General innervation of antebrachium.
anterior: ulnar and median nerves
posterior: radial nerve
What injuries can result from injuries to the superior trunk (C5-C6)? How can this occur?
-result from excessive, forceful increase in angle between neck and shoulder
-Erb’s palsy
+sensory deficit in lateral aspect of upper limb
+loss of arm abduction, loss of elbow flexion, loss of forearm supination, weakness of wrist extension
+presented as the “waiter’s tip,” upper limb adducted, medially rotated and elbow extended and wrist flexed
What results from injuries to the inferior trunk (C8 and T1)? What causes this?
-limb is suddenly and forcefully pulled in superior direction
-Klumpke’s palsy
+medial aspect of upper limb except axilla has sensory deficit
+loss of precise finger movements, weakness in forearm protonation, weakness of wrist and finger extension, weakness of wrist and finger flexion
+presents as “claw hand”, with possible wasting of intrinsic hand muscles, 4th and 5th digits can’t flex
What can result from the radial nerve? What can causes this?
- can occur with mid shaft fractures of the humerus, improper use of crutches
- extensors affected -> wrist drop
- “Saturday night palsy,” nerve pinched due to pinching of nerve
- paresthesia and/or pain along course of nerve
What results from an injury to the axillary nerve? Causes?
- can occur with fractures to the surgical neck of the humerus or dislocation of glenohumeral joint
- improper use of backpack -> quandrangular space syndrome
- can result in impaired or lost function of deltoid and teres minor
- patient would be unable to fully abduct their arm and diminished ability to laterally rotate
What can result from injuries to the long thoracic nerve? Causes?
- can be damaged during surgical removal of lymph nodes or other tissues in axillary region, penetrating trauma
- serratus anterior affected
- “winged scapula”, inability to raise arms above 90 degrees
Affects of ulnar nerve damage? Causes?
- fracture of medial epicondyle or proximal ulna, slashed wrist
- damage will involve flexors of wrist, digits, and intrinsic hand muscles
- radial deviation at wrist joint, loss of ab and adduction of fingers, weak wrist flexion and some loss of flexion digits
Affects of median nerve damage? Causes?
- fracture of humerus above condyles, slashing of wrist, or carpal tunnel syndrome
- flexors of wrist and digits affected and intrinsic hand muscles
- “Pope’s blessing”
- “ape hand”
General innervation of brachium.
anterior: musculocutaneous (flexors of elbow)
posterior: radial nerve (extensors of elbow)
