The document discusses the principle of summation of forces, where maximum force is generated by recruiting muscles sequentially from largest to smallest. It provides examples of how this principle applies to specific athletic skills like kicking a football, serving a tennis ball, and serving a volleyball. The volleyball serve example describes how core, hip, leg, shoulder, arm, and hand muscles are recruited in order from trunk to extremities to transfer force from the body to the ball.
Summation of ForcesTo obtain maximum force with any movement where many muscles are used. In a way that allows maximal force generation – in this way the total force is a sum of the total individual muscles added together . The order they are used follow the same general rule: Larger, stronger muscle groups in central part of body initiates power. Smaller muscles in extremities are used in fine movements and co-ordination.
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Summation of ForcesSummation 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
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Summation of ForcesFor 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 .
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Summation of ForcesFor example, A football kick follows these summation events Body weight is transferred forward with the trunk leading (abdominals) Kicking hip moves forward with the leg trailing Thigh moves forward (abs, quads) Lower leg straigthens (quads, calf muscles) Foot snaps at football (calf muscles)
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Summation of ForcesIn a tennis serve, describe what muscles are used and in what order they are recruited? Core Hips Legs Deltoids Shoulder/Arm Wrist/Hand muscles The force used to hit the ball is a combination of all the individual muscle firing in sequence. For your own sport choose a specific skill and list the order of muscles that are recruited.
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Using the photosbelow and your knowledge of force summation, explain how force is applied in a volleyball serve.
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Force Summation requiresall 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. 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.
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QUESTIONS: Order theletters a to h from most important to least important to prioritise the correct sequence needed for a throwing a ball. Upper body turns in the direction of the throw Run Up Fall Forwards after the ball leaves the hand Arm delivers ball with a whip-like fashion Feet placed side on, with front foot Planted Arm follows through towards the target Body leans forward Throwing arm extended behind the body Explain the effect of the hand following the ball towards the ground when dribbling a basketball.