Posterior Chain EMG Patterns in Athletes With and Without Hamstring Injury

Ankara Yildirim Beyazıt University

Status: Completed

Conditions: Muscle Strain; Athletic Injuries; Neuromuscular Diseases

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

Study type: Observational

Funder types: Other

Identifiers

NCT07171385

2023-350

Details and patient eligibility

About

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.

Enrollment: 42 patients

Sex: Male

Ages: 18 to 30 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

42 participants in 2 patient groups

Injured Group

Description:

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).

Treatment:

Other: Supine Sliding Single-Leg Curl (SSLC)

Other: Nordic Hamstring Curl (NHC)

Other: Kettlebell Swing (KS)

Healthy Control Group

Description:

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).

Treatment:

Other: Supine Sliding Single-Leg Curl (SSLC)

Other: Nordic Hamstring Curl (NHC)

Other: Kettlebell Swing (KS)