An Examination of the Anatomical and Biomechanical Diagnoses That Exist in Athletic Groin Pain Patients and the Effects of a Biomechanics Led Rehabilitation Intervention in These Same Patients

Athletic groin pain (AGP) is a chronic condition common in multi-directional sports (Walden et al. 2007, Robinson et al. 2004, Murphy et al. 2012). It is a complex injury with a challenging diagnosis. Dramatic differences in the anatomical diagnoses of AGP cohorts exist in the literature (Renstrom et al. 1980, Lovell et al. 1995, Holmich et al. 2007, Bradshaw et al. 2008). This may be due to the complexity of the anatomy in the region and the absence of magnetic resonance imaging (MAGNETIC RESONANCE IMAGE) to confirm clinical examination.

Dynamic actions undertaken in field sports (including change of direction cutting) are particularly associated with the development of athletic groin pain (Holmich et al. 2014). Dynamic multi-plane, multi-joint actions can overload musculoskeletal and fascial structures in the hip and groin. Despite this, traditional groin pain assessments do not involve an examination of sport specific actions. An examination of jumping, hopping and cutting mechanics, which is possible with the use of three dimensional motion capture techniques, will provide additional information with which to diagnosis and rehabilitate athletes.

While the majority of published studies on AGP have focused on surgical management (Serner et al. 2015), exercise therapy has been found to be an effective treatment (Holmich et al. 1995). In exercise therapy studies the best results were shown by Holmich et al (1995) where subjects suffered for an average of 9.9 months with symptoms and a strength and stability program focused on adductor strength returned them to sport in 18.5 weeks. The latest paper on rehabilitation by Jardi et al. demonstrates little improvement with a mean time to return to training of 86 days +/-15. The focus remains on improving strength of isolated muscle groups and not attempting to address underlying biomechanical abnormalities that may be leading to overload. Accurate biomechanical assessment and individualized rehabilitation based on the high speed multiplanar movements that drive the athlete's symptoms may enhance the efficiency of rehabilitation. Moreover post-rehabilitation changes in biomechanical factors may provide a further insight into the biomechanical factors associated with AGP.

The purpose of this study was to:

1. Describe clinical presentation (physical examination and magnetic resonance imaging findings) for a group of athletes presenting with AGP
2. To describe the different biomechanical diagnoses that exist in AGP patients
3. To examine the effects of a biomechanics led exercise intervention to rehabilitate chronic groin pain

It is hypothesised that standardised magnetic resonance imaging will aid in the anatomical diagnosis of athletic groin pain patients. From a biomechanics perspective, distinct subgroups/clusters will exist that differ from each other in how they undertake dynamic sport specific actions. These distinct clusters will describe potential biomechanical diagnoses that exist in groin pain patients. A biomechanics led rehabilitation program will return groin pain patients back to sport more quickly than previous rehabilitation programs without biomechanical diagnostic information.

Brief protocol Participants will be recruited from patients with chronic athletic groin pain who present for investigation and rehabilitation at Sports Surgery Clinic, Ireland. A standardised clinical examination will be undertaken including range of motion assessment, pain provocation and load tolerance tests, and palpation.

A Magnetic Resonance Image of the hip and groin region will then be undertaken and read by a consultant sports physician.

Biomechanical assessment will include capturing of jumping, hopping and cutting mechanics through the use of three dimensional motion capture technology and force plates. Here reflective markers are placed on the skin at anatomical landmarks. These markers are picked up by the cameras and tracked at 200 frames per second. Participants will contact the force plate with their foot on undertaking the movements. Force and marker data will be combined to calculate joint angles and moments.

Physical therapy assessment will include an assessment of functional movement, range of motion testing, adductor squeeze tests, strength assessment of hip and trunk. Physiotherapists will utilise three dimensional biomechanical data during cutting and landing to inform individualised rehabilitation. Rehabilitation will consist of movement control, whole body strength and power, linear running mechanics, multi-directional mechanics and conditioning sessions. Participants will have follow up physical therapy appointments approximately every two weeks. A hip and groin outcome score (HAGOS) will be used to monitor the morbidity and severity of the injury throughout the rehabilitation process.

Once the physiotherapist determines that the patient is ready to return to play a biomechanical re-test will be undertaken.