Eccentric strength increase using the Copenhagen exercise
This randomized controlled trial found a significant increase of 36% in eccentric hip adduction strength (EHAD) and a 20% increase in eccentric hip abduction (EHAB) strength after a 8-week Copenhagen adduction exercise (CA) protocol in sub-elite football players. Increasing hamstring eccentric strength has been shown to reduce hamstring injuries. Thus, the CA seems a promising way of reducing adductor-related injuries in footballers.
Hip adductor muscle injuries are the most common acute groin injury in athletes. Weak hip adduction strength has shown to be a risk factor for sustaining hip adductor injuries. There are only few trials concerning groin injury prevention, involving complex programs with no significant effects. A simpler, dynamic alternative like the CA could provide an implementation advantage.
20 players from 2 under-19 sub-elite football clubs were randomly allocated to intervention and control groups. The intervention group performed a 8-week protocol of the Copenhagen Adduction exercise (CA). Players performed 2 sessions/ week containing 2-3 sets of 6-15 repetitions. Outcome measures were maximal EHAD, EHAB, lateral abdominal endurance and EHAD/ EHAB ratio. Mean differences pre-and post intervention and between groups were assessed.
EHAD, EHAB and EHAD/ EHAB ratio showed significant increases of 35.7%, 20.3% and 12.3% in the intervention group. These results show, albeit in a small sample, that a simple, dynamic exercise can have a significant effect in EHAD. Increases in eccentric strength and optimization of the length-tension relationship have shown to reduce hamstring injuries in footballers. Thus, the CA seems a promising method of reducing adductor-related groin injuries in footballers.
> From: Ishøi et al., Scand J Med Sci Sports 26 (2017) 1334-1342(Epub ahead of print). All rights reserved to John Wiley & Sons, Ltd. Click here for the online summary.