Graduate School of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan.
Faculty of Sport Sciences, Waseda University, Tokorozawa, Saitama, Japan.
J Sports Sci Med. 2018 Nov 20;17(4):617-622. eCollection 2018 Dec.
The deceleration sub-phase during the back squat (BSQ) makes it difficult to stimulate the muscles throughout the full range of motion, and it has only been reported for one load during BSQ. The purpose of this study was to investigate whether a deceleration sub-phase occurs during BSQ with different loads and to assess the influence of load on the deceleration sub-phase duration and negative impulse during the deceleration sub-phase. Sixteen healthy men (mean ± standard deviation: age: 25 ± 3 years; height: 1.73 ± 0.07 m; mass: 83.2 ± 16.1 kg; BSQ one repetition maximum (1RM): 163.8 ± 36.6 kg; BSQ 1RM/body weight: 2.0 ± 0.4) who had performed resistance training for at least 1 year were recruited for this study. The subjects performed parallel BSQ with 0%, 12%, 27%, 42%, 56%, 71%, and 85% of each 1RM on a force plate in a random order. The deceleration sub-phase duration and negative impulse during the deceleration sub-phase were calculated from force-time data. The absolute durations of the deceleration sub-phase were not significantly different according to load except for 27% 1RM and 85% 1RM (p = 0.01). However, as the load increased from 12 to 85% 1RM, the relative duration of the deceleration sub-phase decreased (p < 0.05). The negative impulse during the deceleration sub-phase also increased from 0 to 42% 1RM (p < 0.05). A deceleration sub-phase occurs regardless of the load (0%-85% 1RM), and a large portion of the deceleration sub-phase occupied the concentric phase, with low-moderate loads, and a large amount of negative impulse occurred during the short deceleration sub-phase with a high load.
深蹲（BSQ）的减速阶段使得在整个运动范围内很难刺激肌肉，并且仅在 BSQ 的一次负荷下报告过。本研究的目的是调查在不同负荷下 BSQ 是否会发生减速阶段，并评估负荷对减速阶段持续时间和减速阶段负向冲量的影响。本研究招募了 16 名健康男性（平均±标准差：年龄：25±3 岁；身高：1.73±0.07 m；体重：83.2±16.1 kg；BSQ 一次重复最大值（1RM）：163.8±36.6 kg；BSQ 1RM/体重：2.0±0.4），他们已经进行了至少 1 年的抗阻训练。受试者在力量板上以 0%、12%、27%、42%、56%、71%和 85%的每个 1RM 随机顺序进行平行 BSQ。从力-时数据计算减速阶段的持续时间和减速阶段的负向冲量。除了 27% 1RM 和 85% 1RM 外（p=0.01），根据负荷，减速阶段的绝对持续时间没有显著差异。然而，随着负荷从 12%增加到 85% 1RM，减速阶段的相对持续时间减少（p<0.05）。减速阶段的负向冲量也从 0%增加到 42% 1RM（p<0.05）。减速阶段无论负荷（0%-85% 1RM）都会发生，并且在低中等负荷下，减速阶段的大部分时间都占据了向心阶段，而在高负荷下，减速阶段时间短，但会产生大量的负向冲量。
