Hamstring InjuryNCT07831915
Electromyographic Activity During Nordic Hamstring Exercise in Male Soccer Players
An observational study of Hamstring Injury, run by Universidad de Extremadura at 1 site in Spain.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 35 years, men only
- Conditions the study is for
- Hamstring Injury
- How many people
- 17 participants
- Where
- 1 siteSpain
- Study dates
- 1 Jan 2026to 30 Apr 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- Men only
- No healthy volunteers
- Adult
Study population: Male 11-a-side soccer and futsal players recruited by convenience sampling from two amateur sports clubs in Badajoz, Spain. Participants had a previous physician-diagnosed type 2b functional hamstring disorder affecting the dominant lower limb, occurring 1-12 months before assessment, and had returned to regular sporting activity without current pain or active injury.
Who may be able to join
- 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.
Who cannot join
- 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.
- Skin lesions or dermatological conditions preventing placement of surface electromyography electrodes.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: 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
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.
Read the detailed description
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.
- Conditions
- Hamstring Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| 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. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Peak Biceps Femoris Long Head sEMG Activity During the Nordic Hamstring Exercise
Mean peak normalized surface electromyographic (sEMG) activity of the biceps femoris long head during the Nordic hamstring exercise. The highest root mean square (RMS) amplitude recorded during each of the six repetitions was identified, and the six peak values were averaged to obtain a participant-level estimate. Results were expressed as a percentage of the maximal voluntary isometric contraction reference (%MVIC).
Measured: During the single experimental session (six NHE repetitions).
Mean Peak Gluteus Maximus sEMG Activity During the Nordic Hamstring Exercise
Mean peak normalized surface electromyographic (sEMG) activity of the gluteus maximus during the Nordic hamstring exercise. The highest root mean square (RMS) amplitude recorded during each of the six repetitions was identified, and the six peak values were averaged to obtain a participant-level estimate. Results were expressed as a percentage of the maximal voluntary isometric contraction reference (%MVIC).
Measured: During the single experimental session (six NHE repetitions).
Secondary outcomes (2)
Change in Resting Biceps Femoris Long Head sEMG Activity
Change in resting normalized surface electromyographic (sEMG) activity of the biceps femoris long head from immediately before to immediately after the Nordic hamstring exercise protocol. Resting activity was recorded for 10 seconds in a standardized prone position and quantified as the mean root mean square (RMS) amplitude over the central 5 seconds of each recording. The change was calculated as post-exercise minus pre-exercise activity and expressed as %MVIC.
Measured: Immediately before and after the six-repetition NHE protocol, during a single experimental session.
Change in Resting Gluteus Maximus sEMG Activity
Change in resting normalized surface electromyographic (sEMG) activity of the gluteus maximus from immediately before to immediately after the Nordic hamstring exercise protocol. Resting activity was recorded for 10 seconds in a standardized prone position and quantified as the mean root mean square (RMS) amplitude over the central 5 seconds of each recording. The change was calculated as post-exercise minus pre-exercise activity and expressed as %MVIC.
Measured: Immediately before and after the six-repetition NHE protocol, during a single experimental session.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Sep 2026
- Study start1 Jan 2026
- Primary completion30 Apr 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hamstring InjuryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 17 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universidad de Extremadura
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Carlos Fernández-Morales, Universidad de Extremadura
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07831915
- Sponsor's protocol ID
- 14
- Status last verified
- Oct 2026
- First submitted
- 15 Sep 2026
- Last updated
- 20 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data are not planned for public sharing because of privacy and ethical restrictions.
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT07831915
- Acronym / sponsor ID
- 14
- Conditions
- Hamstring Injury
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 17 participants (actual)
- Lead sponsor
- Universidad de ExtremaduraUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 30 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 21 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 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. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Male 11-a-side soccer and futsal players recruited by convenience sampling from two amateur sports clubs in Badajoz, Spain. Participants had a previous physician-diagnosed type 2b functional hamstring disorder affecting the dominant lower limb, occurring 1-12 months before assessment, and had returned to regular sporting activity without current pain or active injury.
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (3 listed)
- 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.
- Skin lesions or dermatological conditions preventing placement of surface electromyography electrodes.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Mean Peak Biceps Femoris Long Head sEMG Activity During the Nordic Hamstring Exercise
Time frame: During the single experimental session (six NHE repetitions).
Mean peak normalized surface electromyographic (sEMG) activity of the biceps femoris long head during the Nordic hamstring exercise. The highest root mean square (RMS) amplitude recorded during each of the six repetitions was identified, and the six peak values were averaged to obtain a participant-level estimate. Results were expressed as a percentage of the maximal voluntary isometric contraction reference (%MVIC).
Mean Peak Gluteus Maximus sEMG Activity During the Nordic Hamstring Exercise
Time frame: During the single experimental session (six NHE repetitions).
Mean peak normalized surface electromyographic (sEMG) activity of the gluteus maximus during the Nordic hamstring exercise. The highest root mean square (RMS) amplitude recorded during each of the six repetitions was identified, and the six peak values were averaged to obtain a participant-level estimate. Results were expressed as a percentage of the maximal voluntary isometric contraction reference (%MVIC).
2 secondary outcomes
Change in Resting Biceps Femoris Long Head sEMG Activity
Time frame: Immediately before and after the six-repetition NHE protocol, during a single experimental session.
Change in Resting Gluteus Maximus sEMG Activity
Time frame: Immediately before and after the six-repetition NHE protocol, during a single experimental session.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2026.
- Individual participant dataSharing planned: No. Individual participant data are not planned for public sharing because of privacy and ethical restrictions.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hamstring Injury, run by Universidad de Extremadura at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean Peak Biceps Femoris Long Head sEMG Activity During the Nordic Hamstring Exercise (time frame: During the single experimental session (six NHE repetitions).). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026.