Independent neural drives and distinct motor unit discharge characteristics in hamstring muscles during isometric knee flexion.

ABSTRACT:

Purpose

Our study investigated the discharge characteristics of motor units (MUs) in the semitendinosus (ST) and biceps femoris (BF) at three knee-joint angles that varied muscle length.

Methods

Fifteen males (21.1 ± 2.8 years) performed steady isometric contractions with the knee flexors at four target torques (10%, 20%, 40%, and 60% of maximal voluntary contraction, MVC) at each of the three knee-joint angles (0°: long, 45°: intermediate, and 90°: short length). High-density electromyographic signals were recorded and decomposed into MU discharge times. We calculated mean discharge rate (MDR), the coefficient of variation for interspike interval (CoV ISI), and the standard deviation of the filtered cumulative spike train (SD of fCST). In addition, the neural drive within a

SUBMITTER: Sahinis C 

PROVIDER: S-EPMC12948821 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature