Epidemiology OOS is a serious medical condition affecting thousands of New Zealanders. It is likely that may other New Zealanders suffer from this condition and the above is a rather conservative estimate 2,5 . Causes OOS usually occurs from a repetition of small, sometimes unfelt injuries. This can cause an injury to develop gradually over weeks, months, or even years. OOS has been associated with five causes of injury.
Repetitive tasks require frequent and rapid muscle contractions.
Also, repetitive movements of joints can cause wear and tear, degeneration, and inflammation of the joints and surrounding areas 6 . The postures that mainly cause OOS are fixed postures, awkward or uneven postures and postures that place large loads on muscles and tendons. Fixed postures reduce the blood flow. This leads to a toxin build-up in the muscles as well as a lack of energy and nutrients being supplied to muscles. This makes muscles prone to swelling and tearing 1,7 .