Biomechanical Considerations on Jumping in Sports an Approach to a Fundamental Understanding (original) (raw)

The effects of initial conditions and takeoff technique on running jumps for height and distance

Journal of Biomechanics, 2011

This study used a subject-specific model with eight segments driven by joint torques for forward dynamics simulation to investigate the effects of initial conditions and takeoff technique on the performance of running jumps for height and distance. The torque activation profiles were varied in order to obtain matching simulations for two jumping performances (one for height and one for distance) by an elite male high jumper, resulting in a simulated peak height of 1.98 m and a simulated horizontal distance of 4.38 m. The peak height reached/horizontal distance travelled by the mass centre for the same corresponding initial conditions were then maximised by varying the activation timings resulting in a peak height of 2.09 m and a horizontal distance of 4.67 m. In a further two optimizations the initial conditions were interchanged giving a peak height of 1.82 m and a horizontal distance of 4.04 m. The four optimised simulations show that even with similar approach speeds the initial conditions at touchdown have a substantial effect on the resulting performance. Whilst the takeoff phase is clearly important, unless the approach phase and the subsequent touchdown conditions are close to optimal then a jumper will be unable to compensate for touchdown condition shortcomings during the short takeoff phase to achieve a performance close to optimum.

Computer Simulation of the Takeoff Phase in Running Jumps

Our purpose was to investigate the effects of initial conditions and takeoff technique on the performance of running jumps. Matching simulations and optimum simulations were determined for the three takeoff phases of a triple jump performance, a running jumping for height and a running jump for distance. For the triple jump, the optimised simulations used symmetrical 'double-arm' shoulder flexion whereas the triple jumper had used an asymmetrical 'single-arm' technique. For the jumps for height and distance, optimising each performance for height / distance demonstrated that the initial conditions at touchdown have a substantial effect on the resulting performance. Whilst the takeoff phase is clearly important, if the touchdown conditions are not close to optimal then a jumper is unable to compensate for these shortcomings to achieve a performance close to optimum.

Three-Dimensional Kinematics during the Take-Off Phase in Competitive Long Jumping

International Journal of Sports Science & Coaching, 2013

The purpose of the present study was to identify the relationships among selected kinematic variables that affect the take-off phase and performance in elite jumpers. The jump distance was found to be related to: I) the athlete's approach speed before the instant of touch down; and ii) the exchange in spatial velocity components at take-off, which results in a gain in maximum vertical velocity of the centre of mass (CM), favoured by the use of an optimum touch-down angle of the take-off leg, an active landing of the foot at touch-down, and a motion of the take-off leg during the compression phase that helps to manage the loss of horizontal velocity. Nonetheless, the results show that an adequate velocity transformation requires an adaptive technical model to help jumpers to build an efficient individual technical pattern.

Features of Takeoff Phase in Long Jumps with Various Run-Up Lengths

The aim of the present study was to compare the kinematic characteristics of jumper's movements in long jumps with short, middle and extended run-ups. For this purpose three male and four female jumpers performed two three strides, eight strides and twelve strides run-up long jumps. All trials were captured on high-speed video. The results of the 2D analysis indicated that ground contact time and takeoff angle were significantly larger when the run-up was short. Also, the distance from the center of gravity to the heel in the horizontal plane and the knee angle at touchdown, as well as the maximum knee flexion of the takeoff leg during takeoff, were significantly smaller when the run-up was short. The heights of the center of gravity at touchdown and takeoff were constant in long jumps with various run-up lengths.

Biomechanical analysis of two long jump take-off techniques

A technique intervention strategy was used whereby the run-up velocities of two long jumpers were systematically varied. The takeoff parameters that define the athlete's takeoff technique showed reproducible changes in response to changes in run-up speed. The two athletes in the study used slightly different takeoff techniques to achieve their performances.

Biomechanical Analysis of the Long Jump at the Vith World Championships in Athletics

2008

From the formula it is clear that the distance (W) is dependent on the height of the CM at the end of the take-off phase, and the horizontal and vertical take-off velocities. From this causal dependency various researchers over the past decades (Hay et al. 1986; Koh & Hay 1990; Hay & Nohara 1990; Lees et al. 1993, 1994) have tried to identify which component (horizontal or vertical) of the take-off velocity plays a larger role concerning the jump distance. The results are often controversial and dependent on the performance level of the analyzed jumpers. Koh and Hay (1990) reported that the goal of the take-off is not to minimize the loss of the horizontal CM velocity. This position was supported by the observation that a loss in horizontal velocity often leads to an increase in vertical velocity (Hay et al. 1986; Hay & Nohara 1990; Koh & Hay 1990; Lees et al. 1993, 1994). For both men and women a loss of total energy has been reported (Witters et al. 1992; Lees et al. 1993, 1994). ...

3D Biomechanical Analysis of the Preparation of the Long Jump Take-Off

The purpose of the present study was to describe the kinematics of the long jump approach and take-off and their effect upon the flight and the landing. Three digital video cameras, were used to capture the last two strides of the approach, the take-off phase, the flight and the landing of the eight jumpers participating in the men's long jump competition at the 2006 European Cup 1st League-Group B Event in Thessaloniki, Greece, on 17 June 2006. A 3D-DLT analysis was conducted for the two final strides of the approach and the take-off and a 2D-DLT analysis for the landing. Results indicate that all participants seemed to utilise the "longer penultimate-shorter last stride" ratio. Two types of approach were revealed, the "straight forward" and the "imbalanced". These approach types did not affect the long jumping technique, but the stride angles of the last stage of the approach were highly correlated (r> .70, p< .05) with the placement of the take-off foot on the board and with the lateral flight path of the Body Centre of Mass.

Biodynamic characteristics of vertical and drop jumps

Acta Kinesiologiae Universitatis Tartuensis, 2012

The aim of the study was to establish the main kinematic and dynamic parameters that generate the efficiency of vertical and drop jumps. The takeoff power was assessed using the following tests: countermovement jump, counter-movement jump with arm swing, jump, drop jump and continuous jump. Kinematic and dynamic parameters of vertical and drop jumps were established using two separate forceplates Kistler Type 9286A and a synchronised 3-D kinematic system CCD SMART-600E. The athlete model was defined with 17 markers sensitive to infra-red light. It was established that the main generators of efficiency in vertical and drop jumps included: takeoff velocity, eccentric-concentric time, eccentric impulse, ground contact time and ankle flexion.