This website uses cookies to ensure you have the best experience. Learn more

Body Acceleration From Muscle Force Of Countermovement Jumps In Comparison To Squat Jumps

1686 words - 7 pages

The main theories behind why muscle forces accelerate the body upwards greater in countermovement jumps in comparison to squat jumps: a brief review
Throughout literature countermovement jumps (CMJ) are seen to be higher in contrast to squat jumps (SJ) (Bobbert et al. 1996; Kubo et al. 1999; Bobbert et al. 2005). However present literature regarding the key potential mechanisms behind why greater muscle forces are seen accelerating the body upwards in CMJ in comparison to SJ is somewhat unclear. A CMJ can be defined as a positioning starting upright, beginning the descending motion in advance of the upward motion in contrast to a SJ where the start position is squatted with no preparatory countermovement (Akl 2013). The higher jump heights seen in CMJ in comparison to SJ are apparent even if at the start of propulsion phase the body configuration is identical (Bobbert et al. 1996). In past literature three main mechanisms have looked to provide an explanation for the greater muscle forces seen in CMJ than the SJ. The first plausible theory is that the muscle stretch in CMJ increases the production of force capability of the contractile machinery (Edman et al. 1978; Ettema et al. 1992; Herzog et al. 2003). Secondly the assumption that the muscle fibres are on the descending limb of their force–length relationship at the start of propulsion in the CMJ and SJ, however in CMJ the stretching of a chain of elastic components, they are not as far past optimum length therefore allowing a greater force over the initial phase of their shortening range, with the stretching of sequences of elastic components, this then causes the storage of elastic energy that is then reutilized in the propulsion phase (Ettema et al. 1992). The final explanation is determined by the fraction of actin binding sites accessible for cross-bridge development known as muscle active state. In CMJ, active state can form in the preparatory countermovement however in SJ the active state forms in the propulsion phase, resulting in the production of force during the initial section of this phase to be submaximal (van Ingen Schenau 1984; Bobbert et al. 1996; Bobbert & Casius 2005). This literature review therefore looks to provide clarity around how each of the three mechanisms function and determine how each may contribute to greater muscle forces seen accelerating the body upwards in CMJ in contrast to SJ.
The theory that the muscle stretch in CMJ increases the production of force capacity of the contractile machinery has been broadly documented in the past (Edman et al. 1978; Ettema et al. 1992; Herzog et al. 2003). The study by Herzog et al. (2003) was carried out on ten cat soleus muscles looking to characterize the mechanical properties contributing to the increase steady-state force after an active muscle stretch in the passive element. The findings of this study supported the theory that the passive component increased force is parallel with the contractile component due to the...

Find Another Essay On Body Acceleration from Muscle Force of Countermovement Jumps in Comparison to Squat Jumps

Newton's Second Law - Practical Report: To determine the relationship between force, mass and acceleration

842 words - 3 pages Aim:a:, To observe changes in motion due to changes in force and measure force, mass and acceleration, and examine their influence on motion.b: To investigate the relationship between the variables; mass, force and acceleration and determine an inertial mass through the use of a trolley, ticker-timer and set of slotted masses.Introduction:Newton's second law states "The acceleration of an object as produced by a net force is directly

In vitro model of human amniotic stem cell differentiation to smooth muscle cells

1971 words - 8 pages , smooth muscle myosin heavy chain, Smad 2, Smad 3, and calponin. Intracellular Ca2+ will be measured using calcium reagent solution as well as luciferase assay. The activation or absence of these genes may show differences in the differentiation of SMC from ASC. The TGF-B-MAPK pathway previously shown to be involved in h-EMSC differentiation into SMCs will be examined.2 By measuring or knocking out the constituents of the MAPK pathway

Change Management in Transition from Traditional Sales Force to Key Account Management: Greece Pharmaceutical Companies

955 words - 4 pages Case. Name: Institution 1. Introduction The pharmaceutical industry is one that has been seeking to enhance efficiency in customer relationship management through strategies that involve a transition from the traditional sales force to Key Account Management. However, the transition requires organization changes and is subject to several factors. In that respect, this analysis refers to the case of pharmaceutical companies in Greece

Use of Police Force and its Evolution from the 1970’s to the Present Time

819 words - 4 pages Since modern policing started almost 200 years ago criminals most of the time never surrender on the first contact. Police and the use of force needed to subdue the suspect have seemed to always and will forever be under the microscope. This essay will be looking at the drastic changes from the 1970’s to present time and the correlations that might have caused the increase or decrease in effective means of force. The 1970’s was statistically

Experiment to Calculate Acceleration of Mass and Velocity of Free-Falling Object

1384 words - 6 pages acceleration due to gravity and compare it to the standard value of 980 cm/s2. Then plot the velocity versus time, find the slope which in turn will provide the experimental value of g. (Air resistance wasn’t considered for the mass in free fall). Theory: According to Newton’s second law acceleration is produce when a force acts on a mass. The greater the mass the greater amount of force needed. This law gives us an exact relationship between

How does Pablo Neruda’s Maturity develop from ‘Body of a Woman’ to ‘Sonnet 89’?

810 words - 4 pages of most lines to give it a more controlled feel. However there is some enjambment in the first stanza; My rough peasant’s body digs in you And makes the son leap from the depth of the earth. The line breaks free from the stanza, which could show that he can’t always keep his emotions under control. Sexual imagery is also used in this section ‘…body digs in you’. It demonstrates the point that Neruda is very naïve about love, and that he is not

Racial Discrimination Kept Black People from Flying in Air Force

1017 words - 5 pages accustom, Brigadier General Leon Johnson indicates that the nation’s demographics are becoming more dynamic and that military pilots for the future are today’s students. But if officials from the Pentagon have established the demand for increasing black officials in the Air Force and Navy as a main component, the question remains why there is still a lack of black pilots in today’s aviation? To generate some possible answers one idea is that

To what extent is Cultural Arrogance a driving force of conflict in The Poisonwood Bible?

4250 words - 17 pages The Poisonwood Bible is a novel written by Barbara Kingsolver, portraying the life of the Price family, coming from Georgia to the Congo as a missionary family. By analyzing the cultural arrogance Kingsolver includes in the novel, it is possible to understand the many compositions the bring books, in relation to how the people live in comparison to different geographical and economical locations of the country, why certain things are necessary

Was nationalism the most important force of change in Europe up to 1870? Justify your answer

1364 words - 5 pages within nations for example France, who turned from monarchical rule into constitutional government and back to monarchical under Napoleon III. Industrial development was another force of change. Industrial development in Western and central Europe in the 1830s and 1840s created a larger middle class. This is social change. These middle class people demanded more liberal concessions from the autocratic rulers. They also demanded social reforms and

Descartes’ Arguments for the Existence of Body as Distinct from the Mind and His Justifications to Princess Elizabeth of Bohemia

1722 words - 7 pages comprehensive attempt to answer the question. In this paper I will examine Descartes’ arguments for the existence of body as distinct from the mind; outline Elisabeth’s objections and proposed solutions, and argue that Descartes’ responses to Elisabeth are inadequate to address the problem of mind-body interaction without resulting in contradiction. Descartes sets out in meditation six to determine what justification there might be for the existence of

Use of Force in Law Enforcement

2430 words - 10 pages When a law enforcement officer uses force on a subject it will be classified into one of three main categories which are, justifiable, excessive, and deadly force. The authority for law enforcement officers to use force comes from the United States Constitution (case law), state statutes, and department policy. Law enforcement use of force is very important because it involves the patrolman on the street, the corrections officer in jails and

Similar Essays

Muscle Cells In The Body Essay

888 words - 4 pages a mesh which enables the it to squeeze the blood out of the heart to the rest of the circulatory system and the rest of the body. If the mesh stops function such as the contractions stopping then this will result in the individual suffering from cardiac arrest. The muscle cells in the arms and legs The body has skeletal cells, which are all around the body, this includes the arms and the legs. If a muscle provides movement then also another

Acceleration Of A Freely Falling Body

897 words - 4 pages distance, ∆x, by the time, ∆t, it took to travel the distance. v=∆x/∆t=(x_1-x_2)/(t_f-t_i ) Acceleration is the change of velocity over a certain time interval. The known acceleration of the force of gravity is 9.8 m/s or 9.80 cm/s. To calculate the acceleration of an object,, divide the change in velocity, ∆v, by the time interval, ∆t. a=∆v/∆t=(v_f-v_i)/(t_f-t_i ) The measurements to measure the speed, velocity and acceleration are feet and

The Acceleration Of A Freely Falling Body

1729 words - 7 pages that change: where . The instantaneous acceleration is defined analogously to the instantaneous velocity: (3) If a body moves in a straight line and makes equal changes of velocity in equal intervals of time, the body is said to exhibit uniformly accelerated motion. This type of motion is produced when the net force upon a body is constant. An example of this is the motion of a body falling freely in a vacuum

How To Gain Muscle And Shed Body Weight

603 words - 3 pages Let us initial understand the correlation in between physique pounds and metabolic charge before we solution the query how to gain muscle and shed body weight? . It is typically viewed that people today with reduced metabolism or metabolic amount are inclined to set on more weight. Rate of metabolism basically is the process of changing food items into power. The system demands energy for its standard performing like respiratory, building new