This thesis set out to deepen our knowledge surrounding the establishment of mature motor control strategies and attention focus for individual task performance as well as task integration in multi-task situations. Healthy children (age 7) and young adults (age 21) balanced a ball on a Frisbee on one hand, while reaching with the other to pick up a toy off the ground, in three postures (seated, standing, walking). An auditory Stroop task was administered simultaneous to onset of their reach. Children scaled their motor and executive function capabilities in order to complete the complex task successfully. In doing so, their response time and variability of control of motor synergies was significantly greater than adults. Children at this transitional age are searching for optimal control strategies over body kinematics. At the age of 7 children are establishing more mature motor control patterns, fine tuning their ability to perform tasks involving high levels of executive function and improving their ability to integrate more than one task.