Muscle of The Shoulder

 MUSCLE OF THE SHOULDER 

Muscle of the shoulder region

=> Muscle of the Shoulder

1) UPPER LIMB + VERTEBRA :-


=> This muscle are connected with upper limb and vertebrae. There are 5 muscle of upper limb and vertebrae


1) Trapezius

2) Lattisimus dorsi

3) Levator scapular

4) Rhomboid major

5) Rhomboid minor


TRAPEZIUS


ORIGIN : External occipetal protuberance, Superior nuchal line of occipetal bone, Spinous processes of 7th cervical and All thoracic vertebrae

INSERTION: lateral 1/3 of clavicle, Medial margin of acromion, spine of scapula

ACTION: Elevates The Scapula , rotation of scapula, retraction of shoulder, draw the scapula
downwards and Abduction Of Shoulder Beyond 90°

NERVE SUPPLY : XI cranial nerve (SPINAL ACCESSORY Nerve)


LATISSIMUS DORSI


ORIGIN: posterior layer of thoraco lumbar fascia,
Spinous processes of lower 6 thoracic vertebrae and Caudal most 3-4 ribs, May attach to iliac crest.

INSERTION: Intertubercular groove of the humerus.

ACTION: extends, adducts and medial rotation of arm

NERVE SUPPLY : Thoraco Dorsal Nerve (C6,C7,C8)


LEVATOR SCAPULAE


ORIGIN: transvers processes of upper 4 cervical vertebrae.

INSERTION: medialborder of the scapula superior portion.


ACTION: elevation of sup.angle of scapula and draws it medially.

NERVE SUPPLY : C3,C4,C5 Nerves


RHOMBOIDUS MINOR


ORIGIN : ligamentum nuchae,spinous process of C7, T1 vertebrae


INSERTION : medial border of the scapula

ACTION : retracts, depress the scapula and fix it to thoracis wall

NERVE SUPPLY : Dorsal Scapular .N (C4,C5)


RHOMBOIDUS MAJOR


ORIGIN: Spinous process of T2, T5

INSERTION: medial border of the scapula, inferior sulcus


ACTION: retracts the scapula, depress the glenoid cavity and fix the scapula to the thoracis wall

NERVE SUPPLY : Dorsal Scapular .N (c4,c5)


2) SCAPULAR MUSCLE :-


There are five Scapular muscle.


1) Suprascapular

2) Infrascapular

3) Subscapularis

4) Teres major

5) Teres minor

6) Deltoid

Scapular Muscle
Scapular Muscle (left side)


SUPRASPINATUS


ORIGIN: supraspinatous fossa of the scapula


INSERTION: superior facet on the gr.tubercle of the humerus


ACTION: initiation of abduction (15*) & lat.Rotation


NERVE SUPPLYSuprascapular.N From Brachial Plexus (C5,C6)


INFRASPINATUS


ORIGIN: infraspinatous fossa of the scapula


INSERTION: middle facet on the gr.tubercle of the humerus


ACTIONlat.rotation of shoulder, strengthen the shoulder by bracing the head of humerus.


NERVE SUPPLY: Suprascapular Nerve of Brachial Plexus (C5,c6)


SUBSCAPULARIS


ORIGIN: medial 2/3 subscapular fossa, lateral border of the scapula


INSERTION: lesser tubercle of the humerus


ACTION: stabilise the shoulder & prevents anterior displacement of the shoulder (medial rotation, adduction of arm)


NEREV SUPPLY: Upper &Lower Subscapular Nerve  (C5, C6)


TERES MINOR


ORIGIN: lateral borderof the scapula


INSERTION: inferio facet on the greater tubercle of the humerus


ACTION: external rotator & weak adductor


NERVE SUPPLY: Axillary nerve (C5,C6)


DELTOID


ORIGIN :- Lateral 1/3 clavicle, sup.surface of acromion, spine of the scapula.


INSERTION: deltoid tuberosity.


ACTION: abduction of arm, flx.&.ext of arm, med.& lat. rotation.


NERVE SUPPLY: Axillary nerve (C5,c6)



3) SCAPULAR MUSCLE :-


There are five Scapular muscle.


1) Suprascapular

2) Infrascapular

3) Subscapularis

4) Teres major

5) Teres minor

6) Deltoid

Scapular Muscle
Scapular Muscle (left side)



SUPRASPINATUS


ORIGIN: supraspinatous fossa of the scapula


INSERTION: superior facet on the gr.tubercle of the humerus


ACTION: initiation of abduction (15*) & lat.Rotation


NERVE SUPPLYSuprascapular.N From Brachial Plexus (C5,C6)


INFRASPINATUS


ORIGIN: infraspinatous fossa of the scapula


INSERTION: middle facet on the gr.tubercle of the humerus


ACTIONlat.rotation of shoulder, strengthen the shoulder by bracing the head of humerus.


NERVE SUPPLY: Suprascapular Nerve of Brachial Plexus (C5,c6)


SUBSCAPULARIS


ORIGIN: medial 2/3 subscapular fossa, lateral border of the scapula


INSERTION: lesser tubercle of the humerus


ACTION: stabilise the shoulder & prevents anterior displacement of the shoulder (medial rotation, adduction of arm)


NEREV SUPPLY: Upper &Lower Subscapular Nerve  (C5, C6)


TERES MINOR


ORIGIN: lateral borderof the scapula


INSERTION: inferio facet on the greater tubercle of the humerus


ACTION: external rotator & weak adductor


NERVE SUPPLY: Axillary nerve (C5,C6)


DELTOID


ORIGIN :- Lateral 1/3 clavicle, sup.surface of acromion, spine of the scapula.


INSERTION: deltoid tuberosity.


ACTION: abduction of arm, flx.&.ext of arm, med.& lat. rotation.


NERVE SUPPLY: Axillary nerve (C5,c6)


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