The most common cause of lower back aches is injury, very often from athletic activities such as team sports, but other causes have nothing at all to do with physical activity. Lower back aches can instead be caused by poor posture, slipped discs in the spine, sitting or standing for extended periods of time, or from accidents, particularly automobile accidents. In all cases, the lower back is burdened with an amount of strain that it cannot reasonably handle, and either the muscles in the back become strained, or the spine is allowed to move unnaturally out of place. Lower back aches can be treated simply if the condition is not severe, but some conditions may require physical therapy and even surgery to correct.
A direct blow to the back can cause lower back aches. Such blows are common in team sports, and the muscles can become bruised, strained, or torn. Such injuries should be treated with rest and ice, though in more severe cases, physical therapy and a regular stretching routine may be necessary. Another common injury in sports occurs when the lower back takes on a sudden weight or more weight than it is prepared to handle. The muscles cannot support the stress, and they become strained. The injured person may complain of soreness or tenderness in the lower back, as well as limited mobility and general weakness.
More serious causes of lower back aches include slipped discs in the spine. A slipped disc occurs when a vertebra slips out of place from its normal position, which can cause compression on another vertebra, surrounding muscles, or the sciatic nerve. Sciatic nerve pain often manifests itself as a sharp, shooting pain in the lower back, buttocks, or down the length of the leg. In most cases, sciatic nerve pain in the lower back can be alleviated with stretching or anti-inflammatory medications. A slipped disc may be treated with physical therapy, but more severe cases may require surgical intervention.
Sitting or standing for long periods of time can lead to undue strain on the muscles of the lower back, and long-term sitting can promote a weakening of lower back muscles. Lower back aches may result, as the muscles are not effectively supporting the spine. The spine will in turn compress, causing dull aches in the lower back. To prevent such muscle loss, one should stand up and walk around for fifteen minutes after every hour of sitting, or sit down for fifteen minutes after one full hour or standing.