How Stable Are Temporal EMG Parameters in Rowing? A Seven-Day Test-Retest Reliability Study Using Wearable sEMG

Area of Science:

• Sports Science and Biomechanics
• Wearable Technology in Athletics
• Neuromuscular Physiology

Background:

• Surface electromyography (sEMG) is crucial for non-invasive muscle activation monitoring during repetitive tasks.
• Clinical utility of wearable sEMG in rowing relies on test-retest reliability for high-intensity, multi-muscle activities.
• Understanding muscle activation patterns is key for optimizing training in competitive athletes.

Purpose of the Study:

• To quantify the between-session reliability of sEMG-derived parameters (onset, offset, active duration, peak position) in seven major rowing muscles.
• To assess the between-session similarity of ensemble-averaged muscle activation waveforms.
• To describe within-trial muscle activation dynamics during rowing.

Main Methods:

• Fifteen competitive rowers performed two 2000 m all-out trials seven days apart using wireless wearable sEMG.
• Advanced sEMG processing was used to analyze parameter reliability (ICC, SEM, MDC95, CV%, Bland-Altman).
• Waveform similarity was quantified using Pearson correlation, cosine similarity, and normalized dynamic time warping (DTW).

Main Results:

• Excellent reliability was found for muscle onset (ICC = 0.943-0.995); offset and peak position showed moderate-to-excellent reliability.
• Active duration reliability varied from poor-to-good (0.077-0.814), while ensemble-waveform similarity was consistently high (Pearson r = 0.832-0.972).
• Reproducible U-shaped patterns were observed for amplitude and active duration within trials.

Conclusions:

• Wearable sEMG demonstrates high test-retest reliability for key muscle activation parameters in rowers.
• Individual muscle activation patterns are stable over a 7-day interval, validating the 'activation fingerprint'.
• Findings support the use of wearable sEMG for reliable, personalized monitoring and training optimization in rowing.