{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T00:40:44Z","timestamp":1792197644140,"version":"4.4.0"},"reference-count":12,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:00:00Z","timestamp":1792108800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:00:00Z","timestamp":1792108800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Surg Radiol Anat"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>Accessory muscles between the levator scapulae and serratus posterior superior are rarely reported and may be interpreted as variants of either adjacent muscle. This study describes bilateral accessory muscles in the posterior cervical and upper thoracic region and discusses their anatomical classification and clinical relevance.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A routine anatomical dissection was performed in a formalin-fixed adult male cadaver. The posterior cervical and upper thoracic regions were dissected to define the topography, attachments, morphology, distal interface, and innervation of the accessory muscles. Morphometric measurements were obtained bilaterally using a caliper.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Bilateral elongated muscular structures were identified between the levator scapulae and serratus posterior superior muscles. Each muscle had an individual proximal attachment at the transverse process of the second cervical vertebra, followed an inferomedial course approximately parallel to the splenius capitis, and remained distinct from the main belly of the levator scapulae. Distally, each muscle was separated from the serratus posterior superior by a bursal interface, without direct muscular or aponeurotic continuity or independent scapular insertion. Both muscles were bicipital and fusiform and were innervated by posterior rami that also supplied the splenius capitis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>These findings support the interpretation of the structures as paired individualized accessory muscles rather than accessory slips of adjacent muscles, expanding the known spectrum of posterior cervical and upper thoracic anatomical variations.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s00276-026-04038-y","type":"journal-article","created":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T23:56:33Z","timestamp":1792194993000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A bilateral cervical accessory biceps muscle: anatomical description and clinical implications"],"prefix":"10.1007","volume":"48","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-1677-8615","authenticated-orcid":false,"given":"Maria Lu\u00edsa Rodrigues Oliveira","family":"Roque","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-5877-3344","authenticated-orcid":false,"given":"Lorenzo Ribeiro Dias","family":"Vieira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-9106-6172","authenticated-orcid":false,"given":"Alice Vi\u00e7osi","family":"da Silva","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0514-8170","authenticated-orcid":false,"given":"Josemberg","family":"da Silva Baptista","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,10,16]]},"reference":[{"key":"4038_CR1","doi-asserted-by":"publisher","first-page":"337","DOI":"10.1007\/s00276-016-1727-5","volume":"39","author":"J Au","year":"2017","unstructured":"Au J, Webb AL, Buirski G, Smith PN, Pickering MR, Perriman DM (2017) Anatomic variations of levator scapulae in a normal cohort: an MRI study. Surg Radiol Anat 39:337\u2013343. https:\/\/doi.org\/10.1007\/s00276-016-1727-5","journal-title":"Surg Radiol Anat"},{"key":"4038_CR2","unstructured":"Bergman RA, Afifi AK, Miyauchi R (n.d.) Illustrated encyclopedia of human anatomic variation: Opus I: Muscular System: Levator Scapulae. Anatomy Atlases. https:\/\/www.anatomyatlases.org\/AnatomicVariants\/MuscularSystem\/Text\/L\/14Levator.shtml. Accessed 27 Sep 2026"},{"key":"4038_CR3","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1016\/j.aanat.2017.05.006","volume":"213","author":"VI de Ara\u00fajoBaptista","year":"2017","unstructured":"de Ara\u00fajo Baptista VI, Mayer WP, Eust\u00e1quio da Silva R, de Vasconcellos Fontes RB, da Silva Baptista J (2017) An alternative didactic, functional and topographic systematization of the spinal muscles. Ann Anat 213:47\u201351. https:\/\/doi.org\/10.1016\/j.aanat.2017.05.006","journal-title":"Ann Anat"},{"key":"4038_CR4","doi-asserted-by":"publisher","first-page":"e42355","DOI":"10.7759\/cureus.42355","volume":"15","author":"LL Gaydarski","year":"2023","unstructured":"Gaydarski LL, Georgiev GP, Olewnik \u0141, Karauda P, Landzhov B (2023) A rare variation of the levator scapulae muscle: a case report and review of literature. Cureus 15:e42355. https:\/\/doi.org\/10.7759\/cureus.42355","journal-title":"Cureus"},{"key":"4038_CR5","doi-asserted-by":"publisher","first-page":"398","DOI":"10.5115\/acb.23.118","volume":"56","author":"SH Kim","year":"2023","unstructured":"Kim SH, Lee HJ (2023) Unusual insertion of the levator scapulae muscle: a case report. 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The authors hereby confirm that every effort was made to comply with all local and international ethical guidelines and laws concerning the use of human cadaveric donors in anatomical research.","order":2,"name":"Ethics","label":"Ethics approval","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Not applicable.","order":3,"name":"Ethics","label":"Consent for publication","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Not applicable.","order":4,"name":"Ethics","label":"Consent to participate","group":{"name":"EthicsHeading","label":"Declarations"}}],"article-number":"267"}}