Sex-Based Differences in Tensiomyography as Assessed in the Lower Erector Spinae of Healthy Participants: An Observational Study

Abstract

Background: Although there is mounting evidence on sex-linked differences in paraspinal muscle function, it is unknown whether sex-based variations in mechanical and contractile characteristics of the lumbar erector spinae (LES) can be monitored noninvasively in healthy participants at rest using tensiomyography (TMG). Hypothesis: Sex-specific effects in muscle displacement (Dm) and velocity of muscle deformation (Vd) will be observed via TMG assessed in the LES. Study Design: Observational study. Level of Evidence: Level 3. Methods: LES response was measured in a relaxed state in 40 healthy adults (20 females). Possible differences between the conditions were investigated using mixed-model analyses of variance. Two-stage hierarchical linear regression analyses were performed to predict the outcome of TMG Dm and Vd based on participant sex. Results: There were significant main effects of sex with large effect sizes for both TMG parameters, resulting from lower mean values in women compared with men (Dm, P < 0.01; Vd, P < 0.01). In contrast, neither the main effect of side (left vs right LES) nor the interaction between the side and sex reached significance (all P > 0.3). Introducing the sex variable in stage 2 of the regression analyses significantly improved the prediction of the TMG parameters (all ∆R2 ≥ 0.18; all P < 0.01; all f2 ≥ 0.29). Conclusion: Sex-based differences in muscle stiffness and contractile characteristics could be observed by TMG on LES muscles in healthy individuals at rest. The data suggest that these disparities are not exclusively attributable to anthropometric measures but may be linked to intrinsic sex-based differences in skeletal muscle characteristics. Clinical Relevance: We recommend implementing TMG in a clinical setting using the obtained results as a basis to factor for the patient’s biological sex when assessing effects of therapeutic/exercise regimens aiming at the optimization of myofascial tissue regeneration and performance.

Contraction Velocity of the Elbow Flexors Assessed by Tensiomyography: A Comparison Between Formulas

“…Given the growing popularity of TMG in research and applied sports science settings, evidence-based recommendations are also required to ensure time-efficient but accurate measurement. The number of trials used in assessment of automated TMG parameters is often not well reported (9,17) or a low number of trials have been used (e.g., 2 trials: (23) and 3 trials: (13)) in some studies. However, it is unclear whether such a low number of trials provides an accurate measurement, especially for V c .…”

“…As healthy young adults free from pain were recruited, and the biceps brachii was the only muscle assessed, it is possible that the present findings and recommendations have limited generalizability. Furthermore, given the fact that only 2 female subjects were recruited, the low proportion of female subjects in previous TMG studies (20), and sex-based differences in TMG (23), a potential risk of sex bias exists and the recommendations made in this article should not be indiscriminately generalized to female subjects. Future studies could seek to examine the current research questions with greater sample sizes and in other populations and other muscle groups.…”

“…This index has been suggested to be a promising additional measure of mechanical function to predict optimal athletic performance and injury risk (27,29), and monitor training adaptations (25). For example, V c is thought to be sensitive to sex-and age-related differences in mechanical muscle function (23,30). Several studies have also demonstrated that V c is sensitive to exerciseinduced fatigue (13,25,30) and is associated with the loss of force after heavy eccentric exercise (29).…”

Effects of Lumbar Stabilization Exercises on Isokinetic Strength and Muscle Tension in Sedentary Men

“…Moreover, myofascial treatment and exercise that can cause muscle fatigue were restricted 48 h before measurement [ 26 ]. To apply the TMG to the participants’ ESM, they were guided to lie face down on the bed and position their legs at 5° flexion using a cushion, and wedge cushions were placed on the ankle and the anterior superior iliac spine (ASIS) to ensure minimal lumbar lordosis [ 27 ]. For accurate measurements, the TMG sensor (GK 40, Panoptik d.o.o., Ljubliana, Slovenia) was perpendicularly placed on a point in the thickest muscle belly marked by a pen upon the ESM’s isometric contraction on the same level as the iliac crest.…”

“…In this study, TMG was used to analyze the contractile properties of muscles and was used to assess the mechanical and neuromuscular properties of the ESM, using a TMG sensor with a 0.17 N/mm spring constant [ 27 ]. The TMG involved a 1 ms electrical stimulus (0~100 mA) to elicit the muscle contraction reaction, while the following variables were measured: the maximal displacement (Dm), the time taken to reach 10–90% of Dm (contraction time [Tc]), the time between the initiation of stimulus and 10% of Dm (delay time [Td]), the time of retention between 50% of Dm and 50% of the falling contour (sustain time [Ts]), and the time taken to reach 90–50% of Dm from the falling contour (relaxation time [Tr]) [ 34 ] ( Figure 3 ).…”