Muscle Fatigue
Conditions
Keywords
Muscle Fatigue, Surface Electromyography, Accelerometry, Muscle Thickness, Mechanomyography
Brief summary
Muscle fatigue is a multifactorial physiological phenomenon characterized by a reduction in the ability of a muscle to generate force during sustained or repetitive contractions. This cross-sectional observational study aimed to investigate the relationships among muscle thickness, surface electromyography (sEMG) median frequency, accelerometer-derived mechanical vibration parameters, and isometric force characteristics in healthy male soccer players. Thirty participants aged 18-30 years underwent ultrasonographic muscle thickness assessment, synchronized sEMG and accelerometer recordings, and isometric strength testing at different knee flexion angles (90°, 60°, and 30°). The study evaluated the interaction between morphological, electrical, and mechanical indicators of muscle fatigue to support the development of multidimensional fatigue monitoring approaches.
Detailed description
Muscle fatigue is commonly assessed using surface electromyography (sEMG), particularly through frequency-domain parameters such as median frequency. However, fatigue-related changes are not limited to electrical activity and may also involve alterations in muscle mechanical behavior and morphological characteristics. Accelerometer-derived signals provide information regarding muscle vibrations and mechanical oscillations, while ultrasonographic measurements of muscle thickness provide information about muscle morphology and force-generating capacity. The purpose of this study was to examine the relationships among muscle thickness, sEMG median frequency, accelerometer-derived mechanical vibration parameters, and isometric force variables during maximal voluntary isometric contractions performed at different knee flexion angles. Healthy male soccer players participated in a laboratory-based assessment protocol including ultrasonography, synchronized sEMG recordings, triaxial accelerometry, and isokinetic dynamometry. Muscle thickness of the vastus lateralis obliquus (VLO), vastus medialis obliquus (VMO), and rectus femoris obliquus (RFO) muscles was measured using ultrasonography. Participants subsequently performed maximal voluntary isometric contractions at 90°, 60°, and 30° knee flexion angles. Surface electromyography, accelerometer signals, and force-related variables were recorded simultaneously. Median frequency values, acceleration-based root mean square (RMS) parameters, peak torque, mean torque, and time-to-peak torque variables were analyzed. The study aimed to provide a multidimensional framework for muscle fatigue assessment by integrating morphological, electrical, and mechanical indicators and to explore their associations in healthy athletic populations.
Interventions
DEVICENeuromuscular Assessment Devices
Participants underwent non-invasive neuromuscular assessment procedures using surface electromyography (sEMG), triaxial accelerometers, ultrasonography, and an isokinetic dynamometer. Measurements were performed during maximal voluntary isometric contractions at 30°, 60°, and 90° knee flexion angles. The devices were used exclusively for data collection and assessment purposes. No therapeutic, pharmacological, behavioral, or rehabilitative intervention was administered.
Sponsors
Giresun University
Study design
Observational model
OTHER
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy male soccer players aged 18-30 years * No lower extremity injury within the previous six months * No condition limiting lower extremity exercise performance * No caffeine or stimulant consumption on the testing day * Non-smoker * Provided written informed consent
Exclusion criteria
* Female athletes * Serious injury to the dominant leg within the previous year * Intense exercise within the previous 24 hours * Use of pain relievers or muscle relaxants on the testing day * Inability to complete testing procedures
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Surface Electromyography (sEMG) Median Frequency | Day 1 | Median frequency (Hz) obtained from the vastus lateralis obliquus (VLO), vastus medialis obliquus (VMO), and rectus femoris obliquus (RFO) muscles during maximal voluntary isometric contractions performed at 30°, 60°, and 90° knee flexion angles. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Muscle Thickness | Day 1 | Ultrasonographic muscle thickness measurements of the VLO, VMO, and RFO muscles (mm). |
| Accelerometer-Derived Mechanical Vibration Parameters | Day 1 | Root mean square (RMS) acceleration values obtained from thigh and shank triaxial accelerometers during isometric contractions. |
| Isometric Strength Parameters | Day 1 | Peak torque, mean torque, and time-to-peak torque measured using an isokinetic dynamometer during maximal voluntary isometric contractions. |
Countries
Turkey (Türkiye)
Contacts
PRINCIPAL_INVESTIGATORTuğçe Namazcı, PhD
Giresun Üniversitesi
Outcome results
None listed