Tensiomyography reliability and prediction of changes in muscle force following heavy eccentric strength exercise using muscle mechanical properties

Abstract

The current study involved the completion of two distinct experiments. Experiment 1 analyzed the inter-day reliability of tensiomyography (TMG) muscle mechanical properties based on the amplitude of the muscle belly radial deformation, the time it takes to occur, and its velocity under maximal and submaximal stimuli, in the muscles rectus femoris, biceps femoris, and gastrocnemius lateralis, from 20 male sport students. Experiment 2 investigated whether changes in maximal voluntary isometric contraction (MVIC) could be predicted based on changes in TMG properties following 24 h after different squat training protocols (MS = multiple sets; DS = drop sets; EO = eccentric overload; FW = flywheel; PL = plyometrics) executed by 14 male strength trained athletes. Maximal electrical stimulation exhibited higher level of reliability. In most of the cases, TMG properties Tc, Td, Dm, V₁₀, and V₉₀ showed ICC scores >.8 and CV <10%. Simple linear regression analysis revealed that changes in Dm, V₁₀, and V₉₀ correlated with changes in MVIC following EO at r = .705, .699, and .695, respectively. TMG is a reliable method to assess muscle mechanical properties particularly within maximal stimuli and can be used for prediction of changes in MVIC following heavy eccentric strength exercises.

Keywords:

• reliability
• muscle mechanical properties
• muscle force prediction
• strength exercises

Acknowledgments

The present study was funded by the German Federal Institute of Sport Science (RegMan - Optimization of Training and Competition: Management of Regeneration in Elite Sports; IIA1-081901/12-16). Rauno Simola gratefully acknowledges CAPES (Brasil) for financial support. The authors would like also to thank the athletes for their participation.