More and more pilots are taking to the pool without having fallen, to try to get rid of this nasty slow injury, compartment syndrome, “Arm pump” in English. Explanations!
Over the course of a season, it is relatively common to see some drivers miss a race following an injury related to a fall. The incredibly rapid recovery of these drivers is impressive: they usually return to the track within a few weeks after a fracture – it's truly astonishing.
Many factors contribute to this, including the funds available to treat them, which means they receive the best care available, the medical procedures performed follow strict and highly evolved protocols to ensure minimal invasive surgery and specialized rehabilitation. The fact that they follow a suitable diet and constant physical training also means that their body adapts and responds effectively to a variety of running hazards.
Despite this, many drivers suffer from a disease called compartment syndrome: Dani Pedrosa, Casey Stoner, Stefan Bradl, Loris Baz, Cal Crutchlow (both arms), Pol Espargaro, Jorge Lorenzo and Fabio Quartararo have suffered one (or several) surgical intervention to reduce their arm pain. Let's come back to this illness from which many pilots suffer.
What is compartment syndrome?
The medical term is Chronic Compartment Syndrome (CECS) or, in more severe cases, Acute Compartment Syndrome (ACS). It is the consequence of the rise in intra-tissue pressure in one or more compartments, that is to say in the muscular compartments closed by an inextensible fibrous membrane called aponeurosis which are present in the leg, the front -arm or hand. This painful pathology can be accompanied by a reduction in blood circulation which increases the suffering of muscle fibers and nerves.
This is called an overuse injury by the limb subject to high-level specific use, as opposed to an injury caused by a one-time collision.
It is characterized by the appearance of intense pain in the minutes following exercise and dissipates approximately 20 minutes after stopping the activity without any long-term effect on the limb.
What is it due to?
In recent years, the pressure on the arms when braking has become much greater for several reasons: drivers must endure up to 1,6 G, thirty times per lap, or around 600 times per lap. race, and as much per day of testing. Indeed, with increasingly high-performance tires, motorcycles have impressive grip when accelerating, but also when braking.
The engine braking has also become terrifyingly powerful, the new Seamless gearboxes further add to the diabolical effectiveness of braking.
And at the end of the day, who does everything to “absorb” the shock? The fork has limited effectiveness at the level of the arms, since it is at the stop, so it is mainly the rider's arms which remove rust.
How is it going ?
The human body has a non-stretchable membrane covering our muscles called fascia. Putting demand on the muscle increases blood flow: the muscle can increase up to 20% in volume and the fascia is not elastic, it tightens internally, restricting blood flow.
This constriction results in severe pain as well as an underperforming limb and there may also be numbness or weakness: the complete opposite of what a very high speed rider wants to experience on a motorcycle.
However, it is not likely to cause permanent damage to the limb.
How is it diagnosed?
The ultimate test for diagnosing compartment syndrome is the compartment pressure test, but it is the most invasive option. Needles are inserted into the affected area connected to a pressure testing system and the muscle is subjected to stimulation to test the pressure in the compartment.
In recent years, some non-invasive techniques have proven to be very effective in accurately diagnosing compartment syndrome in pilots, including MRI scans that can assess fluid volumes in these compartments during exercise.
Near-infrared spectroscopy (NIRS) is a new technique that measures the amount of oxygen in the blood, in the affected tissue. This helps determine if the muscle compartment is experiencing decreased blood flow.
For a MotoGP rider, the less time away from the track the better, so the non-invasive option of new MRI technology is preferred.
How is it treated?
The only real option is surgery called fasciotomy: A slit is made in the fascia membrane to relieve pressure. For the most daring, Cal Crutchlow published photos of his operation...
For the average person, recovery is around 6 weeks, but for MotoGP riders, it takes just 2 weeks before they are back on the track. This is partly due to the procedure performed during the procedure to reduce recovery time.
This was the case for Fabio Quartararo who underwent surgery for compartment syndrome on June 4, 2019 in Barcelona, he was back for the Spanish GP on June 16, which is only a two-week recovery. Even though he hadn't yet reached the point of no return, his team felt it was best to face it sooner rather than later.
Since the main symptom of compartment syndrome is a sudden onset of severe pain that increases within the first few minutes of activity, it is possible that this contributed to his problems earlier in the season.
Of course, like any surgical operation of this kind, there is no guarantee that the procedure will work 100%. This is problematic because the operation may need to be repeated, but issues such as scar tissue can complicate things.
Treatments such as pain relief, modification of training sessions and rest of the limb are not long term treatments and are not good for a MotoGP rider for obvious reasons, as even the slightest loss muscular capacity can be catastrophic on a timed lap.
Pilots showing signs of this disease are immediately sent for required tests and if necessary, surgery. They tend not to expect it to penalize them on too many races.
