Low back pain is a common problem in older individuals, but its etiology, natural history, and therapy are not well defined. Epidemiologic studies have reported the prevalence of back pain in older individuals from 6% to 47%. A recent Israeli study found that 44% of 70-year-olds and 58% of 77-year-olds reported back pain.
In the United States, back pain is the third most frequent symptom in those aged 75 years and older visiting their physicians. This pain is associated with depression, dependence in daily living activities, female gender, and poor self-reported health. The association of back pain and physical function has been quantified; the number of months with restricting back pain is associated with such markers of frailty as worsening rapid gait, chair stands, and foot tap performance. In the study of Medicare beneficiaries 65 years and older, back pain was second only to shortness of breath while climbing stairs in its association with impaired general physical health status.
Back pain is also becoming a substantial drain on health-care resources for older adults. While there was a 42% increase in total Medicare patients from 1991 to 2002, there was 131.7% increase in patients diagnosed with low back pain, and a 387% increase in low back pain charges.
It is clear that low back pain is a common problem for older individuals, is associated with poor outcome, and consumes a significant percentage of health-care resources. Our knowledge of the natural history and outcomes of this problem is limited. The studies during the past two decades that have helped to outline the natural history and outcome of back pain have been conducted exclusively in individuals younger than 60 years of age.
There is very little information in the literature on the natural history, associated features, and the etiology of older patients with back pain.
The clinician must first determine whether the problem is in the hip or back. It can be difficult to distinguish these conditions, as both can give buttock and low back pain. Pain that occurs when going from the supine to sitting position is more apt to be from the back, while groin pain, worsened with weight bearing, favors the hip. A complete examination of the passive range of motion of the hip, done with the patient in the supine position, should reveal 40 degrees of hip abduction, more than 100 degrees of flexion, 50 to 60 degrees of external rotation, and 20 degrees of internal rotation. In addition, a manual muscle examination of the lower extremities, which demonstrates mild weakness of the L4, L5 (hip abductor and great toe extensor) and L5, S1 (hip extensors) innervated muscles of the lower extremities, favors the back as the cause of pain. One recent study demonstrated that the presence of groin pain, a limp, and limited internal rotation of the hip all favored the hip as the cause of pain.