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

Pavlos E Evangelidis,Yasuo Kawakami,Xiyao Shan,Takaki Yamagishi,Shun Otsuka,Chi Yang,Andrew Philip Lavender

doi:10.1371/journal.pone.0251939

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.

Highlights

Hamstring muscle strain injuries present a frequent and persistent impediment in sprintrelated sports [1, 2], with the majority of these injuries occurring in the biceps femoris long head muscle (BFlh) [3, 4]
ST anatomical cross-sectional area (ACSA) exhibited moderate-to-high negative correlations with shear wave velocity (SWV) in ISO across all intensities (r = -0.57 to -0.82), statistical significance was reached only at 50%maximal voluntary contractions (MVCs) (r = -0.65, p = 0.041), 60%MVC (r = -0.82, p = 0.004) and 70%MVC (r = -0.65, p = 0.04) as well as at peak SWV (r = -0.81, p = 0.005, Fig 4)
We found that SWV increased linearly with contraction

Summary

Introduction

Hamstring muscle strain injuries present a frequent and persistent impediment in sprintrelated sports [1, 2], with the majority of these injuries occurring in the biceps femoris long head muscle (BFlh) [3, 4]. While it remains unclear why this muscle is more susceptible than the other biarticular hamstring muscles [i.e. semitendinosus (ST) and semimembranosus (SM)], strain injuries may occur due to excessive localized strains in BFlh [5, 6].

Objectives

Methods

Results

Discussion

Conclusion