Muscle Origin Insertion Innervation Action Trapezius External occipital protuberance Superior nuchal line Ligamentum nuchae Spinous process of CVII-TXII Upper fibres – lateral 1/3 clavicle Middle fibres – acromion Lower fibres – spine of scapula CNXI – Spinal part of Accessory nerve - Elevates the scapula - Rotates the scapula during aBDduction of the humerus above horizontal - Middle fibres retract scapula - Lower fibres depress scapula Latissimus Dorsi T6-T12 Iliac Crest Thoracolumbar fascia Inferior 3 ribs Bicipital groove (intertubercular sulcus) of the humerus Thoracodorsal nerve C6, C7, C8 Extends, aDDucts and medially rotates the upper limb Levator Scapuli Superioris C1-C4 transverse processes Medial border of the scapula Dorsal scapular nerve (branch of the brachial plexus) Elevates the scapula Rhomboid Major (inferior) Rhomboid Minor (superior) T2-T5 vertebrae Posterior surface of medial border of scapula Dorsal scapular nerve (C4, C5) Elevates and retracts the scapula C7-T1 Posterior surface of medial border of scapula Dorsal scapular nerve (C4,C5) Elevates and retracts the scapula Rotator cuff muscles Name Meaning Origin Insertion Nerve Supply Action Supraspinatus Above spine of scapula Medial 2/3rd of supraspinous fossa Capsule of shoulder joint + Greater tubercule of the humerus Suprascapular nerve (C5, C6) aBDuction of arm at glenohumeral joint
(most superior facet) Infraspinatus Below spine of scapula Medial 2/3rd of infraspinous fossa Greater tubercle of the humerus (Lower down than supraspinatous) Suprascapular nerve (C5,C6) Lateral rotation at glenohumeral joint Teres Minor *under the lower border of the teres minor, the axillary nerve leaves the axilla to enter the posterior compartment which lies across the posterior surface of the humerus. Minor rounded muscle Lateral border of the scapula Capsule of shoulder joint + Greater tubercle of the humerus (Below insertion of the infraspinatus) Axillary Nerve (C5,C6) supplies: deltoid teres minor long head of triceps brachii Lateral rotation at glenohumeral joint Subscapularis Muscle below the scapula Subscapular fossa Lesser tubercle of humerus Upper and lower subscapular nerves (C5, C6, (C7)) Medial rotation of arm at the glenohumeral joint Name Origin Insertion Nerve supply Action Deltoid muscle (anterior, middle and posterior) Clavicle Acromion (bony process of the scapula) Spine of scapula Deltoid tuberosity of the humerus Axillary nerve Anterior fibres Flex arm at the shoulder Middle fibres
Branch Root Motor Sensory Musculocutaneous C5-C7 Muscles in the anterior compartment of the arm FLEXORSSSSSS Biceps brachii Brachialis Coracobrachialis Skin on lateral side of the forearm Axillary C5 , C6 Deltoid, Teres Minor Skin over upper lateral part of the arm Radial C5-C8, T1 Muscles in the posterior compartment of the arm EXTENSORSSSSS Skin on the posterior aspects of the arm and forearm Lower lateral surface of arm Dorsal lateral surface of the hand Median (lateral and medial root (C5 sometimes) C6-T1 Anterior forearm All muscles in the anterior compartment of the forearm EXCEPT: Flexor carpi ulnaris Medial half of Flexor digitorum profundus (supplies lateral half of flexor digitorum profundus) Hand Intrinsic muscles of the hand & skin of palm LLOAF LL. (lateral lumbricles) O.A.F (three thenar muscles) Opponens pollicis aBductor pollicis brevis flexor pollicis brevis Skin over palmar surface of the lateral three and one half digits Ulnar C8, T1 Anterior forearm flexor capri ulnaris medial half of flexor digitorum profundus Hand All Intrinsic muscles of the hand & skin of palm EXCEPT: Three thenar muscles Lateral lumbricles Skin over palmar surface – medial one and a half digits Skin over dorsal surface- one and a half digits Thoracodorsal C6-C8 Lattisimus dorsi - Long thoracic nerve C5-C7 Lies on the superficial aspect of the serratus anterior and supplies this muscle DERMATOMES - Sensory supply
Compartment Muscles Action Innervation Anterior Iliopsoas Different action, look below Quadriceps femoris: Vastus lateralis Vastus intermedialis Vastus medialis Rectus femoris Sartorius Pectineus* this compartment in terms of nerve supply Flexion of thigh at the hip Main action – extension of the leg at the knee Femoral nerve (L2-L4) Medial aDductors magnus aDductor longus aDductor brevis obturator externus* gracialis Hip aDductors Obturator nerve (Lumbar plexus) Blood supply : obturator artery Posterior Biceps femoris Semitendinosus Semimembranosus Extend at the hip Flex at the knee Sciatic nerve (L4-L3) Lower limb: Anterior compartment of the thigh General Action: extension of the leg at the knee
Muscle Origin Insertion Action Innervation ADductor longus Pubis Linea aspera of the femur aDuction and medial roation of the thigh Obturator nerve L2-L4 ADductor brevis *lies underneath adductor longus and lies between the anterior and posterior divisions of the obturator nerve Body of pubis and inferior pubic rami Linea aspera of the femur aDduction of the thigh Obturator nerve L2-L4 ADductor magnus *largest muscle in the compartment and lies posteriorly to the other muscles aDuctor part inferior rami of the piubis Hamstring part Ischeal tuberosity aDuctor part linear aspera of the femur Hamstring part Adductor tubercle aDuction of thigh aDductor compartment: flexes thigh too hamstring compartment: extends thigh too Obturator nerve L2-L4 Gracilis This is the most superficial and medial in this compartment. It crosses at both the hip and knee joint Origin: inferior rami of the pubis and body of the pubis Insertion: medial surface of the tibia