A(n) ____ is an injury or disorder of the muscles, nerves, tendons, ligaments, and joints.

Introduction to Muscle, Bursa, and Tendon Disorders

By

, MD, MPH, Brown University

Full review/revision Apr 2022 | Modified Sep 2022

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The muscles, bursae, tendons, and bones must be healthy and functioning correctly for the body to move normally. Muscles, which contract to produce movement, are connected to the bones by tendons. Bursae are flat sacs containing joint (synovial) fluid. They reduce friction in areas where skin, muscles, tendons, and ligaments rub over bones. (See also Biology of the Musculoskeletal System Introduction to the Biology of the Musculoskeletal System The musculoskeletal system provides form, stability, and movement to the human body. It consists of the body's bones (which make up the skeleton), muscles, tendons, ligaments, joints, cartilage... read more .)

Often, muscles, bursae, and tendons are injured during sports activities Overview of Sports Injuries Sports injuries are common among athletes and other people who participate in sports. Certain injuries that are traditionally considered sports injuries can also occur in people who do not participate... read more

Disorders of the muscles, bursae, and tendons include

• Baker cysts Baker Cysts Baker cysts are small sacs filled with joint (synovial) fluid that form in an extension of the joint capsule behind the knee. A Baker cyst results from an accumulation of trapped joint fluid... read more

• Bursitis Bursitis Bursitis is painful inflammation of a bursa (a flat, fluid-filled sac that provides cushioning where skin, muscles, tendons, and ligaments rub over bones). Movement is usually painful, and bursae... read more

• Tendinitis and tenosynovitis Tendinitis and Tenosynovitis Tendinitis is inflammation of a tendon. Tenosynovitis is tendinitis accompanied by inflammation of the protective covering around the tendon (tendon sheath). The cause is not always known. Tendons... read more

Fibromyalgia Fibromyalgia Fibromyalgia is characterized by poor sleep, fatigue, mental cloudiness, and widespread aching and stiffness in soft tissues, including muscles, tendons, and ligaments. Poor sleep, stress, strains... read more , although covered here, is thought to be a central pain syndrome, not a disorder of muscles, bursae, or tendons.

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A repetitive strain injury (RSI), sometimes referred to as repetitive stress injury, is a gradual buildup of damage to muscles, tendons, and nerves from repetitive motions. RSIs are common and may be caused by many different types of activities, including:

• using a computer mouse
• typing
• swiping items at a supermarket checkout
• grasping tools
• working on an assembly line
• training for sports

Some common RSIs are:

• carpal tunnel syndrome
• bursitis
• rotator cuff tendonitis
• tennis elbow

Keep reading to learn more about this type of injury.

What are the symptoms of RSI?

RSI frequently affects your:

• wrists and hands
• forearms and elbows
• neck and shoulders

Other areas of your body can also be affected.

Symptoms include:

• pain, ranging from mild to severe
• tenderness
• swelling
• stiffness
• tingling or numbness
• throbbing
• weakness
• sensitivity to cold or heat

Symptoms may begin gradually and then become constant and more intense. Even with initial treatment, symptoms may limit your ability to perform your usual activities.

What are causes and risk factors for RSI?

RSI can occur when you do repetitive movements. Those movements can cause your muscles and tendons to become damaged over time.

Some activities that can increase your risk for RSI are:

• stressing the same muscles through repetition
• maintaining the same posture for long periods of time
• maintaining an abnormal posture for an extended period of time, such as holding your arms over your head
• lifting heavy objects
• being in poor physical condition or not exercising enough

Previous injuries or conditions, such as a rotator cuff tear or an injury to your wrist, back, or shoulder, can also predispose you to RSI.

Desk jobs are not the only occupations whose workers are at risk for RSI. Other occupations that involve repetitive movements and may increase your risk include:

• dental hygienists
• construction workers who use power tools
• cleaners
• cooks
• bus drivers
• musicians

How is RSI diagnosed?

If you have even mild discomfort completing certain tasks on your job or at home, it’s a good idea to see your doctor to talk about RSI. Your doctor will ask you questions about your work and other activities to try to identify any repetitive movements you do. They’ll also ask about your work environment, such as whether you work at a computer or have an ergonomic work station. They’ll do a physical exam as well. During the exam, they’ll perform range of motion tests and check for tenderness, inflammation, reflexes, and strength in the affected area.

Your doctor may also order magnetic resonance imaging (MRI) or ultrasound to assess tissue damage. An electromyography (EMG) may be ordered to check on nerve damage.

For mild damage, your doctor may refer you to a physical therapist. If the damage is severe, they may also refer you to a specialist or surgeon.

How is RSI treated?

The initial treatment for RSI symptoms is conservative. This may include:

• RICE, which stands for rest, ice, compression, and elevation
• nonsteroidal anti-inflammatory drugs (NSAIDs), both oral and topical
• steroid injections
• exercises, which may be prescribed as part of a physical therapy treatment plan
• stress reduction and relaxation training
• wrapping the area or securing it with a splint to protect and rest the muscles and tendons

Your doctor and physical therapist can also suggest adjustments to your work station, such as readjusting your chair and desk if you work at a computer, or modifications to your movements and equipment to minimize muscle strain and stress.

In some cases, surgery may be necessary.

What’s the outlook for RSI?

Your outlook with RSI depends on the severity of your symptoms and your general health. You may be able to use conservative measures to modify your work routine and minimize pain and damage. Or, you may have to stop certain tasks at work for a while to rest the affected area. If other measures don’t work, your doctor may recommend surgery for specific problems involving nerves and tendons.

Tips for preventing RSI

If you sit at a desk, follow the traditional advice from parents and teachers: Sit up straight and don’t slouch! Good posture is the key to avoiding unnecessary stress on your muscles. This takes practice and mindfulness. There are also many exercises you can do to improve your posture.

• Adjust your work station to promote good posture and comfort.
• Sit in a chair that gives you support for your lower back and keep your feet flat on the floor or on a foot rest. Your thighs should be parallel to the ground, and your hands, wrists, and forearms should be aligned. Your elbows should be in line with your keyboard to avoid strain.
• Avoid sitting cross-legged.
• If possible, spend some of your computer time at a standing desk. Slowly increase the amount of time you stand, aiming for 20–30 minutes each hour or more.
• Place your computer monitor about an arm’s length away from you. The screen should be at eye level so you’re looking straight ahead.
• If you’re on the phone a lot, use a headset to avoid straining your neck, shoulders, and arms.

Taking frequent breaks from your desk throughout the day is as important as having an ergonomic workstation.

• get up to stretch or walk around
• do shoulder stretches at your desk
• march in place
• wiggle your fingers and flex your wrists

Those may sound like little things, but mini breaks can make a big difference in preventing RSI.

If your work is not at a desk, the same principles apply. Maintain good posture, figure out the least stressful positions for the repetitive tasks required, and take frequent mini breaks. If you have to stand a lot, use an antifatigue mat. Use extension poles for cleaning tools to avoid straining your arms, and lift heavy loads properly. If you use tools, take breaks throughout the day to stretch and flex your fingers and wrists.

Most occupations have been studied in detail and have guidelines for reducing worker stress while doing specific tasks. The National Education Association, for example, has a handbook on RSI that provides tips for teachers, drivers, food workers, custodians, and others.

What is considered a musculoskeletal injury?

What is the cause of musculoskeletal Disorder?