A clinician can often diagnose a joint, tendon, and muscle disorder based on the symptoms and on the results of a physical examination. Laboratory tests, imaging tests, or other diagnostic procedures are sometimes necessary to help the clinician make or confirm a diagnosis.
Physical examination: When a person complains of muscle pain, the clinician checks muscles for bulk and texture and for tenderness. Muscles are also checked for twitches and involuntary movements, which may indicate a nerve disease rather than a muscle disease. Clinicians look for wasting away of muscle (atrophy), which can result from damage to the muscle or its nerves or from lack of use, as sometimes occurs with prolonged bed rest. Clinicians also look for muscle enlargement (hypertrophy), which normally occurs with an exercise such as weight lifting. However, when a person is injured, hypertrophy may result from one muscle working harder to compensate for the weakness of another.
Clinicians try to establish the muscles (if any) that are weak and how weak they are. The muscles can be tested systematically, usually beginning with the face and neck, then the arms, and finally the legs. Normally, a person should be able to hold the arms extended, with palms up, for one minute without any sagging, turning, or shaking. Downward drift of the arm with palms turning inward is one sign of weakness. Strength is tested by pushing or pulling while the clinician pushes and pulls in the opposite direction. Strength is also tested by having the person perform certain maneuvers, such as walking on the heels and tiptoes, rising from a squatting position, or getting up and down from a chair rapidly 10 times.
The clinician tests a joint's range of motion and muscle tone by moving the limb around a joint while the person is completely relaxed. Resistance to such movement may be decreased, resulting in observation of a larger range of motion than normal, if the nerve leading to the muscle is damaged. There may be more resistance to such movement and a smaller range of motion when the spinal cord or brain is damaged.
If a person complains of or has observable signs of weakness, clinicians will assess their reflexes using a rubber hammer to tap the person's muscle tendon. Reflexes are involuntary responses of the nerves in the muscles caused by outside stimulus, such as the rubber hammer. Reflexes may be slower than expected when the nerve leading to the muscle is damaged. Reflexes may be more rapid than expected when the spinal cord or brain is damaged.
Laboratory tests: Laboratory tests are often helpful in making the diagnosis of the underlying cause of joint, tendon, and/or muscle pain. A test called an erythrocyte sedimentation rate (ESR) test measures the rate at which red blood cells settle to the bottom of a test tube containing blood. The ESR is increased when inflammation is present. However, because inflammation occurs in so many conditions, the ESR alone does not establish a diagnosis.
The level of creatine kinase (a normal muscle enzyme that leaks out and is released into the bloodstream when muscle is damaged) may also be tested. Levels of creatine kinase may also be increased when there is widespread and ongoing destruction of muscle.
In autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus (lupus), a blood test to identify autoimmune antibodies (antinuclear antibodies) is often used in making the diagnosis.
Nerve tests: Nerve conduction studies measure how well and how fast the nerves can send electrical signals. Nerves control the muscles in the body by electrical signals (impulses), and these impulses make the muscles react
in specific ways. Nerve and muscle disorders cause the muscles to react in abnormal ways.
Nerve conduction studies, together with electromyography, help indicate the primary source of the problem causing pain. Electromyography, often performed at the same time as nerve conduction studies, is a test in which electrical impulses in the muscles are recorded to help determine how well the impulses from the nerves are reaching the connection between nerves and muscles (neuromuscular junction) and, from there, the muscles.
X-rays: X-ray imaging is used most often to evaluate painful, deformed, or suspected abnormal areas of bone. Often, X-ray images can help to diagnose fractures, tumors, injuries, infections, and deformities. Also, X-ray images may be helpful in showing changes that confirm a person has a certain kind of arthritis (for example, rheumatoid arthritis or osteoarthritis). X-ray images do not show soft tissues such as muscles, bursae, ligaments, tendons, or nerves.
Arthrography is an X-ray procedure in which a dye is injected into a joint space to outline the structures, such as ligaments, inside the joint. Arthrography can be used to view torn ligaments and fragmented cartilage in the joint.
Dual-energy X-ray absorptiometry (DEXA): The most accurate way to evaluate bone density, which is necessary when screening for or diagnosing osteoporosis, is with dual-energy X-ray absorptiometry (DEXA). In this test, low-dose X-rays are used to examine bone density at the lower spine, hip, wrist, or entire body. Measurements of bone density are very accurate at these sites. To help differentiate osteoporosis (the most common cause of an abnormal DEXA scan) from other bone disorders, doctors may need to consider the person's symptoms, medical conditions, medication use, and certain blood or urine test results as well as the DEXA results.
Computed tomography (CT) and magnetic resonance imaging (MRI): Computed tomography (CT) and magnetic resonance imaging (MRI) scans show more body detail than conventional X-rays. For this reason, CTs and MRIs may be performed to determine the extent and exact location of joint, tendon, or muscle damage. These tests can also be used to detect fractures that are not visible on X-rays. MRI is especially valuable for imaging muscles, ligaments, and tendons. MRI can be used if the cause of pain is thought to be a severe soft-tissue problem (for example, rupture of a major ligament or tendon or damage to important structures inside the knee joint). The amount of time needed to complete a CT is much less than for an MRI.
Bone scanning: Bone scanning is an imaging procedure that is occasionally used to diagnose a fracture, particularly if other tests, such as X-rays and CTs or MRIs, do not reveal the fracture. Fractures may be a cause of joint pain. Bone scanning involves the use of a radioactive substance (such as technetium-99m-labeled pyrophosphate) that is absorbed by any healing bone. The technique can also be used when a bone infection or a metastasis (spread of cancer) is suspected. The radioactive substance is given intravenously and is detected by a bone-scanning device, creating an image of the bone that can be viewed on a computer screen.
Joint aspiration: Joint aspiration is used to diagnose certain joint problems. A needle is inserted into a joint space and fluid (synovial fluid) is drawn out (aspirated) and examined under a microscope. A doctor can often make a diagnosis after microscopic analysis. For example, a sample of synovial fluid may contain bacteria, which confirms a diagnosis of infection. Joint aspiration is usually performed in a doctor's office and is generally quick, easy, and relatively painless. The risk of joint infection is minimal.
Arthroscopy: Arthroscopy is a procedure in which a small (diameter of a pencil) fiber optic scope is inserted into a joint space, allowing the doctor to look inside the joint and to project the image onto a television screen. The skin incision is very small. A person receives local, spinal, or general anesthesia to numb any pain during the procedure. During arthroscopy, doctors can take a piece of tissue for analysis (biopsy), and, if necessary, perform surgery to correct the condition. Disorders commonly found during arthroscopy include inflammation of the synovium lining (a thin, layer of tissue which lines the joint space) called synovitis; ligament, tendon, or cartilage tears; and loose pieces of bone or cartilage. Such conditions affect people with arthritis or previous joint injuries as well as athletes. All of these conditions can be repaired or removed during arthroscopy. There is a very small risk of joint infection with this procedure.
signs and symptoms
Pain is the main symptom of most joint, tendon, and muscle
disorders. The pain may be dull, sharp, radiating, or local and may be mild to severe. Although pain may be acute (immediate), as is the case with most injuries, it may become chronic (long-term) with illnesses such as rheumatoid arthritis.
Symptoms of muscle pain include pain, weakness, paralysis, muscle spasms, and coordination problems.
Symptoms of joint problems include pain, swelling, stiffness, and/or fever in the joints. In the absence of an injury, pain in one or more of the joints is often caused by inflammation or infection.
Stiffness is the feeling that the range of motion of a joint or muscle is more limited than normal or difficult to move. Some people with stiffness are capable of moving the joint through its full range of motion, although with difficulty. Joint stiffness usually is worse immediately when arising after lying or sitting still. Joint stiffness is common with arthritis.
Joint noises, such as creaks and clicks, are common and harmless in many individuals, but they can also occur with specific problems of the joints. For example, the base of the knee cap may creak when it is damaged by osteoarthritis.
Symptoms of tendon problems include pain, tenderness, redness, warmth, and/or swelling near the injured tendon. Pain may increase with activity. Symptoms of tendon injury may affect the precise area where the injured tendon is located or may radiate out from the joint area, unlike arthritis pain, which tends to be confined to the joint. Other symptoms include crepitus, or a crunchy sound or feeling when the tendon is used. Crepitus is usually painful. Crepitus may occur in osteoarthritis when the cartilage around joints has eroded away and the joint ends grind against one another, or when the fracture surfaces of two broken bones rub together.
Pain and stiffness may be worse during the night or when getting up in the morning. Stiffness may occur in the joint near the affected tendon. Movement or mild exercise of the joint usually reduces the stiffness. However, a tendon injury typically gets worse if the affected tendon is not allowed to rest and heal. Too much movement may worsen existing symptoms or bring the pain and stiffness back after improvement.
Depression: Some individuals with joint, tendon, and muscle problems may suffer from depression. This may happen if the joint, tendon, or muscle disorder interferes significantly with the patient's lifestyle, including causing pain. Individuals should consult their healthcare providers if they experience feelings of sadness, low self-esteem, loss of pleasure, apathy, difficulty functioning, or thoughts of suicide for two weeks or longer with no known underlying cause. These may be signs of depression.
Joint damage: In some cases, joint disorders can lead to severe joint damage. In such cases, surgery, such as a joint replacement, may be necessary. Individuals should regularly visit their healthcare providers to monitor their conditions.
Joint deformity: Joint deformities, major changes in the shape of a joint compared to the average shape, are acquired after birth as the result of injury or disease. An example is hand deformities commonly seen with rheumatoid arthritis.
Decreased mobility: Patients with joint, tendon, and muscle disorders may have decreased mobility in their joints. Joint mobility decreases as the joint becomes more damaged.
Muscular atrophy: Muscle atrophy refers to a decrease in the size of skeletal muscle, which occurs due to age, lack of use, body wasting (such as in cancer), or diseases such as muscular dystrophy (a genetic, hereditary muscle disease caused by progressive muscle weakness). When a muscle atrophies, it necessarily becomes weaker, since the ability to exert force is related to mass.
causes and risk factors
Individuals who are more susceptible to joint, tendon, and muscle problems are those who tend to maintain fixed positions for extended periods of time (such as sitting in a chair or standing), perform repetitive movements of the limbs (such as factory workers), overload particular muscle groups (such as movers or manual workers), and those who apply pressure on body parts and use forceful movements (such as athletes). Previous injury to a muscle or bone will cause susceptibility to joint, tendon, or muscle problems.
Joint, tendon, and muscle pain can be caused by injury to bones, joints, muscles, tendons, ligaments, bursae, or nerves. If pain occurs when there has been no injury to a joint, tendon, or muscle, or if pain from an injury persists for more than a few days, then another cause may be responsible, such as nutrient depletion of magnesium or Coenzyme Q10.
Muscle pain is known as myalgia.
Muscle pain is often less intense than that of bone pain but can be very unpleasant. For example, a muscle spasm or cramp (a sustained painful muscle contraction) in the calf is an intense pain that is commonly called a charley horse.
The most common causes of muscle pain are: injury or trauma, overuse, and tension or stress. Other causes include: certain drugs, including ACE inhibitors for lowering blood pressure, cocaine, and statins for lowering cholesterol (these drugs may deplete certain nutrients from the body); dermatomyositis, a connective-tissue disease that is characterized by inflammation of the muscles and the skin; electrolyte imbalances, such as too little potassium or calcium; fibromyalgia, a condition that causes widespread muscular pain in the body; infections, including influenza, Lyme disease, and malaria; and a breakdown of muscle fibers called rhabdomyolysis, which results in the release of muscle fiber contents (myoglobin) into the bloodstream.
Joint pain, also called arthralgia, is a symptom of injury, infection, illnesses (especially arthritis), or an allergic reaction to medication.
Causes of joint pain include: recent joint injury; joint strain; joint sprain; previous joint injury; infections such as influenza and the common cold; arthritis, including rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis; gout; sickle cell disease; Lyme disease; acute rheumatic fever; and cancer.
Bone pain due to joint damage can be deep, penetrating, dull, or sharp.
Bone pain, or ostealgia, refers to pain within the affected bone. Common causes of bone pain include underlying medical disorders or past bone traumas. Other causes are: viral illness, leukemia, sepsis/bacteraemia (infection of the blood), physical trauma to the bone (such as a fall), arthritic pain, fibromyalgia, neoplasm/cancer, Paget's disease, and osteoporosis.
Tendon pain, also called tendinopathy, affects joint areas, most commonly the shoulder, elbow, wrist, hip, knee, and ankle.
Common causes of tendon pain include tendonitis, bursitis, tenosynovitis (inflammation of the fluid-filled sheath that surrounds a tendon), lateral and medial epicondylitis (tennis elbow), and tendon injuries. Tendon and ligament pain is often worse when the affected and inflamed tendon or ligament is stretched or moved, which happens during walking. Common causes of ligament pain include injuries (sprains).