Hamstrings load bearing in different contraction types and intensities: A shear-wave and B-mode ultrasonographic study

PLoS One. 2021 May 19;16(5):e0251939. doi: 10.1371/journal.pone.0251939. eCollection 2021.

Abstract

The main aim was to examine the load bearing of individual hamstring muscles in different contraction types and intensities, through local stiffness measurement by shear wave elastography (SWE). A secondary aim was to examine the relationship between the SWE stiffness measure and hamstrings morphology. Ten healthy males (age 22.1±4.1 years; height 173.7±5.9 cm; body mass 68.6±12.4 kg; mean ± SD) performed knee flexions on an isokinetic dynamometer at different intensities (20-70%MVC, random order) in three separate, randomized conditions: isometric (ISO), concentric (CON) and eccentric (ECC). SWE was used to measure muscle shear wave velocity (SWV) in biceps femoris long head (BFlh), semitendinosus (ST) and semimembranosus (SM) during contraction. Muscle anatomical cross-sectional area (ACSA) was measured with magnetic resonance imaging and muscle architecture with B-mode ultrasonography. Muscle SWV increased linearly with contraction intensity, but at a varying rate among muscles and contraction types. ST exhibited greater SWV than BFlh and SM in all contraction types, however, there was an upward shift in the SM SWV-torque relationship in ECC compared to ISO and CON. Strong negative correlations were found between peak ISO SWV and ST ACSA (r = -0.81, p = 0.005) and BFlh pennation angle (r = -0.75, p = 0.012). These results suggest that ST has a primary role in hamstrings load bearing in all contraction types, likely due to its morphology; however, there is evidence of increased contribution from SM in eccentric muscle actions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Elasticity Imaging Techniques / methods*
  • Hamstring Muscles / anatomy & histology
  • Hamstring Muscles / diagnostic imaging*
  • Hamstring Muscles / physiology*
  • Healthy Volunteers
  • Humans
  • Isometric Contraction / physiology*
  • Magnetic Resonance Imaging / methods
  • Male
  • Muscle Strength / physiology
  • Torque
  • Weight-Bearing / physiology*
  • Young Adult

Grants and funding

PE was supported by Grant-in-Aid for Japan Society for the Promotion of Science Research Fellows JP 17F17412. YK was supported by Grant-in-Aid for Scientific Research (A) Number 16H01870. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.