An example is the ratio of strength between the overhead press and external rotation of the shoulders with the deltoids being the main muscle in the overhead press and the infraspinatus and teres minor being the protagonists in the external rotation of the shoulder. In an overhead press the deltoids act as the shoulders prime movers and the teres minor and infraspinatus as the shoulders stabilisers. A disproportionate ratio in strength between the prime movers and stabilisers, of any joint, would lead to dysfunction, reduced efficiency and potential, and possible injury. 

In addition to achieving proportionate ratios of strength between the different movement patterns of the body, a proportionate ratio of strength between different segments/heads of a muscle must be achieved in order to avoid dysfunction and injury, and to optimise performance. For example knee pain and injury is in some cases the result of a disproportionate ratio of strength between the outer part and inner part of the quadriceps muscle. The disproportionate ratio of strength results to patellar (knee cap) maltracking, which is when the patella moves sideways from its groove when the leg bends or straightens. Furthermore, in order to achieve structural balance bilateral (between two limbs) deficits in flexibility and strength must be rectified with corrective exercise. 

Also, disproportionate ratios between the mobility of joints and joint strength must be put right in order to achieve structural balance. This is common in participants of flexibility training who do not engage in any strength training. Participants become mobile within joints but do not have the appropriate strength to back up their joint mobility. This in itself creates dysfunction which can lead to pain and injury. 

Proportionate ratios