KNES 377 Lecture Notes - Lecture 8: Acromion, Soft Tissue, Erto E Casso
6 Nov 2016
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Document Summary
Synovial vs. functional joint: synovial: 3; ac, sc, gh, functional: scapulothoracic. Very lax in capsule; not stable due to the shallow glenoid and large humeral head: relies on ligaments and dynamic stabilizers for stability. Static stability: capsule; gives some stability, glenohumeral ligaments, labrum, which deepens socket, adhesive and cohesive force: adhesive (ligaments), cohesive (labrum sucking in humeral head) Dynamic stability: stabilizers for stability: sits: supraspinatus, infraspinatus, teres minor, subscapularis, deltoid, long head of the biceps, scapular stabilizers. Muscle groups cooperate together in timing and intensity to produce desired activities. Infraspinatus, teres minor, subscapularis: depression: rotator cuff, deltoid: centers humeral head within glenoid fossa, upper/lower traps, serratus anterior: elevation/abduction (upward rotation of scapula), pec minor, levator scapula, rhomboid; downward rotation of scapula. Planar joint with possible disc; weak joint capsule with very strong ligaments. Arthrokinematics: follows scapula: slides in the same direction as scapula to accommodate motion. Stability: no active muscles cross this joint, ligaments support stability.
