If a muscle is not given any work to do each little muscle fibre becomes thinner and the whole muscle begins to lose its strength. Some groups of muscles become weak faster than others. When a footballer has a knee injury his quadriceps, the muscles on the front of his thigh get weak very rapidly. These muscles need exercising early on in order to increase their strength so that he can return to his team as soon as possible. It is also very important that all patients are given exercises to restore muscle strength as soon as possible and so minimise the amount of weakness that occurs. These early exercises, therefore, have to be carefully designed so as to complement the other Physio techniques. Exercises are needed for all the muscle groups in the affected area and they are adapted to suit each patient's requirements. Ideally exercises are part of the ongoing treatment once the initial pain has subsided. Muscles only respond to the demands placed on them.
When an injury has healed the muscles will recover in response to the amount of work they are asked to do. If the limb is favoured then the muscle will never recover its normal function. After a period in bed, during which time the leg muscles have been completely inactive, one feels weak at the knees when up. Stay in bed too long and the muscle fibres become so weak that one wouldn't even be able to stand up. So in the case of a long illness or a long-term injury the muscles have to be given specific work to do to build up and restore the power required for every day living. In so many cases, due to the absence of specific exercises, a compromise is struck and the body has to make do. People are heard to say - I've never had any strength in my back since my accident - my shoulder has always been weak since the car crash - that's my bad leg - I'm always going over on that ankle - I've never been able to open a jar with that hand since I broke my wrist - etc. etc. All of these situations are examples of inadequate muscle power. Even after a long period of time muscles can still adapt and strengthen in response to stimuli from the right type of exercises.
Muscular imbalance can lead to problems in the future. For instance a calf injury will result in weakness of the muscles and if not restored to normal strength running and even walking will be slightly out of kilter. This puts strain on other muscles and joints. By being aware of and practising 'special warm-up exercises' prior to any bout of violent exercise many of the torn muscles, trapped nerves, sprained ankles or back problems which occur can be prevented. Exercises only increase the strength in muscles when they are done on a regular basis.