What is the musculoskeletal system?
Your musculoskeletal system includes your bones, cartilage, ligaments, tendons and connective tissues. Your skeleton provides a framework for the muscles and other soft tissues. Together, they support your body’s weight, maintain your posture and help you move.
A wide range of disorders and conditions can lead to problems in the musculoskeletal system. Aging, injuries, congenital anomalies (birth defects) and disease can cause pain and limit movement.
You can keep your musculoskeletal system healthy by focusing on your overall health. Eat a balanced diet, maintain a healthy weight, exercise regularly and see your provider for checkups.
How does the musculoskeletal system work?
The nervous system (your body’s command center) controls your voluntary muscle movements. Voluntary muscles are ones you control intentionally. Some involve large muscle groups to do activities like jumping. Others use smaller movements, like pushing a button. Movements happen when:
- The nervous system (brain and nerves) sends a message to activate your skeletal (voluntary) muscles.
- Your muscle fibers contract (tense up) in response to the message.
- When the muscle activates or bunches up, it pulls on the tendon. Tendons attach muscles to bones.
- The tendon pulls the bone, making it move.
- To relax the muscle, your nervous system sends another message. It triggers the muscles to relax or deactivate.
- The relaxed muscle releases tension, moving the bone to a resting position.
What are the parts of the musculoskeletal system?
The musculoskeletal system works to help you stand, sit, walk, run and move. Adult bodies have 206 bones and more than 600 muscles, connected by ligaments, tendons and soft tissues.
The parts of the musculoskeletal system are:
- Bones: Bones of all shapes and sizes support the body, protect organs and tissues, store calcium and fat and produce blood cells. A bone’s hard outside shell surrounds a spongy center. Bones provide structure and form for your body. They work with muscles, tendons, ligaments and other connective tissues to help you move.
- Cartilage: A type of connective tissue, cartilage cushions bones inside the joints, along the spine and in the ribcage. Firm, rubbery cartilage protects bones from rubbing against each other. You also have cartilage in your nose, ears, pelvis and lungs.
- Joints: Bones come together to form joints. Some joints have a large range of motion, such as the ball-and-socket shoulder joint. Other joints, like the knee, allow bones to move back and forth but not rotate.
- Muscles: Each muscle is made of thousands of stretchy fibers. Your muscles allow you to move, sit upright and stay still. Some muscles help you run, dance and lift. You use others to write your name, fasten a button, talk and swallow.
- Ligaments: Made of tough collagen fibers, ligaments connect bones and help stabilize joints.
- Tendons: Tendons connect muscles to bones. Made of fibrous tissue and collagen, tendons are tough but not very stretchy.
What conditions and disorders affect the musculoskeletal system?
Hundreds of conditions can cause problems with the musculoskeletal system. They can affect the way you move, speak and interact with the world. Some of the most common causes of musculoskeletal pain and movement problems are:
- Aging: During the natural aging process, bones lose their density. Less-dense bones can lead to osteoporosis and bone fractures (broken bones). As you age, muscles lose their mass and cartilage begins to wear away, leading to pain, stiffness and decreased range of motion. After an injury, you may not heal as quickly as you did when you were younger.
- Arthritis: Pain, inflammation and joint stiffness result from arthritis. Older people are more likely to get osteoarthritis as cartilage inside joints breaks down, but the condition can affect people of all ages. Other types of arthritis also cause joint pain and inflammation, including rheumatoid arthritis, ankylosing spondylitis and gout.
- Back problems: Back pain and muscle spasms can result from muscle strains or injuries like a herniated disk. Some conditions, including spinal stenosis and scoliosis, cause structural problems in the back, leading to pain and limited mobility.
- Cancer: Several types of cancer affect the musculoskeletal system, including bone cancer. Tumors that grow in connective tissue (sarcomas) can cause pain and problems with movement.
- Congenital abnormalities: Also known as birth defects, congenital abnormalities can affect the body’s appearance, structure and function. Clubfoot is one of the most common musculoskeletal problems babies are born with. It causes stiffness and reduced range of motion.
- Disease: A wide range of diseases affect how bones, muscles and connective tissues work. Some, such as osteonecrosis, cause bones to deteriorate and die. Other disorders, such as fibrous dysplasia and brittle bone disease (osteogenesis imperfecta), cause bones to fracture easily. Conditions that affect the skeletal muscles (myopathies) include more than 30 types of muscular dystrophy.
- Injuries: Hundreds of injuries can affect bones, cartilage, muscles and connective tissues. Injuries can result from overuse, such as carpal tunnel syndrome, bursitis and tendinitis. Sprains, muscle tears, broken bones and injuries to tendons, ligaments and other soft tissues can result from accidents and trauma.
How common are these conditions?
Everyone has pain in their muscles and joints from time to time. One of the most common musculoskeletal conditions is back pain, especially low back pain. More than 80% of people in the United States have back pain at some point in their lives. Arthritis is also very common. More than 54 million adults in the U.S. have arthritis.
Broken bones, sprains and strains happen to millions of people every year. Most people recover from these injuries without long-term health problems.
How can I keep my musculoskeletal system healthy?
The best way to take care of your musculoskeletal system is to maintain good health overall. To keep your bones and muscles healthy, you should:
- Exercise regularly, and be sure to include a combination of weight-bearing exercises and cardiovascular activity. Strengthening your muscles can support your joints and protect them from damage.
- Get plenty of sleep so your bones and muscles can recover and rebuild.
- Maintain a healthy weight. Extra pounds put pressure on your bones and joints, causing a range of health problems. If you carry extra weight, talk to your provider about a healthy weight-loss plan.
- Make healthy food choices, including a balanced diet of fruits and vegetables, lean protein and milk for strong bones.
- Quit smoking and avoid tobacco. Smoking decreases blood flow throughout your body. Your bones, muscles and soft tissues need adequate blood flow to stay healthy.
- Have regular checkups and age-appropriate health screenings. If you’re over 65, talk to your provider about getting bone density tests.
When should I call my doctor?
Talk to your provider if you have pain, swelling, stiffness, decreased range of motion or problems moving. See your provider right away if any of these changes happen suddenly. Sudden problems could be a sign of a serious condition.
A note from Cleveland Clinic
Everyone has muscle aches and pains from time to time. Although you may not be able to prevent all strains, sprains and broken bones, you can keep your musculoskeletal system healthy. Maintaining good overall health will lower your risk of disease and injuries. And staying healthy will help you heal faster if you do get injured. By seeing your provider regularly, managing your weight and taking care of yourself, you’ll protect your bones and muscles so they can keep protecting you.