Physiological limb tremor modulation by physical exertion: a systematic review and meta-analysis in healthy adults.

INTRODUCTION OR

BACKGROUND

Physiological tremor is a low-amplitude, high-frequency oscillation of body segments influenced by both mechanical and neurogenic factors. Its modulation by physical exertion has emerged as a potential indicator of neuromuscular fatigue in healthy individuals.

SOURCES OF DATA: We conducted a systematic search across four databases (PubMed, Scopus, Web of Science, and SPORTDiscus) in accordance with PRISMA 2020 guidelines. Twenty-eight experimental studies involving healthy adults and reporting tremor outcomes post-exertion were included.

AREAS OF AGREEMENT: The majority of studies (68%) reported increased tremor amplitude following resistance-based or fatiguing exercise, aligning with models of neuromuscular fatigue. Accelerometry and surface electromyography were the most common measurement methods.

AREAS OF CONTROVERSY: Tremor frequency changes were inconsistently reported, with only 46% of studies documenting downward shifts. Few studies reported test-retest reliability or recovery dynamics, and significant heterogeneity was observed in measurement timing and spectral analysis protocols.

GROWING POINTS: There is increasing interest in using physiological tremor as a biomarker of neuromuscular strain. Emerging methods such as empirical mode decomposition and video-microscopy offer promise but remain underutilized and poorly validated.

AREAS TIMELY FOR DEVELOPING RESEARCH: Future studies should adopt standardized tremor measurement protocols, including frequency band targeting (e.g. 6-12 Hz), validated analytical pipelines, and consistent timing of data acquisition. There is a critical need for research in diverse populations and contexts, such as female athletes, older adults, and sport-specific exertion models.