A proposed novel function of the psoas minor revealed through cadaver dissection

There is sparse information about the anatomy and function of the psoas minor, specifically the extent and frequency to which the muscle attaches into the iliac fascia that drapes over the iliopsoas. This information may help clarify the function of the psoas minor, especially regarding the possibility of controlling the position and mechanical stability of the underlying iliopsoas. This descriptive, semiquantitative cadaveric study sought to clarify the gross anatomic detail of the psoas minor, particularly the muscle's distal attachments. Thirty-two embalmed cadaver hips were examined. Hips that presented with a psoas minor underwent further anatomic measurements. The psoas minor was present in 65.6% of the 32 hips. All of the psoas minor tendons attached firmly into iliac fascia, while 90.5% also had a firm bony attachment to the pelvis. On average, the muscle belly occupied the proximal 37.5 ± 6.0% of the entire musculotendinous unit, while the muscle belly's average anatomical cross-sectional area was 52.5 ± 34.3 mm(2) . The psoas minor's firm and consistent distal tendinous attachment into the iliac fascia may allow this muscle to partially control the position and mechanical stability of the underlying iliopsoas as it crosses the femoral head and adjacent regions. This hypothesized function may be clinically related to inflammation and pathology involving the iliopsoas tendon and adjacent tissues in the anterior region of the hip. Further study is now warranted to determine the clinical relevancy and biomechanical validity of this proposed function of the psoas minor.