Pectoral, Axilla Region and Brachial plexus Flashcards
Deltopectoral triangle
- Clavicle is superior border
- pectoralis major
- deltoid (anterior head)
- Contents: cephalic vein
*cephalic vein drains into the subclavian
Pectoralis Major
Origin:
1. clavicular head: medial 1/2 of the clavicle
3. sternal end: sternum and coastal cartilages of ribs 1-7
Insertion:
1. lateral lip of the intertubercular groove
Action:
1. medially rotates the arm
2. flexes the arm
3. adducts the arm
4. sternal end will extend the arm when coming from flexion
Innervation:
1. lateral pectoral nerve C5-C7 (clavicular)
2. medial pectoral nerve C8-T1 (sternal)
Pectoralis Minor
Origin:
1. ribs 3-5
Insertion:
1. coracoid process
Action:
1. protracts the scapula
2. downward rotation of the scapula
Innervation:
1. medial pectoral nerve C8, T1
Subclavian
Origin:
1. medial first rib
Insertion:
1. medial 1/3 of clavicle
Action:
1.stabilize the SC joint
Innervation:
1. nerve to subclavian C5,C6
Serratus Anterior
Origin:
1. Ribs 1-8/9 (lateral surfaces)
Insertion:
1. medial boarder of the scapula
Actions:
1. upwardly/laterally rotates the scapula
2. protracts the scapula
Innervation
1. long thoracic nerve C5-C7
Lateral Pectoral nerve
- innervates pectoralis major at clavicular part
- C5-C7
- comes off the lateral cord of brachial plexus
Medial Pectoral Nerve
- medial cord
- pierces pectoralis minor and then enters sternal part of pec major
- innervates pec major and minor
- C8-T1
Axilla
Borders:
- base: skin of armpit
- Anterior wall: Pec major, pec minor, clavipectoral fascia
- Posterior wall: teres major, latissmius dorsi, subscapularis
- Medial wall: thoracic wall, serratus anterior
- lateral wall: intertubercular sulcus of humerus
Long thoracic nerve
- C5-C7
- innervates serratus anterior on SUPERFICIAL surface
Subscapularis
Origin:
- subscapular fossa
Insertion:
- lesser tubercle
Action:
- IR of humerus
Innervation:
- Upper Subscapular nerve C5-C6
- Lower subscapular nerve C5-C6
Axillary Sheath
- surrounds axillary artery, axillary vein and compoenets of brachial plexus
Brachial plexus parts
- roots
- Trunks
- Divisions
- Cords
- Branches
Roots
Name them and their location, injury
- C5-T1
- located between anterior and middle scalene
- can get compressed between the scalenes
- can get injured with compression or extreme tesnile forces
- if scalenes become hypertrophied than they can get compressed
brachial plexus
Trunks
where are they and where can they get injured
- Superior, middle, inferior
- suprascapular and N. to subclavian come off superior trunk
- located over 1st rib
- can get compressed between 1st rib and clavicle
- some people have a long TP off C7 or an elevated 1st rib
Divisions
- Each trunk splits into an anterior and posterior division of each trunk
- rounded shoulders or a fx clavicle can cause irriation
Cords
- Lateral, posterior, medial
- located in superiro axilla
- named for relationship to axillary artery
Branches off the lateral cord
- Lateral pectoral nerve C5-C7
- Musculocutaneous C5-C6: pierces coracobrachialis
- part of median
Branches from the posterior cord
- Upper subscapular: C5, C7
- Lower subscapular C5, C7
- thoracodorsal C6-C8
- radial C5-T1
- Axillary: C5-C6
Branches of the Medial Cord
- medial pectoral C8-T1
- Medial cutaneous T1
- Part of median
- Ulnar
Brachial plexus entrapments
- above clavicle: scalene triangle
- Below clavicle: costoclavicular space, under pec minor
- Causes: trauma, repetitive stress injury
- Symptoms: pain, numbness/tingling, weakness
Erbs Palsy
- Injury to the brachial plexus
- C5-C6 upper trunks, assoicated divisions, cords, and axillary suprascapular and musculocutaneous nerves
- waiter’s tip hand
Erbs palsy causes
- traction on the neck during difficult childbirth
- breech delivery
- vacuum/forceps delivery
- C-section
- mutipara mother (multiple births)
- maternal obesity, diabetes
Erbs Palsy PT
- depending on severity can slowly resolve or require surgery and rehabd (10% dont recover a functional arm)
- PT: ROM, Stretching, Strengthening, Sensory stimulation
Medical Imaging: erbs palsy
- drooping atrophic shoulder due to loss of deltoid and RTC
- glenoid dysplasia due to improper development from not using the limb
- Small, irregular, displaced humeral head
Thoracic outlet syndrome
- compression of the brachial plexus (neurovascular bundle) in the interscalene triangle, costoclavicular, or pec minor
Thoracic outlet syndrome: brachial plexus involvment
presentation
- Neuro symptoms are more common
- Paresthesia
- pain
- weakness
Thoracic outlet syndrome: subclavian vein
- second most common but only 4%
- venous distention
- edema
- cyanosis
- pain with activity
Thoracic outlet syndrome: subclavian artery
- 1% of patients (least common)
- coolness
- pallor
- diminished pulse
- pain with activity
PT diagnostic tools for ACJ separated shoulder
- Painful arc >140º
- step off deformity
- ACJ manural joint mobility tests (laxity/instability) - mobs
- Horizontal adduction (+) test pain
- Shear test o ACJ (+) test pain
- O’briens test - If test (+) and pain reported as superficial pain (spreads ACJ but alo puts LH biceps under tension)
