DSF Anatomy of Shoulder and Pectoral Region Flashcards
Tendons
Connect muscles to bones
Ligaments
Connect bone to bone
Strain
Muscle/Tendon injury
Sprain
Ligament injury
Arthritis
Cartilage damage
3 bones of shoulder
Scapula - Glenoid Process (socket of shoulder)
Humerus - Humeral Head (ball of shoulder)
Clavicle (collarbone)
Static stabilizers of the shoulder
Glenoid labrum (cartilage) Shoulder capsule Glenohumeral ligaments (superior, middle, inferior)
Acromioclavicular (AC) joint - AC ligaments
Coracoclavicular ligaments - Trapezoid and conoid
Coracoacromial ligament
Glenoid Labrum
Cartilaginous structure: surround the edges of the glenoid
Doubles the depth of the glenoid
Provides 50% of static stability of shoulder
Enhances joint stability by increasing contact SA for humeral head
Resection results in 20% loss of resistance to translation from a compressive load
Shoulder capsule
Twice the SA humeral head
Capsule reinforced by rotator cuff
Lined w/ synovium
Ligamentous thickenings
Inferior Glenohumeral Ligament (IGHL)
Major stabilizer of GH joint
Anterior and posterior bands w/ interposed axillary pouch
Muscles contributing dynamic stability of shoulder
Long head of biceps
Deltoid
Scapular stabilizers
Rotator Cuff Most important
Long Head of the Biceps
Adds to anterior shoulder stability by resisting force in abduction and external rotation
Decreases stress placed on IGHL
Anterior rotator cuff
Subscapularis Origin: subscapular fossa Insertion: Lesser tuberosity Action: Internal rotation Innervation: subscapular nerve
Superior rotator cuff
Supraspinatus Origin: supraspinous fossa Insertion: Greater tuberosity Action: Abduction Innervation: suprascapular nerv
Posterior rotator cuff
Infraspinatus Origin: Infraspinous fossa Insertion: Greater tuberosity Action: external rotation Innervation: suprascapular nerve
Teres Minor Origin: Lateral border of scapula Insertion: Greater tuberosity Action: External rotation Innervation: axillary nerve
4 rotator cuff muscles
Subscapularis
Supraspinatus
Infraspinatus
Teres minor
Deltoid
Origin: clavicle, acromion, scapular spine
Insertion: deltoid tuberosity, mid-humerus
Action: flexion, abduction, extension
Innervation: Axillary nerve
Pectoralis Major
Origin: clavicle, sternum, ribs
Insertion: Humerus
Action: Adduction, internal rotation
Innervation: medial and lateral pectoral nerves
Pectoralis Minor
Origin: 3rd-5th ribs
Insertion: coracoid process
Action: rotates scapula, assists in respiration
Innervation: medial and lateral pectoral nerves
Triceps
Origin: Long head - inferior glenoid, Medial and lateral heads - humerus
Insertion: olecranon
Innervation: radial nerve
Extends elbow
Rotator Cuff disorders
Greatest incidence: >40 age group
Subacromial bursa: sandwiched b/w acromion and proximal humerus
Decreased volume of SA space - increased wear and degeneration of soft tissue structures
Wide range of pathology
