Estimation of VO2 in older individuals with osteoarthritis of the knee and cardiovascular disease.

The American College of Sports Medicine (ACSM) equation for estimating oxygen consumption (VO2) is often inappropriately applied to non-steady-state treadmill exercise. Therefore, it was the purpose of this investigation to develop an equation to estimate VO2 that could be applied to non-steady-state treadmill exercise in a population of patients with osteoarthritis of the knee, and to assess the generalizability of this equation for estimating VO2peak in patients with cardiovascular disease. Subjects for the investigation were 414 participants in the Fitness and Arthritis in Seniors Trial (FAST), and 362 patients with cardiovascular disease. Results from the FAST subjects showed that the ACSM equation was inappropriate for estimating VO2 during non-steady-state incremental treadmill walking. We developed the following equation (FAST) using speed and the interaction between speed and grade as the predictor variables during treadmill walking: VO2(ml.kg-1.min-1) = 0.0698 x speed(m.min-1) + 0.8147 x grade(%) x speed(m.min-1) + 7.533 ml.kg-1.min-1 The generalizability of the FAST equation for estimating VO2peak was evaluated in the patients with cardiovascular disease. The measured VO2peak of these patients was 23.7 +/- 0.3 ml.kg-1.min-1, whereas the VO2peak values estimated from the FAST equation and the ACSM equation were 24.1 +/- 0.3 and 33.2 +/- 0.5 ml.kg-1.min-1, respectively. No significant differences were found between the measured VO2peak and that estimated from the FAST equation. The VO2peak estimated from the ACSM equation was significantly greater than the measured VO2peak. These results suggest it is more appropriate to use the FAST equation rather than the ACSM equation to estimate VO2 in older patients with either osteoarthritis of the knee or cardiovascular disease.

Physical disability from knee osteoarthritis: the role of exercise as an intervention.

Osteoarthritis (OA) of the knee is a common, nonfatal, chronic condition that causes pain and physical disability in older people. Persons with knee OA report difficulty with activities that require ambulation and transfer from the sitting to the standing position. Physical disability from knee OA is the result of a complex interplay among the severity of disease, pain, comorbid conditions, psychosocial factors, and deficits in physical capacity such as low aerobic work capacity and lower extremity muscle weakness. These deficits in physical capacity may be correctable with exercise training. Short-term studies indicate that persons with knee OA show gains in physical capacity and report less pain and disability with exercise training. However, the long-term effectiveness and safety of exercise in persons with knee OA remains unknown.

Musculoskeletal disease in the aged. Diagnosis and management.

Musculoskeletal diseases are the most prevalent conditions affecting the elderly today and cause significant suffering and disability in this population. The diagnosis of musculoskeletal disorders in older persons requires knowledge of the diseases which affect this age group, familiarity with the signs and symptoms, and a working knowledge of laboratory and radiographic abnormalities. Treatment of these disorders is based upon the principles of pain relief and maintenance of function. A multifaceted approach includes physical therapy, patient education, psychological support and the use of medications. Simple analgesics like paracetamol (acetaminophen) are gaining increased importance in the treatment of symptomatic disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most utilised pharmacological treatment and are effective in relieving pain and improving function in most patients. However, elderly persons are at increased risk for NSAID-induced toxicity, and drug choices should be made with this in mind. New data are becoming available as to the relative toxicity of the different NSAIDs, and this should help in choosing between these medications. Disease-modifying drug therapy is the most difficult to administer in elderly subjects. Potential toxicity must be weighed against realistic benefit in older persons prior to and during remittive therapy. With appropriate precautions, these agents can prove invaluable in the treatment of older persons with serious musculoskeletal disease.