Skeletal Muscle Prime mover agonist Antagonist Synergist Fixators

Skeletal Muscle • • Prime mover (agonist) Antagonist Synergist Fixators

Naming of Skeletal Muscles 1. 2. 3. 4. 5. 6. 7. Location of muscle Shape of muscle Size of muscle Direction of fibers # of origins Location of attachments Action

Muscle Mechanics • Arrangement of fascicles – Circular, pennate, parallel, convergent • Lever Systems – Mechanical advantage – moving large load over a small distance with little effort (power lever) – Mechanical disadvantage – effort exerted greater than load (speed lever) – 1 st - seesaws – effort (tension) at one end, load at other, fulcrum in middle, 2 nd - effort and fulcrum at ends, load in middle, 3 rd class – great speed – effort between load and fulcrum

Facial Muscles

Neck Muscles • Sternocleidomastoid – PM head flexion • Scalenes – flexion and rotation • Splenius – extend or hyperextend (posterior neck)

Back Extensors • Erector spinae • Semispinalis • Quadratus lumborum

Breathing • Diaphragm • External intercostals – inspiration • Internal intercostals - expiration

Compression of Abdomen • External obliques, internal obliques, transversus abdominis • Rectus abdominis • Valsalva maneuver – abdominal muscles contract, along with diaphragm; glottis closed

Pelvic Floor and Perineum • • • Levator ani Coccygeus External anal sphincter External urethral sphincter Ischiocavernosus Bulbospongiosus

Shoulder movements • Pectoralis minor • Serratus anterior • Subclavius • Trapezius • Levator scapulae • Rhomboids

Arm Movements • • Pectoralis major Latissimus dorsi Deltoid Subscapularis Supra- and infraspinatus Teres major and minor Coracobrachialis