Longlasting adduction-related groin injuries in athletes; regular care or a novel treatment approach

INTERVENTION: Two different kinds of physiotherapeutic treatments are given for the population. Both treatment strategies are already in use in daily practice. Patients are randomised to receive either pelvic‐stabilizing muscle training or usual care CONDITION: Groin pain ; Signs and Symptoms ; Groin pain PRIMARY OUTCOME: 1. Severity of the pain over the last three days (11‐point visual analogue scale [VAS]); 2. Participation in sports (11‐point VAS‐scale); 3. General disability (adapted Quebec low back pain disability scale); 4. Global change (six‐point Likert scale); 5. How long before return to full athletic activity; 6. Recurrences of the same complaints; Parameters 1, 2, 3 are measured before and directly after the period of treatment and 26 and 52 weeks after the start of treatment. ; Parameters 4, 5 and 6 are only measured at 26 and 52 weeks after treatment. SECONDARY OUTCOME: 1. Hip adduction strength (hand‐held dynamometer);; 2. Contraction pattern of the abdominal musculature (ultrasound echografie);; 3. Active straight leg raise test (ASLR). INCLUSION CRITERIA: Male athletes, 18‐45 years old, hip adduction‐related complaints, for a period of at least six weeks, strong desire to compete in sports.