Muscular System- Rehab Therapy

MUSCULAR SYSTEM If you weigh 120 pounds, how much of the weight is muscle?

Approximately 50 pounds

MUSCLE TISSUE- 3 Types SKELETAL- attached to bone, voluntary, straited (because of stripes & straie) CARDIAC- heart muscle SMOOTH- nonstraited, involuntary, found in visceral(organs) and blood vessel walls

FUNCTION OF MUSCLES- to contract and lengthen SKELETAL MUSCLE FUNCTION 1) MOVEMENT 2) POSTURE- MUSCLE TONE 3) HEAT PRODUCTION

MOVEMENT Muscles move bones by pulling on them, shortening and contracting. The muscle that is the main one responsible for movement is called the PRIME MOVER. The other muscles that help are called SYNERGISTS.

When prime movers & synergists contract, other muscles called ANTAGONISTS relax. When antagonists contract they produce movement opposite to prime movers & synergists.

POSTURE Tonic Contractions- does not move any body part, holds them in position. This is known as posture. Isometric Contractions- muscle does not shorten & no movement occurs. Ex.- pushing against a wall

Isotonic contraction- produces movement at a joint such as walking, running or breathing Twitch contraction- quick jerky contraction

Tetanic contraction- more sustained contraction than a twitch Tetanic contraction- more sustained contraction than a twitch. This is where the name tetanus comes from because of the severe cramping also known as “lock-jaw”.

TENDONS Dense fibrous connective tissue that acts as cords, connects muscle to bone

BURSAE Small fluids filled sacs that lie between some tendons & bones Bursitis- inflammation of the bursae

Bursae lined with synovial membrane which secretes a fluid (synovial) that fills the bursae This fluid acts as a cushion

MOVEMENTS Flexion- movement that makes a joint angle smaller Extension- movement that makes joint angle larger

Abduction- moving body part away from the midline; “abduct” Adduction- moving body part toward the midline; “add”

ROTATION Moving around longitudinal axis example: “shaking your head no”

Supination- turn palm of hand anterior or up as with the anatomical position Pronation- turn the palm to posterior position or down

Dorsiflexion- elevate top of foot toward knee Plantarflexion- point foot downward as if you are standing on toes

LIGAMENTS Strong fibrous connective tissue that grows out of the periosteum & connects two bones together.

MUSCULAR DISORDERS Muscular dystrophy- progressive wasting away of muscles Muscular atrophy- muscle shrinkage. Why would this occur?

Muscular hypertrophy- increase in muscle size

Paralysis Injury to brain or spinal cord in which muscles cannot contract Hemiplegia- paralysis on side Paraplegia- paralysis waist down Quadraplegia- paralysis from neck down

Three parts of a muscle Body- main part of the muscle origin insertion

ORIGIN Muscle Attaches to relatively stationary bone

INSERTION Muscle attaches to part of bone that moves

REFER TO HANDOUT ON INDIVIDUAL MUSCLES- DISCUSS