Sunday, April 12, 2009

Muscle Actions

Upper and Lower arm:
brachialis : flexes forearm

Tricep: Extend the forearm at elbow joint

Bicep: Flexes forearm, rotatoes radius outward

Coracoid-Brachialis: draws arm forward and sideways, rotates outward

Anconeus: extends forearm

Pronator Teres: Flexes and pronates forearm, pronates hand

flexor carpi radialis: Flexes wrists and bends up

Supinator: Supinates forearm


Trapezius: Rotates scapula by lifting lateral end (the outside part) and pulls medial end (inside) downward. Also helps by holding together

Teres minor: Draws humerous outwards, and rotatoes arm backwards (adduction)

Teres major: Draws humerous outward and rotates backward

Deltoid: Abduction of arm, draws humerous forward and backward

Supraspinatus: upwards

Subscapularis: inwards


Serratus Anterior: Pulls shoulderblade forward (punches)

Pec Minor: Depresses point of shoulder (keeps arm in)

Pec Major: Adduction (draws arm downward and raises it up), moves upper limbs toward centre

Rhomboids: adduct scapula

External and Internal Obliques: Twist body

Rectus Abdominus (abs): Flexs/crunches

Lower Body:

Gluteus Maximus: Extension of thigh; adduction and lateral rotation of thigh; important in standing up right. Connection to Illio-Tibial band

Gluteus Medius: Abduction; lateral and medial rotation of inward thigh. Connection to Illio-Tibial band

Tensor Fasciae Latae: flexes and adducts the thigh, extends leg. Connection to Illio-Tibial band

Rotator Cuff of the femur: Piriformis (abducts and out), Objurator Internus (slight outward rotation), Gemellus superior and inferior (weak outward rotation), Quadratus Femoris (adduction and outward rotation)

Sartorius: Flexes les and thigh, medial rotation (crosses leg)

Quadriceps: Rectus Femoris (ontop), Vastus Lateralis (outside), Vastus Medialis (inside, teardrop shape), Vastus Intermedius (joins four heads); Extendsand flexes thigh. Mechanism of upright stance

Adductors: Adducts, lateral and outward rotation of thigh, flex; Adductor magnus, Pectineus, Adductor Longus, Adductor Brevis, Gracilis

Hamstrings: Biceps Femoris (flexes leg, extends thigh; outward rotation), Semitendinous ( flexes leg, inward rotation, extends thigh), Semimembranous (flexes leg, extends thigh)

Gastrocnemius: flex foot (toes down) and leg. Adducts foot, important in walking and standing upright. Plantar Flexion **

Soleus: Extends foot . Plantar flexion **

Tibialis: Flexes sole of foot, adduction and medial rotation

Tibialis Anterior: dorsal flex (arch in foot and up)

Peroneus Brevis and Longus: movement of the sole of the foot away from the median plane (heel outward)

Extensor Digitorm Longus: Extends toes, dorsal flex (up) **

Flexor digitorum longus: flexes toes and soles of foot. Adduction of foot

**Plantar flexion is the movement which increases the angle between the foot and the leg, as when depressing an automobile pedal. The word "plantar" translates as "toward the sole".
The movement in the opposite direction is dorsal flexion. **