Skeletal Muscle Groups Muscles of the head and

Skeletal Muscle Groups

Muscles of the head and neck n n Frontal – raises eyebrows Orbicularis oculi – closes eye Orbicularis oris – puckering Zygomaticus – smiling

Facial muscles contd. n n Masseter – closes jaw, elevates mandible Temporal – closes jaw Sternocleidomastoid – rotation of head/neck, flex neck on chest. Trapezius – extends head backwards and elevates the shoulders

Muscles of the upper extremity n n n Pectoralis major – flexes and helps adduct upper arm Latissimus dorsi – extends and helps adduct upper arm Deltoid – abduct upper arm Biceps brachii – primary flexor of forearm Triceps brachii – extensor of elbow, straightening, boxers muscle

Muscles of the trunk - ABs n n 3 layers running in different directions which leads to strength and support On side n n External oblique – outermost layer Internal oblique- middle layer Transversus abdominis – innermost layer Rectus abdominis – band of muscles running down midline of abdomen from thorax to pubis

Ab muscles n n External oblique, internal oblique and transversus abdominis all compress the abdomen Rectus abdominis – flexes trunk

Muscles that move the lower extremities n n Iliopsoas – flexor of thigh or trunk, posture Sartorius – flexes thigh and rotates lower leg Gluteus maximus – extensor of the thigh, supports torso in erect position Adductor muscles- found on inner thigh, adducts thigh ¡ Adductor longus, gracilis, pectineus

Upper leg muscles ¡ Hamstring muscles – flexes knee n n n ¡ Semimembranosus Semitendinosus Biceps femoris Quadriceps femoris – covers upper thigh, extends lower leg n n Rectus femoris Vastus lateralis, intermedius, medialis

Lower leg muscles n n n Tibialis anterior – dorsiflexes foot Gastrocnemius – (calf muscle) plantar flexion of foot (toe dancers muscle) Peroneus group () – plantar flex foot ¡ ¡ ¡ Peroneus longus – support arch in foot Peroneus brevis Soleus