Walking to Meet Physical Activity Guidelines in Knee Osteoarthritis: Is 10,000 Steps Enough?

Objective: To study if step goals (eg, walking 10,000 steps a day) approximate meeting the 2008 Physical Activity Guidelines for Americans. Design: Cross-sectional observational cohort. Setting: Community. Participants: People with or at high risk of knee OA (N=1788). Interventions: None. Main Outcome Measures: Objective physical activity data were collected over 7 consecutive days from people with or at high risk of knee OA participating in the Multicenter Osteoarthritis Study. Using activity monitor data, we determined the proportion that (1) walked >= 10,000 steps per day, (2) met the 2008 Physical Activity Guidelines, and (3) achieved both recommendations. Results: Of the subjects studied (mean age +/- SD, 67 +/- 8y; mean body mass index +/- SD, 31 +/- 6kg/m(2); 60% women), 16.7% of men and 12.6% of women walked >= 10,000 steps per day, while 6% of men and 5% of women met the 2008 Physical Activity Guidelines for Americans. Of those walking >= 10,000 steps per day, 16.7% and 26.7% of men and women, respectively, also met the 2008 Physical Activity Guidelines. Conclusions: Among this sample of older adults with or at high risk of knee OA, walking >= 10,000 steps a day did not translate into meeting public health guidelines. These findings highlight the disparity between the number of steps believed to be needed per day and the recommended time-intensity guidelines to achieve positive health benefits. Archives of Physical Medicine and Rehabilitation 2013;94:711-7 (C) 2013 by the American Congress of Rehabilitation Medicine