Harøy, Thorborg, Serner, Bjørkheim, Rolstad, Hölmich, Bahr & Andersen (2017) Including the copenhagen adduction exercise in the FIFA 11+ provides missing eccentric hip adduction strength effect in male soccer players: A randomized controlled trial.

Background The FIFA 11+ was developed as a complete warm-up program to prevent injuries in soccer players. Although reduced hip adduction strength is associated with groin injuries, none of the exercises included in the FIFA 11+ seem to specifically target hip adduction strength.
Purpose To investigate the effect on eccentric hip adduction strength of the FIFA 11+ warm-up program with or without the Copenhagen Adduction exercise.
Study Design Randomized Controlled Clinical Trial
Methods: We recruited 45 eligible players from two U19 elite male soccer teams. Players were randomized into two groups; one group carried out the standard FIFA 11+ program, while the other carried out the FIFA 11+, but replaced the Nordic Hamstring exercise with the Copenhagen Adduction exercise. Both groups performed the intervention three times weekly for 8 weeks. Players completed eccentric strength and sprint testing before and after the intervention. Per-protocol analyses were performed, with 12 players excluded due to low compliance (<67% of sessions completed).
Main Outcome Eccentric hip adduction strength (Nm/kg).
Results Between-group analyses showed that there was a significant greater increase in eccentric hip adduction strength of 0.29 Nm/kg (8.9%, p=0.01) in favor of the group performing the Copenhagen Adduction exercise, while there was no within-group change in the group that used the standard FIFA 11+ program (-0.02 Nm/kg (-0.7%), p=0.69).
Conclusion Including the Copenhagen Adduction exercise in the FIFA 11+ program increases eccentric hip adduction strength, while the standard FIFA 11+ program does not.

Ishøi, Sørensen, Kaae, Jørgensen, Hölmich & Serner (2016) Large eccentric strength increase using the C openhagen A dduction exercise in football: A randomized controlled trial

Hip adductor injuries are frequent in football, and players with low adductor strength appear to be at increased risk of injury. High adductor muscle activity has been shown in the Copenhagen Adduction exercise (CA); however, an associated strength gain has not been investigated. This study aims to examine the eccentric hip adduction strength (EHAD) gain using the CA in‐season. Two U‐19 sub‐elite football teams, including 24 football players, were randomized to either an 8‐week supervised progressive training program in addition to the usual training (intervention) or to continue training as usual (control). EHAD, eccentric hip abduction strength (EHAB), and side‐bridge endurance were measured using reliable test procedures at baseline and follow‐up by a blinded tester. There was a significant interaction between group and time on EHAD, EHAB, and EHAD/EHAB ratio (P < 0.025). The intervention group demonstrated a 35.7% increase in EHAD (P < 0.001); a 20.3% increase in EHAB (P = 0.003), and 12.3% increase in EHAD/EHAB ratio (P = 0.019). No significant within‐group differences were found in the control group (P > 0.335). Compliance was 91.25%, and median muscle soreness ranged from 0 to 2. The CA implemented in‐season with an 8‐week progressive training program elicited a large significant increase in EHAD, EHAB, and EHAD/EHAB ratio.

Hölmich, P, Uhrskou, P, Ulnits, L, Kanstrup, IL, Nielsen, MB, Bjerg, AM & Krogsgaard, K (1999) Effectiveness of active physical training as treatment for long-standing adductor-related groin pain in athletes: randomised trial

Background Groin pain is common among athletes. A major cause of long-standing problems is adductor-related groin pain. The purpose of this randomised clinical trial was to compare an active training programme (AT) with a physiotherapy treatment without active training (PT) in the treatment of adductor-related groin pain in athletes.
Methods 68 athletes with long-standing (median 40 weeks) adductor-related groin pain—after examination according to a standardised protocol—were randomly assigned to AT or PT. The treatment period was 8–12 weeks. 4 months after the end of treatment a standardised examination was done. The examining physician was unaware of the treatment allocation. The ultimate outcome measure was full return to sports at the same level without groin pain. Analyses were by intention to treat.
Findings 23 patients in the AT group and four in the PT group returned to sports without groin pain (odds ratio, multiple-logistic-regression analysis, 12·7 [95% CI 3·4–47·2]). The subjective global assessments of the effect of the treatments showed a significant (p=0·006) linear trend towards a better effect in the AT group. A per-protocol analysis did not show appreciably different results.
Interpretation AT with a programme aimed at improving strength and coordination of the muscles acting on the pelvis, in particular the adductor muscles, is very effective in the treatment of athletes with long-standing adductor-related groin pain. The potential preventive value of a short programme based upon the principles of AT should be assessed in future, randomised, clinical trials.

Sailly, M, Whiteley, R, Read, JW, Giuffre, B, Johnson, A & Hölmich, P (2015) Pubic apophysitis: a previously undescribed clinical entity of groin pain in athletes

Background Sport-related pubalgia is often a diagnostic challenge in elite athletes. While scientific attention has focused on adults, there is little data on adolescents. Cadaveric and imaging studies identify a secondary ossification centre located along the anteromedial corner of pubis beneath the insertions of symphysial joint capsule and adductor longus tendon. Little is known about this apophysis and its response to chronic stress.
Aim We report pubic apophysitis as a clinically relevant entity in adolescent athletes.
Methods The clinical and imaging findings in 26 highly trained adolescent football players (15.6 years ±1.3) who complained of adductor-related groin pain were reviewed. The imaging features (X-ray 26/26, US 9/26, MRI 11/26, CT 7/26) of the pubic apophyses in this symptomatic group were compared against those of a comparison group of 31 male patients (age range 9–30 years) with no known history of groin pain or pelvic trauma, who underwent pelvic CT scans for unrelated medical reasons.
Results All symptomatic subjects presented with similar history and physical findings. The CT scans of these patients demonstrated open pubic apophyses with stress- related physeal changes (widening, asymmetry and small rounded cyst-like expansions) that were not observed in the comparison group. No comparison subject demonstrated apophyseal maturity before 21 years of age, and immaturity was seen up to the age of
26 years.
Conclusions This retrospective case series identifies pubic apophyseal stress (or ‘apophysitis’) as an important differential consideration in the adolescent athlete who presents with groin pain

Serner, A, Jakobsen, MD, Andersen, LL, Hölmich, P, Sundstrup, E & Thorborg, K (2014) EMG evaluation of hip adduction exercises for soccer players: implications for exercise selection in prevention and treatment of groin injuries

Introduction Exercise programmes are used in the prevention and treatment of adductor-related groin injuries in soccer; however, there is a lack of knowledge concerning the intensity of frequently used exercises.
Objective Primarily to investigate muscle activity of adductor longus during six traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals.
Materials and methods 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally for the adductor longus during eight hip adduction strengthening exercises and peak EMG was normalised (nEMG) using an isometric maximal voluntary contraction (MVC) as reference. Furthermore, muscle activation of the gluteus medius, rectus abdominis and the external abdominal obliques was analysed during the exercises.
Results There were large differences in peak nEMG of the adductor longus between the exercises, with values ranging from 14% to 108% nEMG (p<0.0001). There was a signi!cant difference between legs in three of the eight exercises (35–48%, p<0.0001). The peak nEMG results for the gluteals and the abdominals showed relatively low values (5–48% nEMG, p<0.001).
Conclusions Specific hip adduction exercises can be graded by exercise intensity providing athletes and therapists with the knowledge to select appropriate exercises during different phases of prevention and treatment of groin injuries. The Copenhagen Adduction and the hip adduction with an elastic band are dynamic high-intensity exercises, which can easily be performed at any training facility and could therefore be relevant to include in future prevention and treatment programmes.

Serner, A, Tol, JL, Jomaah, N, Weir, A, Whiteley, R, Thorborg, K, Robinson, M & Hölmich, P (2015) Diagnosis of acute groin injuries: a prospective study of 110 athletes

Background Acute groin injuries are common in high-intensity sports, but there are insufficient data on injury characteristics such as injury mechanisms and clinical and radiological findings.
Purpose To describe these characteristics in a cohort of athletes.
Study Design Cross-sectional study; Level of evidence, 3.
Methods A total of 110 male athletes (mean age, 25.6 ± 4.7 years) with sports-related acute groin pain were prospectively included within 7 days of injury from August 2012 to April 2014. Standardized history taking, a clinical examination, magnetic resonance imaging (MRI), and/or ultrasound (US) were performed.
Results The most frequent injury mechanism in soccer was kicking (40%), and change of direction was most frequent in other sports (31%). Clinically, adductor injuries accounted for 66% of all injuries and primarily involved the adductor longus on imaging (91% US, 93% MRI). The iliopsoas and proximal rectus femoris were also frequently injured according to all examination modalities (15%-25%). Acute injury findings were negative in 22% of the MRI and 25% of the US examinations. Of the clinically diagnosed adductor injuries, 3% (US) and 6% (MRI) showed a radiological injury in a different location compared with 35% to 46% for clinically diagnosed iliopsoas and proximal rectus femoris injuries.
Conclusions Adductor injuries account for the majority of acute groin injuries. Iliopsoas and proximal rectus femoris injuries are also common. More than 1 in 5 injuries showed no imaging signs of an acute injury. Clinically diagnosed adductor injuries were often confirmed on imaging, whereas iliopsoas and rectus femoris injuries showed a different radiological injury location in more than one-third of the cases. The discrepancy between clinical and radiological findings should be considered when diagnosing acute groin injuries.

Weir, A, Brukner, P, Delahunt, E, Ekstrand, J, Griffin, D, Khan, KM, Lovell, G, Meyers, WC, Muschaweck, U, Orchard, J & Paajanen, H (2015) Doha agreement meeting on terminology and definitions in groin pain in athletes

Background Heterogeneous taxonomy of groin injuries in athletes adds confusion to this complicated area.
Aim The ‘Doha agreement meeting on terminology and definitions in groin pain in athletes’ was convened to attempt to resolve this problem. Our aim was to agree on a standard terminology, along with accompanying definitions.
Methods A one-day agreement meeting was held on 4 November 2014. Twenty-four international experts from 14 different countries participated. Systematic reviews were performed to give an up-to-date synthesis of the current evidence on major topics concerning groin pain in athletes. All members participated in a Delphi questionnaire prior to the meeting.
Results Unanimous agreement was reached on the following terminology. The classification system has three major subheadings of groin pain in athletes:
1. Defined clinical entities for groin pain: Adductor-related, iliopsoas-related, inguinal-related and pubic-related groin pain.
2. Hip-related groin pain.
3. Other causes of groin pain in athletes.
The definitions are included in this paper.
Conclusions The Doha agreement meeting on terminology and definitions in groin pain in athletes reached a consensus on a clinically based taxonomy using three major categories. These definitions and terminology are based on history and physical examination to categorise athletes, making it simple and suitable for both clinical practice and research.

Whittaker, JL, Small, C, Maffey, L & Emery, CA (2015) Risk factors for groin injury in sport: an updated systematic review

Background The identification of risk factors for groin injury in sport is important to develop and implement injury prevention strategies.
Objective To identify and evaluate the evidence examining risk factors for groin injury in sport.
Material and methods Nine electronic databases were systematically searched to June 2014. Studies selected met the following criteria: original data; analytic design; investigated a risk factor(s); included outcomes for groin injury sustained during sport participation.
The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed and two independent authors assessed the quality and level of evidence with the Downs and Black (DB) criteria and Oxford Centre of Evidence-Based Medicine model, respectively.
Results Of 2521 potentially relevant studies, 29 were included and scored. Heterogeneity in methodology and injury definition precluded meta-analyses. The most common risk factors investigated included age, hip range of motion, hip adductor strength and height. The median DB score across studies was 11/33 (range 6–20). The majority of studies represented level 2 evidence (cohort studies) however few considered the inter-relationships between risk factors. There is level 1 and 2 evidence that previous groin injury, higher-level of play, reduced hip adductor (absolute and relative to the hip abductors) strength and lower levels of sport-specific training are associated with increased risk of groin injury in sport.
Conclusions We recommended that investigators focus on developing and evaluating preparticipation screening and groin injury prevention programmes through high- quality randomised controlled trials targeting athletes at greater risk of injury.

Tristan Chai