J Mov Neuromuscul Sci.Journal of Movement & Neuromuscular ScienceJ Mov Neuromuscul Sci.REQUIRED_MISSINGNoventra Scientific PublishingREQUIRED_MISSINGClinical & Applied Movement SciencesSupplementary Material: Myoelectric Manifestations of Fatigue in Sport: Evidence from Repeated Maximal Shooting in Professional Water Polohttps://orcid.org/0009-0007-8518-365XCotellessaFilippo1https://orcid.org/0000-0003-1133-5511CeylanHalil İbrahim2https://orcid.org/0000-0001-8409-868XBragazziNicola Luigi3https://orcid.org/0000-0003-0825-2707PuceLuca1*Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of GenoaItalyPhysical Education and Sports Teaching Department, Faculty of Sports Sciences, Ataturk UniversityErzurum 25240TürkiyeDepartment of Mathematics and Statistics, Laboratory for Industrial and Applied Mathematics (LIAM), York UniversityToronto, Ontario (ON)CanadaCorresponding author: luca.puce@medicina.unige.it29202611REQUIRED_MISSING23202628720261082026© 2026 The Author(s)2026REQUIRED_MISSING

Background: Repeated maximal sport actions may induce localized myoelectric alterations before external performance deteriorates. This study examined whether repeated maximal shooting in professional water polo produces fatigue-compatible myoelectric changes despite preservation of ball velocity.

Methods: Fourteen male professional players performed up to 20 consecutive maximal-effort 5-m penalty shots. Surface electromyography was recorded from 14 throwing-side and trunk muscles and synchronized with multi-view video and stereo-derived ball velocity. Median frequency within a standardized 200-ms late-cocking window was the primary spectral outcome. Phase-specific RMS amplitude, activation-weighted temporal centroid, movement-phase duration, and multimuscle activation-pattern reorganization were also evaluated. Muscle-specific spectral analyses were adjusted for within-athlete ball velocity and concurrent RMS amplitude, with false-discovery-rate correction for multiple comparisons.

Results: The dataset comprised 222 valid EMG shots, including 219 with matched ball velocity. Ball velocity was preserved across the shooting sequence (first five: 79.47 km·h⁻¹; last five: 82.00 km·h⁻¹; mean difference +2.53 km·h⁻¹; p=0.055). Median frequency decreased significantly only in teres major (−14.62 Hz; 95% CI −22.71 to −5.89; q=0.0042) and the clavicular portion of pectoralis major (−10.08 Hz; 95% CI −17.18 to −4.93; q=0.0028). These effects remained directionally robust across alternative spectral specifications and leave-one-athlete-out analyses. Changes in activation amplitude and timing were heterogeneous, and neither complete-montage nor localized measures of EMG reorganization were associated with ball velocity.

Conclusions: Repeated maximal shooting in professional water polo produced selective fatigue-compatible myoelectric changes despite preserved ball velocity. External performance may therefore remain stable while localized myoelectric alterations are already detectable, highlighting the value of combining muscle-specific physiological measures with performance outcomes during repeated explosive sport actions.

surface electromyographymuscle fatiguemedian frequencywater polothrowingball velocityoverhead throwingneuromuscular fatiguefundingThis research received no external funding.ethicsThe study was conducted in accordance with the Declaration of Helsinki and was approved by the Comitato Etico per la Ricerca di Ateneo (CERA; approval no. 2024.55, 14 June 2024).informed-consentWritten informed consent was obtained from all participants involved in the study.data-availabilityThe de-identified processed datasets, complete analysis tables, and analysis code supporting the findings of this study are available from the corresponding author upon reasonable request.competing-interestsThe authors declare no commercial, financial, or other relationships that could be construed as a potential conflict of interest.

Supplementary Material

Myoelectric Manifestations of Fatigue in Sport: Evidence from Repeated Maximal Shooting in Professional Water Polo

Filippo Cotellessa1,Halil İbrahim Ceylan2,Nicola Luigi Bragazzi3,Luca Puce1,*

1 Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Italy2 Physical Education and Sports Teaching Department, Faculty of Sports Sciences, Ataturk University, Erzurum 25240, Türkiye3 Department of Mathematics and Statistics, Laboratory for Industrial and Applied Mathematics (LIAM), York University, Toronto, ON, Canada.

Corresponding author: Luca Puce · luca.puce@medicina.unige.it

Volume 1 Issue 1 Section Clinical & Applied Movement Sciences Received 2 March 2026 Revised 28 July 2026 Accepted 10 August 2026 Published online 2 September 2026

Supplementary Tables

Data quality.

Analysis component Possible Included Completeness (%) Notes
14-muscle late-cocking spectral windows 3,108 2,957 95.1 No imputation
14-muscle × four-phase observations 12,432 11,876 95.5 Amplitude and timing atlas
Recruitment-fatigue-velocity shots 219 velocity-matched 211 96.3 All 14 athletes represented

FDR-significant amplitude phase-selectivity contrasts.

Throwing-side muscle Peak phase Peak vs other phases 95% CI FDR q
Flexor carpi radialis Acceleration +59.79 pp +51.67 to +67.45 0.0012
Clavicular pectoralis Acceleration +37.27 pp +25.88 to +48.44 0.0012
Latissimus dorsi Acceleration +36.40 pp +24.73 to +47.51 0.0014
Lateral triceps Acceleration +31.92 pp +21.89 to +42.14 0.0012
Pectoralis major Acceleration +31.47 pp +25.69 to +37.39 0.0012
Lower rectus abdominis Acceleration +29.99 pp +20.42 to +38.61 0.0012
Teres major Acceleration +20.91 pp +7.46 to +34.76 0.0248
Middle deltoid Preparation +18.89 pp +9.02 to +29.03 0.0056
Middle trapezius Preparation +14.74 pp +4.53 to +23.34 0.0248
Infraspinatus Deceleration +15.44 pp +4.06 to +26.39 0.0296
Thoracic erector spinae Deceleration +13.24 pp +2.56 to +23.62 0.0492

Note. Peak phases were identified from the observed phase atlas; these FDR-corrected contrasts are therefore treated as secondary/exploratory phase-selectivity summaries.

Complete-montage muscle-specific spectral models.

Throwing-side muscle Adjusted endpoint change (Hz) 95% CI FDR q
Teres major -14.62 -22.71 to -5.89 0.0042
Clavicular pectoralis -10.08 -17.18 to -4.93 0.0028
Infraspinatus -8.32 -23.51 to +7.55 0.624
Pectoralis major -6.20 -12.26 to +0.04 0.243
Lower rectus abdominis -4.78 -10.72 to +0.94 0.331
Latissimus dorsi -2.46 -6.51 to +2.02 0.612
Biceps brachii -1.30 -5.26 to +2.66 0.812
Lateral triceps -1.05 -9.42 to +9.02 0.912
Posterior deltoid -0.71 -5.72 to +2.54 0.899
Middle deltoid -0.69 -7.05 to +3.22 0.912
Anterior deltoid +0.05 -10.18 to +9.15 0.958
Flexor carpi radialis +1.25 -5.96 to +9.02 0.899
Middle trapezius +1.87 -3.59 to +8.44 0.812
Thoracic erector spinae +4.81 -1.07 to +11.30 0.331

Integrated all-muscle and localized fatigue models.

Model family Outcome Predictor β 95% CI FDR q
All-muscle fatigue sequence Fatigue burden Sequence +0.415 -1.362 to +2.058 0.946
All-muscle fatigue sequence Fatigue burden Amplitude-pattern distance -0.126 -0.364 to +0.123 0.946
All-muscle fatigue sequence Fatigue burden Timing-pattern distance -0.010 -0.223 to +0.164 0.946
All-muscle velocity Ball velocity All-muscle fatigue burden +0.263 -0.588 to +1.148 0.846
All-muscle velocity Ball velocity Amplitude-pattern distance +0.593 -0.732 to +1.844 0.846
All-muscle velocity Ball velocity Timing-pattern distance +0.033 -1.105 to +1.005 0.944
All-muscle velocity Ball velocity Fatigue × amplitude reorganization -0.322 -1.583 to +0.660 0.846
All-muscle velocity Ball velocity Fatigue × timing reorganization +0.133 -1.173 to +1.278 0.944
Localized fatigue sequence (post-identification) Fatigue burden Sequence +1.779 +0.428 to +2.973 0.030
Localized velocity (post-identification) Ball velocity Localized fatigue burden -0.012 -0.667 to +0.594 0.997
Localized velocity (post-identification) Ball velocity Amplitude-pattern distance +0.412 -0.889 to +1.764 0.817
Localized velocity (post-identification) Ball velocity Timing-pattern distance -0.004 -0.919 to +0.886 0.997
Localized velocity (post-identification) Ball velocity Fatigue × amplitude reorganization +0.497 -0.941 to +1.643 0.761
Localized velocity (post-identification) Ball velocity Fatigue × timing reorganization -1.068 -2.455 to +0.280 0.277

Complete-montage spectral sensitivity analyses.

Variant Amplitude adjusted Standardized endpoint contrast 95% CI FDR q
CWT 20 Hz No -0.422 -0.704 to -0.161 0.0014
CWT 20 Hz Yes -0.405 -0.644 to -0.174 0.0007
CWT 30 Hz No -0.388 -0.671 to -0.143 0.0010
CWT 30 Hz Yes -0.368 -0.588 to -0.162 0.0003
CWT 40 Hz No -0.376 -0.647 to -0.156 0.0008
CWT 40 Hz Yes -0.357 -0.574 to -0.167 0.0003
FFT 20 Hz No -0.311 -0.471 to -0.156 0.0005
FFT 20 Hz Yes -0.307 -0.480 to -0.148 0.0003
FFT 30 Hz No -0.292 -0.483 to -0.109 0.0013
FFT 30 Hz Yes -0.282 -0.484 to -0.105 0.0012
FFT 40 Hz No -0.317 -0.504 to -0.145 0.0005
FFT 40 Hz Yes -0.305 -0.489 to -0.147 0.0003
CWT active window No -0.454 -0.715 to -0.218 0.0005
CWT active window Yes -0.436 -0.642 to -0.233 0.0003
CWT low-band trim No -0.400 -0.698 to -0.125 0.0022
CWT low-band trim Yes -0.378 -0.595 to -0.163 0.0003

Note. Standardized endpoint contrasts are complete-montage sensitivity summaries. Negative values indicate a downward spectral shift across the sequence. FDR q values are calculated within the corresponding adjustment set.

 Supplementary Figure

Observed peak-phase amplitude contrasts across the 14-muscle montage. Points indicate the difference between the observed peak-amplitude phase and the mean of the remaining phases; error bars represent 95% confidence intervals. Colors indicate the observed peak-amplitude phase.

Forest plot of peak-phase amplitude contrasts across the 14-muscle montage, with 95% confidence intervals and colors indicating observed peak-amplitude phase.