Characteristics of muscle contraction of the rectus femoris using Tensiomyography by sex in healthy adolescents: a Cross-Sectional Study

Abstract

Background Tensiomyography (TMG) is a non-invasive instrument for measuring mechanical muscle contraction characteristics, and measures the maximum displacement of the muscle belly in the vertical direction and the time needed to achieve this from electrical stimulation. There have only been few reports of TMG on general healthy adults. A systematic review on TMG reported a low proportion of female participants with a small sample size. Therefore, it is unclear whether there is a difference in TMG parameters by sex and between the dominant and non-dominant feet. Furthermore, the relationship between the TMG parameters and the evaluations commonly used in clinical practice has not been clarified. This study aimed to clarify the characteristics of muscle contraction of the rectus femoris using tensiomyography by sex among healthy adolescents and its relationship with muscle function evaluation, such as lower limb muscle mass and muscle strength. The subjects included 91 healthy university students. The measurement items included TMG, lower limb muscle mass, rectus femoris thickness, isometric knee joint extension torque, and thigh circumference. Results There was a main effect on sex in all parameters (ρ ≤ 0.05). In terms of TMG parameters, maximum displacement (Dm) in the non-dominant foot was significantly lower in women. The correlation between TMG parameters for males and females and lower limb muscle mass, muscle thickness, joint torque, and thigh circumference had a significant correlation with some TMG parameters and lower limb muscle mass (ρ ≤ 0.05). The absolute value of the correlation coefficient was overall low with 0.27 ~0.45. Conclusion In healthy adolescents, there was a difference by sex in TMG parameters and a weak correlation between TMG parameters and the lower limb muscle mass. TMG parameter evaluation may indicate a different function compared with the traditional muscle function assessment used in clinical practice. The TMG parameter is considered as a unique evaluation method for neuromuscular function assessment.