Altering hamstring peak torque-angle: a comparison of the Romanian dead-lift and Nordic hamstring exercise

The purpose of this study was to investigate whether a shift in hamstring peak torqueangle (PT-A) was greater in magnitude following a training intervention that utilised either an exercise performed at long muscle lengths such as the Romanian dead-lift (RDL), or an exercise performed at short muscle lengths such as the Nordic hamstring exercise (NHE). Twelve strength-trained males were randomly allocated into 3 groups, Control (CON), RDL and NHE. A pre-test-post-test experimental design was utilised, with the RDL and NHE groups performing 10 sessions over 5 weeks of progressive resistance training. PT-A was assessed using an isokinetic dynamometer (seated with 90° of hip flexion) with isometric contractions randomly performed at 5 different knee angles (15°, 30°, 45°, 60°, 75°). Non-parametric statistical analysis revealed that there was no significant difference between pre and post testing for PTA (P < 0.05) or peak torque (PT) (P < 0.05). However, effect size calculations revealed the NHE had a large effect (d = -1.0) in PT-A, and the RDL had a large effect (d = 1.14) in PT pre-post testing. There was no significant difference between groups for PT-A (P < 0.05) or PT (P < 0.05) however, the NHE expressed a small effect (d = -0.31) in PT-A in comparison to the RDL, but the RDL expressed a large effect (d = 0.98) in PT when compared to the NHE. Limitations including the sample size reduced the statistical power of this study, however this research may be used as a pilot for future investigations.