MSK: Limbs Over Time
The Limbs Over Time Sarcopaenia: Loss of muscle mass and strength as you age With age: SA of muscles decreases Infiltration of non contractile tissue into muscles - increase in adipose tissue Muscle strength decreases Reduction in motor units Change in type of motor neurones - deinnervation of fast motor neurones therefore increased innervation of slow motor neurones Factors that contribute to Sarcopaenia Nutritional Hormonal Metabolic Immunological This leads to Reduced motor units Decreased muscle fibres Atrophy Loss in muscle mass/strength Reduced physical activity = risk of falls Osteopoenia Bone loss Reduced bone mineral density Bones become more fragile Vertebrae, hip and wrist most at risk Previous fracture, increases risk of fracture Cortical and trabecular bone are affected differently with age. • cortical bone strength ↓ by 2% per decade, from age 20 yrs • toughness ↓ by 7% per...