The effectiveness of the Copenhagen adduction exercise on improving eccentric hip adduction strength among soccer players with groin injury: a randomized controlled trial

ABSTRACT

Introduction

Groin injuries are common in soccer players and often involve adductor muscle strains. The Copenhagen Adduction Exercise (CAE) is a targeted intervention whose effectiveness in rehabilitation for these injuries warrants investigation.

Objective

To investigate the impact of a rehabilitation program, which includes the CAE, on eccentric hip adduction (EHAD) strength, hip joint range of motion (ROM), self-reported disability, and pain among soccer players with adductor-related groin pain. It was hypothesized that the addition of CAE to the rehabilitation program would yield greater improvements.

Methods

Employing a randomized controlled trial with a two-group parallel design, thirty male soccer players with a mean age of 26.4 ± 3.9 years were randomized into an intervention group (IG) including CAE (n = 15) and a control group (CG) without CAE (n = 15), based on a power analysis to ensure 80% power to detect significant differences. Both groups engaged in their respective rehabilitation programs twice a week for eight weeks. The primary outcome measured was EHAD strength, while secondary outcomes included hip joint ROM, self-reported disability measured by the Copenhagen Hip and Groin Outcome Score (HAGOS), and pain levels.

Results

Significant improvements within groups were observed across all measures (p < 0.001). The IG demonstrated a greater increase in EHAD strength (Mean Difference [MD] = 0.49 Nm/kg, 95% Confidence Interval [CI] [0.31, 0.66]), a more pronounced reduction in pain (MD = -1.60, 95% CI [−2.18, −1.02]), and betterment in all HAGOS subscale scores compared to the CG. There were no significant between-group differences in hip joint ROM.

Conclusion

Incorporating the CAE into rehabilitation programs significantly improves EHAD strength, decreases pain scores, and reduces self-reported disability in soccer players with adductor-related groin pain.

Registration

ClinicalTrials.gov identifier: NCT05589623

KEYWORDS:

• Copenhagen adduction exercise
• groin injuries
• groin rehabilitation
• hip adduction strength
• soccer

Acknowledgements

The authors have no acknowledgments.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

All authors have reviewed and approved the contents of the manuscript.

Availability of data

The datasets used and/or analyzed during the current study are available from the corresponding authors upon reasonable request.

Supplementary Material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00913847.2024.2321958

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.