Normalized force curves for the affected limbs of rats with lumbar radiculopathy (six days post-operation). Ground reaction forces represented in these plots were created by normalizing forces to body weight and time to the total limb stance time. Fx curves show a breaking phase (Force <0), during which, the limb is loaded and resists the translation of mass forward. Fx curves also show a propulsion phase (Force >0) during which the limb is generating push-off forces in the direction of travel. Fy force curves show a peak between approximately 0 to 50% of stance time, during which the limb is being loaded as mass is transferred onto the limb for single limb support. A second peak is seen from approximately 50 to 100% of stance time; here, the limb is generating push-off forces that translate mass toward the contralateral limb. Fz force curves show a loading phase from 0 to 30% of stance time, a support phase from 30 to 80% of stance time, and an unloading phase from 80 to 100% of stance time. In general, the shape of the force curves were as expected for each group; however, differences between generalized terms for each group were observed (See Table 2). Each data point is presented as mean ± 95% confidence interval.
Allen et al. Arthritis Research & Therapy 2011 13:R137 doi:10.1186/ar3451