Paper 1 - OCR PE

• Hinge joints


  Knee, elbow, ankle
• Ball and socket joints

  Hip, shoulder
• Flexion at ball and socket joint

  Arms and legs move in front of body
• Flexion at hinge joint


  Elbow/knee bends, insertion moves towards origin
• Extension at ball and socket joint

  Arms and legs move behind body
• Extension at hinge joint


  Elbow/knee straightens, limb is extended
• Abduction


  Movement away from midline of body
• No abduction at hinge joints
• Adduction


  Movement back towards midline of body
• Circumduction


  Arm rotates through extension, abduction, flexion, adduction
• Rotation


  Head can rotate left/right, but not at ball and socket joints
• Adduction


  1. Shoulder will rotate to go through all the movements

  2. Produces a circling action
• Combining different movements produces a circling action of the shoulder
• Rotation is important at a joint, not so much around an axis
• Rotation of the head


  Looking to the side
• Rotation at a ball and socket joint is around the joint's own axis
• Hinge joint


  Flexion and extension are possible movements
• Ball and socket joint

  Flexion, extension, adduction, abduction, and rotation are possible movements
• Ball and socket joints in the hip have more stability compared to the shoulder
• Agonist


  Muscle that produces movement
• Antagonist


  Muscle that relaxes to allow the agonist to work
• Fixator


  Muscle that helps stabilize the joint to prevent unnecessary movement
• Knee flexion


  1. Agonist is the hamstrings

  2. Antagonist is the quadriceps
• Knee extension


  1. Agonist is the quadriceps

  2. Antagonist is the hamstrings
• Elbow flexion


  1. Agonist is the biceps

  2. Antagonist is the triceps
• Elbow extension


  1. Agonist is the triceps

  2. Antagonist is the biceps
• A lever system requires 4 components: lever arm, fulcrum, effort, and load
• First class lever


  Fulcrum is between the load and the effort
• Second class lever


  Load is between the fulcrum and the effort
• Third class lever


  Effort is between the fulcrum and the load
• The biceps tendon inserts onto the radius to cause elbow flexion in a third class lever system
• Full Crum


  The elbow joint
• Load


  The dumbbell
• Effort


  The bicep tendon pulling down on the radius
• Examples of third class levers

  • Goalkeeper catching a low ball
  • Bicep curl
  • Prepping an uppercut
• Mechanical advantage


  Overcoming a large load with little effort
• Effort arm


  The distance from the effort to the fulcrum
• Load arm


  The distance from the load to the fulcrum
• When the effort arm is greater than the load arm, we can overcome large loads with little effort, but there is a tradeoff of low speed and short range of motion
• The majority of joints in the human body have mechanical disadvantage, which allows for flexibility, suppleness, speed and dexterity