Post-contraction potentiation can react inversely to post-activation potentiation depending on the test contraction force

Tomoya Ishii; Syusaku Sasada; Tomoyoshi Komiyama

doi:10.1016/j.neulet.2023.137132

Post-contraction potentiation can react inversely to post-activation potentiation depending on the test contraction force

Neurosci Lett. 2023 Mar 28:801:137132. doi: 10.1016/j.neulet.2023.137132. Epub 2023 Feb 15.

Authors

Tomoya Ishii¹, Syusaku Sasada², Tomoyoshi Komiyama³

Affiliations

¹ Department of Physical Therapy, School of Health Sciences, Japan University of Health Sciences, Saitama, Japan; Division of Health and Sports Education, The United Graduate School of Education, Tokyo Gakugei University, Tokyo, Japan. Electronic address: t-ishii@jhsu.ac.jp.
² Department of Food and Nutrition Science, Sagami Women's University, Kanagawa, Japan. Electronic address: sasada_syusaku@isc.sagami-wu.ac.jp.
³ Division of Health and Sports Education, The United Graduate School of Education, Tokyo Gakugei University, Tokyo, Japan; Department of Health and Sports Sciences, Faculty of Education, Chiba University, Chiba, Japan. Electronic address: komiyama@faculty.chiba-u.jp.

PMID: 36801240
DOI: 10.1016/j.neulet.2023.137132

Abstract

The surface electromyographic (EMG) activity of the biceps brachii during weak elbow flexion reportedly increases immediately after strong elbow flexion, even during the exertion of a given force. This phenomenon is called post-contraction potentiation (EMG-PCP). However, the effects of test contraction intensity (TCI) on EMG-PCP remain unclear. This study evaluated PCP levels at various TCI values. Sixteen healthy participants were asked to perform a force matching task (2%, 10%, or 20% of the maximum voluntary contraction [MVC]) before (Test 1) and after (Test 2) a conditioning contraction (50% of MVC). With a 2% TCI, the EMG amplitude was higher in Test 2 than in Test 1. With a 20% TCI, the EMG amplitude was lower in Test 2 than in Test 1. Furthermore, EMG spectral analyses showed that the α- and β-band power ratios in Test 2 were enhanced by 2% TCI compared with Test 1. These findings suggest that TCI is crucial in determining the EMG-force relationship immediately after a brief intensive contraction.

Keywords: Biceps brachii; Electromyography; Force; Post-activation potentiation; Post-contraction potentiation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Elbow
Elbow Joint* / physiology
Electromyography
Humans
Isometric Contraction* / physiology
Muscle Contraction / physiology
Muscle, Skeletal / physiology