Relative Intensity Influences the Degree of Correspondence of Jump Squats and Push Jerks to Countermovement Jumps

Abstract

The aim of this study was to determine the mechanical similarity between push jerk (PJ) and jump squat (JS) to countermovement jump (CMJ) and further understand the effect increasing external load may have on this relationship. Eight physically trained men (age 22 ± 3; height 176 ± 7 kg; weight 83 ± 8 kg) performed an unloaded CMJ followed by JS under a range of loads (10, 25, 35, and 50% 1RM back squat) and PJ (30, 50, 65, and 75% 1RM push jerk). A portable force platform and high-speed camera both collecting at 250 Hz were used to establish joint moments and impulse during the propulsive phase of the movements. A standard inverse dynamics model was used to determine joint moment and impulse at the hip, knee, and ankle. Significant correlations (p ≤ 0.05) were shown between CMJ knee joint moment and JS knee joint moment at 25% load and PJ knee joint moment at 30 and 50% load. Significant correlations were also observed between CMJ knee joint impulse and JS knee joint impulse at 10% load and PJ knee joint moment at 30 and 65% load. Significant correlation was also observed between CMJ hip joint impulse and PJ hip joint impulse at 30% load. No significant joint × load interaction was shown as load increased for either PJ or JS. Results from the study suggest partial correspondence between PJ and JS to CMJ, where a greater mechanical similarity was observed between the PJ and CMJ. This interaction is load and joint dependent where lower relative loads showed greatest mechanical similarity. Therefore using lower relative loads when programming may provide a greater transfer of training effect.

A biomechanical comparison of the jerk, back jerk, vertical jump and jump squat

“…Cushion found that the greatest mechanical similarity with CMJ was observed at lower relative loads of the jerk and jump squat [19]. The mechanism behind is that subjects would alter the strategy in which they carry out the jumping and jerking as load increased such that the resemblance to CMJ characteristics is altered [19].…”

“…The main finding was that jerk was more like a general training modality than specific in relation to jumping. However, Cushion et al [19] indicated that push jerk was more similar to countermovement jump (CMJ) than jump squat with the notion that jump squat is one of the commonly implemented exercises to strengthen jumping abilities. In contrast, other researchers, who also compared jerk, jump squat and CMJ, suggested that the loaded jump squat exercise was more related to jumping and sprinting abilities than to the push press [20, 21].…”

Weightlifting Overhead Pressing Derivatives: A Review of the Literature

“…More specifically, some studies have compared the similarities between WOPDs and specific sporting activities [ 87 , 95 , 111 – 113 ]. Cushion et al [ 111 ] compared the loaded push jerk and jump squat and a countermovement jump (CMJ). Unexpectedly, the push jerk was more related mechanically to the CMJ than the jump squat, which is one of the exercises commonly used to improve jumping abilities.…”

“…First, the use of WOPDs is a useful and well-supported strategy to improve weightlifting performance, due to the high number of failed attempts during the jerk phase in competition [ 97 , 98 , 105 ]. Second, WOPDs require the ability to develop force rapidly through the kinetic chain from the lower extremities to the upper extremities, which is mechanically similar to many sporting activities [ 55 , 70 , 111 ]. This movement pattern targets not only an impulsive triple extension of the ankles, knees and hips, but also optimizes motor control and coordination due to the key role of the trunk and lower body muscles in stabilising and transmitting forces in the closed kinetic chain [ 70 , 90 , 103 , 106 ].…”

Exercise Technique: The Push Press

“…Although two different exercises are being compared in these studies (push press and push jerk), the underlying message showed some similarities. Cushion et al (4) suggested that although load dependent, a greater mechanical similarity was observed between the push jerk and the CMJ (when compared to the jump squat exercise). Lake et al (11) proposed that the mechanical demand during the push press was comparable to the jump squat.…”