Musculoskeletal disorders are common, affect all age groups, and are associated with a great deal of disability, impairment, and handicap. More than 12 million people in the United States have their activity limited by musculoskeletal disorders, a figure greater than for any other disease category (Fig. 66-1).1 Musculoskeletal impairments affect about 14% of the population, with the spine most commonly involved, followed by the lower extremity or hip and the upper extremity or shoulder (Table 66-1).2 Each year about 11% of the population in the United States experience a musculoskeletal injury severe enough that medical care is sought or activity is restricted for at least half a day.2 The total economic cost to the United States of musculoskeletal conditions was estimated to be $284 billion in 2000,3 second only to diseases of the circulatory system. Indirect costs from lost earnings and services represent a particularly high proportion of this cost, since many people are affected during their most productive years.
Estimated number of persons in the United States in 1984 with limitation of activity attributable to specific disease categories. (Source: Holbrook TL, Grazier L, Kelsey JL, Stauffer RN. The Frequency, Occurrence, Impact, and Cost of Musculoskeletal Conditions in the United States. Chicago: American Academy of Othopaedic Surgeons; 1984.)
TABLE 66-1PREVALENCE OF MUSCULOSKELETAL IMPAIRMENTS IN THE UNITED STATES IN 1995 |Favorite Table|Download (.pdf) TABLE 66-1 PREVALENCE OF MUSCULOSKELETAL IMPAIRMENTS IN THE UNITED STATES IN 1995
|Type of Impairment ||Estimated No. of Affected Individuals ||% of Population |
|All musculoskeletal impairments ||36,438,000 ||13.7 |
|Back or spine ||18,454.000 ||7.0 |
|Lower extremity or hip ||13,421,000 ||5.1 |
|Upper extremity or shoulder ||4,563,000 ||1.7 |
DISORDERS PRIMARILY OF ADULTS
From 75 to 85% of people experience low back pain at some time during their lives.4 Most episodes of low back pain improve within a few weeks, but recurrences are common, and low back pain often becomes a chronic problem with intermittent, usually mild, exacerbations.5 In a study of English patients seen by general practitioners for low back pain, after one year only 25% had no pain or disability, even though the majority were no longer seeking care from their practitioner for their problem.6 In a small proportion of cases the pain becomes constant and severe, and such cases account for a high proportion of the cost; one study found that 25% of the cases accounted for 90% of the costs.7
The specific lesion responsible for low back pain usually is not known. It ...