Musculoskeletal disorders (MSDs) are conditions that affect your muscles, bones, joints, and the connective tissues that hold them together. The term covers more than 150 different diseases and injuries, ranging from a sprained ankle that heals in weeks to chronic conditions like osteoarthritis that can last a lifetime. They are among the most common health problems worldwide, and the leading cause of disability in many countries.
What Counts as a Musculoskeletal Disorder
The umbrella is broader than most people expect. MSDs include conditions affecting four main areas of the body:
- Joints: osteoarthritis, rheumatoid arthritis, psoriatic arthritis, gout, and other forms of inflammatory arthritis
- Bones: osteoporosis, osteopenia, and fractures (both from trauma and from weakened bone)
- Muscles: sarcopenia (age-related muscle loss), strains, and chronic muscle pain
- Multiple body areas: back and neck pain, fibromyalgia, connective tissue diseases like lupus, and even amputation resulting from disease or injury
Some MSDs appear suddenly, like a broken bone or a torn ligament. Others develop gradually over months or years, like the cartilage breakdown in osteoarthritis or the autoimmune joint inflammation of rheumatoid arthritis. What ties them all together is that they limit how well you can move and function physically.
The Most Common Types
Among the 150-plus conditions in this category, three groups cause the most disability: back disorders, osteoarthritis, and inflammatory arthritis.
Chronic low back pain is defined as pain lasting more than three months and is one of the single most disabling musculoskeletal conditions globally. It can stem from disc problems, muscle strain, spinal stenosis, or sometimes no identifiable structural cause at all.
Osteoarthritis, the “wear and tear” form of arthritis, most commonly affects the knees, hips, and hands. It involves the gradual breakdown of cartilage that cushions your joints, leading to pain, stiffness, and reduced mobility. It becomes increasingly common after age 50.
Inflammatory arthritis, including rheumatoid arthritis and psoriatic arthritis, works differently. These are autoimmune conditions where the immune system attacks healthy joint tissue, causing swelling, pain, and potential joint damage even in younger adults. Ankylosing spondylitis, which primarily affects the spine, and juvenile idiopathic arthritis, which affects children, also fall into this group.
Causes and Risk Factors
MSDs don’t have a single cause. Some are driven by genetics and immune system dysfunction, others by physical wear on the body, and many by a combination of both.
In the workplace, the physical risk factors are well documented. Repetitive motions, forceful exertion, and awkward or unnatural postures all place extra stress on muscles, tendons, nerves, and bones. Jobs that involve heavy lifting, bending and twisting, or sustained force through the hands and wrists carry higher risk. The combination of these factors, like repetitive work done in an awkward position while applying force, compounds the danger significantly.
Outside of work, the major risk factors include aging, obesity, physical inactivity, smoking, and existing conditions like diabetes or depression. Sex plays a role too. Women are substantially more likely to develop MSDs than men, likely due to differences in hormones, body composition, and biomechanics. One study of adults over 60 found that women were roughly five and a half times more likely to have a musculoskeletal disorder than men in the same age group.
Depression is both a risk factor and a consequence. Chronic pain limits activity and social participation, which can worsen mood, while depression itself appears to increase vulnerability to MSDs, creating a cycle that can be difficult to break without addressing both problems.
How MSDs Feel
Five hallmark symptoms define musculoskeletal disease: pain, swelling, redness, warmth, and stiffness. Not every condition produces all five, but pain and stiffness are nearly universal.
Stiffness is particularly characteristic. Morning stiffness that lasts more than 30 minutes often points toward an inflammatory condition like rheumatoid arthritis, while stiffness that gets worse with activity and improves with rest is more typical of osteoarthritis. You might also notice reduced range of motion in a joint, a grinding or crackling sensation (called crepitus) when you move, visible deformity or asymmetry, or joints that feel unstable or “give way.”
The location of symptoms matters. In older adults, the lower back is by far the most commonly affected area (about 69% of those with MSDs), followed by the upper back (42%), knees (34%), shoulders (28%), and neck (25%). Elbows, wrists, and ankles are less commonly involved.
How MSDs Are Diagnosed
Diagnosis typically starts with a physical exam. A doctor will check each affected joint for tenderness, swelling, redness, and deformity, and test your range of motion, pain with movement, and joint stability.
X-rays are usually the first imaging test ordered. They’re best at revealing bone problems: fractures, tumors, infections, and the joint changes that confirm specific types of arthritis. They can’t show soft tissues like muscles, ligaments, or tendons, though. When a soft tissue injury is suspected, such as a torn ligament or tendon rupture, MRI is the preferred tool. It provides much more detail for muscles, tendons, and the structures inside joints. CT scans can also detect fractures that don’t show up on standard X-rays and help pinpoint the exact location and extent of damage.
Blood tests play a role for inflammatory conditions, helping identify markers of autoimmune activity that distinguish rheumatoid arthritis from osteoarthritis or other causes of joint pain.
Treatment and Management
Conservative treatment is the first-line approach for most musculoskeletal disorders. This means starting with the least invasive options: patient education, activity modification, pain management with anti-inflammatory medications, and physical therapy.
The strongest evidence supports combining manual therapy (hands-on techniques performed by a physical therapist) with targeted exercises. This combination consistently outperforms exercise alone for reducing pain and improving mobility. Manual therapy techniques like myofascial release and specific muscle relaxation methods help reduce muscle tension and restore normal movement patterns without any permanent structural changes, making them safe to try before considering more aggressive options.
For workplace-related MSDs, ergonomic changes are essential. This means redesigning the work environment, whether that involves adjusting tools, modifying workstation setup, changing lighting, or altering how tasks are performed, so the job fits the worker’s physical capabilities rather than forcing the body to adapt to poorly designed conditions.
When conservative treatment reaches a plateau and symptoms persist, the next step depends on the specific condition. For some joint problems, minimally invasive procedures offer meaningful improvement. For inflammatory conditions like rheumatoid arthritis, medications that calm the immune response can slow or prevent joint damage. The general principle is a stepwise approach: start simple, escalate only when needed.
Who Is Most Affected
MSDs affect people across all age groups, but prevalence rises sharply with age. Among adults over 60, studies have found rates above 70%. Physical inactivity is one of the strongest modifiable risk factors in this group. Older adults who are not physically active are roughly four times more likely to have an MSD than those who stay active.
The economic toll is staggering. In Japan alone, productivity losses from workers showing up to work while dealing with MSD symptoms cost an estimated $27 billion per year. That figure captures only “presenteeism,” the cost of being at work but unable to perform fully, and doesn’t include the cost of missed days, medical treatment, or disability payments. Nurses, construction workers, office workers with prolonged computer use, and others in physically demanding or repetitive jobs carry especially high risk.
Prevention Strategies
Because many MSDs develop from cumulative physical stress, prevention focuses on reducing that stress before symptoms appear. In the workplace, this means designing jobs around the human body. Adjusting workstation height so you aren’t reaching or bending awkwardly, using tools that reduce the force your hands and wrists need to exert, and breaking up repetitive tasks with variation all lower risk.
Outside of work, staying physically active is the single most protective factor. Regular exercise strengthens muscles that support and stabilize joints, maintains bone density, helps control weight (reducing load on weight-bearing joints), and appears to have direct anti-inflammatory effects. Maintaining a healthy weight matters particularly for knee and hip osteoarthritis, where every extra pound adds several pounds of force across the joint with each step. Avoiding smoking and managing conditions like diabetes and depression also reduce your overall risk.