• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Does counter-movement effect jump performance and does using the arms further this improvement when performing a vertical jump?

Extracts from this document...


Does counter-movement effect jump performance and does using the arms further this improvement when performing a vertical jump? Introduction: Vertical jumping contributes to performance in almost all sports, obviously some sports such as basketball use it a lot more that other sports such as tennis. When performing a motor task such as jumping, human beings typically start with countermovement (CM), CM can be described as a quick bend of the knees during which the body's centre of mass drops before being propelled upwards (Harman et al, 1990). There is evidence to support that task performance is improved with CM, for instance, it has been shown that subjects achieve a greater jump height with CM than without. This is because subjects are able to produce more work and/or use the work more effectively in a countermovement jump (CMJ) than a non-CMJ (Bobbert et al, 1996). Researchers to date have proposed different theories as to why CM has a positive effect on vertical jump performance. Enoka (1988) cited in Harman (1990) proposed the performance enhancing effects of the countermovement is that concentric contraction immediately following an eccentric stretch begins with the muscle already under considerable tension, making more chemical energy available for generation of force. A later study conducted by Harman et al (1990) ...read more.


VJ no CM 0.271 0.006 2.306 0.026 141.055 1.573 c. VJ leg only + CM 0.562 0.730 -0.846 3.707 -51.733 226.701 d. UBM straight legs 0.024 0.047 -0.302 0.713 -18.480 43.600 Graphs of Mean Results Subject 1 (mean results) Subject 2 (mean results) Figure 1. Max flight height means for Subject 1 Figure 2. Max flight means for Subject 2 Figure 3. Take off Velocity means for Subject 1 Figure 4. Take off Velocity means for Subject 2 Figure 5. Vertical Impulse means for Subject 1 Figure 6. Vertical Impulse Means for Subject 2 Discussion: The results collected for subject 1 was to be expected (see table 1); the subject-performed best in jump a, using CM and arms. This was hypothesised by the writer and supported by numerous researchers, research has concluded that jumping performance can be greatly improved with CM and arms compared to without (Bobbert et al, 1996; Enoka 1988; Harman et al, 1990; Payne 1968; Lees et al, 2004 and Bishop et al, 2004). When comparing jump a (using CM and arms) to jump b (using no-CM) there is a 15% improvement in overall jumping performance in jump a (see table 1). This is supported by Bobbert et al (1996) who found CMJ's produced greater jump heights than non-CMJ's. ...read more.


The participants had not undergone any training prior to completing the study, which could account for the inaccuracy of results produced by subject 2. Prior to completing the study, the participants were not given proper protocols to warm up, this may have subsided the subjects' true performance potentials, Hunter and Marshall (2002) found that flexibility had a positive effect on jump performance. With the performers not properly warmed up the subjects' flexibility would have been limited as a result. Overall, subject 1 confirmed the writer's hypothesis and met the aims of the study, providing evidence that CM increased vertical jump performance, and CM with the use of arms increased vertical jump performance further. Subject 2 did not confirm the writers hypothesis or meet the aims of the study, however, subject 2 has provided a learning curve for future study, providing evidence that recording data correctly and following strict protocols should remain essential when completing further testing. If the experiment were to be repeated 'controls' would have to be enforced to achieve more valid results. A sheet for recording personal details, such as height and weight should be included, reducing the risk of error when obtaining results. More observers could be used to determine whether jumps were performed correctly, and it not being validated till all of them were agreed. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Sports Science section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Sports Science essays

  1. Nutritional analysis case study

    This second COMP-EAT analysis was compared to the pre intervention results to see if improvements had been made by the dietary modifications. The subject and researcher both discussed the nutritional strategies and agreed that to the goal was to help improve performance in soccer.

  2. Technical Analysis of elite male soccer players by position and success

    Table 2. Individual tasks when in possession of the ball (Van Lingen, 1997) Position Technical Requirements Goalkeeper Positive distribution, communication Sweeper Circulate ball, switch play, play forward Central Defender Support build up play Wingers Good cross delivery, Score goals Midfield (Defensive)

  1. Free essay

    Sports Biomechanics

    Arthroscopic treatment of the meniscus (shock-absorber cartilage) now encompasses repair as well as more limited excision compared to traditional techniques in which the whole meniscus was removed through an open incision. Subsequently more meniscal tissue can be preserved, which is vital in reducing the level of force transmitted through the knee joint.


    In defensive areas is where the highest skill success rate occurs iii. Midfield players demonstrated more superior test scores to defenders Reilly concluded that the greater the distance to the opponents' goal, the more time available on the ball, giving explanation to the high skill success rate in defensive areas as less pressure is applied.

  1. Physiological Adaptations to Exercise

    The graph below illustrates how the three energy systems interact during exercise. Correct training will extent the time to exhaustion thus improving fitness. Fig 2. Energy Systems. Source: Brian Mac, Sports Coach With appropriate training, these energy systems adapt and become more efficient, allowing greater exercise duration at higher intensity, thus resulting in musculoskeletal and cardiovascular adaptations.

  2. Sport industry.The sport industry is important to many people whop work in it and ...

    Grants have quite a big part to play in sports because they are like fund raising but you can't use the money from these to provide things like personal clothing and equipment and team kits. The money that they get from the grants can be put towards the cost of

  1. Physiology of exercise and training.

    governments strategy for health, The Health of the Nation has identified the need to change peoples eating and exercise habits in order to prevent disease and meet its targets for good health by the year 2005 (Department of health 1992).

  2. Physiological and Biomechanical Aspects of the Knee Joint

    The lateral meniscus is nearly circular and has a constant width (Peterson & Renstöm, 2001). The posterior horn merges with the posterior portion of the anterior cruciate ligament (ACL), whilst its anterior horn merges with ACL's attachment (Segal & Jacob 1983). It has a range of movement of approximately 1cm.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work