{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T10:17:44Z","timestamp":1788171464804,"version":"build-2803163510"},"reference-count":20,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T00:00:00Z","timestamp":1787788800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Education"},{"name":"Daejeon Metropolitan City, Republic of Korea","award":["2026-ANCHOR-06-001"],"award-info":[{"award-number":["2026-ANCHOR-06-001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Funct. Morphol. Kinesiol.","JFMK"],"abstract":"<jats:p>Background and Objectives: Ankle instructions during the active straight leg raise (ASLR) are not consistently standardized and may alter lumbopelvic measurements. This study tested whether a relaxed ankle, maximal active dorsiflexion (DF), and maximal active plantarflexion (PF) changed lateral abdominal muscle thickness and pressure biofeedback unit (PBU) responses during a standardized supine ASLR performed at 30\u00b0 of hip flexion. Methods: Thirty-three healthy adults completed three trials per condition according to a pre-specified schedule containing all six possible condition orders. B-mode rehabilitative ultrasound imaging (RUSI) measured transversus abdominis (TrA), internal oblique (IO), and external oblique (EO) thickness at rest and during ASLR. Three end-expiratory images were acquired for each participant, condition, and state; each image was measured three times, and the three image means were averaged. Rest-to-ASLR changes yielded 99 participant-condition values. Pressure biofeedback unit (PBU) pressure was recorded at four prespecified events and analyzed at the trial level. Results: Across participant-condition means, TrA thickness was 2.44 \u00b1 0.59 mm at rest and 2.66 \u00b1 0.70 mm during ASLR; the largest observed mean was 4.46 mm under the study task, not a physiological maximum. DF increased the change in transversus abdominis thickness (\u0394TrA) versus the relaxed ankle by 0.172 mm (95% CI, 0.077\u20130.267; p &lt; 0.001) and total lateral abdominal wall change by 0.672 mm (95% CI, 0.413\u20130.931; p &lt; 0.001). PF increased signed image-moment pressure deviation by 1.505 mmHg (95% CI, 0.985\u20132.025; p &lt; 0.001). Conclusions: Ankle-position instructions changed ultrasound and PBU outcomes during ASLR. Standardizing ankle positioning instructions and image aggregation may improve measurement reproducibility.<\/jats:p>","DOI":"10.3390\/jfmk11030337","type":"journal-article","created":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T10:58:21Z","timestamp":1787828301000},"page":"337","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Standardizing Ankle Position During the Active Straight Leg Raise: Effects on Lateral Abdominal Muscle Thickness and Pressure Biofeedback in Healthy Young Adults"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-1092-3525","authenticated-orcid":false,"given":"Yinghong","family":"Liu","sequence":"first","affiliation":[{"name":"Department of Physical Therapy, Konyang University, 158 Gwanjeodong-ro, Seo-gu, Daejeon 35365, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-8798-3360","authenticated-orcid":false,"given":"Xiaoliang","family":"Qiu","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, Konyang University, 158 Gwanjeodong-ro, Seo-gu, Daejeon 35365, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4258-0878","authenticated-orcid":false,"given":"Dae-Sung","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, Konyang University, 158 Gwanjeodong-ro, Seo-gu, Daejeon 35365, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1167","DOI":"10.1097\/00007632-200105150-00015","article-title":"Reliability and validity of the active straight leg raise test in posterior pelvic pain since pregnancy","volume":"26","author":"Mens","year":"2001","journal-title":"Spine"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1097\/BRS.0b013e318198d212","article-title":"Motor control patterns during an active straight leg raise in chronic pelvic girdle pain subjects","volume":"34","author":"Beales","year":"2009","journal-title":"Spine"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"531","DOI":"10.1016\/j.math.2012.05.010","article-title":"Understanding the active straight leg raise (ASLR): An electromyographic study in healthy subjects","volume":"17","author":"Hu","year":"2012","journal-title":"Man. 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