Achilles problems are the curse of all athletes, particularly runners. They are usually the most severe of lower limb injuries and result in the most training time lost or even cessation of running. The mechanisms of injury are debatable but are usually due to excessive:
- Tensile loading – which is the maximum stress that the tendon/tissue can withstand while being stretched before breaking.
- Shearing stress –opposing forces.
- Hyperthermia – increase temperature in the tissue.
These are the mechanisms but more relevant to the athlete are the potential risk factors, because if identified then preventative measures can be advised or administered.
There has been extensive research into Achilles injuries yet it is still unclear and inconclusive on the specific risk factors. The current opinion is that we need to consider a number of risks factors. These risk factors can be divided into intrinsic such as:
- Increased foot pronation and body mass index.
Or extrinsic such as:
- Running shoes.
- Training programmes.
- Climate and running surfaces.
I would also add running techniques to the intrinsic factors, in particular the relationship between the lower limbs and trunk as well as the position of the runners centre of mass and lines of gravity. Also of paramount importance is the individuals levels of stress and anxiety.
Our purpose as physiotherapists is to assess the individual and determine what risk factors are likely to be contributing to the patients problem. Experience teaches one that the majority of injuries, if not all are multifactorial in cause and this is in correlation with current evidence and research into Achilles tendonopathies and strains.
The title of this blog also includes cumulative calf muscle strains, to be more specific, cumulative strains at the muscle-tendon junction of the calf muscles (roughly half way down the lower leg where the muscle belly changes its composition towards a more tendon like structure).
These type of injuries are often an accumulation of microtrauma that reach a point where the load is too great and a strain occurs with pain and cessation of running. There is very little research in this more proximal type of injury but the mechanisms and risk factors of Achilles injuries in my experience can be a good frame work to use when rehabilitating the runner.