Posterior Chain EMG Patterns in Athletes With and Without Hamstring Injury

NCT ID: NCT07171385

Last Updated: 2025-09-12

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 42 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2023-11-11
• Study Completion Date: 2024-03-10

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

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

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).

Nordic Hamstring Curl (NHC)

Intervention Type: 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.

Kettlebell Swing (KS)

Intervention Type: 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.

Supine Sliding Single-Leg Curl (SSLC)

Intervention Type: 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

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).

Nordic Hamstring Curl (NHC)

Intervention Type: 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.

Kettlebell Swing (KS)

Intervention Type: 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.

Supine Sliding Single-Leg Curl (SSLC)

Intervention Type: 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.

Interventions

Nordic Hamstring Curl (NHC)

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.

Intervention Type: OTHER

Kettlebell Swing (KS)

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.

Intervention Type: OTHER

Supine Sliding Single-Leg Curl (SSLC)

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.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

• 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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 30 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Mersin University

OTHER

Sponsor Role: collaborator

T.C. Dumlupınar Üniversitesi

OTHER

Sponsor Role: collaborator

Eskisehir Technical University

OTHER

Sponsor Role: collaborator

Istanbul Gelisim University

OTHER

Sponsor Role: collaborator

Çanakkale Onsekiz Mart University

OTHER

Sponsor Role: collaborator

Saglik Bilimleri Universitesi

OTHER

Sponsor Role: collaborator

Manisa Celal Bayar University

OTHER

Sponsor Role: collaborator

Ankara Yildirim Beyazıt University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

University of Health Sciences

Ankara, Etlik, Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

2023-350

Identifier Type: -

Identifier Source: org_study_id