Co-contractions – what are they and why do we need them?

One of the fundamental components of the rehab programmes at Agility Physiotherapy is the co-contraction. This is a term used to refer to the muscles of either the upper or lower limb working together (or synergistically), in order to allow forces to travel effectively through the limb and be dispersed throughout the rest of the body.
If these co-contractions are not in place, that is to say, a particular muscle group is not doing its job properly, the resulting increased load trasmitted elsewehere means the brain percieves a threat and that, in turn, can result in an experience of pain. This could be ankle, knee or hip pain for the lower limb and wrist, elbow and shoulder pain for the upper limb. The joint affected is largely down to the muscle groups that are now having to pick up the additional slack.
It also must be considered that this force transmission issue can lead to problems further up the chain such as back or neck pain.

The lack of co-contraction could be born out of a previous injury, no matter how long ago. Injuries on the same side as previous ones could mean that there is some residual protective tone that was never cleared up at the time. Old injuries on the opposite side could indicate that the current injury is one of compensation.

A paper by Minoru Shinohara from the School of Applied Physiology at Georgia Institute of Technology (2009) states that “adaptations in motor performance such as controlling force and posture throughout physical activity can be attributed to alterations in muscle activation strategies”
Of course, there are many factors which can influence these strategies – which I will try to cover in a series of upcoming articles – but restoring muscle imbalances and ensuring co-contractions are present allows us to adopt normal movement patterns that could be the key to unlocking that persistant, niggling injury that is preventing you from becoming pain free.