Physical activity in rheumatoid arthritis

Physical activity confers health benefits in the general population and should also be applied to people with rheumatoid arthritis (RA). However, there is a need for more research in this area. The aim of this thesis was thus to explore attitudes to physical activity, to identify correlates and predictors for self-reported physical activity and general health perception, and to investigate the applicability of aerobic fitness testing among patients with RA.

Sixteen patients were recruited for a phenomenographic study (I). A sample of 556 patients (median age 56 years, disease duration <6.5 years, 75% women) were recruited from 17 rheumatology units for studies on physical activity in RA (PARA studies): 298 for a descriptive cross-sectional study (II), 102 of these for a descriptive prospective study (III), and the 298 together with another 258 patients for a methodological study (IV). Semistructured, in-depth interviews were carried out for Study I. Self-reported data on physical activity, health locus of control and perceived exertion, tests of body functions (aerobic fitness, lower extremity function, grip force, joint range of motion, balance) and measures of the EULAR minimum core set of disease activity (inflammatory activity, general health perception, pain, disability) were collected for Studies II-IV.

Four different categories of attitudes to physical activity were identified: "motivated and satisfied% "unmotivated and satisfied", "motivated and dissatisfied" and "unmotivated and dissatisfied" (I). A majority of the patients displayed impaired body functions compared to norm data, and about half reported physical activity behaviours that were too low to comply with public health recommendations. Correlations between physical activity and other variables were all low. Variation in general health perception was explained mainly by pain (II). Physical activity, perceived general health and pain were stable over one year, while disease activity (DAS28) decreased and three out of four studied body functions improved. High physical activity at baseline was the only predictor of high physical activity after one year. Low pain, high physical activity and good lower extremity function were identified as predictors of good general health perception (III). Seventy-six percent were able to complete a submaximal test of aerobic fitness. The main reasons for never being tested (16%) or for terminating testing prematurely (8%) were use of beta blockers or impairments. Correlations between work heart rates and perceived exertion were low during aerobic fitness testing.

Despite all efforts to treat patients with RA effectively, impairments remain common. Health perception is still mainly influenced by pain, but also by physical activity and lower extremity function. Fitness testing to design and evaluate physical activity interventions is applicable to most patients. Physical inactivity and unmotivated or dissatisfied attitudes to physical activity highlight the challenge for physiotherapists to promote different kinds of physical activity and contribute to good health among patients with RA.

List of scientific papers

I. Eurenius E, Biguet G, Stenstrom CH (2003). Attitudes toward physical activity among people with rheumatoid arthritis. Physiotherapy Theory and Practice. 19: 53-62.
https://doi.org/10.1080/09593980307967

II. Eurenius E, Stenstrom CH (2005). Physical activity, physical fitness, and general health perception among individuals with rheumatoid arthritis. Arthritis Rheum. 53(1): 48-55.
https://doi.org/10.1002/art.20924

III. Eurenius E, Sturk N, Lindblad S, Stenstrom CH, the PARA study group (2006). Predicting physical activity and general health perception among patients with rheumatoid arthritis. [Submitted]

IV. Eurenius E, Sturk N, Stenstrom CH, the PARA study group (2006). Clinical applicability of two tests of aerobic fitness in patients with rheumatoid arthritis. [Submitted]