Background and Significance of the Problems
Osteoarthritis of the knee is a common chronic condition and most often occurs in middle-aged and older women. Typically osteoarthritis manifests after the age of 60 years, but more than 80% of people over 50 years old have radiological evidence of osteoarthritis.' Osteoarthritis is one of the major causes of pain and physical impairment that decrease quality of life.2-1 In Thailand, back pain and arthritis are two of the most health problems among people aged 50-59 years, and tend to increase inprevalence in advancing age.• Another report revealed that over 10% of the Thai population suffers from arthritis and this is predicted to increase to 50% within the next 20 years.• Thai health statistic also demonstrated that musculoskeletal system and connective tissue related symptoms are the second most common reason for outpatient visits in metropolitan hospitals in Bangkok and is the third most common reason for outpatient visit in Thailand .
The goals of treatment of osteoarthritis are: to reduce pain; maintain and / or improve joint mobility; and decrease physical impairment." Presently, the treatments available include pharmacologi cal agents, non-pharmacological interventions, and surgical treatment when indicated. In recent times, exercise has been increasingly accepted as a means of promoting and maintaining health. Moderate intensity exercise can decrease or does not appear to increase the risk of developing osteoarthritis. 12•14 Exercise can also decrease the pain from osteoarthritis, as well as increase physical performance, thereby m aintaining the individual's independence and quality of life. It is generally accepted that exercise regimens for people with osteoarthritis of the knee should start with light intensity and should not