Nordic Hamstring Exercise Effects on Balance and Strength
New research reveals unexpected connections between posterior thigh training and postural control.
Are you constantly worried about hamstring injuries derailing your training progress? This interesting study reveals how a simple 4-week training protocol could significantly improve your balance and reduce injury risk while building stronger hamstrings.
Key Points
Study Aim
This randomised controlled trial investigated whether a 4-week Nordic Hamstring Exercise (NHE) training program could improve postural balance and muscle strength in recreationally active soccer players, compared to a control group that maintained their regular training routine.
Methods
Researchers recruited 32 university soccer players (average age 21.9 years) with over 5 years of training experience and divided them randomly into two groups. The NHE group performed Nordic hamstring exercises three times per week for four weeks, completing 3 sets of 3 repetitions per session. The control group continued their normal training without NHE intervention.
Balance was measured using the sophisticated Biodex Stability System across three different conditions: standing on both feet on a stable platform with eyes closed, standing on both feet on an unstable platform, and single-leg standing on an unstable platform. The researchers tracked three key balance metrics: Overall Stability Index (OSI), Anterior-Posterior Stability Index (APSI), and Medio-Lateral Stability Index (MLSI). Lower scores indicated better balance control.
Muscle strength was assessed using isokinetic testing to measure peak torque of knee flexors and extensors. All measurements were taken at baseline, after 4 weeks of training, and again at 8 weeks to assess lasting effects.
Results
The NHE group demonstrated remarkable improvements across all balance measures. On the stable platform with eyes closed, the NHE group's Overall Stability Index improved from 0.48 to 0.21 (a 56% improvement), while the control group showed no significant changes. Similar dramatic improvements occurred on unstable surfaces, with the NHE group's balance scores improving by approximately 50-60% across all measures.
Both groups showed improvements for muscle strength, but the NHE group demonstrated significantly greater gains. The statistical analysis revealed strong correlations (r = 0.5 to 0.7) between different stability measures, suggesting that NHE training activates shared mechanisms that influence overall balance control.
Importantly, these improvements were sustained at the 8-week follow-up, indicating that the benefits persisted even after completing the intervention.
Key Mechanistic Insight
The most significant mechanistic finding is that NHE training doesn't just strengthen hamstrings in isolation—it creates a coordinated neuromuscular response that improves postural control through enhanced activation of the entire posterior kinetic chain and core stabilising system. This explains why the balance improvements were sustained at 8 weeks post-training, indicating lasting neuromuscular adaptations rather than temporary strength gains.
This multi-system approach to stability enhancement represents a more comprehensive mechanism than traditional isolated muscle strengthening, which may explain the dramatic 50-60% improvements in balance scores observed in this study.
Related
Practical Takeaways
Immediate Implementation: Add Nordic hamstring exercises to your routine 3 times per week. Start with 3 sets of 3 repetitions, focusing on the slow, controlled lowering phase of the movement.
Injury Prevention Strategy: The study suggests NHE training can reduce hamstring injury risk by up to 51% while simultaneously improving balance and stability - crucial for any athletic activity or heavy lifting.
Progressive Overload: Begin with assisted versions (using hands to help push back up) and gradually progress to unassisted repetitions as your eccentric strength improves.
Training Integration: Perform NHE exercises after your main workout when muscles are warm, or as part of your warm-up routine on lower body days.
Balance Benefits: The improved postural control demonstrated in this study translates directly to better performance in compound movements like squats, deadlifts, and single-leg exercises.
Key Takeaways
This study provides compelling evidence that just 4 weeks of Nordic hamstring exercise training can produce substantial improvements in both balance and muscle strength. The research demonstrates that NHE training doesn't just strengthen hamstrings - it enhances overall neuromuscular control and postural stability through activation of posterior thigh muscles and core stabilisers. For athletes and fitness enthusiasts, this represents a highly efficient injury prevention strategy that requires minimal time investment while delivering maximum protective benefits. The sustained improvements observed at 8 weeks suggest that NHE training produces lasting adaptations in neuromuscular function, making it an essential component of any comprehensive training program focused on performance and injury prevention.
Reference
Podczarska-Głowacka, M., Perzanowska, E., Krasowska, K., Trapik, Z., Kalkowska, A., & Klich, S. (2025). The influence of 4-week eccentric Nordic hamstring exercise training on postural balance and muscle strength: A randomized controlled trial. PLOS ONE, 20(6), e0315459. https://doi.org/10.1371/journal.pone.0315459
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