4 Group Control Autism Autism Research and Treatment Table 2: Descriptive statistics (mean and standard error) for temporal-spatial data for the autism and age-matched control group. Cadence (steps/min) 129.11 (2.45) 134.27 (3.32) Velocity (cm/s) 101.82 (3.39) 99.89 (3.14) Stride length (m) 0.95 (0.03) 0.90 (0.03) Swing time (s) 0.38 (0.01) 0.36 (0.01) Stance time (s) 0.57 (0.01) 0.56 (0.02) Double stance time (s) 0.19 (0.01) 0.20 (0.01) Swing/stance ratio 0.68 (0.01) 0.65 (0.01) Table 3: Descriptive statistics (mean and standard error) for the symmetry indices for the autism and age-matched control group. Cadence Stride length Swing time Stance time Double stance time Swing/stance 3. Results Control Autism Control Autism Control Autism Control Autism Control Autism Control Autism 1.02 1.09 0.98 0.98 0.99 0.93 1.00 0.97 1.01 1.00 0.99 0.96 Ratio Mean SIavg Mean SE 0.01 0.05 0.03 0.03 0.03 0.04 0.02 0.03 0.05 0.05 0.02 0.02 6.84 10.57 11.17 8.72 11.79 12.78 9.19 7.70 18.00 14.36 8.52 10.59 No signiﬁcant diﬀerences (P > 0.05) in mean symmetry indices data or mean temporal-spatial data were found between the autism and control group. Descriptive data for the six temporal-spatial measures for the autism and control group are provided in Table 2. No signiﬁcant diﬀerences in mean walking velocity were observed between groups (autism: 99.89 cm/s; control: 101.82 cm/s). Descriptive data for the six symmetry indices for the autism and control group are provided in Table 3. 4. Discussion The purpose of this research was to examine diﬀerences in gait symmetry between a group of children with autism and an age, height, and weight-matched control group. Using temporal-spatial data, six diﬀerent symmetry indices were computed and analyzed using MANOVAs. The results of the statistical analysis showed no signiﬁcant group diﬀerences (P > 0.05) for the six symmetry indices for cadence, stride length, swing time, stance time, double stance time, and swing/stance ratio. Further, no signiﬁcant diﬀerences (P > 0.05) were observed between groups for the mean value of each temporal-spatial measure. To date, most studies of gait symmetry in autism have focused on infants and toddlers. Several of these studies have reported gait asymmetries [2, 3, 11, 20]. However, little is known about the persistence of these deviations with development. Based on the results of this study, children with autism walk with a consistent interlimb pattern compared SE 0.97 3.74 1.86 1.80 1.60 3.41 1.01 2.76 3.19 3.02 2.39 2.36 SIrlr SIrll SA GA Mean 6.59 9.42 11.59 9.03 12.20 14.47 9.45 8.42 19.67 14.90 8.88 11.26 SE 1.00 3.08 1.88 1.98 1.75 4.47 1.01 3.27 3.17 3.32 2.75 2.71 Mean 7.33 12.29 11.12 8.52 11.64 11.68 9.12 7.19 17.70 14.23 8.4 10.13 SE 0.96 4.74 1.96 1.70 1.51 2.78 1.02 2.41 3.59 2.96 2.24 2.13 Mean 29.0 30.72 27.5 27.58 27.9 25.85 28.4 27.22 27.9 28.10 28.02 27.15 SE 0.44 1.37 0.81 0.92 0.89 1.36 0.61 1.04 1.47 1.58 1.10 1.13 Mean 6.88 10.66 11.23 8.74 11.83 12.88 9.22 7.73 18.22 14.43 8.55 10.63 SE 0.98 3.80 1.87 1.81 1.61 3.47 1.01 2.78 3.23 3.04 2.42 2.37 to age-matched controls. Due to a small sample size, further work is needed to validate these results. Previous studies of gait symmetry in children with autism have typically used walking observation scales and video analysis. To our knowledge, no motion capture anal- yses of gait symmetry exist for this speciﬁc population. How- ever, gait symmetry in adults with autism has been examined using similar techniques. Hallett et al. [10] measured gait in 5 adults (aged 25–38 years) with autism versus a control group [10]. No signiﬁcant diﬀerences were found between limbs in the autism group for the kinematic and kinetic gait variables. As a result, the data for each limb was pooled prior to comparison with the control group. Only the ankle range of motion was found to be signiﬁcantly diﬀerent between the adults with autism and the control group, with the autism group showing a smaller range of motion. The results of this study are speciﬁc to the age group, task, and gait parameters selected. In addition, the gait parameters used to compute the indices also play an important role in describing gait symmetry. The present study focused on temporal-spatial data; however, other kinematic (e.g., joint angles) and kinetic (e.g., joint moments) gait parameters may provide insight into gait symmetry in children with autism. Previous research [7] suggests that ankle dorsiﬂexion angles and sagittal hip and ankle moments diﬀer in children with autism versus age-matched controls. Therefore, gait symmetry should also be examined using these parameters. As symmetry assessments are sometimes dependent on the speciﬁc symmetry index used, the present study com- puted several indices using temporal-spatial data. Simi- larly, Patterson et al. [21] used four indices to examine gait