The Effectiveness of the Copenhagen Adduction Exercise on Soccer Players With Groin Pain or Injury

Groin injuries are among the three most common and time-consuming injuries in soccer, accounting for 19% of all injuries, with 0.1-2.1 injuries per 1000 hours of play. The Copenhagen Adduction Exercise (CAE) has been showing promising results in improving Eccentric Hip Adduction Strength (EHADS), leading to reducing the risk of groin pain and injury. This clinical trial aims to evaluate the effects of CAE on adductors strength, hip joint range of motion (ROM), and Patient-reported outcome measures among athletes with groin pain or injury.

The main question it aims to answer is:

Does the CAE improve EHAD strength, hip joint ROM, and patient-reported outcome measures among soccer players with groin pain or injury?

Researchers will assess the participants' pre and post-intervention to determine the effects of CAE on adductors strength, hip joint ROM, and Patient-reported outcome measures.

Study design: A Double-Blinded Randomized Controlled Trial.

Researchers will allocate a specific number for each participant for randomization. Then, an online website will be applied to randomize these numbers into two groups, intervention and control groups. An independent person not involved in the study will allocate the participants using concealed opaque envelopes.

Study setting:

This study will be held at different physical therapy and rehabilitation clinic, ministry of health, Saudi Arabia

Recruitment and study population:

Participants will be recruited from physical therapy outpatient clinics in the South region.

Participants will be recruited and randomized into two groups, intervention (CAE) and control. Participants assigned to the intervention group will receive the CAE in addition to the regular physical therapy rehabilitation program for eight weeks. Due to the heaviness and the high dynamic demands of CAE, a modified progressive Copenhagen adduction (MPCA) program has been created. The MPCA was adapted from the original CAE to lessen the risk of delayed onset muscle soreness (DOMS) and facilitate high participant compliance.

Participants assigned to the control group will receive the same physical therapy rehabilitation program as the intervention group except for the CAE.

Time plan of the study:

Recruitment is expected to commence in January 2023 and conclude in April 2023. After completing the recruitment process, data will be collected for eight weeks. After the last inclusion, the intervention will continue for eight weeks.

Assessment:

An experienced physiotherapist, blinded to the study, will perform all assessments to guarantee that the tests are consistent and that the process is standardized. Assessments will be at baseline and post-intervention. The duration between the baseline assessment and the start of the intervention should not exceed two weeks. After the assessment, every participant will receive the proper group intervention according to his/her randomization. Participants will be told not to reveal their group assignments to the assessor during the study period.

Demographic variables and descriptive:

The investigators will document the following variables: age, sex, height, BMI, Sports level, duration of symptoms, and location of symptoms as recommended by the minimum reporting criteria for clinical research on groin pain in athletes.

Sample size estimation:

The sample size calculation for this study was performed using G\*Power software (v. 3.1, Heinrich-Heine-Universität, Düsseldorf, Germany), with an alpha level of 0.05 and a power (1-β) of 80%. Based on a previous study examining the effects of exercise therapy on adductor-related groin pain in athletes, it required 15 participants per group to detect an expected between-group difference of 0.15 Nm/kg and a standard deviation (SD) of 0.54 Nm/kg.

Statistical analysis:

All analyses will be performed using the Statistical Package for the Social Sciences version 27. The study's findings will be presented following the Consolidated Standards of Reporting Trials (CONSORT). Shapiro-Wilk test will be used to test for normality. The statistical analysis test will be carried out based on the collected data. Demographic data will be presented as mean and standard deviation. The suggested statistical analysis measure will be the repeated measures analysis of variance (ANOVA), calculated for each dependent variable. Each repeated measure ANOVA will have one within factor (test: pre and post) and one between factor (group: training and control). Results will be significant at P value \<0.05 and a Confidence Interval (CI) of 95%. A statistician will be consulted for further correction after data collection.

Eligibility Criteria:
Inclusion Criteria:

* Soccer players aged between 18 to 40 years.
* They have groin pain or injury within two months during sports.
* Pain or tenderness on palpation of adductors in clinical examination.
* Pain on resisted hip adduction movement in clinical examination.
* Desire to continue the sport at the same level.

Exclusion Criteria:

* Groin pain or injury not involving the adductors on clinical examination.
* They have any clinical finding indications of femoral or inguinal hernia.
* Evidence of prostatitis, chronic urinary tract disease.
* Evidence of hip joint osteoarthritis or hip joint disease.
* Bursitis of the hip or groin region.