Table 1.

Definition of key terms for muscle function, balance and bone health (from Heinonen & Kujala, in Kokko et al 2011, p 32).

Term	Definition
Muscle function	Muscle function is to permit movement and maintain posture. Sensory receptors in the muscles monitor the tension and length of the muscles and provide the nervous system with crucial information about the position of the body parts.
Bone Health	Bone health includes bone quality that refers to the capacity of bones to withstand a wide range of loading without breaking. Bone health includes also bone mineral, structure, geometry and strength.
Balance	A performance-related component of physical fitness that involves the maintenance of the body balance while stationary or moving. In addition agility can be seen as a component of dynamic balance. Agility is a performance-related component of physical fitness that is the ability to change position of the entire body in space with speed and accuracy.