor muscles.
    • Median Nerve: Test thumb opposition, index finger flexion, and sensation in the lateral palm and digits.
    • Ulnar Nerve: Test finger abduction and adduction, and sensation in the medial palm and digits.

Special Tests

  • Tinel’s Sign: Percuss over the nerve to elicit paresthesia.
  • Phalen’s Test: Flex the wrists for 60 seconds to reproduce symptoms of carpal tunnel syndrome.

Note: This is a general examination guide. Specific tests and maneuvers may vary depending on the clinical presentation and suspected nerve involvement.

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