The effect of training of the non-dominant knee muscles on ipsi- and contralateral strength gains
BACKGROUND: Although transfer of unilateral training has been quite widely explored, few studies have focused on gains achieved due to concentric isokinetic training of the non-dominant side. OBJECTIVE: To examine the effects of unilateral non-dominant (ND) isokinetic knee extension and flexion training at 60◦/s on ipsilateral and contralateral knee extension and flexion peak moment (PM) in active female population as well investigate the speed specificity nature of this protocol. METHODS: Thirty female were divided into two groups: experimental and control. The experimental group trained concentrically the ND flexors and extensors at 60◦/s according to the following protocol: 5–6 reps X 2–4 sets X 3d X 4w at 100% effort while PM at preand post-training was tested concentrically at 60 and 180◦/s. RESULTS: Significant (p < 0.05) increases in the extensors and flexors PM peak moment in both the trained and untrained limb were noted in the experimental group, ranging 19–27% and 12–17%, respectively. The effects were speed specific in the trained but not in untrained limb. No changes were noted in the PM of the control group. CONCLUSIONS: In physically active female population, concentric isokinetic training of the ND knee extensors and flexors at 60◦/s significantly increase the strength of these muscles at the trained and untrained limb. This cross-education was not speed specific and therefore may obviate the need to use a multiple speed protocol.