Traditional and Band-Assisted Nordic Hamstring Training Improves Knee Flexor Strength and Hip Range of Motion

Purpose. To compare the training effects of traditional (TRAD) and band‑assisted (NHEASSIST) Nordic Hamstring Exercise on knee flexor force‑length characteristics, NHE execution, and hip range of motion (ROM). Methods. Forty-five male (n = 24) and female (n = 21) collegiate athletes were recruited from a variety of sports (soccer, basketball, Gaelic football, rugby, athletics, and netball) to partake in a twice-weekly eight-week TRAD or NHEASSIST training programme; 30 participants completed the intervention with ≥80% adherence. Knee flexor force production capacity (eccentric and isometric [at various lengths]), NHE execution, and hip ROM were examined pre- and post-training. Soreness was self-reported up to 48 h post-training using a visual analogue scale. Results. No significant (p <0.05) group × time interaction effects nor main effects of group were revealed for any metric. Main effects of time revealed significant increases in eccentric (17 ± 19%) and isometric force at longer muscle lengths (180° [full extension] and 150° knee flexion; 9-12 ± 20-22%), break point angle (10 ± 11°), and impulse (139 ± 159%), and hip ROM (5 ± 6°) in both groups after training; larger effect sizes occurred within NHEASSIST compared to TRAD regarding force production capacity, break point angle, impulse, and hip flexion ROM. Conclusion. Eight weeks of NHE improved knee flexor strength (particularly at longer muscle lengths), NHE execution, and hip flexion ROM. NHEASSIST did not confer statistically different adaptations than TRAD; however, early‑phase soreness was transiently lower with NHEASSIST. Larger, standardised, and mechanistically informed trials are warranted to determine whether assistance meaningfully augments adaptations.