Vertical Ground Reaction Force Experiment

Set a 12 to 24-inch box or step securely on the ground in front of you. Swing your arms behind you as you place your body in a short squat position. Jump focusing the momentum through your ankles, knees and hips to propel yourself onto the platform. Make sure you land with your knees bent to help absorb some of the shock and then step down off the box one leg at a time before repeating.

This experiment was completed in order to compare calf circumference as well as weight to jump height. If a person has larger calves then they will likely be capable of reaching a higher vertical height. It can also be shown that since males tend to have larger calves, they can jump higher. A larger calf circumference is more likely to reflect a high vertical jump due to the fact that the fat content of the calves in the experiment was accounted for, therefore a large calf measurement in this experiment means a muscular calf. It is common knowledge that more muscle will result in stronger legs leading to a higher vertical.

Jumping (bilateral): Hip and knee is in extension, while ankle is in plantar flexion, and shoulder abduction and flexion while in the air.

The external and internal forces acting on the human body and the effects produced by these forces is known as the study of biomechanics, it is a very crucial part in sports as it can help detect inadequacy of any physical technique performed, result in enhancing an athlete’s performance. I will be biomechanically analyzing my own volleyball spike.

To determine the acceleration of the ball, the equation g = 7(v2)/10h was derived (Appendix B figure 1) using conservation of energy principles. The variable v represents the final velocity of the ball at the bottom of the ramp and h represents the height of the ball at rest above the table. In measuring the velocity of the ball and height of the ramp there were inaccuracies that could have affected the calculated accelerations for the ball. The accuracy of the height measurement was limited by the meter stick because a meter stick is only accurate to +/- 0.001 m. With a height of 0.070 m, the meter stick would have contributed a significant measurement tolerance. Additionally, friction was not included in conservation of energy calculations.

The researchers chose to use a program called Dartfish 2D Pro Suite Software as a means of gathering their 2D data. The 3D analysis was conducted using a Vicon system. The subjects included sixteen healthy individuals, 9 males and 7 females with ages ranging from 21-30 years old. Before each participant performed the test, a member of the research team demonstrated the drop vertical jump (DVJ) using a 40 cm box. Each participant was given three practice jumps before the test began. Then, each participant had seven trials of the drop jump with less than one minute between each trial. Each trial was recorded with both 3D and 2D analysis. After the Frontal plane projection angle (FPPA), knee to ankle separation ratio (KASR), and knee separation distance (KSD) were measured for each subject based on the video recordings. They concluded that FPPA showed good interrater and intrarater reliability. It was determined that 2D analysis can be used as a cost-effective alternative to 3D analysis. However, of the four 2D techniques, KASR and KSD showed the best results. These two measurements were determined to be reliable, reproducible, and valid when compared with 3D measures. Although, if using 2D analysis, clinicians should be analyzed

This form will include strong bounce with other unwanted momentum. In this kind of form your body will move backword and you will also use your knees to support the weight going up for. This kind of technique allows you to lift more weight.

In the skateboard experiment, when a person was pushed with two different forces, the acceleration of the larger force allowed the person to accelerate more. A direct relationship between force and acceleration is formed. When force is applied, the acceleration also increases (assuming the mass of the person is same). This statement is supported by Newton’s second law, where the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force. The equation that is extracted from the law, Fnet = ma, proves that when constant mass is divided into a larger force (numerator), acceleration should increase. In the second part of the skateboard experiment, two people, one heavier and one lighter, were

One subject was used, and was seated in the same position for each of the three tests performed. Because the patellar reflex is immediate, a video was taken during each tap with the hammer to visually compare the strength differences for each influence that was put into effect. This provided a steady, unwavering result with the option of repeated viewing for the conclusion of the experiment. After all three stages of the experiment were completed, the videos were reviewed for comparison between the baseline reflex and the three changing factors, along with any discrepancies and problematic areas that may have altered the results. The strength of the reflex was recorded as either equal to, more vigorous than, or less vigorous than the baseline reflex and the results were put into a simple chart.

The aim of this investigation is to observe the effects of heart rate on a vertical jump. A group of participants will run on a treadmill and once their heart rate reaches a designated point they will proceed to the vertical jump.

Two questions were analyzed and discussed in the paper, the first one concerning whether the same set of muscle synergies can explain the different phases of jumping movement with various velocities.

Stability refers to the inherent ability of a body to remain in or return to a specific state of balance and not to fall (Pollock, Durward et al. 2000). Optimal postural control requires intact sensory motor functioning. Treating the body’s balance is detected by sensory (afferent) system, and responses through motor (efferent) system. The sensory system has information on COM motion relative to the direction of gravity for vestibular cues, visual orientation for visual cues, and support surface orientation for proprioceptive cues (Peterka 2002). While the motor system counteracts the force of gravity for preventing falling via muscle activity represented as postural control strategies. In quiet standing, the persons never truly stand still, although they try stand still. These unavoidable vertical posture changes or postural sway must be occurred as an inverted pendulum model. The body represents the fixed-support strategy e.g. the ankle and hip strategies during controlling balance, and acts the change-in-support strategy e.g. stepping or grasping strategies during loosing balance (Horak and Nashner 1986, Pollock, Durward et al.

The slip test was conducted on an overground walkway. A sliding device was embedded in the middle section of a 7-m walkway to induce slips during overground walking including a metal beam structure (2.5 × 0.30 × 0.21 m, Bhatt and Pai 2008) (Figure xx). This device consisted of a pair (i.e., right and left) of low-friction (coefficient of friction is 0.02, Bhatt et al., 2005), passively movable platforms (0.65 × 0.30 × 0.006 m, 2.6 kg, Bhatt and Pai 2008). Each platform was mounted to an aluminum track via ball bearings and placed on top of a pair of tandem force plates bolted to the ground (AMTI, Newton, MA) for recording ground reaction forces (Yang, Anderson, & Pai, 2007). Both platforms were firmly locked in place, but could be unlocked

The objective of this lab was to determine how the acceleration of a system is related to the force applied. In order to complete this experiment we had to establish our hypothesis, independent and dependent variables and the control variables. We conducted two trials with the same masses for both trials, and changed the masses from 10 g all the way to 40 g in intervals of 5. We made sure to keep the overall weight of the system constant, since it was a control variable. We had to account for the friction of the system and developed a graph and error bars. At the end of this experiment we determined that our prediction was correct: the more force applied, the faster the acceleration.

A vertical jump “is the act of raising one's centre of gravity higher in the vertical plane solely with the use of one's own muscles; it is a measure of how high an individual or athlete can elevate off the ground (jump) from a standstill” (En.wikipedia.org, 2016). This motion can be used daily alternatively, in the sports industry athletes try to master this motion to get an advantage of the opposing player. An experiment has been conducted to test the improvement of the vertical jump. The aim of the experiment is to investigate the improvement of the vertical jump? the question that will be answered through this experiment is how to improve the vertical jump. The independent