Yesterday, a large proportion of the athletes based at the UK Athletics’ Lee Valley Hi-Performance Centre flew out to California for a 6 week block of warm weather training. Almost on cue, the sun has come out & temperatures in North East London have soared, meaning that conditions here are warmer than those in Los Angeles! I seem to remember the same thing happening last year.
The warm weather camp I am scheduled to cover takes place in a few weeks time in Portugal & so, whilst looking after the few remaining athletes training here, I am taking the opportunity to catch up on several areas of practice that I have been interested in of late.
Following the Sporting Hip & Groin course that I went on in Edinburgh at the end of last month, I have been revising the course material & reading around the references that were cited. I also have managed to spend a couple of sessions with James (Moore) reviewing the practical elements of the weekend, which has been really useful.
The following summary is based upon my personal clinical experience, James’ Sporting Hip & Groin course, the papers I have read whilst reviewing the course material, in addition to discussions I had in Monaco last year with Per Holmich & Kristian Thorburg.
EPIDEMIOLOGY
The incidence of hip & groin pain in sport has probably been best documented in football (soccer for my North American friends) & ice hockey, with papers by Nielsen & Yde (1989), Ekstrand & Hilding (1999) & Pettersson & Lorentzon (1993) reporting that around 10-20% of all injuries in the two sports are hip & groin injuries. However, Thorburg et al (2010) & Thorninger & Lyskesmerter (2004) put the prevalence of hip & groin injuries in elite Danish football to between 40 – 70% of all injuries. Either way, the figures are indicative of a significant problem.
The issue with this reporting of “hip & groin” pain, however automatically groups a large number of different pathological conditions under one umbrella. The hip & groin region is a very intricate anatomical architectural complex with the relationship between the adductors, abdominals & hip joints influencing presentation & challenging the clinician in search of a differential diagnosis, which is often found to be multi-factorial on thorough investigation. Furthermore, the varied terms coined across the globe for the same conditions introduce further scope for confusion.
ADDUCTOR PATHOLOGY
In this post, I am going to concentrate on the adductor piece of the puzzle, as this is the area I see most involved in our sprinters, this is because the adductor longus aids in hip flexion, acts as a stabiliser in weight-bearing single leg stance & also decelerates the hip into hip extension to then prepare the femur for hip flexion. As a result of the latter demand, weak hip flexors will overload the longus. The adductor brevis works with the hip abductors to stabilise the pelvis during the stance phase, whilst the pectineus acts as an adductor in hip flexion but otherwise acts as a hip flexor.
In Australian Rules Football, the demands of kicking on the move also lead to overloaded adductors & Orchard (2003) reports adductor strains accounting for 22% of AFL injuries.
Muscle injuries of the adductors include bony avulsions, enthesopsthies (stress caused by the tendon-bone junction getting overloaded, which can lead to an avulsion of the fibrocartilage in extreme cases) & tears of the musculo-tendinous junction.
Bone & joint issues involving the adductors focus around the pubic joint, as this is the area where the adductors & the abdominals communicate & transfer load. As a result it is sports that demand agility, whilst incorporating kicking (eg. Rugby, AFL & soccer) that demonstrate the highest incidences of groin pain presentations with underlying pubic symphysis pathology.
James points to a paper by Verrall (2007) that identifies the following factors as contributing to pubic bone overload:
- Lumbar spine/sacroiliac joint dysfunction
- Increased rectus abdominus tone
- Shortened iliopsoas muscle
- Increased adductor tone
- Decreased lumbopelvic stability
- Limited hip range of movement
Male athletes are most commonly affected as the recto-gracillis ligament is smaller & weaker than in females. Therefore those presenting initially after an increased training load with a gradual onset of groin pain & weakness, a loss of kicking length or running speed (able to retain the explosiveness but the top end power is missing) & poor performance, where the pain hasn’t been significant enough to miss the game, should start to raise concern of a pubic bone overload.
If not addressed, in acknowledging the relationship between the adductors & abdominals, by training them concurrently, symptoms will progress to pain with kicking, running & cutting movements, abdominal contractions & whilst rolling in bed or sit to stand.
Neural factors affecting the adductor presentation relate to the obturator nerve, which given the proximity between the adductor longus, adductor brevis & pectineus, can get fascially entrapped. This presents as an area of pain & paraesthesia in the medial aspect of the thigh, with an associated adductor weakness brought about by exercise. In chronically adhered tissue, the restriction can lead to a proximal overload which can bring about an adductor tendinopathy or pubic bone stress injury (Bradshaw, 1997).
Pain provocation tests should include:
Squeeze tests at 0/60 & 90 degrees, which assess the pubic joint’s ability to take a compressive load. The most provocative, is the 60 degree test & positive findings will suggest a pubic joint injury.
A bilateral adductor test in straight leg, hip flexion (about 5 inches off the plinth), which tests the functional load capacity of the anterior chain to contribute to force closure of the pelvis & as the abdominals are recruited along with the adductors & hip flexors, this acts as a good clinical test for coronal plane & change of direction capabilities.
The pubic symphysis stress tests can then be performed in a Modified Thomas Test position in an attempt to provoke symptoms under passive & active load, in both coronal & sagittal planes. These positions systematically wind up the compression across the pubic symphysis.
Adductor muscle tone & length should be tested in both long lever tests & short adductor length tests (using a Faber’s), whilst the bent knee fall out test highlights adductor muscle guarding.
In the meantime, please feel free to contribute to the above review & if you are looking to upskill in this area of clinical practice, I can recommend registering for James’ course!!
