Trapezius

*location on back

*origin: spine (spinous process, occipital bone) 

*insertion: clavicle and scapula (acromion and scapular spine)

*action: elevation and depression of scapula

*location on lower back

*origin: spinous processes of inferior thoratic on all lumbar vertebre, ribs 8-12

*insertion: floor of intertubercular groove of the humorous

*actions: depression and retraction of the scapula,

shoulder: extension, adduction, and internal rotation

*location on chest

*origin: cartilages of ribs 2-6, body of sternum, and inferior, medial portion of the clavicle. 

*insertion: crest of greater tubercle, and lateral lip of intertubercular groove of humerus

*actions: protraction of the scapula

shoulder: flexion, adduction, and internal rotation

*location on the chest under the Pectoralis Major

*origin: anterior-superior surfaces of ribs 3-5

*insertion: coracoid process of scapula

*actions: depression and protraction of the scpaula

*location on top of bicep

*origin: short head from the coracoid process; long head from the supraglenoid tubercle

*insertion: tuberosity of radius

*actions: flexion at the elbow and shoulder; supination

*location on back/shoulder

*origin: clavicle and scapula (acromion and adjacent scapular spine)

*insertion: deltoid tuberocity of humerus

*actions: 

Shoulder: abduction, flexion and extension, medial and lateral rotation

*location under Pectoral Girdle 

*origin: supraspinous fossa of scapula

*insertion: greater tubercle of humerus 

*actions: 

Shoulder: abduction, flexion and extension, internal and external rotation 

*location in front of scapula

*origin: subscapular fossa of scapula

*insertion: lesser tubercle of humerus

*actions: 

shoulder: internal rotation

*location in back of scapula 

*origin: infraspinous fossa of scapula

*insertion: greater tubercle of humerus

*actions: 

Shoulder: external (lateral) rotation

Flexors and Extendors

(action only)

*circumduction 

*location on the posterior side of forearm

*origin: lateral head- superior, lateral margin ofhumerus;

long head- infraglenoid tubercle of scapula;

medial head- posterior surface of humerus inferior to radial groove

*insertion: olecranon of ulna

*actions: extension at elbow,  

shoulder: extension and adduction

*location on Proximal end of forearm

*origin: medial epicondyle of humerus and coronoid process of ulna

*insertion: mid lateral surface of radius

*actions: pronation

*location on proximal end of forearm; deep

*origin: lateral epicondyle of humerus, annular ligament, and ridge near radial distal notch of ulna

*insertion: anterolateral (anterior-lateral) surface of radius distal to the radial tuberosity 

*action: supination

*location on distal forearm, wrist

*origin: medial epicondyle of radius

*insertion: metacarpal bones

*action: flexion

Digital flexors

*location on wrist/hand

*origin: medial epicondyle 

*insertion: middle/distal phalanges

*action: flexion of wrist

Extensor carpi

(radial brevis, ulnaris, radialis longus)

*location on forearm/wrist

*origin: lateral supracondylar ridge of humerus, lateral epicondyle of humerus

*insertion: base of metacarpals 

*actions: extension at wrist

*location on posterior radial side of forearm

*origin: lateral epicondyle of humerus

*insertion: posterior surfaces of the phalanges, fingers 2-5

*actions: extension at the wrist

*location on radial side of forearm and into thumb

*origin: anterior shaft of radius, interosseous membrane

*insertion: base of distal phalanx of thumb

*actions: flexion of the thumb

*location: posterior, radial side of forearm (deep)

*origin: posterior and lateral surfaces of ulna and interosseous membrane

*insertion: base of distal phalanx of thumb

*actions: extension of thumb

Extensor pollicis brevis

*location on posterior, radial side of forearm

*origin: shaft of radius, distal to origin of adductor pollicis longus

*insertion: base of the proximal phalanx of thumb

*action: extension at thumb

*location on the radial side of forearm

*origin: proximal dorsal (posterior) surface of ulna and radius 

*insertion: lateral margin of first metacarpal bone

*actions: abduction of thumb

*location on top of thumb

*origin: metacarpal and carpal bones

*insertion: proximal phalanx of thumb

*actions: adduction of thumb

*location on thumb and palm

*origin: trapezium and flexor retinaculum 

*insertion: first metacarpal bone

*actions: opposition of thumb

*location on forearm

*origin: medial epicondyle of humerus; adjacent anterior surfaces of ulna and radius

*insertion: midlateral surface of middle phalanges of fingers 2-5

*actions: flexion of the fingers

*location on the ulnar side of forearm

*origin: medial and posterior surfaces of ulna, medial surface of coronoid process, and interosseous membrane

*insertion: bases of distal phalanges of fingers 2-5

*actions: flexion of the fingers

*location on forearm and index finger

*origin: posterior surface of ulna and interosseous membrane

*insertion: posterior surface of phalanges of index finger (2); with tendon of extensor digitorum 

*action: extension and adduction of index finger

*location on small finger

*origin: via extensor tendon to lateral epicondyle of humerus

*insertion: posterior surface of proximal phalanx of little finger (5)

*action: extension of little finger

*location: in between fingers on hand

*origin: tandons of flexor digitorum profundus 

*insertions: tendons of extensor digitorum to digits 2-5

*actions: flexion 

Dorsal interosseus

*location on proximal side, in between fingers

*origin: each originates from opposing face of two metacarpal bones

*insertion: base of proximal phalanges of fingers 2-4

*action: abduction