When people have an injury to their low back, it will usually sort itself out within the next day or two. However, if it is a major injury or an injury upon an injury or where prolonged positions or repetitive tasks are involved, sometimes the injury can lead to more permanent dysfunction.
Often people can be unaware of the dysfunction as the primary pain of the injury subsides. This remaining underlying problem can lead to muscle imbalance and postural changes as well as progressive stiffness and degeneration. This slow process of degeneration results in "osteoarthritis".
The chiropractic focus is to improve function of the spine, which can have an effect of reducing pain, correcting postural imbalances, and increasing mobility.