MS II Flashcards
anatomy of sternoclavicular jt classification mechanical/ functional resting position closed pack position capsular pattern
- anatomically complex (b/c disc)
- mechanically: bi-axial sadldle / functionally: ball and socket
resting position = arm at side
closed pack= abduction 90 degrees
capsular pattern= pain with extremes of motion
osteokinematics of SC joint (2)
- protraction/retraction = concave on convex
2. elevation/ depression = convex on concave
biomechanics of SC jt: ROM and axis
elevation/ depression
protraction/ retraction
rotation
elevation = 45-60 degrees
depression = 5 degrees
around sagittal axis (z)
protraction & retraction = 15 degrees
around vertical axis (y)
rotation = 30-50 degrees
around longitudinal axis of clavicle (x)
ligaments (3) and capsule of sternoclavicular jt
- capsule is reinforced by SCM fibers
3 ligaments:
- anterior/ posterior sternoclavicular ligament
- **costoclavicular ligament - anterior and posterior bands
- interclavicular ligament
directionality of sternoclavicular ligaments
directionality of costoclavicular ligaments (2)
sternoclavicular lig: a/p- both run inferior and oblique (very short)
costoclavicular lig:
anterior runs upward and laterally
posterior runs upwards and medially
these two criss-cross to increase stability
attachments of costoclavicular ligaments
upper surface of first rib and cartilage -> inferior surface of clavicle
anterior runs laterally, posterior runs medially
anatomy of acromioclavicular jt classification mechanical/ functional resting position closed pack position capsular pattern
classification: anatomically simple
mechanically = compound plane gliding joint/ functionally = ball and socket joint
resting position = arms at side
closed pack position = upward rotation of scap with arm at abduction
capsular pattern = pain with elevating arm or horizontal adduction, ltd full extension
ligaments of AC joint (3)
general purpose/ attachements
- acromioclavicular ligament** -covers superior part of joint * most likely to rupture
- coracoacromial ligament
- coracoclavicular ligament
a. trapezoid
b. conoid (triangular)
both attach to bottom of clavicle and serve to hold down clavicle
biomechanics of AC and ROM (3)
- saggital axis: ab/adduction = upward and downward rotation (of inferior angle of scapula)
ROM 20-30 degrees - vertical axis: winging - vertebral border pulling away from thorax during protraction/ retraction
ROM 30-50 degrees - long axis: tipping = sagittal plane, flexion/extension
ROM 30 degrees
scapulothoracic joint
ligaments (2)
not a true joint, just an articulation
ligaments:
- coraco-humeral
- superior transverse; converts scapular notch into foramen
articular surfaces of GH joint
head of humerus is covered with hyaline cartilage; faces
superior, medially, and posterior
glenoid faces superior, lateral and anterior and is smaller than head of humerus… this is why we have a labrum
glenoid is < 1/3 as wide of head of humerus
inferior capsule of GH joint
redundant fold that allows for movements. the head of humerus needs to drop inferior into capsule for any movement to occur.
adhesive capsulitis affects inferior capsule of GH joint
what arm position puts most stress on SITS?
IR and flexion or aBduction to 90 degrees
4 ligaments of GH joint
- capsule
- superior, middle, inferior lGH ligaments
- coracohumeral ligament
- transverse humeral ligament
capsule of GH joint
encompasses…
least supported…
5 tendons that reinforce capsule
encompasses long head of bicep and goest to mid shaft
weakest inferior
tendons that reinforce capsule:
anterior: subscap tendon
posterior: infraspinatus and teres minor
superior: supraspinatus
inferior: long head of tricep
GH ligament attachments
superior band
middle band
inferior band
blend with labrum; origin at medial margin of glenoid cavity =>
superior band: passes along medial edge of bicep tendon and attaches above lesser tubercle
middle band: lower part of lesser tubercle
lower band: lower part of anatomical neck
coracohumeral ligament attachments
lateral border of root of coracoid => greater tubercle , blends with supraspinatus tendon
transverse humeral ligament attachements/ purpose
canal for bicep tendon
ROM of GH joint
flexion/ abduction = 120
extension = 55
adduction = return to neutral
ER= 90 degrees IR = 60-70 degrees
2 spaces of upper limb girdle and muscles that create them
spaces are for nerves and vessels to pass thru
- triangular space - long head of tricep lateral, teres minor &, teres major
- quadrangular space- tricep (long and short heads) teres major & minor