{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,4]],"date-time":"2026-11-04T03:15:17Z","timestamp":1793762117994,"version":"4.6.1"},"reference-count":54,"publisher":"Public Library of Science (PLoS)","issue":"11","license":[{"start":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T00:00:00Z","timestamp":1701043200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"This study was aimed to analyze in detail how the fatigue effects to kinematic parameters of body weight squat exercise (BSQ) by dividing a squat cycle into four different regions. Twenty-one male athletes participated in this study. Participants were divided into two groups according to their lower limb muscle ratio (LLMR). The BSQ was performed until participants were unable to continue the exercise due to the fatigue. Linear and angular kinematics were obtained by motion analysis software which has high validity and reliability. There was no significant but had large effect size interaction between fatigue conditions and LLMR groups in terms of knee ROM in the extension phase and hip angular velocity in braking phase of the flexion (0.08 > p >0.05, 0.18 > \u03b7<\/mml:mi><\/mml:mrow>\u03c1<\/mml:mi><\/mml:mrow>2<\/mml:mn><\/mml:mrow><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula> > 0.16). Fatigue condition did not have a significant effect on the duration in the acceleration and braking phases of BSQ (p > 0.05). There were many significant main effects on kinematics in the different regions due to the fatigue (0.01 < p <0.05, 0.44 > \u03b7<\/mml:mi><\/mml:mrow>\u03c1<\/mml:mi><\/mml:mrow>2<\/mml:mn><\/mml:mrow><\/mml:msubsup><\/mml:math><\/jats:alternatives><\/jats:inline-formula> > 0.14). In the fatigue condition, there was a polynomial relationship between velocity of shoulder and hip joints (R2<\/jats:sup>flex<\/jats:sub> = 0.82, R2<\/jats:sup>ext<\/jats:sub> = 0.72) rather than linear (R2<\/jats:sup>flex<\/jats:sub> = 0.64, R2<\/jats:sup>ext<\/jats:sub> = 0.53) and coefficient correlations also decreased (r<\/jats:italic>flex<\/jats:sub> = 0.88 to 0.80, r<\/jats:italic>ext<\/jats:sub> = 0.92 to 0.73). The sticking region was observed in the non-fatigue condition and disappeared when fatigue occurred. These results suggest that LLMR may be taken into consideration in the squat exercises, joint tracking may vary for velocity-based squat training and pre-test for sticking region observation may be apply with the BSQ.<\/jats:p>","DOI":"10.1371\/journal.pone.0289089","type":"journal-article","created":{"date-parts":[[2023,11,27]],"date-time":"2023-11-27T19:16:49Z","timestamp":1701112609000},"page":"e0289089","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":11,"title":["The effects of fatigue on linear and angular kinematics during bilateral squat"],"prefix":"10.1371","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0276-1298","authenticated-orcid":true,"given":"Berkant","family":"Erman","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Faik","family":"Vural","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Milivoj","family":"Dopsaj","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet Zeki","family":"Ozkol","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Damla Ercan","family":"Kose","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tolga","family":"Aksit","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2023,11,27]]},"reference":[{"issue":"4","key":"pone.0289089.ref001","first-page":"516","article-title":"Biomechanical model and evaluation of a linear motion squat type exercise.","volume":"16","author":"KG Abelbeck","year":"2002","journal-title":"J Strength Cond Res"},{"issue":"6","key":"pone.0289089.ref002","doi-asserted-by":"crossref","first-page":"984","DOI":"10.1097\/00005768-200106000-00019","article-title":"A three-dimensional biomechanical analysis of the squat during varying stance widths.","volume":"33","author":"RF Escamilla","year":"2001","journal-title":"Med Sci Sports Exerc"},{"issue":"12","key":"pone.0289089.ref003","doi-asserted-by":"crossref","first-page":"3497","DOI":"10.1519\/JSC.0b013e3181bac2d7","article-title":"Squatting kinematics and kinetics and their application to exercise performance.","volume":"24","author":"BJ Schoenfeld","year":"2010","journal-title":"The Journal of Strength & Conditioning Research."},{"issue":"5","key":"pone.0289089.ref004","doi-asserted-by":"crossref","first-page":"871","DOI":"10.26603\/ijspt20180871","article-title":"Comparison of bilateral and unilateral squat exercises on barbell kinematics and muscle activation","volume":"13","author":"W Eliassen","year":"2018","journal-title":"International journal of sports physical therapy"},{"issue":"5","key":"pone.0289089.ref005","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1249\/00005768-198910000-00019","article-title":"Effect of load, cadence, and fatigue on tibio-femoral joint force during a half squat.","volume":"21","author":"HC Hattin","year":"1989","journal-title":"Med Sci Sports Exerc"},{"issue":"1","key":"pone.0289089.ref006","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1519\/SSC.0b013e318195eb2f","article-title":"The bodyweight squat: A movement screen for the squat pattern.","volume":"31","author":"M Kritz","year":"2009","journal-title":"Strength & Conditioning Journal."},{"issue":"1","key":"pone.0289089.ref007","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s13102-018-0103-7","article-title":"How to squat? 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