Muscles, bones and joints make up the musculoskeletal system that allows us to move and function normally. Musculoskeletal problems can cause pain and restricted or reduced movement. Simple muscle aches and pains can be relieved with anti-inflammatory medicines like ibuprofen and diclofenac. Diseases affecting the joints, for example rheumatoid arthritis, can be treated with medicines that affect the immune system, like methotrexate and leflunomide. Osteoporosis is the gradual thinning and weakening of bones, a process that can be prevented or slowed with medicines such as alendronic acid or risedronate.