{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,18]],"date-time":"2026-10-18T02:42:37Z","timestamp":1792291357844,"version":"4.4.0"},"reference-count":42,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T00:00:00Z","timestamp":1783382400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T00:00:00Z","timestamp":1783382400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["esskajournals.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Knee surg. sports traumatol. arthrosc."],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Despite considerable research, strength screening has shown limited value for injury prediction. The concept of muscle stability assessed by Adaptive Force (AF) offers a distinct perspective\u2014addressing neuromuscular holding capacity closer to injury\u2010prone motions rather than pushing strength. This study aimed to assess the prevalence and distribution of muscle stability deficits in football players and their discriminative capacity relative to conventional strength parameters.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>AF and maximal voluntary isometric contraction (MVIC) were measured in 23 male semi\u2010professional football players. Five muscle groups were tested bilaterally (knee extensors\/flexors; hip flexors\/adductors\/abductors). AF was assessed by objectified manual muscle tests with a handheld device recording force and angular velocity. AF parameters, MVIC and the conventional hamstrings\u2010to\u2010quadriceps (H:Q) ratio were compared between stability categories.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Stability deficits were highly prevalent: 83% of players had at least one deficit; 31% of all tested muscle groups were unstable, highest in hip abductors (52%) followed by hamstrings (46%). The maximal holding capacity was selectively impaired in unstable muscles (on average 61% lower than the maximal force output), while MVIC and maximal AF did not differ between stability categories. The ratio of holding capacity to maximal AF (AF\u2010Ratio) was the strongest discriminator (stable vs. unstable:\n                      <jats:italic>d<\/jats:italic>\n                      \u2009=\u20096.62,\n                      <jats:italic>\u03c9<\/jats:italic>\n                      <jats:sup>2\u2009<\/jats:sup>\n                      =\u20090.88), largely consistent across muscle groups and uncorrelated with the H:Q ratio. The H:Q ratio failed to discriminate between stable and unstable hamstrings (\n                      <jats:italic>d<\/jats:italic>\n                      \u2009=\u2009\u22120.04), whereas the AF\u2010Ratio discriminated strongly (\n                      <jats:italic>d<\/jats:italic>\n                      \u2009=\u20096.43).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Muscle instability represents a selective impairment of holding capacity with preserved maximal strength, not detected by MVIC testing. By capturing a distinct neuromuscular function, AF offers a novel mechanistic framework beyond pushing strength. Further studies in larger samples and prospective designs are required to assess the potential utility of stability assessment in clinical practice.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Level of Evidence<\/jats:title>\n                    <jats:p>Level III, diagnostic studies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/ksa.70525","type":"journal-article","created":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T15:12:46Z","timestamp":1783437166000},"page":"2987-3001","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["High prevalence of muscle stability deficits in semi\u2010professional football players\u2014Adaptive Force assessment reveals selective impairment of holding capacity with preserved maximal strength: A cross\u2010sectional study"],"prefix":"10.1002","volume":"34","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6289-6987","authenticated-orcid":false,"given":"Laura V.","family":"Schaefer","sequence":"first","affiliation":[{"name":"Centre of Orthopaedics, Traumatology and Plastic Surgery University Hospital Brandenburg, Brandenburg Medical School Theodor Fontane Brandenburg an der Havel Germany"},{"name":"Faculty of Health Sciences Joint Faculty of University of Potsdam, Brandenburg Medical School Theodor Fontane and Brandenburg Technical University Cottbus\u2010Senftenberg Brandenburg Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4514-8060","authenticated-orcid":false,"given":"Frank N.","family":"Bittmann","sequence":"additional","affiliation":[{"name":"Regulative Physiology and Prevention, Department of Sports and Health Sciences University of Potsdam Potsdam Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-0467-9693","authenticated-orcid":false,"given":"Jaali","family":"Ulrich","sequence":"additional","affiliation":[{"name":"Centre of Orthopaedics, Traumatology and Plastic Surgery University Hospital Brandenburg, Brandenburg Medical School Theodor Fontane Brandenburg an der Havel Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4916-1206","authenticated-orcid":false,"given":"Robert","family":"Prill","sequence":"additional","affiliation":[{"name":"Centre of Orthopaedics, Traumatology and Plastic Surgery University Hospital Brandenburg, Brandenburg Medical School Theodor Fontane Brandenburg an der Havel Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1833-7608","authenticated-orcid":false,"given":"Roland","family":"Becker","sequence":"additional","affiliation":[{"name":"Centre of Orthopaedics, Traumatology and Plastic Surgery University Hospital Brandenburg, Brandenburg Medical School Theodor Fontane Brandenburg an der Havel Germany"},{"name":"Faculty of Health Sciences Joint Faculty of University of Potsdam, Brandenburg Medical School Theodor Fontane and Brandenburg Technical University Cottbus\u2010Senftenberg Brandenburg Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,7,7]]},"reference":[{"issue":"5","key":"e_1_2_12_2_1","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1007\/s40279-016-0638-2","article-title":"Effect of injury prevention programs that include the Nordic hamstring exercise on hamstring injury rates in soccer players: a systematic review and meta\u2010analysis","volume":"47","author":"Al Attar WSA","year":"2017","journal-title":"Sports 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Results of the experimental study support a distinction between a holding and a pushing isometric muscle function","volume":"9","author":"Schaefer LV","year":"2017","journal-title":"BMC Sports Sci Med Rehabil"},{"issue":"5","key":"e_1_2_12_30_1","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0238331","article-title":"Paired personal interaction reveals objective differences between pushing and holding isometric muscle action","volume":"16","author":"Schaefer LV","year":"2021","journal-title":"PLoS One"},{"key":"e_1_2_12_31_1","doi-asserted-by":"crossref","unstructured":"SchaeferLV BittmannFN. From strength to stability: muscular holding capacity characterized by Adaptive Force\u2014relevance and implications of an alternative approach to musculoskeletal complaints and non\u2010contact injuries. bioRxiv [Preprint]. 2025 [cited 2026 Apr 19]. 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