Early and late rapid torque characteristics and select physiological correlates in middle-aged and older males

Authors

Alex A. Olmos, Kennesaw State University
Matthew T. Stratton, Texas Tech University
Phuong L. Ha, Kennesaw State University
Benjamin E. Dalton, Kennesaw State University
Trisha VanDusseldorp, Kennesaw State UniversityFollow
Gerald Mangine, Kennesaw State UniversityFollow
Yuri Feito, Kennesaw State UniversityFollow
Micah J. Poisal, Kennesaw State University
Joshua A. Jones, Kennesaw State University
Tyler M. Smith, Kennesaw State University
Garrett Hester, Kennesaw State UniversityFollow

Department

Exercise Science and Sport Management

Document Type

Article

Publication Date

4-1-2020

Abstract

Purpose

The purpose of this study was to compare early and late rapid torque parameters of the plantar flexors (PFs) in middle-aged (MM) and older (OM) males, and determine the effect of normalization to peak torque (PT) and muscle cross-sectional area (CSA).

Methods

Twenty-nine healthy, MM (n = 14; 45 ± 2 yrs) and OM (n = 15; 65 ± 3 yrs) performed rapid, maximal isometric contractions of the PFs. PT, as well as rate of torque development and impulse during the early (0–50 ms; RTD_0-50, IMP_0-50) and late (100–200 ms; RTD_100-200, IMP_100-200) contraction phases were calculated. Torque at 50 (TQ₅₀), 100 (TQ₁₀₀), and 200 (TQ₂₀₀) ms was also obtained. CSA and echo-intensity (EI) of the gastrocnemii were acquired via ultrasonography. Torque variables were normalized to PT and CSA. Rate of EMG rise (RER) for the medial gastrocnemius was calculated at 30, 50 and 75 ms.

Results

TQ₁₀₀ (MM = 69.71 ± 16.85 vs. OM = 55.99 ± 18.54 Nm; p = 0.046), TQ₂₀₀ (MM = 114.76 ± 26.79 vs. OM = 91.56 ± 28.10 Nm; p = 0.031), and IMP_100-200 (MM = 4.79 ± 1.11 vs. OM = 3.83 ± 1.17 Nm·s; p = 0.032) were lower in OM. PT, TQ₅₀, RTD_0-50, IMP_0-50, RTD_100-200, RER, CSA, and EI were similar between groups (p > 0.05). No differences were found for normalized torque variables (p > 0.05). EI was moderately associated with normalized torque parameters only (r = -0.38 –-0.45). RER, at 75 ms, was moderately correlated with early, absolute torque measures and rapid torque variables made relative to PT and CSA (r = 0.41 –-0.64).

Conclusion

Late rapid torque parameters of the PFs were preferentially impaired in OM compared to MM, and PT as well as CSA appeared to mediate this result.

Journal Title

PLoS ONE

Journal ISSN

1932-6203

Volume

15

Issue

4

Digital Object Identifier (DOI)

10.1371/journal.pone.0231907

Comments

This article received funding through Kennesaw State University's Faculty Open Access Publishing Fund, supported by the KSU Library System and KSU Office of Research.