{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:15:54Z","timestamp":1787616954358,"version":"build-2736575974"},"reference-count":41,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,4,18]],"date-time":"2024-04-18T00:00:00Z","timestamp":1713398400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JFMK"],"abstract":"<jats:p>During the ascent phase of a maximal barbell back squat after an initial acceleration, a deceleration region occurs as the result of different biomechanical factors. This is known as the sticking region. However, whether this region is similar in the last repetition of different repetition maximums and if sex has an impact on biomechanics of this region are not known. Therefore, this study investigated the effect of sex (men\/women) and repetition maximum (1-, 3-, 6-, and 10RM) on kinematics and surface electromyography around the sticking region. Twenty-six resistance-trained individuals comprising 13 men (body mass: 82.2 \u00b1 8.7; age: 23.6 \u00b1 1.9; height: 181.1 \u00b1 6.5) and 13 women (body mass: 63.6 \u00b1 6.6; age: 23.9 \u00b1 4.5; height: 166.0 \u00b1 4.5) participated in the study. The main findings were that women, in comparison to men, displayed larger trunk lean and lower hip extension angles in the sticking region, possibly due to different hip\/knee extensor strength ratios. Moreover, an inverse relationship was discovered between repetition range and timing from V0 to Vmax2, in which lower repetition ranges (1- and 3RM) were shorter in Vmax2 compared to higher ranges (6- and 10RM). It was concluded that this occurrence is due to more moments of inertia in lower repetition ranges. Our findings suggest that both sex and repetition range might induce different requirements during the squat ascent.<\/jats:p>","DOI":"10.3390\/jfmk9020075","type":"journal-article","created":{"date-parts":[[2024,4,18]],"date-time":"2024-04-18T07:55:54Z","timestamp":1713426954000},"page":"75","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["The Effect of Sex and Different Repetition Maximums on Kinematics and Surface Electromyography in the Last Repetition of the Barbell Back Squat"],"prefix":"10.3390","volume":"9","author":[{"given":"Andreas","family":"Hegdahl Gundersen","sequence":"first","affiliation":[{"name":"Department of Sports Sciences, Nord University, 7600 Levanger, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hallvard","family":"Nygaard Falch","sequence":"additional","affiliation":[{"name":"Department of Sports Sciences, Nord University, 7600 Levanger, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-8968-3081","authenticated-orcid":false,"given":"Andrea","family":"Bao Fredriksen","sequence":"additional","affiliation":[{"name":"Department of Sports Sciences, Nord University, 7600 Levanger, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4481-4490","authenticated-orcid":false,"given":"Roland van den","family":"Tillaar","sequence":"additional","affiliation":[{"name":"Department of Sports Sciences, Nord University, 7600 Levanger, Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,4,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1671","DOI":"10.1519\/JSC.0b013e3181d8eb4e","article-title":"Quantifying the movement and the influence of load in the back squat exercise","volume":"24","author":"McKean","year":"2010","journal-title":"J. Strength Cond. Res."},{"key":"ref_2","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":"Escamilla","year":"2001","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Maddox, E.U., and Bennett, H.J. (2021). Effects of external load on sagittal and frontal plane lower extremity biomechanics during back squats. J. Biomech. Eng., 143.","DOI":"10.1115\/1.4049747"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Maddox, E.U., Sievert, Z.A., and Bennett, H.J. (2020). Modified vector coding analysis of trunk and lower extremity kinematics during maximum and sub-maximum back squats. J. Biomech., 106.","DOI":"10.1016\/j.jbiomech.2020.109830"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"van den Tillaar, R. (2019). Effect of descent velocity upon muscle activation and performance in two-legged free weight back squats. Sports, 7.","DOI":"10.3390\/sports7010015"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"63","DOI":"10.2478\/hukin-2014-0061","article-title":"The existence of a sticking region in free weight squats","volume":"42","author":"Andersen","year":"2014","journal-title":"J. Hum. Kinet."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"691459","DOI":"10.3389\/fspor.2021.691459","article-title":"New insights about the sticking region in back squats: An analysis of kinematics, kinetics, and myoelectric activity","volume":"3","author":"Larsen","year":"2021","journal-title":"Front. Sports Act. Living"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1519\/SSC.0000000000000103","article-title":"The back squat: A proposed assessment of functional deficits and technical factors that limit performance","volume":"36","author":"Myer","year":"2014","journal-title":"Strength Cond. J."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Larsen, S., Kristiansen, E., Nygaard Falch, H., Estifanos Haugen, M., Fimland, M.S., and van den Tillaar, R. (Sports Biomech., 2022). Effects of barbell load on kinematics, kinetics, and myoelectric activity in back squats, Sports Biomech., online ahead of print.","DOI":"10.1080\/14763141.2022.2085164"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/0021-9290(85)90005-3","article-title":"In vivo moment arm lengths for hip extensor muscles at different angles of hip flexion","volume":"18","year":"1985","journal-title":"J. Biomech."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1007\/BF00236067","article-title":"Length and moment arm of human leg muscles as a function of knee and hip-joint angles","volume":"61","author":"Visser","year":"1990","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1519\/0744-0049(1993)015<0007:EEAT>2.3.CO;2","article-title":"Explosive exercise","volume":"15","author":"Stone","year":"1993","journal-title":"Natl. Strength Cond. Assoc. J."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Schoenfeld, B.J., Grgic, J., Van Every, D.W., and Plotkin, D.L. (2021). Loading recommendations for muscle strength, hypertrophy, and local endurance: A re-examination of the repetition continuum. Sports, 9.","DOI":"10.3390\/sports9020032"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Larsen, S., Haugen, M., and van den Tillaar, R. (2022). Comparison of kinematics and electromyographic activity in the last repetition during different repetition maximums in the bench press exercise. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph192114238"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1249\/01.MSS.0000121945.36635.61","article-title":"Fundamentals of resistance training: Progression and exercise prescription","volume":"36","author":"Kraemer","year":"2004","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"645","DOI":"10.1139\/y04-081","article-title":"The resilience of the size principle in the organization of motor unit properties in normal and reinnervated adult skeletal muscles","volume":"82","author":"Gordon","year":"2004","journal-title":"Can. J. Physiol. Pharmacol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1007\/BF00235103","article-title":"Gender differences in strength and muscle fiber characteristics","volume":"66","author":"Miller","year":"1993","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1152\/jappl.2000.89.1.81","article-title":"Skeletal muscle mass and distribution in 468 men and women aged 18\u201388 yr","volume":"89","author":"Janssen","year":"2000","journal-title":"J. Appl. Physiol."},{"key":"ref_19","first-page":"79","article-title":"Male relative muscle strength exceeds females for bench press and back squat","volume":"19","author":"Monteiro","year":"2016","journal-title":"J. Exerc. Physiol. Online"},{"key":"ref_20","first-page":"131","article-title":"Muscle activation and force production during bilateral and unilateral concentric and isometric contractions of the knee extensors in men and women at different ages","volume":"37","author":"Kraemer","year":"1997","journal-title":"Electromyogr. Clin. Neurophysiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1249\/MSS.0b013e3181e3b3f","article-title":"Thigh strength and activation as predictors of knee biomechanics during a drop jump task","volume":"41","author":"Shultz","year":"2009","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1007\/s00421-002-0739-5","article-title":"Gender-specific knee extensor torque, flexor torque, and muscle fatigue responses during maximal effort contractions","volume":"89","author":"Pincivero","year":"2003","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1177\/036354659602400405","article-title":"Neuromuscular performance characteristics in elite female athletes","volume":"24","author":"Huston","year":"1996","journal-title":"Am. J. Sports Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1249\/MSS.0b013e31827c0b94","article-title":"Influence of relative hip and knee extensor muscle strength on landing biomechanics","volume":"45","author":"Stearns","year":"2013","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1123\/jab.22.1.41","article-title":"Relationship between hip and knee strength and knee valgus during a single leg squat","volume":"22","author":"Claiborne","year":"2006","journal-title":"J. Appl. Biomech."},{"key":"ref_26","first-page":"136","article-title":"Quantitative measurements of hip strength in different age groups","volume":"246","author":"Cahalan","year":"1989","journal-title":"Clin. Orthop. Relat. Res. (1976\u20132007)"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1097\/00003677-200107000-00004","article-title":"Sex differences in human skeletal muscle fatigue","volume":"29","author":"Hicks","year":"2001","journal-title":"Exerc. Sport Sci. Rev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1007\/BF00422739","article-title":"Endurance capacity of untrained males and females in isometric and dynamic muscular contractions","volume":"55","author":"Maughan","year":"1986","journal-title":"Eur. J. Appl. Physiol. Occup. Physiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"890","DOI":"10.1519\/JSC.0000000000003021","article-title":"Body mass and femur length are inversely related to repetitions performed in the back squat in well-trained lifters","volume":"33","author":"Cooke","year":"2019","journal-title":"J. Strength Cond. Res."},{"key":"ref_30","first-page":"101","article-title":"Comparison of quadriceps and hamstring muscle activity during an isometric squat between strength-matched men and women","volume":"18","author":"Nimphius","year":"2019","journal-title":"J. Sports Sci. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1016\/S1050-6411(00)00027-4","article-title":"Development of recommendations for SEMG sensors and sensor placement procedures","volume":"10","author":"Hermens","year":"2000","journal-title":"J. Electromyogr. Kinesiol."},{"key":"ref_32","unstructured":"Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences, Lawrence Erlbaum Associates."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"van den Tillaar, R., Kristiansen, E.L., and Larsen, S. (2021). Is the Occurrence of the Sticking Region in Maximum Smith Machine Squats the Result of Diminishing Potentiation and Co-Contraction of the Prime Movers among Recreationally Resistance Trained Males?. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18031366"},{"key":"ref_34","first-page":"15","article-title":"Kinematics and muscle activation around the sticking region in free-weight barbell back squats\/kinematika in misicna aktivacija okrog obmocja prevelikega odpora pri pocepih z bremenom zadaj med dvigovanjem utezi","volume":"21","year":"2015","journal-title":"Kinesiol. Slov."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1111\/j.1748-1716.1983.tb07306.x","article-title":"Influence of lactate accumulation of EMG frequency spectrum during repeated concentric contractions","volume":"119","author":"Tesch","year":"1983","journal-title":"Acta Physiol. Scand."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1127","DOI":"10.1097\/JSC.0000000000000237","article-title":"Effects of fatigue from resistance training on barbell back squat biomechanics","volume":"28","author":"Hooper","year":"2014","journal-title":"J. Strength Cond. Res."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"2031","DOI":"10.1007\/s00421-015-3249-y","article-title":"Non-local muscle fatigue: Effects and possible mechanisms","volume":"115","author":"Halperin","year":"2015","journal-title":"Eur. J. Appl. Physiol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2820","DOI":"10.1519\/JSC.0b013e31826791a7","article-title":"Effect of squat depth and barbell load on relative muscular effort in squatting","volume":"26","author":"Bryanton","year":"2012","journal-title":"J. Strength Cond. Res."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Gorostiaga, E.M., Navarro-Amezqueta, I., Calbet, J.A., Hellsten, Y., Cusso, R., Guerrero, M., Granados, C., Gonzalez-Izal, M., Ibanez, J., and Izquierdo, M. (2012). Energy metabolism during repeated sets of leg press exercise leading to failure or not. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0040621"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1436","DOI":"10.1249\/01.mss.0000227408.91474.77","article-title":"Oxidative stress response in trained men following repeated squats or sprints","volume":"38","author":"Bloomer","year":"2006","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_41","unstructured":"Baechle, T.R., and Earle, R.W. (2008). Essentials of Strength Training and Conditioning, Human kinetics."}],"container-title":["Journal of Functional Morphology and Kinesiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2411-5142\/9\/2\/75\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T14:29:51Z","timestamp":1760106591000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2411-5142\/9\/2\/75"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,4,18]]},"references-count":41,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2024,6]]}},"alternative-id":["jfmk9020075"],"URL":"https:\/\/doi.org\/10.3390\/jfmk9020075","relation":{},"ISSN":["2411-5142"],"issn-type":[{"value":"2411-5142","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,4,18]]}}}