Perceptions of an over-ground induced temporal gait asymmetry by healthy young adults

Nearly 60% of individuals with stroke walk with temporal gait asymmetry (TGA; a phase inequality between the legs during gait). About half of individuals with TGA are unable to correctly identify the presence or direction of their asymmetry. If patients are unable to perceive their gait errors, it will be harder to correct them to improve their gait pattern. Perception of gait pattern error may be affected by the stroke itself; therefore, the objectives of this study were to determine how the gait of neurotypical individuals changes with an induced temporal asymmetry, and how perception of that TGA compares to actual asymmetry both before and after 15-min of exposure to the induced asymmetry. After baseline symmetry (measured as symmetry index (SI)) was assessed with a pressure sensitive mat, participants (n = 29) walked for 15 min over-ground with cuff weights (7.5% of body weight) on their non-dominant leg to induce TGA. Presence, direction, and magnitude of TGA was measured at five time points: 1) baseline, 2) immediately after unilateral loading (early adaptation (EA)), 3) at the end of 15 min of walking (late adaptation (LA)), 4) immediately after load removal (early deadaptation (EDA)), and 5) after the participant indicated that their gait had returned to baseline symmetry (late deadaptation (LDA). Presence, direction, and magnitude of perceived TGA was measured by self-report. Measured and perceived TGA changes over time were assessed with separate one-way repeated measures analyses of variance. Agreement between measured and perceived TGA was assessed. During EA, all participants walked asymmetrically, spending more time on the non-loaded limb compared to baseline (-12.67 [95%CI -14.56, -10.78], p < 0.0001). All but one participant perceived this TGA, however only fifteen (52%) correctly perceived both TGA presence and direction. At LA, the group remained asymmetric (-9.22 [95%CI -11.32, -7.12], p < 0.0001), but only 9 participants (31%) correctly perceived both the presence and direction of their TGA. Visual inspection of the data at each time point revealed most participants perceived TGA magnitude as greater than actual TGA. Overall, we find that TGA can be induced and maintained in neurotypical young adults. Perception of TGA direction is inaccurate and perception of TGA magnitude is grossly overestimated. Perceptions of TGA do not improve after a period of exposure to the new walking pattern. These preliminary findings indicate that accurately perceiving an altered gait pattern is a difficult task even for healthy young adults.