Persistent Neuromuscular Deficits in the Posterior Kinetic Chain Following Hamstring Strain Injury: A Cross-Sectional Study Using EMG
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 42
- Locations
- 1
- Primary Endpoint
- Gluteus Maximus Activation (%MVIC)
Study Overview
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.
Study Design
- Study Type
- Observational
- Observational Model
- Other
- Time Perspective
- Cross Sectional
Eligibility Criteria
- Ages
- 18 Years to 30 Years (Adult)
- Sex
- Male
- Accepts Healthy Volunteers
- Yes
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
Outcomes
Primary Outcomes
Gluteus Maximus Activation (%MVIC)
Time Frame: Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)
Surface EMG amplitude (RMS) normalized to MVIC, averaged across three functional exercises. Mean %MVIC compared between groups.
Biceps Femoris Long Head Activation (%MVIC)
Time Frame: Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)
Surface EMG amplitude (RMS) normalized to MVIC. Mean %MVIC across repetitions compared between injured and healthy athletes.
Latissimus Dorsi Activation (%MVIC)
Time Frame: Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)
Surface EMG amplitude (RMS) normalized to MVIC, averaged across three functional exercises. Mean %MVIC compared between groups.
Iliocostalis Lumborum Activation (%MVIC)
Time Frame: Single laboratory visit; measurements during 3 repetitions of each exercise (Nordic Hamstring Curl, Kettlebell Swing, Supine Sliding Single-Leg Curl)
Surface EMG amplitude (RMS) normalized to MVIC. Mean %MVIC across repetitions compared between injured and healthy athletes.
Secondary Outcomes
No secondary outcomes reported