RELIABILITY AND COMPARISON OF FORCE CHARACTERISTICS OF THE NODIC HAMSTRING EXERCISE

The purpose of the current study was to ascertain the between-trial reliability of peak force (PF) and mean force (MF) during the Nordic hamstring exercise (NHE) performed on the Nordbord and determine bilateral differences in PF, MF and instantaneous force (IF). Nineteen strength-trained males performed three NHEs on the Nordbord. PF showed a trivial-small non-significant increase between trials (d = 0.15 – 0.29, p = 0.125 – 0.459), MF was significantly higher in the left limb in trial 3 compared to trial 1 (p = 0.021 d = 0.29).  Reliability and variability of PF was moderate-excellent (95%CI ICC = 0.666 – 0.926) and acceptable (CV <10%), respectively, MF was poor-good (95%CI ICC = 0.413 – 0.835) and unacceptable (CV >10%) across trials. Reliability and variability of PF and MF, between trials 2 and 3 were moderate-excellent (95%CI ICC = 0.627 – 0.950,) and acceptable (CV <10%). No between limb-differences in PF were observed (p = 0.071; d = 0.16), however, significant-small differences (p = 0.005; d = 0.34) were evident in MF. IF was higher for the right limb between 10 and 89% of normalized time across trials 1-3 but was not significant across trials 2-3. There were no significant (p ≥0.05) between limb differences in PF, but significant-small between limb differences in MF (p = 0.005, d = 0.26-0.34). Reliability of Nordbord PF were moderate-excellent; however. Practitioners should use >3 repetitions of the NHE and  disregard the first repetition, while including analysis of MF and IF.