Picture it... you're gliding up your
favourite long hill, breathing well, legs feeling strong.
You reach the top, and happily you start running downhill.
Everything is perfect: it is a beautiful morning, that hill
has never felt easier, and you are even sweating less than
usual. Suddenly it all changes in one simple step. You feel
a sharp pulling pain in the back of your thigh, and you are
reduced to a hobble - all the way home. While you do contemplate
throwing your running shoes away, you are also puzzled. You
can't think of anything you have done incorrectly to cause
this injury. You have been increasing your training gradually,
without doing any major speed or hill sessions. You have even
been stretching a bit, and certainly felt no niggling pain
or stiffness in the muscle up until now. Then you remember
that this hamstring gave you problems last year, and the year
before, also without warning.
Sound familiar? Recurrent hamstring strains
are one of the most common running injuries. We aim to explain
why, how you can get back on the road as quickly as possible,
and what you can do to remain injury-free.
The running cycle
When running, a stretch-shortening cycle of muscle action
occurs, to allow for efficient movement. The hamstrings work
strongly during the "swing" (when your foot is off
the ground) phase of the running cycle. The hamstrings work
eccentrically, to control the movement of the knee, and to
store elastic energy in the muscle. When your foot strikes
the ground in the "stance" phases of the running
cycle, the hamstrings work concentrically with a release of
stored energy. The hamstrings contract to stabilise the knee
joint, to extend your hip and, with the quadriceps, absorb
vertical forces of 3.5 - 4.5 times body weight through the
stance leg.
As the hamstrings are working throughout
the running cycle, there are a number of mechanisms of injury
that need to be considered in order to prevent the problem
from recurring.
View the articles relating to the hamstring:
This
article is provided by Teri Burgess, resident Physiotherapist
from Time-to-Run 