The human skeletal system has many important functions, including movement. As a person ages, movement can become difficult. Ligaments become less elastic and cartilage is damaged. 7. Considering the function of ligaments, explain why less elastic ligaments could cause movement to be difficult. 8. Considering the function of cartilage, explain why damaged cartilage could cause movement to be difficult. 9. Identify two functions of the skeletal system besides movement.