Proximal hamstring morphology and morphometry in men: an anatomic and MRI investigation

Area of Science:

• Anatomy
• Biomechanics
• Sports Medicine

Background:

• The proximal musculo-tendinous junction (MTJ) is a frequent site for hamstring strain injuries.
• The precise anatomy of this region remains incompletely defined.
• Understanding hamstring anatomy is vital for injury pathogenesis.

Purpose of the Study:

• To conduct a detailed morphometric analysis of the proximal musculo-tendinous junctions (MTJs) of the biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM).
• To provide a comprehensive understanding of hamstring anatomy relevant to injury mechanisms.

Main Methods:

• Dissection of 10 male cadaver thighs.
• Magnetic Resonance Imaging (MRI) of 20 thighs from 10 active young men.
• Three-dimensional reconstruction and morphometric calculation (length, volume, cross-sectional area, interface area) of proximal tendons, MTJs, and muscle bellies.

Main Results:

• Proximal tendons and MTJs were found to be expansive, especially in the semimembranosus (SM) and biceps femoris long head (BFlh).
• Semimembranosus (SM) exhibited the longest proximal tendon and MTJ, along with the greatest muscle-tendon interface area.
• Muscle belly volumes were significantly larger in young men compared to elderly cadavers (P < 0.001).

Conclusions:

• This study provides novel morphometric data on proximal hamstring musculo-tendinous junctions (MTJs).
• The detailed anatomical insights enhance understanding of hamstring anatomy.
• These findings are important for elucidating the pathogenesis of hamstring strain injuries.