Human Movement 2 Report: Kinetic Characteristics of Squat and CMJ

This report provides a comparative analysis of the kinetic characteristics of squat jumps (SJ) and countermovement jumps (CMJ), drawing on secondary data and existing research. It explores the application of sports biomechanics to understand human motion, particularly in athletic contexts. The report delves into the methodologies used to assess jump performance, including the calculation of the Reactive Strength Index (RSI) using various formulas. It highlights the superiority of CMJ as a performance indicator due to its effective utilization of the stretch-shortening cycle and elastic energy. The discussion examines the mechanisms underlying jump performance, such as muscle activation and angular joint velocities, and concludes that while both jumps are valuable for assessing athletic capabilities, CMJ offers a more comprehensive assessment of an athlete's ability to transfer energy efficiently into a jump. The report also touches upon the benefits of SJ for overall health and fitness and provides practical advice for incorporating these exercises into training programs. Finally, it emphasizes the importance of proper technique and breathing exercises to maximize performance and minimize the risk of injury.

A comparison of the kinetic characteristics of the squat and countermovement jumps
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Introduction
Sports biomechanics studies indicated human motion during exercise and sports activities.
Athletic and any physical activity in sports are conducted on the basis of the principle of the
law of mechanics. Not only in sports but biomechanics can be applied to normal physical
activity also (Aeles, 2018). With the help of sports biomechanics, athletes and performers
learn effectively about analysing their movement during exercise and sports activity
(Cushion, Goodwin and Cleather, 2016). In this report, there will be a discussion about a
comparison of the kinetic characteristics of the squat and countermovement jumps by
utilizing secondary collected data. This discussion will also incorporate the utilization of
theories and formulas of relevant measures in an effective and efficient way.
Methodology
For this section, secondary data will be utilized. This secondary data will incorporate the lab
studies and research of peer-reviewed literature. As research indicates that the relativeness in
squat movement as compared to kinetic energy utilizes elastic energy for the performance
enhancement in countermovement jump (CMJ) (García-Ramos, et. al., 2017). As this
secondary study is based on the test of 6 male volleyball players that performed CMJ with
squat jumps. In this observation, the primary parameters for incorporation include kinematics,
kinetics, and muscle electrical activity that directly creates pressure on the six muscles of
push-off that is the same as SJ and CMJ. In another word, this study indicates that while
playing volleyball three energy take incorporation (similar to as the law of mechanics) which
are kinematics, kinetics and muscle electrical activity. With this relevance energy, it creates
pressure on the functions of the six muscles of legs in an effective and efficient way (Driller,
et. al., 2017).
The formula for calculating reactive strength index are:

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 Formula 1: Reactive strength index (RSI) = Jump of the jump Height / Time (in which
body comes back to the ground)
 Formula 2: RSI = Flight time / time
 Formula 3 = Height measure of jump/ take off time (Gencer, et. al., 2018).
These are the formulas for calculating RSI for CMJ and SJ. In calculating these formulas, the
law of mechanics plays an important role. While calculating ground time, knees should be
bent at 90 degrees. At the time for calculating take-off time, jumps should be done in the
vertical position as much high as possible (Lorenzetti, et. al., 2019).
(Norton, 2018)
Results
It is analysed that CMJ and SJ are widely recognised as the major performance indicator to
analyse the performance of an athletes. As compare to these both jumps (CMJ and SJ), CMJ
is better performance indicator as compare to the SJ because in CMJ it is important to
properly utilize the stretch-shortening cycle which drives accurate results while conducting a
session for judging the performance of the athletic in an effective and efficient way (Wells,
et. al., 2018). Moreover, it is also derived that understanding this mechanism is also

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necessary. As monitoring and testing the performance of the athletic are the important part of
the periodization. Athletics incorporate SJ and CMJ as the two indicators in the field of
strength. As the duration of the CMJ is a measure between the downward movement to take-
off between 500 to 1000 milliseconds (Low, et. al., 2019).
In a similar way, elastic energy also has a contribution to the performance process in order to
enhance the countermovement jump performance. Apart from this, the utilization of the
elastic energy also indicates that the massive difference between the jumps does not surely an
accurate indicator of high-intensity performance that is used in the sports. Although, this
large difference indicates that the well-developed capacity of the jumps utilizes the elastic
energy in CMJ because of the involvement of the co-activated muscles and their quick build-
up stimulation (Oranchuk, et. al., 2019). It not only reflects poor performance but it also
reflects the improper training. So, it is important to make coordination of the moves so that
no muscles will get extra pressure and elastic energy will also be utilized in a systematic way
while performing the important functions of the jumps in an effective and efficient way
possible (O’Donnell, et. al., 2018).
Discussion & Conclusion
CMJ is better than SJ because the difference in performance measures they both provide is
directed to the reflection of the effective utilization of the stretch-shortening cycle. Apart
from this, it is also analysed that the mechanism which is responsible for the performance-
enhancing is frequently changed but still as per the perspective of athletics, CMJ is better
performance indicator the SJ (Vanderka, et. al., 2016). As in CMJ, there is a greater uptake of
muscle slack and stimulation build up during the countermovement process. Here, elastic
energy also has a little contribution in order to enhance CMJ performance. Thus, it can be
concluded that the large and significant difference between the jumps is not being marked as

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the better indicator of high-intensity sports performance. Apart from this, the primary
difference between movements and without countermovement is caused because of the
performance-enhancing efforts. Thus, as a result, difference in the stretch-shortening cycle is
the utilization of elastic energy (Pérez-Castilla, et. al., 2020).
It is also important to take notes of the muscle-tendon interaction to understand better about
the mechanisms that primarily indicates to enhanced CMJ performance in an effective and
efficient way possible (Pueo, et. al., 2017). In the process, it is commonly assuming that the
fascicles of the leg muscles that are utilized during the process should be fascicles of the leg
muscles during the downward movement. This lengthens during the downward phase of a
CMJ indicates that mostly passive and occurs primarily. There is usually no active
lengthening of the fascicles during the downward movement of the CMJ. Apart from this,
there is not usually active lengthening such as the eccentric action of the CMJ. Thus, it is
important to analyse the upwards and downwards phrase of this rather than analysing the
eccentric and concentric phases of a CMJ. Another mechanism believed for the great acute
effect observed during the CMJ is increased muscle activation. As the average angular
velocities of the ankle, hip joint and knee should be at the certain measurements 133-199
degrees, 216 per second (Poulos, et. al., 2018).

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(Sheridan, 2017)
Here, muscle fibres do not necessarily lengthen during the downward phase of the
countermovement. Angular joint velocities are high to evoke a stretch reflex, the reflex is
muscles fibres. However, it is also important to consider the range of motion that produces
force in the process of CMJ and SJ. These both are the successful assessing athletic
performance movements (Samozino, et. al., 2018). The CMJ is much more assessment that
took at the ability to effectively transfer energy into a jump in an effective and efficient way.
However, the biomechanics of jumping is a good approach to involve blocking horizontal
inertia and turning into vertical inertia. Redirecting the forward momentum generates more
upward momentum during the process of the jump (Rivière, et. al., 2017). On the other hand,
the squat jumps are also useful in burning excessive calories with boosting sports
performance, it also improves health, it tones the butt and abs muscles in a systematic way.
According to the trainers, for enhancing vertical and potentiate bodies for better lifts it starts
with squat jumps for 2-3 sets for 3-5 reps. Here, an individual considers that it is important to
do these exercises in high volume but according to the trainer's high volume is not important

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as 2-3 sets for 3-5 reps are enough. For an individual, it is important to understand that squat
jumps should not be overdone because when a person holds weights and jumps then it creates
pressure on the knee flexion. So, it is important that this exercise should be done in control
and should be done in a proper manner. Well, this principle not only applies to squat but
every exercise should be done in a systematic way with the proper training. Learning to
inhale and exhaling breath while doing a squat is the simple process to learn and it is a
powerful process too. SJ is an excellent example of a plyometric exercise that built power. It
is suggested to an individual that with SJ and CMJ they should also focus on the frog jumps,
repeated long jumps, split squat jumps, etc.
To athletes it is suggested that they should also learn the methods of the deep breathing
exercise in order to proper flow of the oxygen in an effective and efficient way. Practicing
deep breathing will help the athletes to get proper oxygen and it is also beneficial for their
mental health. Thus, practising deep breathing do not just have benefits on the physiology
level but its also the benefits at the psychological state.

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