Temporal gait pattern. At day 9, gait symmetry was near 0.5 for all groups, indicating that the gait pattern was symmetric. However, with time, the gait pattern of the medial meniscus transection (MMT) group became progressively asymmetric (open box, left). At day 16, the gait pattern of MMT rats was near asymmetric (×; P = 0.089); by day 23, the gait of MMT rats was significantly different from that of symmetric gait rats (ǂ, symmetry ≠ 0.5; P = 0.020). Although naïve controls (solid box) and medial collateral ligament (MCL) sham animals (shaded box) had reasonably equivalent stance time on the left and right hindlimbs, MMT rats tended to have imbalanced stance times (balance ≠ 0.0, right). Although not significant for each time point, a general trend for MMT rats to spend less time on their operated limb relative to the contralateral limb can be observed (P = 0.077, 0.039, and 0.061 at days 9, 16, and 23, respectively). Data are presented as mean ± SEM. ǂValues that are significantly different from the mathematical definition for symmetric, balanced gait at a level of P < 0.05; ×values near significance at a level of 0.1 <P ≤ 0.05. *Significant differences between surgical groups at a level of P < 0.05.
Allen et al. Arthritis Research & Therapy 2012 14:R78 doi:10.1186/ar3801