Items tagged “muscle”

The piriformis muscle is a muscle of the posterior pelvic wall and gluteal region of the lower limb. It is an important anatomical landmark.  Summary origin: anterolateral surface of the sacrum course: exits the pelvis through the greater sciatic foramen insertion: greater trochanter of the ...

Muscles of the shoulder can be subdivided into a variety of groups depending on origin, topography, function or innervation. The system used here groups the muscles based on their function and topography (which are closely related in the upper limb): Muscles of the shoulder girdle Muscles that...

The supraspinatus muscle is one of the four muscles that make up the rotator cuff, the others being: infraspinatus, teres minor, and subscapularis. Summary origin: supraspinous fossa of the scapula insertion: superior facet of the greater tubercle of the humerus innervation: suprascapular ne...

The Infraspinatus muscle is one of the four muscles that make up the rotator cuff, the others being: supraspinatus, teres minor and subscapularis. origin: infraspinous fossa of the scapula insertion: middle facet of the greater tubercle of the humerus innervation: suprascapular nerve (C5-6) ...

The biceps femoris is one of the large muscles in the posterior compartment of the thigh and a component of the hamstrings. It has a long and a short head, each with different functions and innervation. Its medial border forms the superolateral border of the popliteal fossa. Summary origin l...

The lateral rectus muscle is one of the six extraocular muscles that control eye movements. It is responsible for abduction and is the only muscle that is innervated by the abducens nerve (CN VI). Summary innervation: abducens nerve (CN VI) origin: annulus of Zinn (tendinous ring) insertion:...

The sternocleidomastoid muscle (also known as sternomastoid) is found in the neck. It has two heads that meld to form one insertion. Sternocleidomastoid muscle, along with the trapezius muscle, is invested by the superficial layer of the deep cervical fascia, which splits around it. Sternocleido...

The anconeus epitrochlearis muscle is an accessory muscle of the upper limb at the medial aspect of the elbow. It is also known as the accessory anconeus muscle or epitrochleoanconeus muscle and should not be confused with the anconeus muscle which is present at the lateral aspect of the elbow. ...

The pectoralis major muscle is a large fan-shaped muscle of the pectoral region, overlying the anterior chest wall but often considered an upper limb muscle due to its function.  Summary origin: medial clavicle, sternum, costal cartilages, and external oblique aponeurosis insertion: bicipital...

The deltoid muscle (also known as deltoideus muscle) is the largest of the shoulder muscles. The muscle is composed of three heads (clavicular, acromial and spinous), although electromyography suggests that there are at least seven control regions that could act independently 1. Summary origin...

Teres major muscle is one of the seven scapulohumeral muscles that act around the glenohumeral joint to facilitate shoulder movement. Summary origin: caudal two thirds of lateral border and inferior angle of scapula insertion: medial border of the intertubercular groove, which is the crest of...

The coracobrachialis muscle is one of the three muscles of the anterior compartment of the arm. It sits beneath the biceps brachii, inserting via a flat tendon into the medial shaft of the humerus. origin: coracoid process of scapula insertion: via a flat tendon onto the midportion of the medi...

The anconeus muscle is a small muscle in the posterior compartment of the arm at the lateral aspect of the elbow. Its functional significance is not well understood 5. An accessory muscle, anconeus epitrochlearis is present in up to one third of people, and may be implicated in some cases of cu...

The articularis cubiti muscle lies in the posterior compartment of the arm: origin: posterior surface of the distal humerus insertion: posterior surface of the elbow joint capsule innervation: radial nerve action: tenses the posterior elbow joint capsule during elbow extension

Pronator teres muscle is a two-headed flexor and pronator of the forearm, found superficially in the anterior compartment of the forearm. Summary origin humeral head: medial epicondyle of the humerus ulnar head: coronoid process of the ulna insertion: lateral surface of the middle-third rad...

Flexor carpi radialis (FCR) is found in the first layer of the anterior compartment of the forearm and is one of the extrinsic muscles of the hand. It does not pass through the carpal tunnel, but rather by itself in a small separate FCR tunnel. Summary origin: medial epicondyle of the humer...

Palmaris longus (PL) muscle is a superficial, weak flexor of the wrist located in the anterior compartment of the forearm. It is one of the extrinsic muscles of the hand. Summary origin: medial epicondyle of the humerus insertion: palmar aponeurosis arterial supply: anterior ulnar recurrent ...

Latissimus dorsi muscle (plural: latissimi dorsi muscles, and colloquially often shortened to the lats) is one of the muscles that attaches the upper limb to the vertebral column. Summary origin ​spinous processes of T7-T12 vertebrae and thoracolumbar fascia posterior third of the iliac cres...