Proximal hamstring morphology and morphometry in men: an anatomic and <scp>MRI</scp> investigation

<jats:p>The proximal musculo‐tendinous junction (<jats:styled-content style="fixed-case">MTJ</jats:styled-content>) is a common site of hamstring strain injury but the anatomy of this region is not well defined. A morphometric analysis of the proximal <jats:styled-content style="fixed-case">MTJ</jats:styled-content>s of biceps femoris long head (<jats:styled-content style="fixed-case">BF</jats:styled-content>lh), semitendinosus (<jats:styled-content style="fixed-case">ST</jats:styled-content>), and semimembranosus (<jats:styled-content style="fixed-case">SM</jats:styled-content>) was undertaken from dissection of 10 thighs from five male cadavers and magnetic resonance imaging of 20 thighs of 10 active young men. The length, volume, and cross‐sectional area of the proximal tendon, <jats:styled-content style="fixed-case">MTJ</jats:styled-content> and muscle belly, and muscle‐tendon interface area were calculated. In both groups, <jats:styled-content style="fixed-case">MTJ</jats:styled-content>s were reconstructed three‐dimensionally. The proximal tendons and <jats:styled-content style="fixed-case">MTJ</jats:styled-content>s were expansive, particularly within <jats:styled-content style="fixed-case">SM</jats:styled-content> and <jats:styled-content style="fixed-case">BF</jats:styled-content>lh. Morphology varied between muscles although length measurements within individual muscles were similar in cadavers and young men. Semimembranosus had the longest proximal tendon (cadavers: mean 33.6 ± 2.0 cm; young men: mean 31.7 ± 1.6 cm) and <jats:styled-content style="fixed-case">MTJ</jats:styled-content> (>20 cm in both groups) and the greatest muscle‐tendon interface area, followed by <jats:styled-content style="fixed-case">BF</jats:styled-content>lh and <jats:styled-content style="fixed-case">ST</jats:styled-content>. Mean muscle belly volumes were more than three times greater in young men than elderly male cadavers (<jats:italic>P</jats:italic> < 0.001). These unique morphometric data contribute to a better understanding of hamstring anatomy, an important factor in the pathogenesis of hamstring strain injury.</jats:p>