Joint protection Properly functioning joints are essential for everyday activities, not to mention trouble-free movement. What are these elements specifically responsible for? What are the symptoms of joint defects? What can you do to support their functioning? Why are more and more people using supplements to increase joint strength? What are the functions of joints? Joints are basically connections between the structures that make up our musculoskeletal system. We can distinguish different types of joint connections depending on their elements, movement capabilities, as well as the planes in which given activities take place.