shoulder muscles 1 Flashcards
group 1 shoulder muscles (6 muscles)
what do they connect?
trunk to shoulders
- serratus anterior
- trapezius (upper/middle/ lower)
- pectoralis minor
- levator scapula
- subclavius
- Rhomboids
serratus anterior nerve and roots attachments 2 movements test
LTN/ C5-C7
attachments: top 8-9 ribs => ant surface of scapula (costal surface)
movements:
1. abduction
2. upward rotation
to test: flex 135 deg push on arm or have them punch to palpate against ribs
trapezius
nerve & roots
upper - attachements and 2 movements and test
middle - attachments and 1 movement and test
lower - attachement and 3 movements
nerve/ roots: CN XI & ventral rami of C3-C4 spinal nerves
attachments:
Upper traps: occipital and cervical vertebrae -> lat 3rd clavicle and acromion
movements:
1. elevate
2. upward rotation
test: have patient bring shoulders to ears and try to push down
Middle: (t1-t5) -> superior lip of spine of scapula (relatively straight muscle)
movement
1. adduction
test: pinch shoulder blades back
Lower: (T6->T12) -> root of spine of scapula
movement
1. depression
2. upward rotation
3. adductor
rhomboids major/ minor nerve/ roots attachments 3 movements test
nerve/ roots: dorsal scapular nerve/ C4-C5 (mostly C5)
attachments:
rhomboid minor: nuchal ligaments & spinous process of C7-T1 -> medial border spinous scapula
rhomboid major: T2-> T5 -> lower medial border scapula
movements:
- adductor
- downward rotation
- weak elevator
test: have patient touch small of back and adduct
levator scapula
nerve/ roots
attachments
2 movements
nerve/ roots: ventral rami of spinal nerve 3 &4 & dorsal scapular nerve/ C4-C5
attachments: TP C1-C4 -> btwn spine of scapula and superior border
movements:
- elevator
- downward rotator - pulls from top- like tipping scapula forward => downward rotation of glenoid fossa
pec minor
nerve/ roots
attachments
3 movements
nerve/ roots: medial pectoral nerve/ C8-T1
ribs 3->5 (ant/lat surface) -> coracoid process
movements:
- elevates ribs
- depresses shoulder girdle
- downward rotation
Subclavius
nerve/ roots
attachements
movement (1)
nerve/ roots: nerve to subclavius (C5-C6)
attach lower surface of clavicle
movements:
depresses clavicle/ elevates 1st rib. mostly a stabilizing muscle
Group 2 shoulder muscles (7)
what do they attach?
Shoulder girdle -> humerus
- Coracobrachialis
- Supraspinatus*
- Deltoids
- Infraspinatus*
- Teres major
- Teres minor*
- Subscapularis*
Coracobrachialis
nerve/ roots
attachments
2 movements
nerve/ roots: median nerve: C5-C6
attachments:
coracoid process -> 1/2 way down medial border of humerus
movements:
- shoulder flexor
- Adductor
Supraspinatus
nerve/ roots
attachments
2 movements
nerve/ roots: suprascapular nerve/ C5-C6
attachment: Supraspinatus fossa -> (under acromial shelf) -> greater tuberosity; lies in scapular plane
movements:
- Primary aBductor
- Stabilizes GH joint and steers humeral head when elevated
deltoids nerve/ roots ant: attachment 2 movements middle: attachement 1 movements posterior: attachements 3 movements
nerve/ roots: axillary. C5-C6
Ant: lat 1/3 of clavicle -> deltoid tuberosity
movements:
1. flexion
2. horizontal adduction
3. weak internal rotation
Middle- acromion -> deltoid tuberosity
movements:
1. abduction
Posterior- inferior lip of spine of scapula -> deltoid tuberosity
movements:
1. horizontal aB
2. extension
3. external rotator
infraspinatous
nerve/ roots
attachements
2 movements
nerve/ roots: suprascapular nerve/ C5-C6
attachments: infraspinatous fossa -> greater tuberosity
movements:
1. external rotator - important for abduction because otherwise greater tuberosity would get in the way
2. upward rotation
teres minor
nerve/ roots
attachments
2 movements
nerve/ roots: axillary nerve; C5-C6
attachments: upper (superior to teres major) 2/3 inferior angle of scapula -> greater tuberosity
movement:
- external rotator
- adductor
subscapularis
nerve/ roots
attachement
movement
nerve/ roots: upper & lower subscap nerve; C5-C6
attachements: subscapular fossa (in axilla) -> lesser tuberosity
movement:
1. internal rotator
teres major
nerve/ roots
attachement
3 movements
nerve/ roots: lower subscap; C5-C6
attachement: inferior 1/3 angle of scapula -) bicipital groove of lesser tuberosity
movement:
- internal rotator
- adductor
- extension
Group 3 shoulder muscles (2)
what do they attach
trunk to humerus (these work on trunk and GH)
- lattismus dorsi
- pectoralis major
lats
nerve/ roots
attachement
4 movements
nerve/ roots: thoracodorsal (a.k.a. middle subscapularis) C6-C8
attachment: SP of T7-L5, thoracolumbar fascia, inf angle of scapula, lower ribs -> intertubercle groove of humerus
movements:
- extensor
- internal rotator
- adductor
- depress/ down rotation of shoulder girdle
pec major
nerve/ roots
attachments (both heads)
4 movements
nerve/ roots: lateral pectoral nerve (C5-C6/ clavicular head) & medial pectoral nerve (sternal head) C7-T1
- sternal head: medial 1/2 clavicle -> lateral to bicipital groove
- clavicular head: costal cartilage -> lateral to bicipital groove
movements of both heads:
- adductors (primary action)
- protraction*
- depressor* especially sternal head
- weak flexor @ - costal head
synergies of rotator cuff and delts
- delts do elevation while rotator cuff stabilize humeral head pulling down => elevation
synergy of upper and lower trap and serratus
upward rotation (raising hand)
synergy of rhomboids and teres major
rhomboids contract for down rotation -> prevent upward rotation of scapula (by teres major) during adduction, ext and int rotation
synergy of deltoids and upper traps
deltoids pull scapula down- upper traps prevent shoulder girdle from being pulled down (depression) and downward rotation
syndergy of levator scap, rhomboids, and pec minor
downward rotation
synergies of bicep and deltoids
deltoids prevent shoulder flexion (from bicep) during elbow flexion
synergy of pronator teres and bicep w/ tricep
tricep stops elbow flexion during pronation/ supiniation
