Posterior Chain EMG Patterns in Athletes With and Without Hamstring Injury

NCT07171385 | Completed DMC

• 1 other identifier: 2023-350
• Study Type: observational
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

This cross-sectional observational study investigated posterior chain muscle activation patterns in football players with and without a history of hamstring strain injury. Forty-two male athletes were assessed using surface electromyography (sEMG) during Nordic Hamstring Curl, Kettlebell Swing, and Supine Sliding Leg Curl exercises. Results demonstrated persistent deficits in biceps femoris, gluteus maximus, latissimus dorsi, and iliocostalis lumborum activation in previously injured athletes compared to controls, suggesting that neuromuscular alterations extend beyond the hamstring itself and may increase reinjury risk.

Conditions

Muscle Strain; Neuromuscular Diseases; Athletic Injuries

Keywords

Hamstring Muscles; Electromyography; Athletic Injuries; Muscle, Skeletal; Exercise Therapy; Soccer; Rehabilitation; Biceps Femoris; Nordic Hamstring Curl; Kettlebell Swing; Supine Sliding Leg Curl; Reinjury Prevention

Outcome Measures

Primary Outcomes (4)

• Gluteus Maximus Activation (%MVIC)

  Surface EMG amplitude (RMS) normalized to MVIC, averaged across three functional exercises. Mean %MVIC compared between groups.

  Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)

• Biceps Femoris Long Head Activation (%MVIC)

  Surface EMG amplitude (RMS) normalized to MVIC. Mean %MVIC across repetitions compared between injured and healthy athletes.

  Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)

• Latissimus Dorsi Activation (%MVIC)

  Surface EMG amplitude (RMS) normalized to MVIC, averaged across three functional exercises. Mean %MVIC compared between groups.

  Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)

• Iliocostalis Lumborum Activation (%MVIC)

  Surface EMG amplitude (RMS) normalized to MVIC. Mean %MVIC across repetitions compared between injured and healthy athletes.

  Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)

Study Arms (2)

Injured Group

Male football players aged 18-30 years with a history of unilateral hamstring strain injury (HSI) within the past 6 months, BMI 18.5-24.9 kg/m², able to perform study exercises (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Leg Curl). Surface electromyography (sEMG) was used to measure activation of biceps femoris, gluteus maximus, latissimus dorsi, and iliocostalis lumborum during a single session. No interventions were applied (observational study).

Other: Nordic Hamstring Curl (NHC); Other: Kettlebell Swing (KS); Other: Supine Sliding Single-Leg Curl (SSLC)

Healthy Control Group

Male football players aged 18-28 years, no history of hamstring strain injury in the past 6 months, BMI 18.5-24.9 kg/m², straight-leg raise on dominant limb \<80°, able to perform study exercises (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Leg Curl). Surface electromyography (sEMG) measured activation of biceps femoris, gluteus maximus, latissimus dorsi, and iliocostalis lumborum in a single session. No interventions were applied (observational study).

Other: Nordic Hamstring Curl (NHC); Other: Kettlebell Swing (KS); Other: Supine Sliding Single-Leg Curl (SSLC)

Interventions

Nordic Hamstring Curl (NHC) OTHER

Knee-dominant eccentric hamstring strengthening exercise performed on a padded surface. Participants control the descent of the torso while knees remain fixed, emphasizing eccentric activation of hamstring muscles.

Healthy Control Group; Injured Group

Kettlebell Swing (KS) OTHER

Hip-dominant ballistic movement involving rapid hip flexion-extension using a kettlebell (16-20 kg depending on participant's ability). Each repetition includes concentric, isometric, and eccentric phases standardized by metronome pacing.

Healthy Control Group; Injured Group

Supine Sliding Single-Leg Curl (SSLC) OTHER

Closed-chain exercise performed in supine position with heels placed on sliding discs. One leg is extended while the other leg performs concentric-eccentric sliding curl.

Healthy Control Group; Injured Group

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Forty-two male football players aged 18-30 years participated, including 21 with a history of unilateral hamstring strain injury and 21 healthy controls. All were recreational to semi-professional athletes with BMI within the normal range and able to complete functional posterior chain exercises.

You may qualify if:

• Male football players, aged 18-30 years
• Body mass index (BMI) between 18.5-24.9 kg/m²
• Voluntary participation and written informed consent
• Ability to perform all test exercises (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)
• For injured group: unilateral hamstring strain within the past 6 months
• For control group: no hamstring injury within the past 6 months

You may not qualify if:

• Professional sports background
• Lower or upper extremity injury within the last year (other than index hamstring strain for the injured group)
• Neurological, musculoskeletal, respiratory, or cardiovascular conditions limiting participation
• Recent spinal surgery
• Acute low-back or lower-limb pain
• Sensory impairments interfering with performance
• History of malignancy

Sponsors & Collaborators

• Ankara Yildirim Beyazıt University: lead
• Mersin University: collaborator
• T.C. Dumlupınar Üniversitesi: collaborator
• Eskisehir Technical University: collaborator
• Istanbul Gelisim University: collaborator
• Çanakkale Onsekiz Mart University: collaborator
• Saglik Bilimleri Universitesi: collaborator
• Manisa Celal Bayar University: collaborator

Study Sites (1)

University of Health Sciences

Ankara, Etlik, 06100, Turkey (Türkiye)

Location

Related Publications (1)

• Gulgosteren E, Yuksel O, Gurol B, Yildirim O, Atar O, Soylu C, Altundag E, Acar G. Persistent neuromuscular deficits in the posterior kinetic chain following hamstring strain injury: EMG insights from nordic hamstring curl, kettlebell swing, and supine sliding leg curl. BMC Sports Sci Med Rehabil. 2025 Nov 29;18(1):6. doi: 10.1186/s13102-025-01435-5.

  PMID: 41318473 DERIVED

MeSH Terms

Conditions

Sprains and Strains; Neuromuscular Diseases; Athletic Injuries

Condition Hierarchy (Ancestors)

Wounds and Injuries; Nervous System Diseases

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: CROSS SECTIONAL
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 6, 2025
• First Posted: September 12, 2025
• Study Start: November 11, 2023
• Primary Completion: December 10, 2023
• Study Completion: March 10, 2024
• Last Updated: September 12, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: De-identified individual participant data (IPD), study protocol, and statistical analysis plan will be available beginning 6 months after publication of the main results article and will remain available for a period of 5 years thereafter.
• Access Criteria: Qualified researchers affiliated with academic or research institutions may request access to de-identified IPD, the study protocol, and the statistical analysis plan. Requests must be made in writing to the corresponding author and will be reviewed by the study team. Access will be granted for scientifically sound proposals, with data shared via secure transfer following institutional data protection policies.

Locations

TU (1)