Online first
Case report
Published online: 2024-04-25
An unusual occurrence of a four-headed psoas major: a case report
DOI: 10.5603/fm.98920
Pubmed: 38757502
Abstract
Background: While many structures within the human body demonstrate anatomical variations, this is not typically the case for the iliopsoas muscle complex. However, the present paper describes a case of an anomalous psoas major composed of four different muscular heads in a 78-year-old male cadaver. Materials and methods: During a routine dissection of the right posterior abdominal wall, an unusual psoas major was observed, measured and photographed. Results: The psoas major was found to possess four muscular heads, otherwise the anatomy of the wall was normal. Conclusions: The presence of so many heads could interfere with the functions of the psoas major muscle. Therefore this anatomical variation merits further study.
Keywords: accessory headsiliopsoas muscle complexmorphological variabilitypsoas major
References
- Aleksandrova JN, Malinova L, Jelev L. Variations of the iliacus muscle: report of two cases and review of the literature. Int J Anat Var. 2013; 6: 149–152.
- Clarkson RD, Rainy H. Unusual Arrangement of the Psoas Muscle. J Anat Physiol. 1889; 23(Pt 3): 504–506.
- Fabrizio PA. Anatomic variation of the iliacus and psoas major muscles. Int J Anat Var. 2011; 4: 28–30.
- Hansen L, de Zee M, Rasmussen J, et al. Anatomy and biomechanics of the back muscles in the lumbar spine with reference to biomechanical modeling. Spine (Phila Pa 1976). 2006; 31(17): 1888–1899.
- Hanson P, Magnusson SP, Sorensen H, et al. Anatomical differences in the psoas muscles in young black and white men. J Anat. 1999; 194 ( Pt 2)(Pt 2): 303–307.
- Hides J, Stanton W, Freke M, et al. MRI study of the size, symmetry and function of the trunk muscles among elite cricketers with and without low back pain. Br J Sports Med. 2008; 42(10): 809–813.
- Izumoto Y, Kurihara T, Suga T, et al. Bilateral differences in the trunk muscle volume of skilled golfers. PLoS One. 2019; 14(4): e0214752.
- Jelev L, Shivarov V, Surchev L. Bilateral variations of the psoas major and the iliacus muscles and presence of an undescribed variant muscle--accessory iliopsoas muscle. Ann Anat. 2005; 187(3): 281–286.
- Joshi SD, Joshi SS, Dandekar UK, et al. Morphology of Psoas Minor and Psoas Accessorius. J Anat Soc India. 2010; 59(1): 31–34.
- Khalid S, Iwanaga J, Loukas M, et al. Split femoral nerve due to psoas tertius muscle: a review with other cases of variant muscles traversing the femoral nerve. Cureus. 2017; 9(8): e1555.
- Koptas K, Zielinska N, Tubbs RS, et al. An unreported infraspinatus muscle variation-two-headed infraspinatus minor muscle and three-headed fusion with the teres minor muscle. Surg Radiol Anat. 2022; 44(9): 1305–1308.
- Modi HN, Suh SW, Yang JH, et al. Spontaneous regression of curve in immature idiopathic scoliosis - does spinal column play a role to balance? An observation with literature review. J Orthop Surg Res. 2010; 5: 80.
- Moore K, Dalley AF, Agur AM. R. Clinically Oriented Anatomy (7th ed.). Lippincott Williams and Wilkins, Philadelphia 2014.
- MORI M. Statistics on the musculature of the Japanese. Okajimas Folia Anat Jpn. 1964; 40: 195–300.
- Nachemson A. Electromyographic studies on the vertebral portion of the psoas muscle; with special reference to its stabilizing function of the lumbar spine. Acta Orthop Scand. 1966; 37(2): 177–190.
- Nachemson A. The possible importance of the psoas muscle for stabilization of the lumbar spine. Acta Orthop Scand. 1968; 39(1): 47–57.
- Olewnik Ł, Zielinska N, Koptas K, et al. Accessory part of the deltoid muscle. Folia Morphol. 2024; 83(1): 226–230.
- Olewnik Ł, Zielinska N, Ruzik K, et al. A new look at quadriceps tendon — Is it really composed of three layers? Knee. 2023; 40: 292–304.
- Parker A, Olewnik Ł, Iwanaga J, et al. Iliacus minor and psoas quartus muscles traversing the femoral nerve. Morphologie. 2022; 106(355): 307–309.
- Protas M, Voin V, Wang JMh, et al. A Rare Case of Double-Headed Psoas Minor Muscle with Review of its Known Variants. Cureus. 2017; 9(6): e1312.
- Ruzik K, Westrych K, Tubbs RS, et al. Case report of the double-headed extensor hallucis longus. Folia Morphol. 2023; 82(2): 429–433.
- Singh D, Agarwal S. Morphological Study of Psoas Minor Muscles with Embryological Basis and Clinical Insights. J Clin Diagn Res. 2021.
- Stewart S, Stanton W, Wilson S, et al. Consistency in size and asymmetry of the psoas major muscle among elite footballers. Br J Sports Med. 2010; 44(16): 1173–1177.
- Tsuyoshi S. Abdominal Wall uscles. In: Tubbs RS, Shoja MM, Loukas M. ed. Bergman’s Comprehensive Encyclopedia of Human Anatomic Variation. John Wiley & Sons, Inc., Hoboken 2016.
- Tubbs RS, Oakes WJ, Salter EG. The psoas quartus muscle. Clin Anat. 2006; 19(7): 678–680.
- Watanabe K, Ohashi M, Hirano T, et al. The influence of lumbar muscle volume on curve progression after skeletal maturity in patients with adolescent idiopathic scoliosis: a long-term follow-up study. Spine Deform. 2018; 6(6): 691–698.e1.
- Wong TL, Kikuta S, Iwanaga J, et al. A multiply split femoral nerve and psoas quartus muscle. Anat Cell Biol. 2019; 52(2): 208–210.
- Xu JJ, Zhu XL, Li T, et al. Assessment of the cross-sectional areas of the psoas major in patients with adolescent idiopathic scoliosis before skeletal maturity. Acta Radiol. 2021; 62(5): 639–645.
- Zielinska N, Tubbs RS, Łabętowicz P, et al. Two variant muscles in the gluteal region. Folia Morphol. 2024; 83(1): 235–238.
