Year 11 GCSE PE A healthy, active lifestyle and your muscular system Starter Label the diagram provided with the muscles learnt last lesson. Learning Objectives C - I can explain the difference between isometric and isotonic muscle contractions? B- I can describe and apply different movements at joints A/A* I can apply muscles and movement and explain it in a sporting situation? Movements at joints… Flexion - The bending of a joint so that the bones forming the joint are brought closer together. Extension - The straightening of a joint so that the bones forming the joint are moved farther apart Movements at joints… Abduction - to move away from the midline plane of the body Adduction – to bring back towards the midline plane of the body Muscle action table MUSCLE MUSCLE ACTION SPORTING ACTION Triceps Extends lower arm at the elbow Volleyball player has arms outstretched to block the ball Biceps Flexes arm at the elbow Tennis serve – racket preparation, when racket is behind head Deltoids Abducts upper arm at the shoulder Preparation for a cartwheel in gymnastics Pectorals Adduction of upper arm at the shoulder Arm action in front crawl (pull) Trapezius Adducts and rotates the scapula, rotation of head at atlas and axis Lifting of the head to watch the flight of the shuttle in badminton. Back crawl swimming action Gluteals Extends the leg at the hip Running action, one leg is left stretched back behind the other Quadriceps Extends the leg at the knee Follow through after kicking a ball in football Hamstring Flexes the leg at the knee Tacking the leg back in preparation to strike a ball in a drop goal attempt in rugby gastrocnemius Plantar flexion of the foot (pointing your toes) Going up onto toes prior to take off in a diving competition Latissimus dorsi Adducts and rotates the humerus at the shoulder (draws the arm back and towards the body) Pulling the arm back in archery Abdominals Flex, rotate and laterally bend trunk Forward action in sit-ups Task • In your pairs, discuss the sporting example provided on the picture - What joint is the movement occurring at? - What movement has occurred at the joint? - Which muscle is contracting? - Which muscle is relaxing? Types of Muscle Contractions There are two types of muscle contractions you need to know about: 1). Isometric contractions 2). Isotonic Contractions (of which there are two types) Muscle Contraction (Isometric) • Muscles contract in 3 ways • When muscles are working but stay the same length this is called isometric contraction. There is no movement The arms can now work effectively to complete the exercise Muscle Contraction (Isotonic) • In Isotonic contractions our muscles create movement as they contract • There are two types of Isotonic contraction • When a muscle shortens as it contracts this is called a concentric contraction • An example of this would be the bicep when lifting the weight while doing a ‘curl’ • When a muscle lengthens while still being tense this is called an eccentric contraction • This happens as you lower the weight under control while doing a curl Homework Complete the exam questions. Due in Thursday 8th May. Plenary • One partner to perform a movement with a body part – the other partner to identify the muscle contracting