Associations of passive muscle stiffness, muscle stretch tolerance, and muscle slack angle with range of motion: individual and sex differences

Abstract

Joint range of motion (ROM) is an important parameter for athletic performance and muscular injury risk. Nonetheless, a complete description of muscular factors influencing ROM among individuals and between men and women is lacking. We examined whether passive muscle stiffness (evaluated by angle-specific muscle shear modulus), tolerance to muscle stretch (evaluated by muscle shear modulus at end-ROM), and muscle slack angle of the triceps surae are associated with the individual variability and sex difference in dorsiflexion ROM, using ultrasound shear wave elastography. For men, ROM was negatively correlated to passive muscle stiffness of the medial and lateral gastrocnemius in a tensioned state and positively to tolerance to muscle stretch in the medial gastrocnemius. For women, ROM was only positively correlated to tolerance to muscle stretch in all muscles but not correlated to passive muscle stiffness. Muscle slack angle was not correlated to ROM in men and women. Significant sex differences were observed only for dorsiflexion ROM and passive muscle stiffness in a tensioned state. These findings suggest that muscular factors associated with ROM are different between men and women. Furthermore, the sex difference in dorsiflexion ROM might be attributed partly to that in passive muscle stiffness of plantar flexors.

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

“…The ROM is believed by practitioners to reflect muscle elasticity. However, it is well documented that the parameter can be strongly by the examiners' or examinees' subjectivity (including individual variability in stretch tolerance) [5,6]. Another approach to evaluate joint flexibility is to assess the slope of passive torque-joint angle curve, which is often used in laboratory experiments and referred to as joint stiffness.…”

“…Currently, ultrasound shear wave elastography (SWE) has been used to quantify tissue shear modulus (a measure of elasticity, expressed in kPa) independently of the influences of other anatomical structures, by measuring shear wave propagating speed [7,8]. Using this technique, some studies have examined associations between muscle elasticity (i. e., shear modulus) and joint flexibility (e. g., ROM and joint stiffness) in plantar flexors [6,9,10]. Others have quantified the shear modulus of individual muscles of the hamstring [11][12][13][14][15], which is the most frequently strained muscle group and one of the most studied muscles in terms of joint flexibility [16][17][18].…”

“…With the above in mind, the present study aimed to identify whether and to what extent the individual differences in ROM and joint stiffness of the hip flexion can account for those in elasticity of each muscle of the hamstring, respectively. Based on the previous findings that the determination of ROM is influenced by stretch tolerance [5,6], we hypothesized that, compared with the joint stiffness, the hip flexion ROM would be less strongly related to the hamstring shear modulus. Besides, based on the previous findings that the SM shear modulus is the highest in the hamstring [12], we also hypothesized that both the hip flexion ROM and the joint stiffness could be strongly related to the SM shear modulus rather than the BF and ST shear modulus.…”

Is There a Sex Difference in the Minimum Number of Static Stretch Repetitions That Should Be Recommended to Improve Flexibility?

“…Other studies have also shown no sex diŠerence in joint ROM and PT (Gajdosik et al, 2006;Morse, 2011). However, most previous studies have shown that joint ROM in women is greater than that in men (Cipriani et al, 2012;Davis et al, 2008;Marshall and Siegler, 2014;Miyamoto et al, 2018). In addition, the stiŠness of muscles, tendons and MTUs was greater in men (Blackburn et al, 2004;Kubo et al, 2003;Morse, 2011).…”

“…Some previous studies have suggested the involvement of estrogen, which aŠects collagen synthesis and tissue behavior (Burgess et al, 2009;Kjaer and Hansen, 2008;Morse, 2011). However, one recent study found no signiˆcant changes in ROM and muscle elasticity during the menstrual cycle (Miyamoto et al, 2018). Furthermore, sex diŠerences have been shown during menses, when estradiol levels are lowest (Hoge et al, 2010).…”