The Effect of Drop Jump Starting Height and Contact Time on Power, Work Performed, and Moment of Force

Walsh, Mark; Arampatzis, Adamantios; Schade, Falk; Brüggemann, Gert–Peter

doi:10.1519/00124278-200408000-00030

Cited by 15 publications

(15 citation statements)

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“…As expected, the peak force increased steadily in conjunction with decreases in contact time, which agrees with previous work (33). This further adds to the importance of contact time in drop jump exercises and the consideration of its minimization.…”

Section: Effects Of Contact Duration On Force and Neuromuscular Factorssupporting

confidence: 91%

“…Shorter contact duration coupled with a stiffer landing is considered necessary for better athletic performance in stretch-shortening cyclic movements such as sprinting or repeated jumping (15); indeed, shorter contact times are considered to be an indicator of high leg stiffness values (2,7). Longer contact durations have also been shown to have a higher contribution of power from the knee and are largely the result of increased knee flexion, which increases the absorption of the force applied at contact (14,15,33). However, this study indicated that increased mean peak EMG for all triceps surae as contact duration increased was coupled with a decrease in force; therefore, hypothesis 5 is rejected.…”

Section: Effects Of Contact Duration On Force and Neuromuscular Factorsmentioning

confidence: 57%

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Bilateral Neuromuscular and Force Differences During a Plyometric Task

Ball

Scurr

2009

Journal of Strength and Conditioning Research

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The purpose of this article is to compare the bilateral neuromuscular and force contribution during a plyometric bounce drop jump task and to assess the affects of nonsimultaneous foot placement. Sixteen male participants performed bounce drop jumps from a height of 0.4 m. Mean peak electromyography activity of the soleus, medial, and lateral gastrocnemius of both legs was recorded from each phase of the drop jump and normalized to a reference dynamic muscle action. Resultant ground reaction force, ground contact time, and duration of the drop jumps were recorded from each leg. Multivariate analysis of variance was used to compare bilateral electromyographic activity, resultant peak ground reaction force, and contact duration. Pearson's correlations (r) ascertained relationships between normalized electromyographic activity and contact time. Significant differences were shown between left and right triceps surae normalized electromyography during precontact and contact40ms (p < 0.01). No significant differences were present in the contactpost40ms phase (p > 0.01). Significant differences were found between normalized soleus electromyography and both gastrocnemii for both legs during precontact (p < 0.01). No significant differences were found for within-leg normalized electromyography for the contact40ms phases and contactpost40ms phase (p > 0.01). Weak relationships were found between normalized electromyographic activity and nonsimultaneous foot contact (r < 0.2). This study showed differences between left and right triceps surae in neuromuscular strategies engaged in the early stages of a drop jump task. Differences in contact time initiation were present; however, they are not significant enough to cause neuromuscular differences in the plantar flexor muscles.

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Section: Effects Of Contact Duration On Force and Neuromuscular Factorssupporting

confidence: 91%

Section: Effects Of Contact Duration On Force and Neuromuscular Factorsmentioning

confidence: 57%

Bilateral Neuromuscular and Force Differences During a Plyometric Task

Ball

Scurr

2009

Journal of Strength and Conditioning Research

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“…There may also be a ceiling as far as how high drop height can be and still elicit increased power output in DJ, which was previously mentioned as being one of the training goals of plyometrics. Walsh et al (17) reported that maximum and mean power output decreased insignificantly as drop height increased from 40 to 60 cm, even while joint moments generally increased with drop height. Thus, in sporting activities where maximum power output is important (typically sports involving a single or repeated countermovement jump), it might benefit performance coaches to abstain from implementing landings from heights of 60 cm or greater.…”

Section: Discussionmentioning

confidence: 99%

“…Most authors have indicated that as drop height increases, peak ground and joint reaction forces also increase (1,10,11,17), but not all (5). Bobbert et al (1) reported that peak VGRF increased significantly in a linear fashion between 20 and 40 cm and 40 and 60 cm in physically active men when landing from bounce jumps, as did McNittGray (11) with DDs performed by gymnasts and recreationally trained men from heights ranging from 23 to 128 cm.…”

Section: Discussionmentioning

confidence: 99%

Quantification of Vertical Ground Reaction Forces of Popular Bilateral Plyometric Exercises

Wallace

Kernozek²,

White

et al. 2010

Journal of Strength and Conditioning Research

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The purpose of this study was to quantify the vertical ground reaction forces (VGRFs) developed during the performance of popular bilateral plyometric movements. Fourteen power-oriented track and field men of collegiate and national level randomly performed 3 trials of 9 different bilateral plyometric exercises in a single testing session. Three depth drop (DD) and 3 depth jump (DJ) conditions from 30, 60, and 90 cm heights (DD30, DD60, and DD90 and DJ30, DJ60, and DJ90) were tested, in addition to vertical jump (VJ), standing long jump (SLJ), and 2 consecutive jump (2CJ) conditions. Peak impact VGRFs were normalized to body weight. Additionally, all conditions were compared against the VJ in an intensity index. The SLJ condition resulted in a significantly higher peak VGRF than the 2CJ condition (p < or = 0.05). 90DD, 90DJ, 60DD, and SLJ had a significantly greater peak VGRF (5.39, 4.93, 4.30, and 4.22 times body weight, respectively) than the VJ condition (3.34 times body weight). The 30DJ condition had an insignificantly smaller peak VGRF (2.78 times body weight) when compared with the VJ. Practitioners may use these findings to more effectively progress athletes in these movements based on their intensities.

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“…In the L-J movement, the biomechanical condition in not only jumping but also landing will be an important factors influencing jump performance. Among the various L-J patterns, the drop jump, which requires a quick jump from a landing, has been extensively studied as a representative L-J movement (Arampatzis et al 2001b;Baca 1999;Bobbert 1990;Bobbert et al 1986Bobbert et al , 1987aEloranta 1997;Hoffren et al 2007;Horita et al 1996Horita et al , 2002Kovacs et al 1999;Lees and Fahmi 1994;McMillan et al 2010;Mrdakovic et al 2008;Walsh et al 2004;Walshe and Wilson 1997). Many studies have focused on the electromyographic (EMG) activities of lower limb muscles in drop jump, in relation to the jump performance (Arampatzis et al 2001a, b;Dyhre-Poulsen et al 1991; the pre-contact phase influenced the knee joint torque at the end of body descending that was associated with drop jump height.…”

Section: Introductionmentioning

confidence: 99%

Role of the coordinated activities of trunk and lower limb muscles during the landing-to-jump movement

et al. 2011

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This study aimed to clarify how the activities of trunk and lower limb muscles during a landing-to-jump (L-J) movement are coordinated to perform the task effectively. Electromyography (EMG) activities of trunk and lower limb muscles as well as kinematic and ground reaction force data were recorded while 17 subjects performed 5 L-Js from a height of 35 cm. The L-J was divided into four phases: PRE phase, 100 ms preceding ground contact; ABSORPTION phase, from ground contact through 100 ms; BRAKING phase, from the end of the ABSORPTION phase to the time of the lowest center of mass position; and PROPULSION phase, from the end of the BRAKING phase to takeoff. The trunk extensor and flexors showed reciprocal activation patterns through the L-J. In the PROPULSION phase, the timings when the EMG activities of the extensor muscles peaked were characterized as a sequential proximal-to-distal pattern. Furthermore, the peak vertical ground reaction force in the ABSORPTION phase relative to body mass negatively correlated to the jump height of the L-J movement and positively correlated with the magnitude of the EMG activities of the soleus in the PRE phase and those of the soleus and rectus abdominis in the ABSORPTION phase. These findings indicate that the intensities and peak timings of muscle activities in the trunk and lower limb are coordinated during the L-J movement and, the coordinated activities would play functional roles such as impact absorption, braking against the descent of body and force generation and direction control for jumping.

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The Effect of Drop Jump Starting Height and Contact Time on Power, Work Performed, and Moment of Force

Cited by 15 publications

References 0 publications

Bilateral Neuromuscular and Force Differences During a Plyometric Task

Bilateral Neuromuscular and Force Differences During a Plyometric Task

Quantification of Vertical Ground Reaction Forces of Popular Bilateral Plyometric Exercises

Role of the coordinated activities of trunk and lower limb muscles during the landing-to-jump movement

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