Shoulder Anatomy 2 Flashcards
what is the ratio of movement between GH and scapulothoracic motion?
2:1
what is the ideal length-tension relationship?
80-120
what is the purpose of the scapulohumeral rhythm?
promotes optimal length tension relationship
where does the initial 60 degrees of flexion or 30 degrees of abduction occur?
at the GH joint
where does the midrange of motion occur?
scapula
where does the latter part of motion occur?
GH joint
which 2 muscles contribute to elevation?
serratus anterior
trapezius
what do you have after the 1st phase of motion?
30 degrees scapular
60 degrees GH
SC joint has to be working
what do you have after the 2nd phase of motion?
30 degrees scapular
60 degrees Gh
rotation of clavicle happens at the AC joint
what is close-packed position?
most stable position (most congruence)
what is open chain?
when the ends of the limbs are free to move without causing motion at another joint
what is closed chain?
when motion at one joint will produce motion at all the others in the chain
what is an isometric contraction?
tension develops and there is not movement
what is an isotonic contraction?
tension overcomes load and movement occurs
- concentric-shortening
- eccentric-lengthening
what are the origin/insertion of deltoid?
O:acromial end of clavicle/acromion/spine of scapula
I: deltoid tuberosity
how is deltoid innervated?
axillary nerve
what are the O/I of supraspinatus?
O: suprapsinous fossa
I: greater tubercle
how is supraspinatous innervated?
suprascapular nerve
what are the O/I of infraspinatous?
O: infraspinous fossa
I: greater tubercle
how is the infraspinatous innervated?
suprascapular nerve
what are the O/I of teres minor?
O: upper lateral border of scapula
I: greater tubercle
how is the teres minor innervated?
axillary nerve
what are the O/I of subscapularis?
O: subscapular fossa
I: lesser tubercle
how is the subscapularis innervated?
subscapular nerve
which 2 muscle cause external rotation?
infraspinatous
teres minor
which muscle causes internal rotation?
subscapularis
what are the O/I of trapezius?
O: occipital bone, ligamentum nuchae, C7 and all thoracic vertebrae
I: acromion and spine of scapula and lateral third of clavicle
how is trapezius innervated?
CN XI and C3, C4
what is function of middle trapezius?
scapular elevation and adduction
what is function of rhomboids?
scapular elevation and adduction
what are the O/I of rhomboids?
O: spinous process C7-T5
I: medial border of scapula
how are rhomboids innervated?
dorsal scapular nerve
what are the O/I of serratus anterior?
O: ribs 1-8
I: entire anterior surface of vertebral border of scapula
how is serratus anterior innervated?
long thoracic nerve
what are the O/I of lats?
O: lumbodorsal fascia into spines of lower 6 thoracic vertebrae, L vertebrae, lower 3 ribs and iliac crest.
I: floor of intertubercular groove of humerus
how are the lats innervated?
thoracodorsal nerve
what are the O/I of pec major?
O: sternal end of clavicle, sternum, ribs 1-7, aponeurosis of external oblique
I: intertubercular groove of humerus
how is pec major innervated?
lateral and medial pectoral nerves
what are the O/I of pec minor?
O: ant. surface of ribs 3-5
I: coracoid process of scapula
how is pec major innervated?
medial and lateral pectoral nerves
which muscle groups impact action of teres major?
rhomboids
what are the O/I of teres major?
O: post. surface of scapula near inferior angle
I: intertubercular groove of humerus/fused with lats
how is teres major innervated?
lower subscapular nerve
what is the role of biceps in shoulder functin?
forward flexion
what are the O/I of biceps brachi
O: long head from tubercle above glenoid cavity
I; radial tuberosity
how is biceps brachi innervated?
musculocutaneous
