The Plastic Body
It’s the time of year when many of you are hitting the pavements or the treadmill at the gym in order to get some much needed fitness for the coming winter sports season.
This rush of enthusiasm means that you may push yourself too hard, too quickly and end up with aches and pains that just don’t seem to settle. It might be pain in the Achilles tendon, the shins, the heel, the knees…
Our bodies are in essence “plastic”. This means that the tissues which make up our bodies –bone, muscle, tendon, cartilage; adapt to the stresses which we impose upon them. Most of us would not consider that our bone density and strength changes much until we get older. In fact bone is in a constant state of flux-bone cells are resorbed by the body and new bone is laid down. The laying down of new bone is determined by the amount of loading applied to the bone. Astronauts in space lose a significant amount of bone mass because an environment without gravity means body tissues are not exposed to loading.
Weight bearing activity signals our bodies to lay down more bone cells. But beware- too much loading too quickly means that our bones cannot lay down new bone rapidly enough, leading to bone stress, pain and ultimately perhaps tiny hairline fractures.
The same effects happen with muscle and tendon. When we run or jump our tendons respond by becoming stronger and more able to cope with load. But again, too much too quickly and tendons become painful. That is why you are more likely to develop Achilles tendon pain when you suddenly take up running or change your running routine such as increasing your distance or introducing hills.
All tissues will respond to change in loading provided that change is gradual and there is sufficient time between training sessions for tissues to repair- usually a day or two. As tissues get stronger you can train more intensively. The risk factors for pain and tissue damage are when you commence a new activity or when you haven’t trained over the summer meaning that you have some ground to make up quickly before the start of the winter sports season. So just make sure that you start any new activity slowly, have some rest days between training sessions and allow yourself plenty of time to get to where you need to be.
Michelle Sintmaartensdyk is a physiotherapist at the Oamaru Physiotherapy Clinic. She has post graduate qualifications in sports medicine, acupuncture and manual therapy.