Skeletal and muscular systems

• Hinge joint


  Types of synovial joint

  
• Elbow joint


  • Biceps Brachii - muscle which contracts to cause flexion
  • Triceps Brachii - muscle which contracts to cause extension

  
• Flexion


  Decreasing the angle at a joint (bending the arm at the elbow joint)

  
• Extension


  Increasing the angle at a joint (straightening the arm at the elbow joint)

  
• Knee joint


  • Muscles which contract to cause flexion
  • Muscles which contract to cause extension

  
• The ankle is a hinge joint. The articulating bones are the tibia, fibula and talus.

  
• Dorsiflexion


  Pushing the toes up towards the knee
• Plantarflexion


  Pointing the toes
• Tibialis anterior


  Muscle which contracts to cause dorsiflexion
• Gastrocnemius and soleus


  Muscles which contract to cause plantarflexion
• Ball and socket joint


  Where the rounded end of one bone fits inside the cup-shaped end of another bone. Allows movement in all directions. Examples are the shoulder and hip joints.

  
• Shoulder joint


  • Deltoid - divided into 3 sections, contracts to raise the arms
  • Trapezius, Teres Minor, Latissimus Dorsi - muscles of the back that oppose the deltoid
  • Pectoralis Majoris - muscle of the chest that opposes the deltoid

  
• Flexion (shoulder)


  Bringing the arms up from the anatomical position forwards over the head
• Extension (shoulder)


  Moving the arms forwards and down from above the head
• Medial rotation (shoulder)


  Movement towards the midline of the body
• Lateral rotation (shoulder)


  Movement away from the midline of the body
• Abduction


  Sideways moving limb away from midline of the body
• Adduction


  Sideways moving limb towards midline of the body
• Wrist joint


  Condyloid joint, second most moveable synovial joint
• Wrist flexion


  Hand brought forwards and upwards from anatomical position
• Wrist extension


  Hand brought backwards and downwards from anatomical position
• Wrist flexors


  Muscles that contract to cause wrist flexion
• Wrist extensors


  Muscles that contract to cause wrist extension
• Frontal plane


  Divides the body into front and back halves, movements towards or away from midline
• Transverse plane


  Any form of rotation around the longitudinal axis, also associated with horizontal flexion and extension
• Sagittal plane


  Divides the body into left and right halves down the midline, largely associated with flexion and extension
• Agonist


  Muscle responsible for creating movement at a joint, also known as prime mover
• Antagonist


  Muscle that opposes the agonist, providing resistance for coordinated movement
• Fixator


  Muscle that contracts to stabilize an area of the body to enable efficient movement
• Isotonic contraction


  Muscle contracts and changes length, creating movement at the joint
• Isometric contraction


  Muscle contracts creating force but no movement takes place
• Concentric contraction


  Muscle contracts and shortens, reducing the angle between articulating bones
• Eccentric contraction


  Muscle contracts and lengthens, producing tension to resist forces and control joint movement
• Movement analysis requires identifying joint type, movement produced, agonist and antagonist muscles, and types of muscle contraction

  
• Concentric contraction


  Muscle contracts and shortens, reducing the angle between articulating bones at a joint

  
• Eccentric contraction


  Muscle contracts and lengthens, producing tension to resist forces like gravity and control joint movement
• Muscle contractions
• Movement analysis


  • Identify joint type, movement produced, agonist and antagonist muscles, types of muscular contraction
• Movement analysis table


  • Joint
  • Joint type
  • Movement
  • Agonist
  • Antagonist
• A skeletal muscle can only contract when stimulated by an electrical impulse sent from the central nervous system