In 1965 Muska's first book, Developmental Movement, was published by Charles E. Merrill. This book offers the field of physical education "an integrated concept of movement designed to achieve total physical development" (vii). Muska believed that all fields have their own intrinsic conceptual framework. Conceptual frameworks are like blueprints, linking ideas to form a structure. Developmental Movement delineated the blueprint (the structure) from which all movement is connected.
Muska's cognitive structure demanded conceptual logic. How do ideas connect? What underlying principle connects seemingly unrelated and random ideas? What is the relative position of one idea to another? What is the factor or variable that links one idea to another to eventually establish an overarching conceptual framework? Cognitively, Muska searched for structural order. For him, structural order revealed the patterns that linked and connected knowledge.
Additionally, Muska was an avid supporter of the developmental possibilities inherent in physical movement. He believed that the subject matter of physical education should be a prominent content area in schools, particularly for younger students, because of the rich and varied developmental opportunities movement offered. He promoted the now established findings that moving influences and stimulates thinking. Few content fields so effortlessly embrace the implementation of all teaching styles, and few fields provide simultaneous developmental opportunities on all the Developmental Channels – the physical, social, emotional, cognitive, and ethical, etc. domains. Muska believed physical activity was critical for development and health.
Why did Muska select physical education as the initial content field for developing and testing his Spectrum ideas? Movement provided the visual verification of students' thinking and showed how they made decisions. Seeing the decision process enabled Muska to make predictions about different learning opportunities in each teaching style.