Development of musculoskeletal stiffness: Anthony Blazevich, Charlie Waugh and Thomas Korff
We move when our muscles generate forces that are transferred through tendons to the skeleton. Far from being a simple system, in which the muscles function like motors and the tendons as cables, both muscle and tendon can stretch and recoil as forces vary, so each movement requires a unique muscle activation sequence to account for the ‘spring-like’ properties of our musculoskeletal system. Understanding how differences in this spring-like property influence movement in children is vital so that we can determine which movement patterns are optimal for children and how these patterns should vary with normal growth and development. In this chapter we first discuss concepts relating to the mechanical properties of elastic tissues. Within this context, we describe the different relevant biomechanical measurement techniques. In the second part of the chapter we synthesize the literature relating to age-related changes in the elastic properties of the musculoskeletal system during childhood, and we derive practical implications from this body of knowledge.