Effect of spaceflight on the human body of muscle fibre prominent in muscles also change. Slow twitch endurance fibres used to maintain posture are replaced by fast twitch rapidly contracting fibres that are insufficient for any heavy labour. Advances in research on exercise, hormone supplements and medication may help maintain muscle and body mass. Bone metabolism also changes. Normally, bone is laid down in the direction of mechanical stress. However, in a microgravity environment there is very little mechanical stress. This results in a loss of bone tissue approximately 1.5% per month especially from the lower vertebrae, hip and femur. Due to microgravity and the decreased load
The Bone People the shape of a shell with many spirals. The end of the novel, despite many things remaining in the air, is a happy one. Isolation is one of the major themes of "The Bone People". Kerewin isolates herself from the world in her tower; Simon is isolated from the world by his inability to speak; Joe is isolated by his grief. Characters' motivations are shown to the reader through paragraphs that detail their thoughts, which serve to illustrate how their isolation leads to misunderstanding. Additionally, violence plays a role as a means of communication and, in their culture, as what