Appendicular Muscles

Coracobrachialis

Flexes arm, shoulder adduction.

Origin: Coracoid process of scapula.

Insertion: Medial aspect of humeral shaft.

Prime mover of elbow flexion.

Origin: anterior surface of distal half of humerus.

Insertion: Coronoid process and tuberosity of ulna.

Brachialis

Synergist of elbow flexion, rapid forearm supination, helps support GHJ.

Origin: Long Head: superior margin of glenoid cavity; Short Head: Coracoid process of scapula.

Insertion: Tuberosity of radius; fascia of forearm.

Biceps Brachii

Extends elbow, Long Head extends and adducts humerus.

Origin: Long Head: inferior margin of glenoid cavity and joint capsule; Lateral Head: posterior surface of proximal end of humerus; Short Head: posterior surface of distal end of humerus.

Insertion: Olecranon; fascia of forearm.

Triceps Brachii

Aids deltoid in abduction of arm, supports humeral head when carrying weight.

Origin: Supraspinous fossa of scapula.

Insertion: Greater tubercle of humerus.

Supraspinatus

Modulates deltoid action, prevents humeral head from sliding upward, rotates humerus laterally.

Origin: Infraspinous fossa of scapula.

Insertion: Greater tubercle of humerus.

Infraspinatus

Modulates deltoid action, prevents humeral head from sliding upward when abducted, rotates humerus laterally.

Origin: Lateral border and adjacent posterior surface of scapula.

Insertion: Greater tubercle of humerus; posterior surface of joint capsule.

Teres minor

Modulates deltoid action, prevents humeral head from sliding upward when abducted, rotates humerus medially.

Origin: Subscapular fossa of scapula.

Insertion: Lesser tubercle of humerus; anterior
surface of joint capsule.

Subscapularis

Anterior fibers flex and medially rotate arm
Abducts arm, extends and laterally rotate arm.

Origin: Acromion and spine of scapula; lateral portion of clavicle.
Insertion: Deltoid tuberosity of humerus.

Deltoid

Extends the arm, medially rotates humerus.

Origin: Inferior angle of scapula.
Insertion: Intertubercular sulcus of humerus.

Teres major

Assists in rapid pronation, weakly flexes elbow.
Origin: Humeral shaft near medial epicondyle; coronoid process of ulna.
Insertion: Lateral surface of radial shaft.

Pronator teres

Flexes wrist anteriorly.
Origin: Medial epicondyle of humerus.
Insertion: Base of metacarpals II-III.

Flexor carpi radialis

Anchors skin and fascia of palmar region, weakly developed and may be absent.
Origin: Medial epicondyle of humerus.
Insertion: Flexor retinaculum, palmar aponeurosis.

Palmaris longus

Flexes wrist anteriorly.

Flexor carpi ulnaris

Flexes wrist, metacarpophalangeal and proximal interphalangeal joints.

Flexor digitorum superficialis

Flexes elbow.

Brachioradialis

Extends wrist, aids in radial flexion of wrist.

Extensor carpi radialis longus

Extends wrist.

Extensor carpi radialis brevis

Extends wrist, metacarpophalangeal and interphalangeal joints.

Extensor digitorum

Extends wrist, fixes wrist when fist is clenched or hand grips.

Extensor carpi ulnaris

Supinates forearm.

Supinator

Helps extend elbow.

Anconeus

Abducts thigh, medial and lateral rotation of the hip, helps shift the weight of the trunk.

Gluteus minimus

Abducts thigh, medially rotates thigh, helps shift weight of trunk.

Gluteus medius

Extends thigh at hip, abducts thigh, helps stabilize femur on tibia.

Gluteus maximus

Lateral rotation of thigh.

Piriformis

Extends knee, laterally rotates tibia.

Tensor fasciae latae

Flexion of thigh (hip), lateral rotation of thigh, lateral flexion of trunk.

Psoas major (iliopsoas)

Flexion of thigh (hip), lateral rotation of thigh.

Iliacus (iliopsoas)

Aids in knee and hip flexion, abducts and laterally rotates thigh.

Origin: Anterior superior iliac spine.

Insertion: Medial surface of proximal end of tibia.

Sartorius

Flexes and adducts thigh.

Pectineus

Adducts thigh.

Adductor brevis

Adducts and medially rotates thigh, flexes thigh at hip.

Adductor longus

Adducts and medially rotates thigh, extends thigh at hip.

Adductor magnus

Flexes knee, medially rotates tibia at knee.

Gracilis

Flexes knee, extends hip.

Origin: Long Head: ischial tuberosity; Short Head: linea aspera and lateral supracondylar line of femur.

Insertion: Head of fibula.

Biceps femoris

Flexes knee, extends thigh.

Origin: Ischial tuberosity.

Insertion: Medial condyle and nearby margin of tibia.

Semimembranosus

Flexes knee, extends thigh.

Origin: Ischial tuberosity.

Insertion: Medial surface of upper tibia.

Semitendinosus

Extends knee.

Origin: anterior and lateral surfaces of femoral shaft.
Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia.

Vastus intermedius

Extends knee, aids in fixing patella

Origin: Femur at greater trochanter and intertrochanteric line, gluteal tuberosity, and linea aspera.

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia.

Vastus lateralis

Extends knee, aids in fixing patella during knee movements.

Origin: Femur at spiral line, linea aspera, and medial supracondylar line.

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia.

Vastus medialis

Extends knee, flexes thigh at hip.

Origin: Ilium at anterior inferior spine and superior margin of acetabulum.

Insertion: Patella; tibial tuberosity; lateral and medial condyles of tibia.

Rectus femoris

Dorsiflexes and inverts foot, resists backward tipping of body.

Origin: Lateral condyle and lateral margin of tibia.

Insertion: Medial cuneiform; metatarsal I.

Tibialis anterior

Extends toes, dorsiflexes foot.

Extensor digitorum longus

Extends hallux, dorsiflexes foot.

Extensor hallucis longus

Plantar flexes foot, steadies leg on ankle during standing.

Origin: fibula and proximal one-fourth of tibia; interosseous membrane.

Insertion: Calcaneus.

Soleus

Plantar flexes foot, flexes knee.

Origin: condyles, popliteal surface, and lateral supracondylar line of femur; capsule of knee joint.

Insertion: Calcaneus.

Gastrocnemius

Everts and plantar flexes foot.

Origin: head and lateral surface of proximal two-thirds of fibula.
Insertion: medial cuneiform, metatarsal I.

Fibularis (peroneus) longus

Everts and plantar flexes foot.

Origin: lateral surface and distal two-thirds of fibula.

Insertion: base of metatarsal V.

Fibularis (peroneus) brevis

Flexes wrist, metacarpophalangeal and distal interphalangeal joints.

Flexor digitorum profundus

Flexes phalanges of pollex.

Flexor pollicis longus

Prime mover of forearm pronation; resists separation of radius and ulna when force is applied to forearm through wrist.

Pronator quadratus

Abducts pollex in frontal (palmar) plane, extends pollex at carpometacarpal joint.

Abductor pollicis longus

Extends distal phalanx I, aids in extending proximal phalanx I and metacarpal I.

Extensor pollicis longus

Extends metacarpal I and proximal phalanx of pollex.

Extensor pollicis brevis