Front Muscles Orbicularis oculi closes eyelids Temporalis elevates retracts jaw Orbicularis oris closes mouth Masseter elevates jaw Sternocleidomastoid rotates head flexes neck laterally Pectoralis major flexes adducts arm shoulder joint medially rotates arm Serratus anterior abducts scapula rotates scapula upward Bicep brachii flexes elbow joint supinates forearm Brachioradialis flexes elbow joint Flexor carpi flexes wrist fingers Extensor carpi extends wrist fingers Rectus abdominis flexes spine supports abdominal wall External oblique rotates trunk flexes spine laterally Internal oblique rotates trunk flexes spine laterally Sartorius flexes thigh hip joint assists hip abduction external rotation Vastus lateralis extends knee joint Tibialis anterior dorsiflexes foot inverts foot Back Muscles Trapezius elevates retracts rotates scapula supports head Latissimus dorsi extends adducts medially rotates arm shoulder joint Triceps brachii extends elbow joint Gluteus maximus extends hip joint externally rotates hip Hamstring group flexes knee joint extends hip joint Biceps femoris Semitendinosus Semimembranosus Gastrocnemius plantarflexes foot Soleus plantarflexes foot Achilles tendon transmits force calf muscles plantarflex foot