Time for a brief anatomy lesson with a bit of trivia from the "Happiest Place on Earth" thrown in.
One of the classic rides at Disney Land is the Hall of the Presidents. Visitors to the park are seated in a theatre where the players on stage are animitronic representations of the US's greatest leaders. When the attraction was being developed by the imagineers they initially had difficulty achieving natural motions for the creations. They could move in a given direction OK but to stop, change or reverse direction of this motion the illusion would be lost as a limb would have to decelerate first. Where a real person could initiate a move then immediately stop, the robots just couldn't. They found they could overcome this short-coming by adding opposing motors that would act to brake the motion as they applied force in the reverse direction.What they had done was actually replicate the function of opposing muscle groups we all have.
When you make a move the action involves tensioning one group of muscles and the relaxing of the opposing muscles.
As I've written about previously, I've had an ongoing issue with my calves. With annoying regularity,and at odd occasions I have experienced sharp pain down the centre of this group whilst running. When I say "odd occasions" I mean that it does not seem to have a predictable trigger. It has struck during both easy jogs and hard efforts, sometimes it's at the start of a run whilst warming up, several times at the end, running downhill, and once immediately after a swim (on the beach during IronMan Melbourne earlier this year). Regardless , it seems that if I run whilst wearing compression calf sleeves I tend to be able to avoid the strain.
So, with my amazing knowledge of the bodies muscular function and armed with my vague understanding of what the hell was going on with my own, I finally made AND attended an appointment with the physio to get a second (read "professional") opinion. Following a short interview and massage of the effected area I was referred to have an ultra-sound done to get a definitive (third?) opinion. He had his assumptions but was perplexed that my calf guards were proving so successful. Some improvement could be expected but to be able to cover such a high volume of running and remain pain free didn't sound right.
Running from the back of the knee and under the two main calf muscles resides the plantaris muscle; well, it does in most of us... Apparently evolution is phasing this particular muscle out of our anatomy as it is not functionally required. Somewhere between 7 and 20% of the population have already relinquished it. I am told that, if you were to ever require a muscle graft this is the muscle they will remove to use.
The nice man with the gel and the ultrasound wand tells me that, not only do I still have mine, but also, I've actually found a way to "fray" the muscle I don't really need - in both calves...
When you damage this muscle, it doesn't hinder your leg's mechanics, just hurts. (well, the limp resulting from the pain might hold you back a little)
A return visit to the physio with this outcome and weighing up all of the causational evidence we have we came to the following verdict - continue to run, keep monitoring it and always wear the compression sleeves.
At some point my plantaris muscles will likely heal themselves but there's no telling how long that might take. After the last race of the season I took a full two weeks off running but first light hit out following and it sprung again. So, in the meantime I'll just have to stock up on sleeves to avoid having to constantly wear the same pair, and also find a way to abbreviate this and still explain the strange tan lines I'll inevitably develop.

