Brachial Plexus Flashcards
Brachial Pexus
Musculocutaneous Nerve Median Nerve Ulnar Nerve Radial Nerve Axillary Nerve
Infraclavicular
Divisions Cords Major Terminal Branches (brachial plexus)
Supraclavicular
Roots (ventral rami) Trunks
C5 Root
Dorsal Scapular Nerve
C5, 6, 7
Long Thoracic Nerve
Upper Trunk (C5 and C6)
Nerve to Subclavius Suprascapular Nerve
Anterior Compartment Nerve Divisions
Lateral Cord Medial Cord
Posterior Compartment Nerve Divisions
Posterior Cord
Lateral Cord
Lateral Pectoral Nerve Musculocutaneous Nerve Median Nerve
Medial Cord
Medial Pectoral Nerve Medial Brachial Cutaneous Nerve Medial Antebrachial Cutaneous Nerve Median Nerve Ulnar Nerve
Posterior Cord
Upper Subscapular Nerve Lower Subscapular Nerve Thoracodorsal Nerve Radial nerve
Upper Limb Innervation
Anterior Compartment of Arm (Brachium) Musculocutaneous Nerve Elbow Flexors Posterior Compartment of the Arm Radial Nerve Elbow Extensors
Forearm Innervation
Antebrachium and Hand Anterior Compartment Ulnar and Median Nerve Posterior Compartment of Forearm and Hand Radial Nerve
Upper Superior Trunk Lesion (brachial plexus injury)
Erb’s Palsy Excessive foreceful inc. in angle between neck and shoulder Most common Can occur in adults from fall on shoulder as well
Clinical Presentation of Erb’s Palsy
Shoulder: Arm ABducted Arm internally rotated Elbow: Prontated Extended
Nerve Deficits in Erb’s Palsy
C5 Spinal Nerve Root Axillary Nerve (deltoid & teres minor weakness) Suprascapular nerve (supra/infraspinatus weakness) Musculocutaneous nerve (biceps weakness) C6 Spinal Nerve Root Radial Nerve (brachioradialis and supinator weakness)
Inferior/Lower Trunk Lesion
Klumpke’s Palsey From force abduction of arm Rare Associated w/ Homer Syndrome
Clinical Presentation of Klumpke’s Palsey
Median and ulnar Nerves Wrist: extended Hand and fingers: MC/Prox. phalanx joint hyperextended Fingers flexed Claw hand
Injuries to Radial Nerve
Axillary region (before triceps) Improper use of crutches weakness difficult to extend wrist difficult to extend fingers and open hand wrist drop posture
Injuries to Radial Nerve: Spinal groove of humerus
Compression along midshalf of humerus Humeral fracture Sleep Palsey Clinical Presentation: difficult to extend wrist difficult to extend/straighten/open hand wrist drop
Injuries to Axillary Nerve (C5, C6)
Causes: fracture of surgical neck of humerus Ant. dislocation of glenohumeral joint Rotator cuff repair surgery Clinical Presentation: Numbness in post. deltoid region difficulty ABducting arm diminished lateral rotation of arm deltoid muscle wasting (prolonged injury)
Injury to Long Thoracic Nerve (C5-7) (innervation of Serratus Ant.)
Causes: Penetrating wound to axillary region Surgical removal of axillary lymph nodes Clinical Presentation: Cannot raise arm above 90 degrees winged scapula
Injuries to Ulnar Nerve (C7, C8, T1)
Causes: fracture to medial epicondyle of humerus Entrapment of nerve in cubital tunnel Rotator cuff repair surgery Damage will involve wrist digit flexors and intrinsic hand muscles Clinical Presentation: Numbness/tingling in 4th/5th fingers worse when elbow is bent Weak grip/loss of flexion loss of ab/adduction of fingers
Injuries to Median Nerve (C6-T1)
Causes: Fracture of humerus above condyles Entrapment by pronator teres Inflammation or irritation in carpal tunnel (syndrome) Damage affects wrist/digit flexors and intrinsic hand muscles (mainly those that move thumb) Clinical Presentation: Pain & Tenderness in ant. proximal Decreased sensation along median nerve course Hand of Benedication Ape hand (latrophy of thenar eminence) Inability to flex 2nd and 3rd digits
Brachial Plexus Map
Hand of Benedication (Median Nerve Damage)
Cutaneous Innervation of Hand
Ulnar Claw Simplified:
Nerve: Ulnar at wrist
Presentation: long standing
Digits: little and ring
Muscles paralysed: medial 2 lumbricals
Movements:
unopposed extension at the MCP joints
Unopposed flexion at IP joints
Hand of Benediction Simplified
Nerve: Median at elbow or wrist
Presentation: when pt attempts to make fist
Digits: middle and index
Muscles Paralyzed: Lateral 2 lumbricals & lateral half of FDP
Movements:
Inability to flex at MCP and IP joints of middle & index
Voluntary flexion at MCP and IP joints of ring and little fingers
