Exploring the effects of a weighted vs unweighted low-dose isometric Copenhagen adduction exercise training programme on hip adduction and abduction strength: a randomised controlled trial in senior-level male amateur rugby union players.

OBJECTIVES

To explore the effect of an isometric weighted Copenhagen adduction (WCA) exercise programme and an isometric unweighted Copenhagen adduction (CA) exercise programme on hip adduction strength, abduction strength and adduction:abduction strength ratio.

DESIGN

Randomized controlled trial, with flat outcome structure.

SETTING

Rugby training facility.

PARTICIPANTS

Thirty-one male rugby players.

MAIN OUTCOME METHODS

Between-group differences in hip adduction strength, abduction strength and adduction:abduction ratio were assessed using independent-sample t-tests. Within-group differences in hip strength were assessed using paired-sample t-tests.

RESULTS

15 participants were assigned to the CA group and sixteen to the WCA group. Post-intervention, a significant between-group difference in hip adduction:abduction strength ratio was observed (0.09 Nm/kg, p = 0.032) with large effect size (ES = 0.812). No significant between-group differences were evident for hip adduction strength (0.21 Nm/kg, p = 0.058) or hip abduction strength (0.01 Nm/kg, p = 0.856). The WCA group demonstrated significant increases in hip adduction (0.22 N/kg, +10 %, p = 0.008) and hip adduction:abduction ratio (0.06 N/kg, +7 %, p = 0.036), but not hip abduction (0.08 N/kg, +4 %, p = 0.055), following the 8-week programme. No significant changes in hip strength were observed in the CA group.

CONCLUSIONS

A low-dose 8-week adductor exercise programme using the isometric WCA exercise elicits significant increases in hip adduction:abduction strength ratio when compared to an isometric CA exercise.