Surface Electromyographic Analysis of Gluteus Maximus and Biceps Femoris Activation During the Nordic Hamstring Exercise in Male Futsal and 11-a-Side Soccer Players With Previous Hamstring Injury
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 16
- 试验地点
- 1
- 主要终点
- Peak Normalized Biceps Femoris Surface Electromyographic Amplitude During Nordic Hamstring Exercise
研究概览
简要总结
This observational comparative study evaluates the surface electromyographic response of the gluteus maximus and biceps femoris during the Nordic Hamstring Exercise in adult male soccer players with a previous hamstring muscle injury.
Participants are classified according to their usual soccer discipline as 11-a-side soccer players or futsal players. All participants complete the same standardized Nordic Hamstring Exercise assessment during a single experimental session. Surface electromyography is recorded from the gluteus maximus and biceps femoris before, during, and immediately after the exercise protocol.
The main objective is to compare normalized electromyographic activation between soccer disciplines during the exercise, with particular attention to peak muscle activation across six valid Nordic Hamstring Exercise repetitions. Secondary analyses evaluate the immediate change in normalized muscle activation from pre-exercise to post-exercise.
详细描述
Participants complete a single standardized assessment session. Baseline sociodemographic and anthropometric characteristics are recorded before testing. The Nordic Hamstring Exercise is performed from a kneeling position while an evaluator or training partner stabilizes the participant's ankles and lower legs. The participant maintains the trunk and thighs aligned and controls the forward descent primarily through eccentric hamstring action. The descent is paced at approximately 3 seconds. The hands and arms are used to arrest the fall and assist the return to the initial position in order to minimize concentric loading.
Six valid maximal-effort Nordic Hamstring Exercise repetitions are recorded, with recovery between repetitions. Surface electromyographic activity is collected throughout the assessment from the biceps femoris and gluteus maximus.
Surface electromyography is recorded using the mDurance® system (mDurance Solutions SL, Granada, Spain), based on a portable Shimmer3 EMG unit with two surface EMG channels, a sampling frequency of 1024 Hz, 24-bit signal resolution, and an overall amplification range of 100-10,000 V/V. The recorded signals are processed using the mDurance methodology, including a fourth-order Butterworth band-pass filter with cut-off frequencies of 20-450 Hz and root mean square smoothing with a 0.025-second window and 0.0125-second overlap. Skin preparation and electrode placement follow standardized surface electromyography procedures.
Electromyographic amplitude is normalized to a maximal voluntary isometric contraction reference and expressed as a percentage of MVIC (%MVIC). The main variables are the peak normalized RMS amplitude of the biceps femoris and gluteus maximus during the six repetitions, together with pre-exercise and immediately post-exercise normalized activation. Comparisons are performed between 11-a-side soccer and futsal players.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •Male soccer or futsal player aged 18 years or older.
- •Regular participation in 11-a-side soccer or futsal.
- •Previous physician-diagnosed hamstring muscle injury classified as type 2b according to the Munich Consensus during the previous 12 months, but not within the month preceding assessment.
- •Absence of current lower-limb pain or active musculoskeletal injury at the time of assessment.
- •Ability to understand and perform the study procedures.
- •Voluntary agreement to participate and provision of written informed consent.
排除标准
- •Participation in an organized hamstring stretching program that could interfere with the assessment.
- •Current pain, musculoskeletal injury, or recent surgery involving the lumbar spine, abdominal region, or lower limbs.
- •Evidence or history of a neurological disorder affecting lower-limb function.
- •Skin lesions or dermatological conditions preventing placement of surface electromyography electrodes.
- •Moderate-to-vigorous physical activity within the 72 hours preceding testing.
研究组 & 干预措施
11-a-side soccer players
Male 11-a-side soccer players with a previous type 2b hamstring injury who complete the same single-session Nordic Hamstring Exercise electromyographic assessment protocol as the futsal cohort.
Futsal players
Male futsal players with a previous type 2b hamstring injury who complete the same single-session Nordic Hamstring Exercise electromyographic assessment protocol as the 11-a-side soccer cohort.
结局指标
主要结局
Peak Normalized Biceps Femoris Surface Electromyographic Amplitude During Nordic Hamstring Exercise
时间窗: During six Nordic Hamstring Exercise repetitions in a single assessment session.
Peak root mean square surface electromyographic amplitude of the biceps femoris during the six Nordic Hamstring Exercise repetitions, normalized to the participant's maximal voluntary isometric contraction and expressed as %MVIC. The peak response is compared between 11-a-side soccer and futsal players.
Peak Normalized Gluteus Maximus Surface Electromyographic Amplitude During Nordic Hamstring Exercise
时间窗: During six Nordic Hamstring Exercise repetitions in a single assessment session.
Peak root mean square surface electromyographic amplitude of the gluteus maximus during the six Nordic Hamstring Exercise repetitions, normalized to the participant's maximal voluntary isometric contraction and expressed as %MVIC. The peak response is compared between 11-a-side soccer and futsal players.
次要结局
- Change in Normalized Biceps Femoris Surface Electromyographic Amplitude From Pre-Exercise to Post-Exercise(Immediately before the Nordic Hamstring Exercise protocol and immediately after completion of the sixth repetition.)
- Change in Normalized Gluteus Maximus Surface Electromyographic Amplitude From Pre-Exercise to Post-Exercise(Immediately before the Nordic Hamstring Exercise protocol and immediately after completion of the sixth repetition.)
研究者
Carlos Fernández-Morales
Clinical Professor
Universidad de Extremadura