Quantity versus quality of gait and quality of life in patients with osteoarthritis

Purpose This study investigated the relationship between the quality of life, quality of gait and the quantity of gait in patients with impairments in the lower extremities. Methods Twenty-six subjects (age 58.6 ± 13.4 years) suffering from knee or hip osteoarthritis were investigated before implantation of an endoprosthesis. Quality of life was assessed using the SF-36 survey. The quality of gait was assessed with a six camera motion analysis system in combination with two force plates. For evaluation of the quantity of gait, two monitors were applied: (a) the accelerometer-based DynaPort activity monitor measured locomotion and posture for 1 day and (b) The Step-Activity-Monitor, a small microprocessor-operated acceleration sensor, measured the number of gait cycles in 1-min intervals for 1 week. Spearman correlation coefficients were calculated between quantity of gait, quality of gait and quality of life. Results The patients showed typical gait impairments caused by osteoarthritis. Locomotion accounted for 10.5 ± 5% of the daily recorded time, 4782 ± 2116 gait cycles were counted per day. The sub-categories of the SF-36 showed limited physical functioning and general health with 38 and 56 out of 100 points, respectively. Computation of Spearman-rho revealed no relevant correlations between quality and quantity of gait but moderate correlations between quality of life and quantity of gait. Conclusion The findings underline that a patientʹs level of mobility cannot be reliably estimated from quality of gait or from quality of life. Instead, adequate methods should be chosen to measure the quantity of gait in daily life.