{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T17:46:09Z","timestamp":1792086369588,"version":"4.4.0"},"reference-count":16,"publisher":"International Journal of Sports Physical Therapy","issue":"10","license":[{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:sec id=\"background\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Trunk rotation (TR) strength and power play an important role in overhead sports for both sport-specific performance and injury risk-reduction. However, clinically applicable, reliable and valid methods to measure isometric TR strength have not been previously described.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"purpose\">\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To assess a) the test-retest reliability of a novel isometric TR strength test, performed in a half-kneeling position, and b) the convergent validity of the isometric TR strength test by assessing its correlation with a seated dynamic TR power test.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"study-design\">\n                    <jats:title>Study Design<\/jats:title>\n                    <jats:p>Cross-sectional cohort study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"methods\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Eighteen participants, recruited from the general public, took part in this study. Isometric TR strength was measured over two consecutive days in a half-kneeling position using a digital dynamometer. Dynamic TR power was measured once in a seated position, using a pulley system and inertial sensors. The test-retest reliability of the isometric TR strength test was assessed with Intraclass Correlation Coefficient (ICC) 3.3, and standard error of measurement (SEM) and minimal detectable change (MDC90) were calculated. The convergent validity was interpreted based on the correlation between peak values of the isometric TR strength test and the dynamic TR power test.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"results\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The results showed excellent test-retest reliability for the isometric TR strength test (ICC 3.3 = 0.95, 95% CI 0.91-0.98), with a SEM of 6.7 N, and a MDC90 value of 15.6 N. A strong correlation was found between the peak values for the isometric TR strength test and the dynamic TR power test (rs = 0.73, p &lt; 0.001, 95% bootstrap confidence interval 0.40-\u200a0.89).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"conclusions\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>This study addresses a gap in the literature regarding reliable and valid methods to measure isometric TR strength, thus contributing to our understanding of injuries and performance in overhead sports. The results provide professionals working with overhead athletes with a convenient and practical test to measure isometric TR strength.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"level-of-evidence\">\n                    <jats:title>Level of Evidence<\/jats:title>\n                    <jats:p>3<\/jats:p>\n                  <\/jats:sec>","DOI":"10.26603\/001c.171300","type":"journal-article","created":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T17:08:36Z","timestamp":1792084116000},"source":"Crossref","is-referenced-by-count":0,"title":["The Reliability and Validity of a Novel Isometric Trunk Rotation Strength Test"],"prefix":"10.26603","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7638-4843","authenticated-orcid":true,"given":"Kari","family":"Arnason","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01db6h964","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Iceland","department":["Department of Physical Therapy"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hildur H","family":"Sigmarsdottir","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01db6h964","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Iceland","department":["Department of Physical Therapy"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rosey","family":"Bjorgvinsdottir","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01db6h964","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Iceland","department":["Department of Physical Therapy"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0606-991X","authenticated-orcid":false,"given":"Kristin","family":"Briem","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01db6h964","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Iceland","department":["Department of Physical Therapy"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"11140","published-online":{"date-parts":[[2026,10,1]]},"reference":[{"issue":"3","key":"ref1","doi-asserted-by":"publisher","first-page":"720","DOI":"10.1519\/JSC.0b013e318227664d","article-title":"A reliable method for assessing rotational power","volume":"26","author":"M. J. Andre","year":"2012","journal-title":"J Strength Cond Res"},{"issue":"5","key":"ref2","doi-asserted-by":"publisher","first-page":"1763","DOI":"10.1213\/ANE.0000000000002864","article-title":"Correlation coefficients: Appropriate use and interpretation","volume":"126","author":"P. Schober","year":"2018","journal-title":"Anesth Analg"},{"key":"ref3","article-title":"Foundations of clinical research: Applications to evidence-based practice","author":"L. G. Portney","year":"2020","edition":"4"},{"issue":"1","key":"ref4","doi-asserted-by":"publisher","first-page":"e000365","DOI":"10.1136\/bmjsem-2018-000365","article-title":"The Athletic Shoulder (ASH) test: Reliability of a novel upper body isometric strength test in elite rugby players","volume":"4","author":"B. Ashworth","year":"2018","journal-title":"BMJ Open Sport Exerc Med"},{"issue":"10","key":"ref5","doi-asserted-by":"publisher","first-page":"1454","DOI":"10.1016\/j.jse.2014.01.006","article-title":"Measuring shoulder external and internal rotation strength and range of motion: Comprehensive intra-rater and inter-rater reliability study of several testing protocols","volume":"23","author":"A. M. Cools","year":"2014","journal-title":"J Shoulder Elbow Surg"},{"issue":"4","key":"ref6","doi-asserted-by":"publisher","first-page":"905","DOI":"10.26603\/001c.83259","article-title":"Maximal and explosive muscle strength during hip adduction squeeze and hip abduction press test using a handheld dynamometer: An intra- and inter-tester reliability study","volume":"18","author":"L. Ishoi","year":"2023","journal-title":"Int J Sports Phys Ther"},{"issue":"3","key":"ref7","doi-asserted-by":"publisher","first-page":"815","DOI":"10.1519\/JSC.0b013e3181aa36b8","article-title":"The reliability and validity of handheld dynamometry for the measurement of lower-extremity muscle strength in older adults","volume":"24","author":"C. M. Arnold","year":"2010","journal-title":"J Strength Cond Res"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"125","DOI":"10.1016\/0021-9290(93)90084-r","article-title":"Sequential motions of body segments in striking and throwing skills - descriptions and explanations","volume":"26","author":"C. A. Putnam","year":"1993","journal-title":"J Biomech"},{"issue":"12","key":"ref9","doi-asserted-by":"publisher","first-page":"1541","DOI":"10.26603\/001c.126187","article-title":"Let\u00b4s swing it \u2013The interaction between participation-related shoulder load and pre-season trunk rotation power on shoulder problems in male handball players","volume":"19","author":"K. Arnason","year":"2024","journal-title":"Int J Sports Phys Ther"},{"issue":"1","key":"ref10","first-page":"73","article-title":"Performance and kinematics of various throwing techniques in team-handball","volume":"10","author":"H. Wagner","year":"2011","journal-title":"J Sport Sci Med"},{"issue":"1","key":"ref11","doi-asserted-by":"publisher","first-page":"42","DOI":"10.1123\/jab.23.1.42","article-title":"Effects of upper trunk rotation on shoulder joint torque among baseball pitchers of various levels","volume":"23","author":"A. L. Aguinaldo","year":"2007","journal-title":"J Appl Biomech"},{"issue":"1","key":"ref12","doi-asserted-by":"publisher","first-page":"261","DOI":"10.2478\/hukin-2021-0024","article-title":"The effect of eight weeks of sling-based training with rotational core exercises on ball velocity in female team handball players","volume":"77","author":"K. S. Dahl","year":"2021","journal-title":"J Hum Kinet"},{"issue":"3","key":"ref13","doi-asserted-by":"publisher","first-page":"S69","DOI":"10.1016\/j.pmrj.2015.11.015","article-title":"The kinetic chain revisited: New concepts on throwing mechanics and injury","volume":"8","author":"S.K. Chu","year":"2016","journal-title":"PM & R"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"177","DOI":"10.1515\/hukin-2017-0035","article-title":"Effect of core training on male handball players' throwing velocity","volume":"56","author":"C. Manchado","year":"2017","journal-title":"J Hum Kinet"},{"issue":"9","key":"ref15","doi-asserted-by":"publisher","first-page":"2089","DOI":"10.1177\/0363546514536871","article-title":"Improper trunk rotation sequence is associated with increased maximal shoulder external rotation angle and shoulder joint force in high school baseball pitchers","volume":"42","author":"S. Oyama","year":"2014","journal-title":"Am J Sport Med"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"1451174","DOI":"10.3389\/fspor.2024.1451174","article-title":"Are there kinematic and kinetic parameters correlated with racket velocity during the tennis serve? A preliminary comparison between a slow and a fast serve for performance improvement","volume":"6","author":"P. Gorce","year":"2024","journal-title":"Front Sports Act Living"}],"container-title":["International Journal of Sports Physical Therapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/ijspt.scholasticahq.com\/article\/171300-the-reliability-and-validity-of-a-novel-isometric-trunk-rotation-strength-test","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T17:08:37Z","timestamp":1792084117000},"score":1,"resource":{"primary":{"URL":"https:\/\/ijspt.scholasticahq.com\/article\/171300-the-reliability-and-validity-of-a-novel-isometric-trunk-rotation-strength-test"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,1]]},"references-count":16,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2026]]}},"URL":"https:\/\/doi.org\/10.26603\/001c.171300","relation":{},"ISSN":["2159-2896"],"issn-type":[{"value":"2159-2896","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,1]]}}}