Intrinsic muscles of the shoulder Flashcards
Origin of deltoid
Scapula and clavicle
Attachment of deltoid
Deltoid tuberosity on lateral humerus
What are the intrinsic muscles of the shoulder
Deltoid,
Teres major,
Rotator cuff muscles (supraspinatus, infraspinatus, subscapularis, teres minor)
Actions of deltoid
Anterior fibres flex arm at shoulder,
Middle fibres abduct arm at shoulder (15-90)
Posterior fibres extend arm at shoulder
Innervation of deltoid
Axillary nerve
Origin of teres major
Posterior surface of inferior angle of scapula
Attachment of teres major
Intertubercular groove of humerus
Action of teres major
Adduction and medial rotation of arm at shoulder
Innervation of teres major
Lower subscapular nerve
Origin of supraspinatus
Supraspinatous fossa of scapula
Attachment of supraspinatus
Greater tubercle of humerus
Innervation of supraspinatus
Suprascapular nerve
Action of supraspinatus
Abduction 0-15 and assists deltoid for 15-90
Origin of infraspinatus
Infraspinatous fossa of scapula
Attachment of infraspinatus
Greater tubercle of humerus
Innervation of infraspinatus
Suprascapular nerve
Action of infraspinatus
Lateral rotation of arm
Origin of subscapularis
Subscapular fossa on costal surface of scapula
Attachment of subscapularis
Lesser tubercle of humerus
Innervation of subscapularis
Upper and lower subscapular nerves
Action of subscapularis
Medial rotation of arm
Origin of teres minor
Posterior surface of scapula adjacent to its lateral border
Attachment of teres minor
Greater tubercle of humerus
Innervation of teres minor
Axillary nerve
Action of teres minor
Lateral rotation of arm
What is rotator cuff tendinitis
Inflammation of tendons of rotator cuff muscles (supraspinatus tendon and subacromial bursa), usually secondary to repetitive shoulder use.
During abduction of arm, the supraspinatus muscle rubs against the coracoacromial arch
Treatment of rotator cuff tendinitis
Rest, analgesia and physiotherapy
More severe cases require steroid injections and surgery
