No association between passive material property and cross-sectional area in human hamstring

Abstract

The passive material properties of a muscle, as evaluated by shear or Young's modulus, can vary depending on the muscle cross-sectional area (CSA), since intramuscular compositions such as adipose tissue and connective tissue change with muscle hypertrophy and atrophy. However, the relationship remains unclear between the passive material properties and CSA of a muscle. Therefore, we examined whether passive muscle shear modulus is related to muscle CSA in the human hamstring. The shear modulus and anatomical CSA of the biceps femoris, semitendinosus, and semimembranosus were measured in 71 healthy young males with the hip flexed at 70° and knee fully extended. The shear modulus of each muscle was measured using ultrasound shear wave elastography. Muscle CSA was assessed using panoramic ultrasound imaging. There were individual differences in muscle shear modulus as well as muscle CSA. The coefficients of variation (CVs) of muscle shear modulus were 41.4% (range: 8.8 -54.3 kPa), 33.0% (range: 8.4 -57.3 kPa), and 41.1% (range: 18.2 -107.1 kPa) for the biceps femoris, semitendinosus, and semimembranosus, respectively. There were no significant correlations between shear modulus and CSA in each or overall hamstring muscle (absolute r < 0.113). The present findings indicate that, although the passive material property of muscle is not the same among individuals, it is substantially independent of the muscle CSA, at least in the hamstring.

Acute Effect of Active and Passive Static Stretching on Elastic Modulus of the Hamstrings

“…Recently, Miyamoto et al examined whether passive muscle shear modulus is related to muscle cross-sectional area in the hamstrings. As a result, they suggested that there were no significant correlations between shear modulus and cross-sectional area in each or overall hamstrings 13 . On the other hand, it is reported that the fascicle length is shorter in the SM (5.43±0.87 cm) and BF-lh (7.02±1.28 cm) than in the ST (14.87±3.52 cm) 18 .…”

Non‐uniform distribution of passive muscle stiffness within hamstring

“…13,14 Contradictory findings have been reported regarding the shear modulus of the hamstring in passively lengthened positions. Hirata et al 7 and Miyamoto et al 9 showed that, among the hamstring muscles, SM had the highest shear modulus, whereas Le Sant et al 8 reported that the BFlh had the highest shear modulus although the testing posture was similar (ie supine) in the Hirata et al's and Le Sant et al's studies. These contradictions may be due to different measurement sites for muscle shear modulus.…”

“…Ultrasound shear wave elastography (SWE) has been used to quantify localized shear modulus (a measure of stiffness, expressed in the unit of Pascal) of individual muscles, 1,[7][8][9][10][11][12] based on the propagation speed of remotely induced shear waves. 13,14 Contradictory findings have been reported regarding the shear modulus of the hamstring in passively lengthened positions.…”

“…These contradictions may be due to different measurement sites for muscle shear modulus. Specifically, the muscle shear modulus was measured at 50% of thigh-length in the studies of Hirata et al 7 and Miyamoto et al, 9 whereas the measurement was performed over the muscle belly but not strictly controlled in Le Sant et al's study. 8 Heterogenous distribution of shear modulus within a muscle was previously reported for biarticular muscles (such as the medial and lateral gastrocnemii 15 and rectus femoris 16 ) where muscle injuries including muscle strain more frequently occur compared to mono-articular muscles.…”