{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T04:53:13Z","timestamp":1781499193305,"version":"3.54.1"},"reference-count":48,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,6,13]],"date-time":"2026-06-13T00:00:00Z","timestamp":1781308800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"EU\u2014NextGenerationEU","award":["09I03-03-V05-00006"],"award-info":[{"award-number":["09I03-03-V05-00006"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JFMK"],"abstract":"<jats:p>Background: Isokinetic strength of the knee joint represents a significant determinant of athletic performance and injury prevention; however, its relationship with explosive performance in young female athletes remains insufficiently explored. The aim of the study was to analyze the relationships between isokinetic strength of the knee joint at different angular velocities and explosive jumping performance in young female athletes. Methods: The research sample consisted of 13 young female athletes enrolled in sport-oriented educational programs specializing in athletics. Explosive lower-limb power was assessed using performance tests for countermovement jump (CMJ), countermovement jump free arms (CMJ FAs) and squat jump (SJ) administered with the Chronojump system. Isokinetic strength of the knee flexors and extensors was assessed using the Humac Norm dynamometer in the concentric mode at angular velocities of 60\u00b0\/s, 180\u00b0\/s, and 300\u00b0\/s. Peak torque, the ipsilateral H:Q ratio, and bilateral asymmetries were evaluated. Pearson\u2019s correlation coefficient was used to analyze the relationships between the investigated parameters. Results: The strongest relationships with explosive performance were observed for hamstring strength at an angular velocity of 180\u00b0\/s, where significant high correlations were identified with performance in the CMJ (r = 0.693), CMJ FA (r = 0.754), and SJ (r = 0.713). In contrast, quadriceps strength demonstrated predominantly low to moderate associations with jumping performance, while no significant correlations were confirmed at an angular velocity of 300\u00b0\/s. Bilateral asymmetries of the knee extensors and flexors were generally low, ranging approximately between 7 and 10%, whereas the values of the ipsilateral H:Q ratio were within the physiological range of approximately 50\u201355%. Conclusions: The results suggest that the ability to generate force at higher contraction velocities, particularly in the hamstrings, is significantly associated with explosive performance in young female athletes. At the same time, isokinetic strength assessment appears to be an appropriate tool for evaluating muscular strength, muscle balance, and potential asymmetries in youth sports. However, explosive performance cannot be explained solely by the level of maximal muscular strength, but rather by a complex interaction of neuromuscular and biomechanical factors.<\/jats:p>","DOI":"10.3390\/jfmk11020237","type":"journal-article","created":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T03:01:27Z","timestamp":1781492487000},"page":"237","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Associations Between Isokinetic Knee Strength at Different Angular Velocities and Explosive Jump Performance in Young Female Athletes: A Pilot Study"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-1538-0574","authenticated-orcid":false,"given":"Daniela","family":"Falat Le\u00fctterov\u00e1","sequence":"first","affiliation":[{"name":"Department of Music, Art and Physical Education, Faculty of Education, University of Presov, 080 01 Presov, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-3028-3385","authenticated-orcid":false,"given":"Jaroslav","family":"Su\u010dka","sequence":"additional","affiliation":[{"name":"Department of Educology of Sports, Faculty of Sport, University of Presov, 080 01 Presov, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.jor.2025.08.035","article-title":"Three Decades of Research on Knee Isokinetic Strength: A Bibliometric and Visual Exploration of Global Trends and Emerging Frontiers","volume":"71","author":"Lv","year":"2026","journal-title":"J. Orthop."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Cozette, M., Lepr\u00eatre, P.-M., Doyle, C., and Weissland, T. (2019). Isokinetic Strength Ratios: Conventional Methods, Current Limits and Perspectives. Front. Physiol., 10.","DOI":"10.3389\/fphys.2019.00567"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Duarte, J.P., Valente-dos-Santos, J., Coelho-e-Silva, M.J., Couto, P., Costa, D., Martinho, D., Seabra, A., Cyrino, E.S., Conde, J., and Rosado, J. (2018). Reproducibility of isokinetic strength assessment of knee muscle actions in adult athletes: Torques and antagonist-agonist ratios derived at the same angle position. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0202261"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Dvir, Z. (2025). Isokinetics: Muscle Testing, Interpretation and Clinical Applications, Taylor & Francis.","DOI":"10.4324\/9781003380719"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"15023","DOI":"10.1038\/s41598-026-45803-8","article-title":"Isokinetic Knee Strength Profiles, Conventional Hamstring-to-Quadriceps Ratio, and Performance Decrement in Weightlifting and Wrestling Athletes: A Cross-Sectional Study","volume":"16","author":"Sung","year":"2026","journal-title":"Sci. Rep."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Kabacinski, J., Szozda, P.M., Mackala, K., Murawa, M., Rzepnicka, A., Szewczyk, P., and Dworak, L.B. (2022). Relationship between Isokinetic Knee Strength and Speed, Agility, and Explosive Power in Elite Soccer Players. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19020671"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"77","DOI":"10.5114\/biolsport.2025.148534","article-title":"Knee Isokinetic Strength Benchmarks in Athletes across Sports Categories and Performance Levels","volume":"42","author":"Freire","year":"2025","journal-title":"Biol. Sport"},{"key":"ref_8","unstructured":"\u015eahin, \u0130.H., and K\u0131vrak, A.O. (2026, April 22). Analysis of the Phases of Sprint in Terms of Isokinetic Leg Strength, Anaerobic Endurance, and Balance. Available online: https:\/\/www.jomh.org\/articles\/10.22514\/jomh.2025.127?utm_source=chatgpt.com."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Kural, B., \u00c7a\u011flar, E.\u00c7., Akku\u015f U\u00e7ar, M., \u00d6zer, U., Yent\u00fcrk, B., \u00c7ay\u0131r, H., \u00c7elik, N.M., \u00c7imen, E., Ar\u0131kan, G., and Ceylan, L. (2025). Isokinetic Knee Strength as a Predictor of Performance in Elite Ski Mountaineering Sprint Athletes. Medicina, 61.","DOI":"10.3390\/medicina61071237"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1016\/j.jsams.2014.08.002","article-title":"Analysis of the Association between Isokinetic Knee Strength with Offensive and Defensive Jumping Capacity in High-Level Female Volleyball Athletes","volume":"18","author":"Sattler","year":"2015","journal-title":"J. Sci. Med. Sport"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Chen, L., Zhang, Z., Huang, Z., Yang, Q., Gao, C., Ji, H., Sun, J., and Li, D. (2023). Meta-Analysis of the Effects of Plyometric Training on Lower Limb Explosive Strength in Adolescent Athletes. Int. J. Environ. Res. Public Health, 20.","DOI":"10.3390\/ijerph20031849"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Westwood, C., Welbeck, A., Killelea, C., Howard, P., Faherty, M., Le, D., Zerega, R., Reiter, C.R., and Sell, T.C. (2025). Examining Isokinetic Knee Peak Torque and Time to Peak Torque as Predictors of Vertical Jump Height in Division I Men\u2019s Basketball Players. PLoS ONE, 20.","DOI":"10.1371\/journal.pone.0303701"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1016\/j.jshs.2022.01.002","article-title":"Is Hamstrings-to-Quadriceps Torque Ratio Useful for Predicting Anterior Cruciate Ligament and Hamstring Injuries? A Systematic and Critical Review","volume":"12","author":"Kellis","year":"2023","journal-title":"J. Sport Health Sci."},{"key":"ref_14","first-page":"234","article-title":"Understanding and Preventing Acl Injuries: Current Biomechanical and Epidemiologic Considerations\u2014Update 2010","volume":"5","author":"Hewett","year":"2010","journal-title":"N. Am. J. Sports Phys. Ther."},{"key":"ref_15","first-page":"5","article-title":"Effects of different strength training on sprint, jump and strength performance in female soccer players. A systematic review","volume":"78","author":"Jelaska","year":"2025","journal-title":"Med. Dello Sport"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2314","DOI":"10.1519\/JSC.0000000000002579","article-title":"Normative Quadriceps and Hamstring Muscle Strength Values for Female, Healthy, Elite Handball and Football Players","volume":"32","author":"Risberg","year":"2018","journal-title":"J. Strength Cond. Res."},{"key":"ref_17","first-page":"44","article-title":"The Relationship between Isokinetic Knee Flexion and Squat Jump Performance","volume":"34","year":"2024","journal-title":"J. Kinesiol. Exerc. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3305","DOI":"10.1519\/JSC.0000000000002231","article-title":"Determination of Vertical Jump as a Measure of Neuromuscular Readiness and Fatigue","volume":"31","author":"Watkins","year":"2017","journal-title":"J. Strength Cond. Res."},{"key":"ref_19","first-page":"a1","article-title":"Muscular Coordination during Vertical Jumping","volume":"1","author":"Cleather","year":"2019","journal-title":"J. Hum. Perform. Health"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"35","DOI":"10.15406\/mojsm.2025.08.00180","article-title":"Comprehensive Assessment and Individualized Training Guidance in Vertical Jump Performance: From Force\u2013Velocity Profiling to Neuromuscular Diagnostics","volume":"8","author":"Andraos","year":"2025","journal-title":"MOJSM"},{"key":"ref_21","first-page":"167","article-title":"Vpliv tehni\u010dne izvedbe na vi\u0161ino vertikalnega enono-\u017enega skoka z nasprotnim gibanjem pri rokometa\u0161ih","volume":"72","author":"Pori","year":"2024","journal-title":"Rev. \u0160port"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1123\/ijspp.7.4.340","article-title":"Speed and Countermovement-Jump Characteristics of Elite Female Soccer Players, 1995-2010","volume":"7","author":"Haugen","year":"2012","journal-title":"Int. J. Sports Physiol. Perform."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1519\/JSC.0000000000001815","article-title":"The Effect of Standard Strength vs. Contrast Strength Training on the Development of Sprint, Agility, Repeated Change of Direction, and Jump in Junior Male Soccer Players","volume":"31","author":"Hammami","year":"2017","journal-title":"J. Strength Cond. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"107","DOI":"10.3233\/IES-2002-0092","article-title":"The Relationship between Jumping Performance and Isokinetic Strength of Hip and Knee Extensors and Ankle Plantar Flexors","volume":"10","author":"Tsiokanos","year":"2002","journal-title":"Isokinet. Exerc. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1016\/S1440-2440(01)80042-6","article-title":"Isokinetic Strength Related to Jumping but Not Kicking Performance of Australian Footballers","volume":"4","author":"Saliba","year":"2001","journal-title":"J. Sci. Med. Sport"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1080\/02640410500189124","article-title":"Effects of Allometric Scaling and Isokinetic Testing Methods on the Relationship between Countermovement Jump and Quadriceps Torque and Power","volume":"24","author":"Pua","year":"2006","journal-title":"J. Sports Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"149","DOI":"10.2478\/v10078-012-0016-6","article-title":"The Relationship Between Muscle Strength, Anaerobic Performance, Agility, Sprint Ability and Vertical Jump Performance in Professional Basketball Players","volume":"31","year":"2012","journal-title":"J. Hum. Kinet."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1121","DOI":"10.1080\/02640410500128189","article-title":"Isokinetic Knee Extension and Vertical Jumping: Are They Related?","volume":"23","author":"Iossifidou","year":"2005","journal-title":"J. Sports Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"227","DOI":"10.2478\/hukin-2014-0050","article-title":"Isokinetic Leg Strength and Power in Elite Handball Players","volume":"41","year":"2014","journal-title":"J. Hum. Kinet."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1055\/s-2001-11331","article-title":"Isokinetic Strength and Anaerobic Power of Elite, Subelite and Amateur French Soccer Players","volume":"22","author":"Cometti","year":"2001","journal-title":"Int. J. Sports Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"139","DOI":"10.3233\/IES-2003-0140","article-title":"Identification of Previous Hamstring Muscle Injury by Isokinetic Concentric and Eccentric Torque Measurement in Elite Soccer Player","volume":"11","author":"Dauty","year":"2003","journal-title":"Isokinet. Exerc. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1111\/j.1475-097X.2007.00786.x","article-title":"Reliability of Isokinetic Strength Imbalance Ratios Measured Using the Cybex NORM Dynamometer","volume":"28","author":"Impellizzeri","year":"2008","journal-title":"Clin. Physiol. Funct. Imaging"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"175","DOI":"10.2519\/jospt.1992.15.4.175","article-title":"Reliability of Concentric and Eccentric Measurements of Quadriceps Performance Using the KIN-COM Dynamometer: The Effect of Testing Order for Three Different Speeds","volume":"15","author":"Wilhite","year":"1992","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1568","DOI":"10.1080\/00140130500101585","article-title":"Comparison of Muscle Strength and Flexibility between the Preferred and Non-Preferred Leg in English Soccer Players","volume":"48","author":"Rahnama","year":"2005","journal-title":"Ergonomics"},{"key":"ref_35","unstructured":"Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences, Routledge. [2nd ed.]."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1925","DOI":"10.1097\/00005768-200111000-00019","article-title":"Aerobic Endurance Training Improves Soccer Performance","volume":"33","author":"Helgerud","year":"2001","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_37","first-page":"369","article-title":"The Effect of a Combined High-Intensity Strength and Speed Training Program on the Running and Jumping Ability of Soccer Players","volume":"19","author":"Kotzamanidis","year":"2005","journal-title":"J. Strength Cond. Res."},{"key":"ref_38","first-page":"379","article-title":"Changes Evaluated in Soccer-Specific Power Endurance Either with or without a 10-Week, in-Season, Intermittent, High-Intensity Training Protocol","volume":"17","author":"Siegler","year":"2003","journal-title":"J. Strength Cond. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1136\/bjsm.2007.035113","article-title":"Does Plyometric Training Improve Vertical Jump Height? A Meta-Analytical Review","volume":"41","author":"Markovic","year":"2007","journal-title":"Br. J. Sports Med."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"20371","DOI":"10.1038\/s41598-024-70194-z","article-title":"An Arm Swing Enhances the Proximal-to-Distal Delay in Joint Extension during a Countermovement Jump","volume":"14","author":"Cefai","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_41","first-page":"131","article-title":"Countermovement Jump Performance in Elite Male and Female Sprinters and High Jumpers","volume":"235","author":"Philpott","year":"2021","journal-title":"Proc. Inst. Mech. Eng. Part P J. Sports Eng. Technol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1111\/j.1600-0838.2008.00780.x","article-title":"Muscular Strength, Functional Performances and Injury Risk in Professional and Junior Elite Soccer Players","volume":"19","author":"Lehance","year":"2009","journal-title":"Scand. J. Med. Sci. Sports"},{"key":"ref_43","first-page":"1479","article-title":"Muscle Injuries in Athletes. The Relationship between H\/Q Ratio (Hamstring\/Quadriceps Ratio)","volume":"7","author":"Bhatt","year":"2018","journal-title":"Ital. J. Sports Rehabil. Posturol."},{"key":"ref_44","first-page":"364","article-title":"Lower Limb Strength in Professional Soccer Players: Profile, Asymmetry, and Training Age","volume":"9","author":"Fousekis","year":"2010","journal-title":"J. Sports Sci. Med."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Fern\u00e1ndez-Baeza, D., Diaz-Urena, G., and Gonz\u00e1lez-Mill\u00e1n, C. (2022). Effect of an Individualised Training Programme on Hamstrings and Change Direction Based on Tensiomyography in Football Players. Appl. Sci., 12.","DOI":"10.3390\/app122110908"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1027","DOI":"10.1080\/14763141.2020.1775877","article-title":"Leg Extension Force-Velocity Imbalance Has Negative Impact on Sprint Performance in Ball-Game Players","volume":"22","author":"Junge","year":"2023","journal-title":"Sports Biomech."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1123\/pes.2017-0081","article-title":"The Effects of Maturation on Measures of Asymmetry During Neuromuscular Control Tests in Elite Male Youth Soccer Players","volume":"30","author":"Read","year":"2018","journal-title":"Pediatr. Exerc. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.knee.2024.10.020","article-title":"Association between Intra and Inter-Limb Strength Asymmetry with Sprint Kinematics and Force-Velocity Profile in Youth Team Athletes","volume":"52","author":"Tortu","year":"2025","journal-title":"Knee"}],"container-title":["Journal of Functional Morphology and Kinesiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2411-5142\/11\/2\/237\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T04:09:22Z","timestamp":1781496562000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2411-5142\/11\/2\/237"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,13]]},"references-count":48,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["jfmk11020237"],"URL":"https:\/\/doi.org\/10.3390\/jfmk11020237","relation":{},"ISSN":["2411-5142"],"issn-type":[{"value":"2411-5142","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,13]]}}}