{"title":"Post-Activation Performance Enhancement of Lower Limb with Variable Resistance Back Squat at Different Depths.","authors":"Choon Yeow Ng, Danny Lum","doi":"10.3390/jfmk10030347","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>This study compared the acute effect of performing quarter (QS) and parallel (PS) squat with variable resistance (VR) on countermovement jump (CMJ) performance.</p><p><strong>Methods: </strong>Fifteen resistance trained athletes (age: 27.0 ± 3.7 years, bodyweight: 68.4 ± 7.7 kg, height: 169.7 ± 6.9 cm) performed either the QS or PS to induce post-activation performance enhancement on two separate occasions. During each session, participants performed three repetitions of baseline CMJ prior to performing three repetitions of either QS or PS at their three-repetition maximum load. Participants then performed the post-test CMJ after a five-minute recovery period.</p><p><strong>Results: </strong>Both conditions resulted in increased jump height (QS: <i>p</i> < 0.001, <i>g</i> = 0.19, PS: <i>p</i> < 0.001, <i>g</i> = 0.35). Countermovement depth and time to take-off were significantly decreased in QS (<i>p</i> < 0.001, <i>g</i> = 0.63 and <i>p</i> = 0.005, <i>g</i> = 0.30, respectively) but significantly increased in PS (<i>p</i> = 0.027, <i>g</i> = 0.39 and <i>p</i> < 0.001, <i>g</i> = 0.36, respectively). Mean propulsion force was significantly increased in QS (<i>p</i> < 0.001, <i>g</i> = 0.23) but significantly decreased in PS (<i>p</i> = 0.083, <i>g</i> = 0.13). PS resulted in greater change in jump height (<i>p</i> < 0.001, <i>g</i> = 1.34) and time to take-off (<i>p</i> = 0.005, <i>g</i> = 1.25), while QS resulted in greater change in countermovement depth (<i>p</i> < 0.001, <i>g</i> = 2.33) and mean propulsion force (<i>p</i> < 0.001, <i>g</i> = 1.67).</p><p><strong>Conclusions: </strong>The results showed that performing PS and QS with VR was effective in enhancing CMJ height. However, the two conditions resulted in participants adopting different jump strategies when performing the post-test CMJ.</p>","PeriodicalId":16052,"journal":{"name":"Journal of Functional Morphology and Kinesiology","volume":"10 3","pages":""},"PeriodicalIF":2.5000,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12452786/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Functional Morphology and Kinesiology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/jfmk10030347","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"SPORT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Background: This study compared the acute effect of performing quarter (QS) and parallel (PS) squat with variable resistance (VR) on countermovement jump (CMJ) performance.
Methods: Fifteen resistance trained athletes (age: 27.0 ± 3.7 years, bodyweight: 68.4 ± 7.7 kg, height: 169.7 ± 6.9 cm) performed either the QS or PS to induce post-activation performance enhancement on two separate occasions. During each session, participants performed three repetitions of baseline CMJ prior to performing three repetitions of either QS or PS at their three-repetition maximum load. Participants then performed the post-test CMJ after a five-minute recovery period.
Results: Both conditions resulted in increased jump height (QS: p < 0.001, g = 0.19, PS: p < 0.001, g = 0.35). Countermovement depth and time to take-off were significantly decreased in QS (p < 0.001, g = 0.63 and p = 0.005, g = 0.30, respectively) but significantly increased in PS (p = 0.027, g = 0.39 and p < 0.001, g = 0.36, respectively). Mean propulsion force was significantly increased in QS (p < 0.001, g = 0.23) but significantly decreased in PS (p = 0.083, g = 0.13). PS resulted in greater change in jump height (p < 0.001, g = 1.34) and time to take-off (p = 0.005, g = 1.25), while QS resulted in greater change in countermovement depth (p < 0.001, g = 2.33) and mean propulsion force (p < 0.001, g = 1.67).
Conclusions: The results showed that performing PS and QS with VR was effective in enhancing CMJ height. However, the two conditions resulted in participants adopting different jump strategies when performing the post-test CMJ.
背景:本研究比较了变阻力四分之一蹲(QS)和平行蹲(PS)对反动作跳(CMJ)表现的急性影响。方法:15名阻力训练运动员(年龄:27.0±3.7岁,体重:68.4±7.7 kg,身高:169.7±6.9 cm)分别在两个不同的场合进行QS或PS诱导激活后性能增强。在每次训练中,参与者在进行三次最大负荷的QS或PS三次重复之前,先进行三次基线CMJ重复。然后,参与者在五分钟的恢复期后进行测试后的CMJ。结果:两种条件均使跳高升高(QS: p < 0.001, g = 0.19; PS: p < 0.001, g = 0.35)。QS的反动作深度和起飞时间显著降低(p < 0.001, g = 0.63和p = 0.005, g = 0.30), PS的反动作深度和起飞时间显著增加(p = 0.027, g = 0.39和p < 0.001, g = 0.36)。平均推进力在QS组显著增加(p < 0.001, g = 0.23),在PS组显著降低(p = 0.083, g = 0.13)。PS对起跳高度(p < 0.001, g = 1.34)和起飞时间(p = 0.005, g = 1.25)的影响较大,QS对反动作深度(p < 0.001, g = 2.33)和平均推进力(p < 0.001, g = 1.67)的影响较大。结论:PS和QS配合VR可有效提高CMJ高度。然而,这两种情况导致参与者在执行后测CMJ时采用不同的跳跃策略。