Contributions of Hamstring Stiffness to Straight-Leg-Raise and Sit-and-Reach Test Scores

2019

Int J Sports Med

Self Cite

The main purpose of the present study was to identify whether and to what extent the individual differences in range of motion and stiffness of the hip joint can account for that in muscle elasticity of the hamstring. Hip extension torque and shear moduli (a measure of elasticity) of the biceps femoris, semitendinosus, and semimembranosus were assessed in 21 young males during unilateral passive hip flexion in the knee-extended position from the anatomical position to the individual’s maximal hip flexion angle. Muscle shear modulus was quantified by using ultrasound shear wave elastography. The maximal hip flexion angle correlated negatively with the shear modulus of each muscle (−0.750 ≤ r ≤ −0.612). The joint stiffness correlated positively with the shear modulus of each muscle (0.711 ≤ r ≤ 0.747). These findings suggest that hip flexion ROM and joint stiffness can reflect significantly but only moderately the muscle elasticity of the hamstring.

Section: Introductionmentioning

confidence: 99%

Moderate Associations of Muscle Elasticity of the Hamstring with Hip Joint Flexibility

Miyamoto

2019

Int J Sports Med

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“…Joint flexibility is an important component of physical fitness and is often evaluated by measuring joint range of motion (ROM) . While joint flexibility can be influenced by environmental factors such as engagement in habitual stretching exercise, it is also substantially influenced by genetic factors .…”

Section: Introductionmentioning

confidence: 99%

Association analysis of the ACTN3 R577X polymorphism with passive muscle stiffness and muscle strain injury

Miyamoto

Miyamoto‐Mikami

Scandinavian Med Sci Sports

et al. 2017

Passive muscle stiffness is considered to be a major factor affecting joint flexibility and is thought to relate to the occurrence of muscle strain injury. In skinned muscle fiber experiments, the R577X polymorphism of the α-actinin-3 gene (ACTN3) has been associated with passive muscle stiffness. Our primary purpose was to clarify whether the ACTN3 R577X polymorphism influences passive stiffness of human muscle in vivo. We also examined whether the ACTN3 R577X polymorphism is associated with the occurrence of hamstring strain injury. Seventy-six healthy young male subjects were genotyped for the ACTN3 R577X (rs1815739) polymorphism. Shear modulus (an index of stiffness) of each hamstring muscle (biceps femoris, semitendinosus, and semimembranosus) was assessed using ultrasound shear wave elastography, and history of hamstring strain injury was collected via a questionnaire. The muscle shear moduli of the semitendinosus and semimembranosus were significantly higher in R-allele (RR + RX genotype) carriers than in XX genotype carriers, whereas the shear modulus of the biceps femoris did not differ among the ACTN3 R577X genotypes. Frequency of past hamstring strain injury also did not differ between the 3 genotypes nor between the R-allele and XX genotype carriers. This study indicates that RR and RX genotypes of the ACTN3 R577X polymorphism (corresponding to the presence of α-actinin-3 in type II muscle fibers) are associated with increased passive muscle stiffness of the human hamstring in vivo. However, this altered mechanical property might not affect the risk of hamstring muscle strain injury.

“…Subjects were seated on a bench with their hip flexed at 70° and the right knee fully extended. This hip joint angle was chosen according to a recent study 16) , which aimed to define an angle where the hamstring could be stretched to a tensioned state without pain and the shear modulus could be quantified for all subjects. The passive shear modulus of the long head of the biceps femoris (BF), semitendinosus (ST), and semimembranosus (SM) of the right leg was assessed using an ultrasound SWE scanner (Aixplorer, Supersonic Imagine, France) with a linear probe (SL15-4, Supersonic Imagine, France) in "SWE" mode (MSK preset; persistence = Med, smoothing = 5).…”

Section: Methodsmentioning

confidence: 99%

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

Miyamoto‐Mikami

Kimura

et al. 2017

JPFSM

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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.