Potential strategies to reduce medial compartment loading in patients with knee osteoarthritis of varying severity: reduced walking speed.

OBJECTIVE: To determine whether reducing walking speed is a strategy used by patients with knee osteoarthritis (OA) of varying disease severity to reduce the maximum knee adduction moment.
METHODS: Self-selected walking speeds and maximum knee adduction moments of 44 patients with medial tibiofemoral OA of varying disease severity, as assessed by using the Kellgren/Lawrence grade, were compared with those of 44 asymptomatic control subjects matched for sex, age, height, and weight.
RESULTS: Differences in self-selected normal walking speed explained only 8.9% of the variation in maximum knee adduction moment for the group of patients with knee OA. The severity of the disease influenced the adduction moment-walking speed relationship; the individual slopes of this relationship were significantly greater in patients with less severe OA than in asymptomatic matched control subjects. Self-selected walking speed did not differ between patients with knee OA, regardless of the severity, and asymptomatic control subjects. However, knees with more-severe OA had significantly greater adduction moments (mean +/- SD 3.80 +/- 0.89% body weight x height) and were in more varus alignment (6.0 +/- 4.5 degrees ) than knees with less-severe OA (2.94 +/- 0.70% body weight x height; and 0.0 +/- 2.9 degrees, respectively).
CONCLUSION: Patients with less-severe OA adapt a walking style that differs from that of patients with more-severe OA and controls. This walking style is associated with the potential to reduce the adduction moment when walking at slower speeds and could be linked to decreased disease severity.