In child development circles, a motor milestone is a discrete event in a person's progressive mastery of control over the body's movements. To most parents, each milestone-sitting up without support, grasping a raisin between thumb and forefinger, holding a cup, taking the first step all by herself—is a joyous occasion in their child's life. Children of the seventies, however, exhibit a new set of motor milestones made possible by our affluent society. None of these is cause for celebration. The modern milestones are discrete events marking the child's progressive involvement with engine-driven vehicles.
As early as 4 years of age, children may ride their first minibike.