Biomechanics of Volleyball free essay sample

The purpose of this experiment is to analyze the efficiency and technique of the students over arm volleyball serve after the use of biomechanical principles has been applied. In order to complete the experiment the student performed a pre and post test which was evaluated by the program Dartflsh and a serving indicator test to assess the changes and improvements of the students technique and performance of the over arm serve. It was found that by applying the three biomechanical principles to the students serve the technique improved from the pre test to the post test as the serve became stronger, faster and longer. 0 Introduction 2. 1 The intention of this report is to use the principles of biomechanics to analyze the efficiency and to improve the skill of the volley ball over-arm serve of a student from Mrs. Crellins year 11 PE class. Biomechanics is the field of study which makes use of the laws of physics and engineering concepts to describe motion of body segments, the forces w hich act upon them during activity, and the efficiency of movement. Oacobs university book). The benefits of biomechanics are to develop new skills, detect errors in movement, improve safety, prevent injury, develop new equipment nd form a basis of high quality and performance. The ultimate goal in sports biomechanics is the performance improvement of skills (source-howell). Biomechanics is applied in the volley ball serve by assisting the student to detect errors in the skill, improve safety and to effectively improve the skill itself by the way it is performed. 2. 2 There are four steps in biomechanical analysis which include identifying; the objective of the skill, the movement patterns, skill classification and the skill phases. The objective of the over-arm volleyball serve is to get the ball over the net uccessfully at a fast, forceful, downward angle to ensure that it is harder for the opposition to return the ball back over the net. Movement patterns allow to identify the specific skills that fit within a given pattern. The movement pattern for the over- arm serve includes; throwing the ball in the air, striking it over the net and standing. Skill phases are the breaking down of the skill into meaningful phases, each of which may be quite different in terms of technique and the underlying biomechanical principles (Amezdroz et al. 004). In the volleyball serve the skill phase is identified as the toss (refer appendix , bow and arrow (refer appendix ) and the strike follow- through (appendix ). The skill classification of the over-arm serve includes discrete, closed, non-locomotor, and gross. The skill is classified that way as it has a distinct beginning and end, uses the larger muscles of the body, is pe rformed in a highly predictable environment and as it is manipulative skill that occurs on one spot. 2. If biomechanical principles are applied to the students over-arm volleyball serve then the skill should improve as using the correct technique should make it hard, long and fast. 3. 0 Research e odology 3. There are three major principles of biomechanics that come into analysis when evaluating the technique of a skill. These three principles are force and momentum, inertia and levers and projectile motion. This background knowledge of biomechanical principles assists in the learning of the over-arm volleyball serve by applying the techniques to them for improvement. Pre and post tests will both be performed with Dartflsh being used to evaluate the video footage and a serving indicator to analyse the efficiency of the serve. 3. 2 Force and momentum can be broken down into three subcategories of: linear omentum, summing momentum and generating momentum. Though throughout the skill acquisition of the volleyball serve the concepts of summing and generating momentum were applied to assist in both the learning and improvement. The concepts of inertia and levers were also used during the learning stage of the serve. There are three classes of levers and the volleyball serve is classified as a third class using the shoulder as the axis, muscles as the effort force and the ball as the resistance force (refer appendix_) and inertia refers to Newtons Law of Inertia. The ast biomechanical principle that was applied over the term of learning to improve the efficiency of the students volleyball serve technique was projectile motion. 3. 3 The program Dartflsh is used to give a thorough analysis of the over-arm serve to assist in the evaluation of physical performance and biomechanics within the skill. It is utilized to track movements of Joints, the angle in which the ball has been hit, how high the ball has been thrown and to analyse the pre and post test and ideal server. 3. 4 The Indicator 1: Serving Performance Test is a used to see how much the student has mproved over the time of the skill acquisition of the volleyball serve by comparing results from the pre and post test serving performance. The aim of this test is to objectively measure performance of the students over-arm serve. The student performed six over-arm serves from any position on the volleyball baseline and each serve was scored objectively based on the landing position of the ball (refer appendix _) out of a possible five marks. Any serve hitting fixtures or landing out received no score. Individual serves were scored and the total score was then added to indicate a level of achievement (LOA). 4. Statement of Findings/Results 4. 1 Using the Dartflsh Program the students post and pre test of the serve was analyzed to view changes that may have occurred within the students techniques. Many similarities and differences can be observed by looking at the two video performances and snapshots made from using Dartflsh in Figure 1. 0 and 3. 0. By the changes evident in the two performances it is known that the biomechanical principles that have been applied to the serve have helped to improve the students performance and technique. It can be seen by comparing figures 1. 0 to 2. 0 that the students serve in the post test as acquired a larger optimum stretch as the body parts and muscles are all stretched to optimal lengths. By doing this the students post test serve uses as many body parts as possible, each body segment makes it optimum contribution, has a larger range ot motion and a greater amount ot momentum and energy is being transfer from the arm swing to the ball (stabilization). This is why the post test serve is an improvement on the pre test as it achieves and applies maximum speed and strength into the serve. The major difference in the post test serve to the pre test serve is the use of the stabilizing arm (left arm). In the post test the student uses the stabilizing arm to further speed up the rotation of the striking arm by bringing it into the chest quickly; this increases full body rotation as well as the speed of the rotation of the lever. During the pre test serve the student does bring the stabilizing arm into the chest but at a much slower rate, therefore, decreasing the speed of rotation. This improvement in the serve shows that by applying this biomechanical principle of inertia and levers to the serve the students serve was able to improve as it is the correct technique and makes the serve faster and harder. Figures 1. 0 and 2. 0 show the similarities between the height and speed of release and contact of the ball between the pre and post test. In both tests the students striking arm was close to full length and had the same high ball toss. Howell says that this gives more time for the student to get from the skill phases of bow and arrow (refer appendix ) to alternating to a straight striking arm for follow through (refer appendix ), and contributes to get the optimal angle. The pre tests angle of release is closer to the ideal angle than the post tests angle. Amezdroz says that the ideal ngle of _ will create a lower and flatter flight path. This flight path is the correct technique to perform a serve as it will create it to be long, hard and fast as the biomechanical principle improves the performance. 4. 2 Using the Volleyball Serving Indicator Test (refer appendix_) the student was able to objectively measure the performance of her over arm volley ball serve by performing a pre, mid and post test of six serves scored on the landing position of the ball.