The purpose of this study was to determine the long-term effects of aerobic walking and weight training interventions on gait mechanics and knee pain in older adults with knee osteoarthritis (OA). One hundred three older adults (age ≥60 years) with radio-graphic evidence of knee OA were randomized to one of three treatment groups: aerobic walking, health education control, or weight training. Both exercise intervention groups exercised 3 days · week-1 for 18 months. The aerobic group significantly improved temporal components of gait as well as knee and ankle joint kinematics relative to the health education group across the 18-month intervention. Moreover, the weight training group exhibited significantly greater ankle plantar flexion velocity. Analysis of the ground reaction forces indicated that the aerobic group exhibited significantly greater force relative to the health education group. Finally, both exercise groups exhibited significantly less knee pain than the health education group. The results suggest that long-term aerobic walking and, to a lesser extent, weight training regimens improve walking mechanics in older adults with knee osteoarthritis. These improvements in gait are associated with a reduction in knee pain during activities of daily living.
Stephen P. Messier, Christopher D. Thompson, and Walter H. Ettinger Jr.
W. Jack Rejeski, Karen M. Neal, Martine E. Wurst, Peter H. Brubaker, and Walter H. Ettinger Jr.
An elderly patient population was used to investigate whether an acute bout of aerobic exercise (AE) would reduce systolic blood pressure (SBP) to a greater extent than would a bout of weight lifting (WL). SBPs were studied in the context of a laboratory Stressor as well as during activities of daily living using ambulatory monitoring devices (AMBPs). Patients participated in a laboratory Stressor and were monitored via AMBP for 8 hr. SBPs were lower for up to 5 hr postexercise for the AE treatment only. In addition, in comparison to no-exercise control data, baseline SBP was lower for the AE group than the WL group prior to the Stressor. Subjects in the AE condition also tended to have lower SBP responses following exercise than patients in the WL group, although these differences did not reach a conventional level of statistical significance. These data provide evidence that single bouts of AE, but not WL, may lower SBP in elderly patients, even for those who have compromised function due to osteoarthritis of the knee.
Stephen P. Messier, Walter H. Ettinger Jr, Thomas E. Doyle, Timothy Morgan, Margaret K. James, Mary L. O'Toole, and Robert Burns
The purpose of our study was to examine the association between obesity and gait mechanics in older adults with knee osteoarthritis (OA). Subjects were 101 older adults (25 males and 76 females) with knee OA. High-speed video analysis and a force platform were used to record sagittal view lower extremity kinematic data and ground reaction forces. Increased body mass index (BMI) was significantly related to both decreases in walking velocity and knee maximum extension. There were no significant relationships between BMI and any of the hip or ankle kinematic variables. BMI was directly related to vertical force minimum and maximum values, vertical impulse, and loading rate. Increases in braking and propulsive forces were significantly correlated with increased BMI. Maximum medially and laterally directed ground reaction forces were positively correlated with BMI. Our results suggests that, in subjects with knee OA, obesity is associated with an alteration in gait.