Minoshima Y, Nishimura Y, Tsuboi H, Sato H, Ogawa T, Kamijo YI, Umezu Y, Tajima F. Differences in Muscle Fatigability of Vastus Medialis between Sexes Using Surface Electromyographic Power Spectral Analysis in Healthy Adults.
Prog Rehabil Med 2022;
7:20220051. [PMID:
36188139 PMCID:
PMC9475374 DOI:
10.2490/prm.20220051]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
Objectives:
With a relatively high percentage of type I fibers in the vastus medialis (VM), its
fatigability may be more sensitive to the effects of muscle activity in the quadriceps.
However, sex-related differences in the muscle fatigability of the VM remain unknown.
The purpose of the present study was to assess the differences in fatigability of the VM
between healthy adult men and women.
Methods:
Surface electromyographic (EMG) activities of VM oblique (VMO) and VM long (VML) were
recorded during sustained isometric contraction on a leg press machine. The results of
EMG power spectral analysis were compared between healthy adult men and women. The
decline in the median frequency (MF), defined as MF slope, was calculated using spectrum
analysis after fast Fourier transform of the raw EMG signals of VMO and VML.
Results:
The endurance time and the MF slopes of the VMO and VML were significantly longer and
lower, respectively, in women than in men. The present results demonstrated that both
VMO and VML are more fatigue-resistant in women than in men.
Conclusions:
Understanding the sex differences in fatigability could help to design more effective
exercise regimens for VMO and VML in healthy individuals. A similar approach should be
considered when prescribing practical exercise regimens for patients with muscle
atrophy.
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