Sam Blanchard is a senior lecturer in physiotherapy at the University of Brighton and co-writer for plinthsandplatforms.wordpress.com. He joins us today to talk about groin pain and the issues that surround it. Sam has a great lecture coming up on exercise prescription and is playing a key role in the October ACPSEM conference detailed at the foot of the page.
You say Athletic Pubalgia, I say Tomato. Let’s call the whole thing off!…
Google groin pain and you will be hit with a myriad of terminology relating to different conditions. Anyone interested in publishing a book could probably write a thesaurus on “Groin Pain Terminology” and you’d get a few editions out of it as we rebrand our “diagnosis of the day” for groin pain. Gilmores Groin; Osteitis Pubis; Sportsman’s Hernia; Athletic Pubalgia – none of these terms actually help us identify a problem, our source of pain. Especially Athletic Pubalgia! Per Holmlich recently said at the World Groin Conference – “it’s as accurate as saying knee-algia to diagnose knee pain.”
I’ll admit we typically associate “groin pain” with hyperextension or hyperabduction of the hip; cutting actions and rapid change of direction, not necessarily drills we see with good old fashioned running alone. Paajanen et al (2011), looked at 613 athletes from multiple disciplines and reported 2 acute groin injuries in long distance runners and no chronic groin injuries. Although, Holmlich (2007) did report runners to be the second most prevalent sub-group behind football related groin injuries, and in a later study found “over-use injuries” to account for 61% of all sporting groin injuries (Holmlich 2014). Despite the mechanism that causes the problem, it is often straight line running that proves problematic during rehab.
Running styles that fall into “normal” variations of running will not always be your text book runner you see on Nike adverts, with perfect posture and nothing moves apart from the hip and knees. We will see upper body rotation through transverse plane coupled with dipping shoulders as they side flex through the trunk; rotation of the pelvis, again through multiple planes; the femurs will rotate differently in individuals from internal to external extremes – but all extremes of normal.
What this leads us to is potential stresses that can occur around this pubic region.
Considering the amount of structures that contribute to pain in the groin, it would take a pretty long blog to discuss all of them. You have to consider Lumbar spine, hip flexor muscles, hip adductors, the hip joint and its articular surfaces and capsules, the pubic symphysis, the sacroiliac joint, the hip extensor muscles – to name a few.
Let us consider the anatomy briefly:
The anterior pivot for the pelvis is the Pubic Symphysis. Where posteriorly we can dissipate load through two sacroiliac joints and the lumbar spine, anteriorly we have one focus point where both right and left innominate bones join. Meyers et al (here) coined the terminology of the “Pubic Joint” to try and broaden people’s understanding and stop the tunnel vision of assessment to the Pubic Symphysis – a key . They describe the Pubic joint as all of the musculoskeletal structures that attach to the pubic ring of the innominates, as well as the pubic symphyseal joint.
Meyers et al describe the Pubic joint as a complex, rotational joint undergoing separation and compression, gliding and rotational forces. Despite big arcs of movements created by the lower limbs and the trunk, the amount of movement around the pubic symphysis itself is negligible. Millimeters and a few degrees of motion at most. Picture two ends of a pendulum – minimal movement at the top, big movement at the bottom. However, like with any small joint with minimal movement – we have less margin for error. A change in a joint this small is amplified more than a change of the same severity in a larger joint. Lose a millimetre or half a degree of range from the knee and you won’t notice. A little bit of inflammation or irritation in a small joint and you’ll know about it.
This zone around the pubic symphysis is the city centre. With loads of different rail and road networks meeting here;
We have the rectus abdominis muscle sheath attaching superiorly. The Ilioinguinal ligaments attaching from a superolateral angle, adductor longus and brevis and gracilis attaching from the inferior side, posteriorly we have the influence of the hamstrings plus all of the smaller rotators of the hip. All of these structures can contribute to irritation around this area. And rarely is it exclusively one structure (Moore 2014).
What could possibly go wrong with a run?
If we consider the roles and demands of the structures mentioned above using, I don’t know, let’s say your everyday runner on Brighton seafront (pictured below)
OK.. a bit dramatic.
With a longer stride length you can hopefully picture what is happening around the pubic joint. The lead leg is flexing causing some posterior rotation through the right innominate bone. Potentially in this picture there’s some mild external rotation of the femur – which will change with individuals of course, but here there would be some lengthening of those structures attaching inferiorly. The right rectus abdominis is proximally helping to stabilise the trunk while distally assisting with that posterior tilt.
On the left, the extended trail leg will be pulling the left innominate into anterior tilt – opposite to that of the right – again, consider what’s happening at that pubic joint. The left side of rectus abdominis is now eccentrically controlling that anterior tilt via the distal fibres while the proximal end is helping the right side to maintain an upright trunk.
Alongside all of this, we have extension of the lumbar spine and rotation of the lumbopelvic region.
All in all, a lot happening across many planes of movement and at speed with momentum of long levers. Poor little pubic zone I say!
Does this thought process change your assessment?
I’d say groin assessments are amongst the most challenging to perform in clinic. Remember I’ve narrowed this down! But if we are suspecting problems in this pubic joint I think we need to consider these elements. The abdominal muscles gets a bad rep due to its association as a “mirror muscle” but we shouldn’t neglect it as a contributor to pain.
As part of a larger assessment, I would always assess the ability to (progressively of course, stop at step one if painful): perform a sit up; a resisted sit up; resisted rotation mid-range of sit up (remember that we don’t just run through the sagittal plane motions) all to build a picture of the Rectus Abdominis involvement in groin pain. We can also change the lever involved – bent hip and knees, straight hip and knees, unilateral hip and knee flexion.
The other thing to do is assess the impact of shearing through the pubic symphysis. Again, consider that unilateral rotation that can occur between the innominate bones. Following a Thomas Test, we can add over pressure to the flexed leg while stabilising the extended leg – creating some shear though the pubic symphysis. Painful? Compare to the other side – if we get pain bilaterally than our common denominator is the Pubic Symphysis. If not, then we are probably considering a unilateral structure attaching to the pubic zone. If this Thomas test with overpressure is pain free, we can increase the torque through the joint by resisted 1) flexion of the extended leg and 2) adduction of the extended leg. The same principles of unilateral / bilateral pain apply.
It is worth noting that these tests are potentially irritable, so you should leave them to the end.
I’ve been careful not to apply any diagnosis to this zone, as I think most practitioners would struggle to be that accurate. I always tell my students to be comfortable with the unknown. There is a difference between knowing where the problem is coming from and what exactly the problem is. I think we can achieve the “where“. We can determine a unilateral or bilateral involvement in groin pain and in doing so, our treatment and rehab can be guided:
- Unilateral – Potentially looking at insertional pathologies, mid-tendon reactions or muscle strains. All of those will obviously have different rehabilitation needs, but at least we are heading in the right direction.
- Bilateral – we are more likely to be looking at an irritation or inflammation of the pubic symphysis or structures that cross and influence the pubic joint (think: rectus abdominus). Consider activities that may induce shearing or rotation of the pubic zone and initially try to avoid these, along with exercises that do the same and wait for irritation to calm down. Exercises from this point can be progressively controlled with this rotational / shear focus in mind (more here; exercise progression blog).
Hopefully by discarding the waffled-terminology around groin pain, we can be more comfortable with our assessments. We also have to start looking more globally at contributing factors, considering proximal and distal attachments of structures and their multiple roles in movement. Our temptation is to try and put a name on something.. but all of a sudden, “Athletic Pubalgia” is beginning to sound like a bit of a cop-out diagnosis, right?
Sam is the South East representative for the ACPSEM (Physios in Sport) and Lead organiser of the 2015 biennial conference in Brighton, 9-10th October: “The Young Athlete” – early bird tickets available until 31st May 2015 please visit physiosinsport.org for more information or click the picture below.