{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T01:42:27Z","timestamp":1793410947987,"version":"4.5.0"},"reference-count":36,"publisher":"PeerJ","license":[{"start":{"date-parts":[[2024,7,9]],"date-time":"2024-07-09T00:00:00Z","timestamp":1720483200000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Innovation Center for Sports and Health Project Youth Fund","award":["JSCIC-YP21001"],"award-info":[{"award-number":["JSCIC-YP21001"]}]},{"name":"Nanjing Sport Institute","award":["XSTD202317"],"award-info":[{"award-number":["XSTD202317"]}],"id":[{"id":"https:\/\/ror.org\/04gy42h78","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Vertical jumping is an important evaluation tool to measure muscle strength and power as well as lower limb symmetry. It is of practical importance and value to develop and utilize a portable and low-cost mobile application (APP) to evaluate jumping. The \u201cMy Jump 2\u201d app is an iPhone camera-based application for measuring jumping movements, which is applied to the countermovement jump (CMJ) vertical jumps of the lower limbs of athletes in different sports. The validity of this application and previous versions applied to different forms of vertical jump tests has been preliminarily demonstrated in different population, which has an obvious progress in research. Therefore, the reliability and validity of the jump height, time of flight parameters and symmetry of the CMJ vertical jump of athletes in different sports are needed to be verified by more experiments.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>The purpose of this study is to verify whether \u201cMy Jump 2\u201d can effectively and reliably assess jump height, flight practice and lower limb symmetry in CMJAM (countermovement jump free arm) tests in fencing, swimming and diving athletes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Seventy-nine fencers, swimmers and divers with training experience participated in this study. They completed a total of three CMJAM vertical jump and lower limb symmetry tests in 1 day, while being assessed by using the \u201cMy Jump 2\u201d application and a force platform. The intra-group correlation coefficient (ICC) was used to verify reliability, while the Cronbach\u2019s alpha and coefficient of variation (CV%) was used to analyze the stability of the CMJAM vertical jump test over three jumps. The Pearson correlation coefficient was used to verify the strength of the relationship between methods (\n                      <jats:italic>i.e<\/jats:italic>\n                      ., concurrent validity), and the Bland-Altman plot was used to represent consistency, meanwhile, the t-test was used to determine the systematic bias between methods.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Compared with the force platform, the cumulative height values of the total number of jumps (r = 0.999;\n                      <jats:italic>p<\/jats:italic>\n                      = 0.000), the cumulative time to vacate (r = 0.999;\n                      <jats:italic>p<\/jats:italic>\n                      = 0.000) for the CMJAM test obtained by the \u201cMy Jump 2\u201d application, the height (ICC = 0.999\u20131,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.000), the time to vacate flight (ICC = 0.999\u20131,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.000), contact time symmetry (ICC = 0.976\u20130.994,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.000), and flight time symmetry (ICC = 0.921\u20130.982,\n                      <jats:italic>p<\/jats:italic>\n                      = 0.000), respectively. Showed high correlation between the results of \u201cmy jump 2\u201d app and the force platform.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>The \u201cMy Jump 2\u201d application is a valid tool to assess CMJAM vertical jump and lower limb symmetry in fencing, swimming and diving athletes with training experience.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.7717\/peerj.17658","type":"journal-article","created":{"date-parts":[[2024,7,9]],"date-time":"2024-07-09T03:05:57Z","timestamp":1720494357000},"page":"e17658","source":"Crossref","is-referenced-by-count":7,"title":["Reliability and validity of \u201cMy Jump 2\u201d application for countermovement jump free arm and interlimb jump symmetry in different sports of professional athletes"],"prefix":"10.7717","volume":"12","author":[{"given":"Yong","family":"Peng","sequence":"first","affiliation":[{"name":"Jiangsu Collaborative Innovation Center for Sports and Health Project, Nanjing Sport Institute, Nanjing, China"},{"name":"Key Laboratory of Human Sports Science for Jiangsu Province, Nanjing Sport Institute, Nanjing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaotong","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Sport Health, Nanjing Sport Institute, Nanjing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yudi","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Physical Education and Nursing, Chengdu College of Arts and Sciences, Chengdu, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ya xuan","family":"Qin","sequence":"additional","affiliation":[{"name":"School of Sport Health, Nanjing Sport Institute, Nanjing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Di","family":"Qin","sequence":"additional","affiliation":[{"name":"School of Sport Health, Nanjing Sport Institute, Nanjing, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"4443","published-online":{"date-parts":[[2024,7,9]]},"reference":[{"issue":"19","key":"10.7717\/peerj.17658\/ref-1","doi-asserted-by":"publisher","first-page":"2220","DOI":"10.1080\/02640414.2019.1626114","article-title":"Jump higher, run faster: effects of diversified sport participation on talent identification and selection in youth basketball","volume":"37","author":"Arede","year":"2019","journal-title":"Journal of Sports Sciences"},{"issue":"12","key":"10.7717\/peerj.17658\/ref-2","doi-asserted-by":"publisher","first-page":"1365","DOI":"10.1080\/02640414.2018.1559525","article-title":"Association of the functional movement screen\u2122 with match-injury burden in men\u2019s community rugby union","volume":"37","author":"Attwood","year":"2019","journal-title":"Journal of Sports Sciences"},{"issue":"15","key":"10.7717\/peerj.17658\/ref-3","doi-asserted-by":"publisher","first-page":"1574","DOI":"10.1080\/02640414.2014.996184","article-title":"The validity and reliability of an iPhone app for measuring vertical jump performance","volume":"33","author":"Balsalobre-Fern\u00e1ndez","year":"2015","journal-title":"Journal of Sports Sciences"},{"issue":"2","key":"10.7717\/peerj.17658\/ref-4","doi-asserted-by":"publisher","first-page":"528","DOI":"10.1519\/JSC.0b013e318299a52e","article-title":"The concurrent validity and reliability of a low-cost, high-speed camera-based method for measuring the flight time of vertical jumps","volume":"28","author":"Balsalobre-Fern\u00e1ndez","year":"2014","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-5","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1123\/ijspp.2019-0981","article-title":"Assessing interlimb jump asymmetry in young soccer players: the My Jump 2 app","volume":"16","author":"Barbalho","year":"2021","journal-title":"International Journal of Sports Physiology and Performance"},{"key":"10.7717\/peerj.17658\/ref-6","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1097\/00003086-199006000-00028","article-title":"Quantitative assessment of functional limitations in normal and anterior cruciate ligament-deficient knees","volume":"255","author":"Barber","year":"1990","journal-title":"Clinical Orthopaedics and Related Research"},{"issue":"4","key":"10.7717\/peerj.17658\/ref-7","doi-asserted-by":"publisher","first-page":"927","DOI":"10.1519\/JSC.0000000000003567","article-title":"Jump and change of direction speed asymmetry using smartphone apps: between-session consistency and associations with physical performance","volume":"36","author":"Bishop","year":"2022","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"4","key":"10.7717\/peerj.17658\/ref-8","doi-asserted-by":"publisher","first-page":"941","DOI":"10.1519\/JSC.0000000000003927","article-title":"Seasonal variation of physical performance and inter-limb asymmetry in professional cricket athletes","volume":"35","author":"Bishop","year":"2021","journal-title":"Journal of Strength and Conditioning Research"},{"key":"10.7717\/peerj.17658\/ref-9","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/S0140-6736(86)90837-8","article-title":"Statistical methods for assessing agreement between two methods of clinical measurement","volume":"1","author":"Bland","year":"1986","journal-title":"Lancet"},{"issue":"10","key":"10.7717\/peerj.17658\/ref-10","doi-asserted-by":"publisher","first-page":"3708","DOI":"10.3390\/ijerph17103708","article-title":"Validity, reliability, and usefulness of My Jump 2 app for measuring vertical jump in primary school children","volume":"17","author":"Bogataj","year":"2020","journal-title":"International Journal of Environmental Research and Public Health"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-11","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1080\/02640414.2011.624539","article-title":"Validity of vertical jump measurement devices","volume":"30","author":"Buckthorpe","year":"2012","journal-title":"Journal of Sports Sciences"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-12","doi-asserted-by":"publisher","first-page":"55","DOI":"10.5604\/20831862.1086733","article-title":"Reliability and validity of an accele-rometric system for assessing vertical jumping performance","volume":"31","author":"Choukou","year":"2014","journal-title":"Biology of Sport"},{"issue":"2","key":"10.7717\/peerj.17658\/ref-13","doi-asserted-by":"publisher","first-page":"106","DOI":"10.1016\/S1440-2440(99)80190-X","article-title":"The influence of plyometric training on the freestyle tumble turn","volume":"2","author":"Cossor","year":"1999","journal-title":"Journal of Science and Medicine in Sport"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-14","doi-asserted-by":"publisher","first-page":"e11099","DOI":"10.2196\/11099","article-title":"Assessing the validity of the MyJump2 app for measuring different jumps in professional cerebral palsy football players: an experimental study","volume":"7","author":"Coswig","year":"2019","journal-title":"JMIR Mhealth and Uhealth"},{"issue":"7","key":"10.7717\/peerj.17658\/ref-15","doi-asserted-by":"publisher","first-page":"e5804","DOI":"10.7717\/peerj.5804","article-title":"The validity and reliability of the \u201cMy Jump App\u201d for measuring jump height of the elderly","volume":"6","author":"Cruvinel-Cabral","year":"2018","journal-title":"PeerJ"},{"issue":"7","key":"10.7717\/peerj.17658\/ref-16","doi-asserted-by":"publisher","first-page":"2049","DOI":"10.1519\/JSC.0000000000001304","article-title":"Intersession and intrasession reliability and validity of the My Jump app for measuring different jump actions in trained male and female athletes","volume":"30","author":"Gallardo-Fuentes","year":"2016","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"4","key":"10.7717\/peerj.17658\/ref-17","doi-asserted-by":"publisher","first-page":"294","DOI":"10.1055\/s-2004-820962","article-title":"The validation of a new method that measures contact and flight times during vertical jump","volume":"26","author":"Garc\u00eda-L\u00f3pez","year":"2005","journal-title":"International Journal of Sports Medicine"},{"issue":"2","key":"10.7717\/peerj.17658\/ref-18","doi-asserted-by":"publisher","first-page":"556","DOI":"10.1519\/JSC.0b013e3181ccb18d","article-title":"Validity and reliability of optojump photoelectric cells for estimating vertical jump height","volume":"25","author":"Glatthorn","year":"2011","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"11","key":"10.7717\/peerj.17658\/ref-19","doi-asserted-by":"publisher","first-page":"2347","DOI":"10.1177\/0363546511417085","article-title":"Single-legged hop tests as predictors of self-reported knee function in nonoperatively treated individuals with anterior cruciate ligament injury","volume":"39","author":"Grindem","year":"2011","journal-title":"The American Journal of Sports Medicine"},{"issue":"13","key":"10.7717\/peerj.17658\/ref-20","doi-asserted-by":"publisher","first-page":"2806","DOI":"10.1016\/j.jbiomech.2008.07.002","article-title":"Effect of arm swing direction on forward and backward jump performance","volume":"41","author":"Hara","year":"2008","journal-title":"Journal of Biomechanics"},{"issue":"2","key":"10.7717\/peerj.17658\/ref-21","doi-asserted-by":"publisher","first-page":"253","DOI":"10.23736\/S0022-4707.18.08195-1","article-title":"The validity and reliability of the My Jump 2 app for measuring the reactive strength index and drop jump performance","volume":"59","author":"Haynes","year":"2019","journal-title":"The Journal of Sports Medicine and Physical Fitness"},{"issue":"7","key":"10.7717\/peerj.17658\/ref-22","doi-asserted-by":"publisher","first-page":"1849","DOI":"10.1519\/JSC.0000000000000343","article-title":"The MARS for squat, countermovement, and standing long jump performance analyses: are measures reproducible?","volume":"28","author":"H\u00e9bert-Losier","year":"2014","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"11","key":"10.7717\/peerj.17658\/ref-23","doi-asserted-by":"publisher","first-page":"2044","DOI":"10.1249\/mss.0b013e31814fb55c","article-title":"A vertical jump force test for assessing bilateral strength asymmetry in athletes","volume":"39","author":"Impellizzeri","year":"2007","journal-title":"Medicine & Science in Sports & Exercise"},{"key":"10.7717\/peerj.17658\/ref-24","first-page":"229","article-title":"Clinical agreement in quantitative measurements","volume":"7","author":"Indrayan","year":"1994","journal-title":"The National Medical Journal of India"},{"issue":"20","key":"10.7717\/peerj.17658\/ref-25","doi-asserted-by":"publisher","first-page":"1304","DOI":"10.1136\/bjsports-2022-106588","article-title":"Performance and symmetry measures during vertical jump testing at return to sport after ACL reconstruction","volume":"57","author":"Kotsifaki","year":"2023","journal-title":"British Journal of Sports Medicine"},{"issue":"15","key":"10.7717\/peerj.17658\/ref-26","doi-asserted-by":"publisher","first-page":"946","DOI":"10.1136\/bjsports-2015-095908","article-title":"Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture","volume":"50","author":"Kyritsis","year":"2016","journal-title":"British Journal of Sports Medicine"},{"issue":"12","key":"10.7717\/peerj.17658\/ref-27","doi-asserted-by":"publisher","first-page":"1929","DOI":"10.1016\/j.jbiomech.2004.02.021","article-title":"Understanding how an arm swing enhances performance in the vertical jump","volume":"37","author":"Lees","year":"2004","journal-title":"Journal of Biomechanics"},{"issue":"2","key":"10.7717\/peerj.17658\/ref-28","doi-asserted-by":"publisher","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":"Scandinavian Journal of Medicine & Science in Sports"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-29","doi-asserted-by":"publisher","first-page":"81","DOI":"10.1177\/036354659702500116","article-title":"Preseason hamstring muscle weakness associated with hamstring muscle injury in Australian footballers","volume":"25","author":"Orchard","year":"1997","journal-title":"The American Journal of Sports Medicine"},{"issue":"5","key":"10.7717\/peerj.17658\/ref-30","doi-asserted-by":"publisher","first-page":"674","DOI":"10.1123\/ijspp.2018-0482","article-title":"Effects of drop height on jump performance in male and female elite adolescent handball players","volume":"14","author":"Prieske","year":"2019","journal-title":"International Journal of Sports Physiology and Performance"},{"key":"10.7717\/peerj.17658\/ref-31","first-page":"115","article-title":"Reliability and validity of a wireless microelectromechanicals based system (keimove\u2122) for measuring vertical jumping performance","volume":"11","author":"Requena","year":"2012","journal-title":"Journal of Sports Science and Medicine"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-32","doi-asserted-by":"publisher","first-page":"196","DOI":"10.1519\/JSC.0000000000001476","article-title":"Traditional vs. sport-specific vertical jump tests: reliability, validity, and relationship with the legs strength and sprint performance in adult and teen soccer and basketball players","volume":"31","author":"Rodr\u00edguez-Rosell","year":"2017","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"1","key":"10.7717\/peerj.17658\/ref-33","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1080\/1091367X.2018.1517088","article-title":"The validity and reliability of the MyJump2 application to assess vertical jumps in trained junior athletes","volume":"23","author":"Rogers","year":"2019","journal-title":"Measurement in Physical Education and Exercise Science"},{"issue":"2","key":"10.7717\/peerj.17658\/ref-34","doi-asserted-by":"publisher","first-page":"482","DOI":"10.1177\/0363546514523388","article-title":"Assessing the effectiveness of neuromuscular training programs in reducing the incidence of anterior cruciate ligament injuries in female athletes: a systematic review","volume":"43","author":"Stevenson","year":"2015","journal-title":"The American Journal of Sports Medicine"},{"issue":"10","key":"10.7717\/peerj.17658\/ref-35","doi-asserted-by":"publisher","first-page":"3001","DOI":"10.1519\/JSC.0000000000000478","article-title":"Determinants of olympic fencing performance and implications for strength and conditioning training","volume":"28","author":"Turner","year":"2014","journal-title":"Journal of Strength and Conditioning Research"},{"issue":"4","key":"10.7717\/peerj.17658\/ref-36","doi-asserted-by":"publisher","first-page":"950","DOI":"10.1519\/JSC.0b013e3181c8656f","article-title":"Strength and power predictors of swimming starts in international sprint swimmers","volume":"25","author":"West","year":"2011","journal-title":"Journal of Strength and Conditioning Research"}],"container-title":["PeerJ"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/peerj.com\/articles\/17658.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/17658.xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/17658.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/peerj.com\/articles\/17658.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,7,9]],"date-time":"2024-07-09T03:06:19Z","timestamp":1720494379000},"score":1,"resource":{"primary":{"URL":"https:\/\/peerj.com\/articles\/17658"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,7,9]]},"references-count":36,"alternative-id":["10.7717\/peerj.17658"],"URL":"https:\/\/doi.org\/10.7717\/peerj.17658","archive":["CLOCKSS","LOCKSS","Portico"],"relation":{},"ISSN":["2167-8359"],"issn-type":[{"value":"2167-8359","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,7,9]]},"article-number":"e17658"}}