by Katherine Balfany, CSCS and Robert Lockie, PhD, TSAC-F
TSAC Report November 2020
Vol 58, Issue 3
Tactical personnel perform unique movements while on the job. To initiate movement in the body, the brain sends an electrical signal to the spinal cord (via neurons), which discharges an action potential and creates a muscle contraction. When the contraction of the muscles is sufficient, they pull on the bony landmarks to which they are attached (typically via tendons), and movement is generated. When an individual wants to produce more force (e.g., when lifting a heavier load), motor neurons discharge action potentials more rapidly or activate additional motor units (24). The size principle is in effect where the smallest motor units are recruited first, eventually leading to the recruitment of the largest motor units (24). This recruitment pattern should lead to greater muscular force production (15). The summed action potentials result in muscle activation that can be measured via electromyography (EMG).
This article originally appeared in TSAC Report, the NSCA’s quarterly, online-only publication geared toward the training of tactical athletes, operators, and facilitators. It provides research-based articles, performance drills, and conditioning techniques for operational, tactical athletes. The TSAC Report is only available for NSCA Members. Read more articles from TSAC Report
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