Hands are critically important for brain development--but the use of large muscle activities that involve legs, arms, shoulders, etc. are also mandatory for the development of young children--including health and wholesome living! Here's an interesting view of the debate between large vs. small muscles in schools and recreation.

*Source: "Recreation and the Total Personality: An analysis of goals and methods for enriching recreation's contribution to wholesome living" by S.R. Slavson (1946)
*Photo by Ron Jones