Force summation powerpoint


Published on

Basic Description of the biomechanics principle Force Summation.

  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Force summation powerpoint

  1. 1. Summation of Forces
  2. 2. Summation of Forces <ul><li>To obtain maximum force with any movement where many muscles are used. </li></ul><ul><li>In a way that allows maximal force generation – in this way the total force is a sum of the total individual muscles added together . </li></ul><ul><li>The order they are used follow the same general rule: </li></ul><ul><li>Larger, stronger muscle groups in central part of body initiates power. </li></ul><ul><li>Smaller muscles in extremities are used in fine movements and co-ordination. </li></ul>
  3. 3. Summation of Forces Summation of Forces 2. Sequential and simultaneous force 1. Heavest and slowest body parts move first. Smaller, faster body parts move last 3. Use as many body parts as possible to get maximum force
  4. 4. Summation of Forces <ul><li>For humans when throwing a ball, this means the core muscles are used first, then the shoulder and arms followed by the weaker, lighter muscles in the wrist and hand . </li></ul>
  5. 5. Summation of Forces <ul><li>For example, </li></ul><ul><li>A football kick follows these summation events </li></ul><ul><li>Body weight is transferred forward with the trunk leading (abdominals) </li></ul><ul><li>Kicking hip moves forward with the leg trailing </li></ul><ul><li>Thigh moves forward (abs, quads) </li></ul><ul><li>Lower leg straigthens (quads, calf muscles) </li></ul><ul><li>Foot snaps at football (calf muscles) </li></ul>
  6. 6. Summation of Forces <ul><li>In a tennis serve, describe what muscles are used and in what order they are recruited? </li></ul><ul><li>Core </li></ul><ul><li>Hips </li></ul><ul><li>Legs </li></ul><ul><li>Deltoids </li></ul><ul><li>Shoulder/Arm </li></ul><ul><li>Wrist/Hand muscles </li></ul><ul><li>The force used to hit the ball is a combination of all the individual muscle firing in sequence. </li></ul><ul><li>For your own sport choose a specific skill and list the order of muscles that are recruited. </li></ul>
  7. 7. Using the photos below and your knowledge of force summation, explain how force is applied in a volleyball serve.
  8. 8. <ul><li>Force Summation requires all body parts to move in sequence. In order for maximum force to be generated, a volleyball player needs a good stable base from which to start the movement. The volleyball serve begins with flexion of the knee joint caused by the hamstrings, then extention of knees as well as hip flexion to start the movement; both of these movements are initiated by the quadriceps. The Erector Spinae muscle causes trunk extension to allow the abdominals to fully flex the trunk and generate the force that is then transferred to the upper body. </li></ul><ul><li>The deltoids and pectorals major are used to flex the shoulder. These muscles are used to accelerate the whole arm while also stablising the shoulder. Once the arm has begun to accerate towards the ball, the triceps is then used to extend the elbow , thus accelerating the forearm and wrist. Just before contact with the ball, the wrist flexors contract, which allows the combined forces of all muscles to be applied to the ball by way of the hand. The timing of movements at each joint determines the control of the hand and the size and direction of the force applied to the ball. The end result is a more powerful force that can be transferred to the ball so that it travels as hard as it can, over the net to the opposite side. </li></ul>
  9. 9. QUESTIONS: <ul><li>Order the letters a to h from most important to least important to prioritise the correct sequence needed for a throwing a ball. </li></ul><ul><li>Upper body turns in the direction of the throw </li></ul><ul><li>Run Up </li></ul><ul><li>Fall Forwards after the ball leaves the hand </li></ul><ul><li>Arm delivers ball with a whip-like fashion </li></ul><ul><li>Feet placed side on, with front foot Planted </li></ul><ul><li>Arm follows through towards the target </li></ul><ul><li>Body leans forward </li></ul><ul><li>Throwing arm extended behind the body </li></ul><ul><li>Explain the effect of the hand following the ball towards the ground when dribbling a basketball. </li></ul>