ANATOMY – MUSCLES – ROTATOR CUFF
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S.I.T.S. MUSCLES: Supraspinatus | Infraspinatus | Teres Minor | Subscapularis
· These muscles work in unison to stabilize the shoulder – Physiopedia .
· They are involved in actions other than External & Internal Rotation
· Lateral Raises Full Can & Empty Can: E3 Rehab .
· Rows; Lat Pulls; Chin-ups; Pull-ups
· External/Lateral Rotation & Internal/Medial Rotation Exercises
- SUPRASPINATUS
(1) Function:
– Assists abduction of the arm and stabilization of the humerus head during arm movements.
– Initiates abduction and depress the humeral head against the upward pull of the deltoid.
– Primary Abductor of the arm from 0 to 15º (Lateral Raises)
– Assists Deltoid from 0 to 90º reaching peak forces from 30 to 60º
– Lateral Raise variations of angle & hand position
(2) Origin: Supraspinatus Fossa of the Scapula
(3) Insertion: Superior Facet of the Greater Tuberosity of the Humerus
(4) Nerve Supply: Suprascapular Nerve, C5 & 6, Superior Trunk of the Brachial Plexus - INFRASPINATUS
(1) Function:
– It provides shoulder joint stability and along with the teres minor muscle externally rotates the arm at the shoulder
– External/Lateral Rotation (Exorotation) of the arm (multiple specific exercises)
– Assists in Shoulder Extension (approx. shoulder width Rows, Lat Pulls, Chins)
– Abducts inferior angle of scapula when arm is fixed
(2) Origin: Infraspinatus fossa of scapula
(3) Insertion: The posterior aspect of Greater Tuberosity of Humerus, and the capsule of shoulder joint
(4) Nerve Supply: Suprascapular Nerve (C5 & C6) - TERES MINOR
(1) Function:
– It provides shoulder joint stability and externally rotates the arm at the shoulder; it is sometimes fused with the infraspinatus
– External/Lateral Rotation (Exorotation) of the arm (multiple specific exercises)
– Assists in Adduction and Extension of the shoulder (Rows, Lat Pulls, Chins)
(2) Origin: upper 2/3 of the lateral border of the scapula
(3) Insertion: Greater Tubercle of the Humerus
(4) Nerve Supply: axillary nerve (roots C5, C6) from the posterior cord of the Brachial Plexus - SUBSCAPULARIS
(1) Function:
– largest and most powerful of the rotator cuff muscles contributing to internal rotation strength, humeral head depression, shoulder adduction and extension, and active stabilization of the glenohumeral joint
– Internal/Medial Rotation (Endorotation) of the arm (multiple specific exercises)
– Adduction & Extension when the arm is elevated (Lat Pulls & Chins)
(2) Origin: Medial 2/3 of the Subscapular Fossa of the Scapula
(3) Insertion: Lesser Tuberosity of the Humerus
(4) Nerve Supply: Upper and Lower Subscapular Nerves (C5-C6); Posterior Cord of the Brachial Plexus
VIDEOS
- Dr. Ebraheim – Rotator Cuff .
- DR. Sechrest – Deltoids & Rotator Cuff .
(1) Bones, Joints, Ligaments (2) Tendons, Muscles (3) Nerves, Blood Vessels (4) Bursae - Noted Anatomist – Deltoids & Rotator Cuff .
- Webster – Rotator Cuff .
- Anatomy Zone – Rotator Cuff .
- Anatomy Zone – Supraspinatus .
- Anatomy Zone – Infraspinatus .
- Anatomy Zone – Teres Minor .
- Anatomy Zone – Subscapularis .