Week 11 Flashcards
Brachial plexus roots
Where do they come out from
What is different about the cervical and thoracic nerve roots?
C5, C6, C7, C8, T1
Each root comes out between 2 vertebrae
The cervical roots come out above their respective vertebrae (C5 root comes out above C5 vertebrae)
There is no C8 vertebrae so this comes out between c7 and t1.
The thoracic root comes out below its respective vertebrae (t1 root comes out between t1 and t2)
What happens to the brachia plexus roots early on?
Where do they go between?
C5 and C6 join
C7 remains on its own
C8 and T1 join
They go between 2 muscles, the anterior scalene and the medial scalene
The brachial plexus trunks’
3 trunks form
The c5 and c6 form the superior trunk
The c7 forms the middle trunk
The c8 and t1 forms the inferior trunk
Brachial plexus anterior and posterior divisions
The superior and middle trunks’ anterior divisions join
The inferior trunks’ anterior division remains on its own
All of the trunks’ posterior divisions join
The cords of the brachial plexus
The lateral cord is made up of the anterior divisions of the superior and middle trunks
The posterior cord is made up of all the posterior divisions
The medial cord is made up of the anterior division of the inferior trunk
The terminal branches of the brachial plexus
The lateral cord terminates in the musculocutaneous nerve and it gives fibres (along with the medial cord) wich forms the median nerve
The medial cord terminates in the ulnar nerve
The terminal branches of the brachial plexus
The lateral cord terminates in the musculocutaneous nerve and it gives fibres (along with the medial cord) wich forms the median nerve
The medial cord terminates in the ulnar nerve
The posterior cord terminates in the axillary nerve and the radial nerve
What nerve comes off the c5 root
What muscle does it innervate
The dorsal scapular nerve
Innervates the levator scapulae, rhomboids
What comes off the c5, c6 and c7 roots
What does it innervate
The long thoracic nerve
Serratus anterior
What nerves leave at the superior trunk
What does it innervate
The subclavian nerve and the supra scapula nerve
Innervates the supraspinatus and infraspinatus anterior
What nerves leave at the lateral cord
The lateral pectoral nerve
Innervates the pec major
What nerves leave at the posterior cord
What does it innervate
The upper, middle (thoraco-dorsal nerve) and lower subscapular nerve
Innervates the subscapularis
What nerves leave at the medial cord
The medial pectoral nerve
Medial cutaneous nerve of forearm
Medial cutaneous nerve of the arm
The axillary nerve
Brief course
Innervation
Sensory nerve distribution
Comes off the posterior cord
Wraps inferiorly underneath the neck of humerus
Innervates teres minor
Brings sensory information from just below proximal area of shoulder joint
The radial nerve
Comes into the posterior compartment of the upper arm and sits alongside the spiral groove of the arm, then wraps towards the anterior, crossing anteriorly over the elbow joint. Keeps going down on the radial and ends at the back of the thumb and first 3 fingers
Sensory distribution
-anteriorly it innervates lateral bicep area
-posteriorly it innervates a large area - upper arm, elbow and in hand (thumb and first 3 fingers)
Musculocutaneous nerve
Comes down to the anterior compartment of the forearm
Descends between the brachialis and the biceps brachii
Sensory distribution
-lateral side of anterior arm
Median nerve
Comes down the medial part of anterior arm, crosses over elbow anteriorly, passes centrally at wrist through carpal tunnel. Branches then supply the fingers
Sensory distribution
-palmar aspect of hand - thumb and first 3 fingers
-dorsal aspect of hand - tips of thumb and first 3 fingers
Ulnar nerve
Runs down the medial part of anterior arm, runs posteriorly at the elbow. Runs down medial forearm
Sensory distrubution
-palmar/dorsal aspect of hand - forth and firth finger
Acromioclavicular joint (ACJ) injury
Direct impact to the lateral aspect of the acromion with the arm in adduction
Falling onto an outstretched arm
Acromioclavicular joint (ACJ) injury
Static and dynamic stabilisers
S - acromioclavicular ligament: anterior-posterior stability
D - deltoid and trapezius
Anterior glenohumeral joint dislocation
Indirect force often with a combination of extension, abduction and external rotation
Other names for tennis and golfers elbow
Tennis elbow = lateral epicondylitis
Golfers elbow = medial epicondylitis
Lateral epicondylitis
Overuse injury to forearm muscles which originate on the lateral epicondyle of the humerus
Primarily involves the extensor carpi radialis brevis
Inserts into 3rd metacarpal - extends the wrist
Tennis elbow is named due to the repetitive nature of maintaining wrist extension against force in a backhand position
Medial epicondylitis
Overuse of muscles which originate on the medial epicondyle
Primarily flexor carpi radialis and pronator teres
Insertion and action of the muscles in medial epicondylitis
Flexor Carpi Radialis:
Insertion: Bases of 2nd and 3rd Metacarpal (anterior aspect)
Action: Flexion and radial deviation of the wrist
Pronator teres:
Insertion: Lateral surface of radius
Action: Pronation of forearm at the proximal radioulnar joint, flexion of the forearm at the elbow joint
Therefore
Golfer’s elbow stems from repetitive stress of wrist flexion/elbow pronation
Boxers fracture
Most common site of injury is to the neck of the fifth Metacarpal, 10% of all hand fractures
Mechanism of injury: Direct axial load with a
clenched fist
Stingers and burners
Nueropraxia of the brachial plexus
Very common in contact sports
