Influence of dual task constraints during walking for children.

The effects of dual-task constraints on bimanual coordination and walking in three age groups: young (4-6 years old), middle (7-9 years old), and older groups (10-13 years old) were examined. Children were asked to first walk along a path (baseline condition) and then to walk along the same path while carrying a box steady and level (dual-task condition). The young group showed less bimanual coordination with less level and more variable normalized vertical box positioning (mean hand differences, young: 3.68%, middle: 2.42%, older: 1.61%), less correlated hand movements (mean correlation, young: r(8)=0.58, middle: r(8)=0.77, older: r(8)=0.79), and more elbow and shoulder joint excursion on the dominant side (all Ps<0.05). In addition, the young group had shorter stride lengths and less normalized anterior/posterior ground reaction forces under the dual-task condition than the baseline condition (all Ps<0.05). These findings indicate that 4- to 6-year-old children might still be developing their ability to perform activities requiring dual-task constraints that involve simultaneous use of the upper and lower extremities.