Variability and coordination patterns of walking with different speeds in active and non-active children with Down syndrome: A cross-sectional case-control study.

Purpose: Children with Down syndrome (DS) have multiple difficulties in gait pattern. So, the effect of the activity level and speed on the gait coordination and variability was investigated. Methods: In this case-control observational study, 24 participants in three groups of active and non-active children with DS, and the control group without intellectual disability were asked to walk on a treadmill with two speeds of 0.8 and 1.2 m/s. Continuous Relative Phase (CRP) and variability of CRP in thigh-leg and leg-foot coupling were assessed. Results: CRP and variability of CRP in the leg-foot coupling in the control group were significantly higher than active and non-active groups with DS. Speed led to increase the CRP of leg-foot in the active group with DS and increase the variability of this coupling in non-active group with DS. Conclusion: In this study, the activity level provided the compatibility with speed changes of walking in CRP of leg-foot in children with DS.

Pre-programming in overhand throwing of children with Down syndrome: role of the generalized motor program.

OBJECTIVE: It is unclear whether slowness and higher reaction time of individuals with Down syndrome (DS) are because of inability to pre-program and using the generalized motor program (GMP) or not. So, the purpose of this study was to examine the consistency of relative timing as a fixed feature of a GMP in overhand throwing with changing the distance to target as a varied feature. METHODS: Fifteen individuals with DS (age = 13 ± 2 y) and a control group of 12 individuals without intellectual disability (ID; age = 13 ± 2 y) were asked to throw a tennis ball to a fixed target from three distances of 2, 2.75, and 3.25 m, respectively. Instant of occurrence of the following discrete variables was recorded by motion analysis: initiation of elbow extension, maximum shoulder angular velocity, maximum elbow angular velocity, and maximum resultant hand velocity. RESULTS: Results of two-way analysis of variance test did not show any significant difference in any of the relative kinematic variables in distances and groups (p > 0.05). CONCLUSION: It seems that individuals with DS are able to motor preprogram and they use a GMP to overhand throwing from different distances as well as those without ID. Also, slowness and reaction time are unrelated to pre-programming and GMP as it relates to overhand throwing.