An accessory navicular is an extra bone on the inner side of your foot. It's connected to the bone we call the "navicular," which helps form the foot's arch. Most people don't have an accessory navicular, and you can have one and not know it. But in some people, this extra bone causes problems.

This arthritis affects a joint at the top of your shoulder. It's where the shoulder blade's bony protrusion (called the "acromion") meets the clavicle. This joint acts as a pivot point when you raise your arm above your head.

This is a problem you can develop after spinal fusion. It happens when the vertebrae above and below the fusion become weak and damaged. We say they "degenerate." And as they degenerate, more vertebrae are at risk for harm.

Your hands are complex and versatile. They're strong and nimble, and can do very delicate movements. Let's look at the main structures of your hands so we can see how they do all the things they do.

The hip joint is one of the largest weight-bearing joints in the body. This ball-and-socket joint allows the leg to move and rotate while keeping the body stable and balanced. Let's take a closer look at the main parts of the hip joint's anatomy.

The knee is the body's largest joint. It's the place where three bones meet: the tibia, the femur and the patella. The knee is a "hinge" joint. It allows the leg to bend in one direction only. Let's take a closer look at the main parts of the knee's anatomy.

The shoulder is a complex structure made of three separate joints. They work together to give the shoulder a tremendous range of motion. Let's take a closer look at the main parts of the shoulder's anatomy.

The spinal column is the body's main support structure. Its thirty-three bones, called vertebrae, are divided into five regions: cervical, thoracic, lumbar, sacral and coccygeal.

Ligaments are fibrous, elastic bands of tissue that connect and stabilize the bones. An ankle sprain is a common, painful injury that occurs when one or more of the ankle ligaments is stretched beyond the normal range of motion. Sprains can occur as a result of sudden twisting, turning or rolling movements.

The anterior cruciate ligament, commonly called the ACL, is a thick, elastic band of tissue that runs from the bottom of the femur to the top of the tibia. It helps stabilize the knee joint. The ACL can become stretched or torn when the knee is twisted or hyperextended. For reasons that are not fully understood, ACL injuries are much more common in women than in men.

This is a weakening and collapse of the bone in the head of your femur. That's the ball that fits in the socket of your hip. As this bone gradually dies and breaks apart, you can develop painful arthritis in your hip.

This bulge, also called a "popliteal cyst," forms behind the knee. It's a swollen bursa. A bursa is a fluid-filled sac that helps reduce friction between soft tissues and bones. There are several of these sacs in the knee and in other joints. A swollen bursa can be uncomfortable, or even painful.

This condition is a degeneration of cartilage in the joints at the base of the thumb, collectively called the basal joint. The main component of the basal joint is the thumb carpometacarpal (CMC), joint. This joint, which allows the thumb to pivot and swivel, can wear out even early in life.

This is a problem with a tendon in your shoulder. Most often, it's the "long head of biceps" tendon. It travels from the front of your upper arm to the top of your shoulder socket. With this condition, the tendon becomes painfully inflamed or irritated.

This is a problem with a tendon in your elbow. It's called the "distal biceps tendon." It connects the biceps muscle of your upper arm to the radius bone at the elbow. With this condition, the tendon becomes painfully inflamed or irritated.

This deformity affects the joint at the base of the big toe. It is a bony bump beneath the skin on the inner side of the foot. A bunion starts small, but over time it can grow to become very large. Bunions are more common in women.

These are warm or painful sensations caused by an injury to the brachial plexus. This is a network of nerves that passes through your shoulder. They travel down your arm and to your hand.

This is an irritation or swelling of the trochanteric bursa. This small, fluid-filled sac is found on the outer side of the femur. It acts as a cushion for the iliotibial band, a thick tendon in your leg.

Pain, numbness and tingling in your hand may be from carpal tunnel syndrome. It happens when the area around the main nerve to your hand is too tight. The nerve is called the median nerve. And the small space in your wrist where it passes is called the carpal tunnel.

This is a problem with the facet joints of the cervical spine. They are the joints found where one vertebra connects to another. Facet joints support your spine, while allowing it to bend and twist. With this syndrome, these joints become stiff and painful in the upper part of your spine.

This condition is an irritation or compression of one or more nerve roots in the cervical spine. Because these nerves travel to the shoulders, arms and hands, an injury in the cervical spine can cause symptoms in these areas. Cervical radiculopathy may result from a variety of problems with the bones and tissues of the cervical spinal column.

This condition, which most often occurs as a complication of long-term diabetes, is a progressive degenerative condition that affects the foot. It is characterized by nerve damage in the foot along with severely weakened foot bones. This combination can result in a person fracturing the foot, but continuing to walk on the broken bones, which leads to debilitating foot deformity.

This debilitating disorder causes severe exhaustion that doesn't go away after you rest. It makes even the most ordinary daily activities difficult to do.

This is a pain on the outer side of your ankle. It's a lasting pain that you may feel all the time. It can make it hard for you to walk and run, and it can increase the possibility of ankle sprains.

These are intensely painful headaches that come in patterns or clusters. You can have them regularly over weeks or months. They may stop for months or years, and then return again.

This condition is an inflammation of the tip of the tailbone, called the coccyx. It causes pain and tenderness between the buttocks.

This happens when a muscle stretches too far. It causes the muscle fibers to tear, leaving the muscle in two separate pieces. The two parts of the muscle may pull apart, leaving a gap between them.

This is a type of chronic, long-lasting, pain. In most cases, it develops in an arm or a leg that you have previously injured. With CRPS, you may have unexplained pain that won't go away. It may be severe, and it may spread.

This is a collapse of vertebral bone. It can affect one or more vertebrae. Compression fractures typically develop in your mid or lower back. This can change the shape of your spine.

This is a serious brain injury. It happens when your brain bumps back and forth violently inside your skull. A concussion can affect the way your brain functions. It can cause permanent problems.

This condition, also called OIC, is a temporary problem with the function of your bowels. It is an uncomfortable side-effect from taking certain drugs that contain opioids. These drugs are commonly taken to control pain.

This condition, also called "ulnar nerve entrapment," happens to the ulnar nerve in your elbow. This nerve travels along the inner side of your elbow and down to your hand. It's the nerve that makes the jolt you feel when you bump your "funny bone." With this condition, your ulnar nerve is compressed, stretched or irritated.

This condition, also called stenosing tenosynovitis of the first dorsal compartment of the wrist, is an inflammation of the sheath that wraps around the tendons at the thumb side of the wrist.

This condition is a weakening of one or more vertebral discs, which normally act as a cushion between the vertebrae. This condition can develop as a natural part of the aging process, but it may also result from injury to the back.

This pain comes from one of your spinal discs. Those are the soft cushions that allow the bones of your spine to flex and twist. Discogenic pain is a common reason for chronic lower back pain.

This condition is a deterioration of the facet joints, which help stabilize the spine and limit excessive motion. The facet joints are lined with cartilage and are surrounded by a lubricating capsule that enables the vertebrae to bend and twist.

This chronic condition is believed to be a type of interference with the way your brain processes pain signals. It leaves you highly sensitive to pain. If you have this condition, you may feel long-lasting pain throughout your body.

The flexor tendons of the hand are responsible for flexion of the fingers and thumb toward the palm. These long structures are connected to the flexor muscles in the forearm. An injury to one of these tendons can cause pain and inability to flex the finger or thumb and grasp with the hand. Common flexor tendon injuries include lacerations, ruptures and inflammation.

This is stiffening of your shoulder. It happens over time, and you may not know what caused it. With a frozen shoulder, it can be hard for you to be as active as you like.

If you have pain in your shoulder, you may have a torn labrum. That's the thick band of tissue that goes around your shoulder socket. It helps make the socket deeper. It cushions the bone of your upper arm and keeps it from slipping.

The hamstrings are three powerful muscles that travel along the back of your thigh. They are the semitendinosus, the semimembranosus and the biceps femoris muscles. They help bend your knee and extend your leg behind your body. Because these muscles handle high loads of stress, they are susceptible to stretching and tearing. This is called a muscle "strain." Hamstring strains are common among runners, dancers, and athletes who play sports that require sudden starts and stops.

Between the vertebrae of your spine are soft discs. They let your spine twist and bend. They absorb shocks. But if damaged, the disc's soft center can push through the disc wall. That's a herniated disc. This bulge presses against nerves in your spine.

This condition is a rupture of one of the vertebral discs in your neck. A herniated disc can allow disc material to press harmfully against the spinal nerves.

This condition is a sprain of one or more of the ligaments that hold the tibia and fibula together at the ankle. This joint, called the ankle syndesmosis, is made up of ligaments on the front and rear of the ankle, and in the space between the tibia and fibula.

This is a problem on the outer side of your thigh. It's an inflammation of the iliotibial band. That's a thick band of tissue that spans from your hip to your shinbone. When this band becomes in inflamed, it can hurt.

This is a type of arthritis that can affect people of all ages. It's not the same as the most common form of arthritis, called "osteoarthritis." That type commonly comes from wear and tear. Inflammatory arthritis can develop without any wear and tear at all.

Joint pain is a common problem for many people. It can keep you from doing the things you want to do. It can make it hard for you to be as active as you like. Let's take a moment to learn about the causes of joint pain, and what you can do about it.

Our knees take a lot of force. They support the weight of the body. They keep us upright and stable. They cushion us when we walk and run. So it's not unusual to feel knee pain at some time in our lives. Let's learn about knee pain, and what you can do about it.

This condition is a deformity of the spine. With it, your vertebrae change from a cylindrical shape to a wedge shape. Your spine may begin to curve forward. Eventually, this gives your upper back a rounded appearance.

If your hip joint hurts, or if it catches or clicks when you move your leg, you may have a torn labrum. That's a rim of tissue that surrounds the hip's socket. It helps to deepen the socket and cushion the joint. A torn labrum can keep the hip joint from working smoothly.

This is a stretching or tearing of a ligament on the outer side of your knee. The lateral collateral ligament, commonly called the "LCL", connects the femur to the fibula. The LCL helps stabilize your knee. This ligament, along with the medial collateral ligament, helps prevent excessive side-to-side movement of your knee joint. It helps keep the upper and lower leg aligned properly.

This condition, commonly called tennis elbow, is an inflammation of the tendons that connect the muscles of the forearm to the elbow. The pain is primarily felt at the lateral epicondyle, the bony bump on the outer side of the elbow.

"This condition is an irritation or compression of one or more nerve roots in the lumbar spine. Because these nerves travel to the hips, buttocks, legs and feet, an injury in the lumbar spine can cause symptoms in these areas. Sciatica may result from a variety of problems with the bones and tissues of the lumbar spinal column. "

This is an injury of a growth plate on the elbow's inner side. Growth plates are places where new bone tissue forms. They are found near the ends of the long bones of growing children. But growth plates are weaker than the surrounding bone. That makes them easier to injure.

This is a stretching or tearing of a ligament on the inner side of your knee. The medial collateral ligament, commonly called the "MCL", is connected to the femur and to the tibia. The MCL helps stabilize your knee. This ligament, along with the lateral collateral ligament, helps prevent excessive side-to-side movement of your knee joint. It helps keep the upper and lower leg aligned properly.

This condition, commonly called golfer's elbow, is an inflammation of the tendons that connect the muscles of the forearm to the elbow. The pain is primarily felt at the medial epicondyle, the bony bump on the inner side of the elbow.

This is a common injury of the knee. Your knee joint is cushioned by two c-shaped wedges of cartilage called the "menisci." Each individual cushion is called a "meniscus." This injury is a tear of one of these cushions.

This form of cancer develops in or near the spinal cord or within the vertebrae. It can spread through multiple levels of the spine. It can lead to a wide range of serious complications.

A migraine is an intense, throbbing headache that may be accompanied by nausea or dizziness. A migraine can last from hours to days.

This common injury is an overstretching of a muscle. It causes muscle fibers to tear. A muscle strain can happen to any muscle in the body, and it can range from mild to severe. A very bad strain can cause a complete muscle tear.

The hip is where the femur meets the pelvis. Several strong muscles are found here. They handle high loads of stress. They may suffer from overstretching and tearing. This is called a muscle "strain." It's a common injury among athletes who play sports that require sudden starts and stops.

Your thigh has groups of powerful muscles. The quadriceps, the adductors and the hamstring muscles handle high loads of stress. They may suffer from overstretching and tearing. This is called a muscle "strain." It is a common injury among athletes who play sports that require sudden starts and stops.

This common injury is a stretching or tearing of the trapezius. This large muscle group spans the upper back, shoulders and neck. These muscles are commonly called the "trap" muscles.

This is a chronic pain disorder. It affects the muscles and the connective tissue (called the "fascia") that surrounds them. With this syndrome, you may develop sensitive areas on your body called "trigger points." When these places are pressed or stressed, you feel pain. This condition can affect muscles throughout your body.

This condition is a distinct type of headache caused by irritation or injury of the occipital nerves. These nerves travel from the base of the skull through the scalp. This condition can result in severe pain and muscle spasms.

This is a type of injury that causes knee pain in children. It's an inflammation of a growth plate in the tibia. Growth plates are places where new bone tissue forms. They are found in the long bones of growing children. But growth plates are weaker than the surrounding bone. That makes them easier to injure.

Osteoarthritis is the most common form of arthritis. It develops over time, often because of the wear and tear of daily activities.

This type of arthritis, also called "degenerative joint disease," is a breakdown of the cartilage in your hip joint. As this protective cartilage wears away, bone rubs against bone. Bony growths called "bone spurs" may form in the joint. Pain from osteoarthritis can keep you from being as active as you like.

Knee pain may keep you from being as active as you like. And it may come from a gradual breakdown of your knee's cartilage. That's a protective tissue on the ends of your bones. In a healthy knee, the bones glide smoothly against each other. But in a knee with osteoarthritis, cartilage begins to wear away. Bone rubs against bone. Bony bumps we call "bone spurs" may form.

Osteoarthritis, also called degenerative arthritis, is a gradual breakdown of cartilage in the joints. Cartilage is a tough, flexible connective tissue that protects the ends of bones in the joints. Osteoarthritis of the shoulder can severely impact a person's lifestyle.

If you have back or neck pain that doesn't go away, you may have osteoarthritis of the spine. Osteoarthritis is the most common form of arthritis. For many of us, it develops slowly as we age. And it can keep you from being as active as you like.

This is a disorder that most often affects young athletes. It happens when part of a bone in the elbow loses its blood supply. It weakens, and so does the cartilage that covers it. Bone and cartilage may break off and drift around in the elbow. That can cause the joint to catch and lock up.

This condition is characterized by the death of an area of cartilage and bone in the knee joint. The dead section may remain in place, forming a lesion, or it may loosen and partially detach from the surrounding bone. It may break away completely and float around inside the joint.

If you are an athlete, or if you work with your arms and hands, your elbows may be at risk for an overuse injury. This is an injury caused by repetitive motions. This type of injury can be a problem for people who play sports such as tennis or baseball. Children also have a higher risk, because their bones are still growing.

If you suffer from pain, you know how hard it can be to live with. Pain management is a branch of medical care that specializes in pain control. It can help you enjoy a better quality of life.

This is a pain you feel just below your patella (the bone we commonly call the "kneecap"). It's an injury to your patellar tendon, which connects the bottom of the kneecap to the shinbone.

This is a pain you feel in the front of your knee. It involves the patella. That's the bone we commonly call the "kneecap." The patella slides up and down in a groove on your femur as you bend and extend your knee. If you have this syndrome, you may have injured the soft tissues that support and cushion your kneecap. Or, you may have some damage to the cartilage on the underside of the kneecap.

This condition is a problem with the peripheral nervous system. These are the nerves that branch out from your brain and spinal cord and travel to all of the other parts of your body.

This condition is an inflammation of one or both peroneal tendons, which travel down the lower leg, behind the lateral malleolus and along the outer side of the ankle.

If you have lost a limb or another part of your body, you may feel painful sensations that seem to be coming from the missing part. This phenomenon is called "phantom pain." It is common among amputees. It can become a chronic problem for some people.

If you have unexplained pain or other problems, you may have a pinched nerve. That's when something presses against a nerve in your body. It can interfere with the nerve's function. Nerves can be pinched anywhere in the body but they are common in the spine and the wrist.

This is a pain and numbness you feel in your buttock and down the back of your leg. It involves the sciatic nerve. That's a large nerve that travels from your lower spine down to your foot.

Plantar fasciitis is an irritation of the plantar fascia. This thick band of connective tissue travels across the bottom of the foot between the toes and the heel. It supports the foot's natural arch. It stretches and becomes taut whenever the foot bears weight.

This is a set of symptoms that you may have after a concussion. That's when your head is hit so hard your brain is injured. You can have a concussion even if you don't lose consciousness.

This condition, also called "failed back surgery syndrome," is a type of chronic pain. It can develop in some people after spine surgery.

This is a chronic headache. It can develop after a whiplash injury (a violent back-and-forth jerking of the neck).

This condition is a tear of the tendon that connects the patella to the quadriceps muscles of the thigh. The quadriceps muscle is used to straighten the leg from the bent position. A complete rupture of the quadriceps tendon is a disabling injury.

This condition involves the radial nerve in your elbow. The radial nerve passes down your arm to your hand. Its branches travel into your thumb, forefinger and middle finger. With this condition, your radial nerve is compressed, stretched or irritated.

Rheumatoid arthritis, a condition that can attack joints throughout the body, commonly affects the joints and surrounding tendons of the wrist and fingers. It can cause the joints to become swollen, painful and possibly deformed. This can interfere with normal hand function. It can significantly impact a person's quality of life.

Rheumatoid arthritis, a condition that can attack joints throughout the body, commonly affects the joints and surrounding tendons of the wrist and fingers. It can cause the joints to become swollen, painful and possibly deformed, interfering with normal hand function and significantly impacting a persons quality of life.

Rheumatoid arthritis is a disease of the immune system. This is the system that protects you from infection. RA may cause pain and stiffness in your shoulder where the humerus (the bone of the upper arm) meets the shoulder socket. It can also affect the joint where your clavicle meets your scapula.

Rheumatoid arthritis (we call it "RA") is a chronic disease. It affects joints throughout your body. It commonly starts in your hands or feet. For many people, it causes problems in the feet and ankles.

The rotator cuff muscles and tendons hold your upper arm bone in your shoulder socket. A hard fall, repetitive arm motions or problems with the structure of your shoulder can injure the rotator cuff.

The rotator cuff is a group of muscles and tendons in each shoulder. It holds your upper arm bone in your shoulder socket. It keeps your arm stable while allowing it to lift and rotate. Too much stress on the rotator cuff can cause a tear. This can be a painful injury.

Your sacroiliac joints (we call them the "SI" joints) are the places where your hips meet your spine. These joints don't have a lot of flexibility, but they do move slightly as you move your body. And if SI joints become damaged or diseased, it can be painful.

This condition is an abnormal curvature of the spine. It most often develops in early childhood, just before a child reaches puberty.

This is a dangerous buildup of serotonin in your body. That's a chemical your body makes naturally. It's used by your brain and your nervous system. It helps regulate things like body temperature, digestion and breathing. But too much serotonin can be bad for you.

This is pain you feel in the front of one or both of your lower legs. It can be a problem for runners, dancers, gymnasts and other active people.

This is a painful pinching of soft tissues in your shoulder. It happens when these tissues rub and press against a part of your shoulder blade called the "acromion." This can irritate your rotator cuff tendons, and also a soft sac called the "subacromial bursa."

Our shoulders are the most movable joints in the body. They give our arms great range of motion. They allow us to lift and control heavy loads. Shoulder pain is a problem many of us feel at some time in our lives. Let's learn about shoulder pain, and what you can do about it.

This mass is a collection of pus that forms in the spinal canal. It forms between the spinal cord (or nerve roots) and the vertebral bones. In the cervical and thoracic regions of the spine, it can press against the spinal cord. In the lumbar region, it can press against the nerve roots. A spinal epidural abscess can cause problems throughout the body.

This is an infection most often caused by staphylococcus or E. coli bacteria. It may involve the bones, discs and soft tissues of your spine. It can start in one area of your spine and spread to other parts. It can cause pain and other problems.

Your spinal nerves travel through your spinal canal and exit through openings we call "foramen." If any of these spaces are too narrow, your nerves become compressed. We say you have "spinal stenosis." It's a problem that most often happens in the neck and lower back.

This problem affects the spinal nerves in your neck. It's a narrowing of the spinal canal. That's the space your spinal nerves travel through. In a healthy spine, the spinal canal protects these nerves. It keeps them free from injury. But with spinal stenosis, the spinal canal is too narrow, and your nerves get compressed.

This condition affects the thoracic spine between the neck and the lower back. It is a narrowing of the spinal canal that results from degeneration of bones in the spine, disc herniation, or thickening of the tissues that surround the spinal cord.

This condition occurs when a lumbar vertebra slips out of place. It slides forward, distorting the shape of your spine. This may compress the nerves in the spinal canal. The nerves that exit the foramen (open spaces on the sides of your vertebrae) may also be compressed. These compressed nerves can cause pain and other problems.

This is a crack that forms in a narrow bridge of bone at the back of a vertebra. A vertebra is one of the bones that forms your spine. Often, this injury happens in the lumbar spine. It can happen to people of all ages. But, we most often see it in children and teens. That's because their bones are still growing.

This condition is a degeneration of the spine that can affect the spine at any level, resulting in pain and discomfort that can grow worse over time.

This is a strain or a tear of soft tissue. It often involves the muscles and tendons that travel from your lower abdomen to your pubic bone. A sports hernia does not create a hole in your abdominal wall. This injury can be difficult to diagnose, because it does not cause a bulge in your skin.

This is a pain or weakness from an irritated nerve in your shoulder. It's called the "suprascapular" nerve. It travels from the neck down through your shoulder.

This is a common type of headache that can be painful and frustrating for many people. It tends to start in the back of the head and then move forward to surround your head.

This is a label given to a group of disorders. In these disorders, nerves or blood vessels are compressed in the space between your collarbone and the underlying rib. This space is called the "thoracic outlet."

Throwing overhand again and again puts a lot of stress on your elbow. It can lead to injury. Young athletes, in particular, are at risk. Some play sports all year without learning how to throw properly. And, their bones are still growing. Let's look at how the elbow can be damaged.

This condition, also called skier's thumb, is an acute sprain or tear of the ulnar collateral ligament (UCL) on the ulnar side of the metacarpal-phalangeal (MCP) joint of the thumb. A related condition, called gamekeeper's thumb, is a chronic injury that develops over time from repeated stretching of the UCL.

This is a sudden loss of bone density in the head of the femur. That's the ball that fits into the socket of your pelvis to form the hip joint. With transient osteoporosis, the femur's head weakens and your hip begins to hurt.

This condition is a degenerative or traumatic tear of one or more parts of the triangular fibrocartilage complex (TFCC), which stabilizes the ulna. The TFCC is composed of a group of ligaments that form connections between the radius, ulna and the carpal bones of the hand. At the center of these ligaments lies the most commonly injured structure, the triangular fibrocartilage disc, which is connected between the radius and the base of the ulnar styloid.

This is an inflammation of a tendon at the back of your elbow. It's called the "triceps" tendon. It anchors your upper arm's triceps muscle to the ulna (one of the bones of your forearm).

This chronic condition is caused by a misfiring of the trigeminal nerve. An attack causes brief episodes of extreme, shooting pain.

This common condition, also known as stenosing tenosynovitis, is a narrowing of a portion of the tendon sheath in the finger or thumb that interferes with normal finger movement. This condition most commonly affects the ring finger, but can affect any digit. It is more common in middle-aged women, but anyone can be affected, even newborns.

Like other joints, the elbow is held together by strong bands of tissue called "ligaments." On the elbow's inner side is the ulnar collateral ligament complex. We call it the "UCL." It's made of three bands that connect the humerus (the upper arm bone) to the lower arm's ulna. The UCL is the elbow ligament most often injured by baseball pitchers and by other athletes who play throwing sports.

If overuse has led to pain in the front of your shoulder, you may have an injury we call "weightlifter's shoulder." It's a type of damage that most often affects the end of the clavicle (commonly called the "collarbone").

Lower back pain is a common problem that severely impacts the quality of your life. It can limit your ability to be active. It can cause you to miss work. Many different causes may lead to pain in your lower back.

Neck pain is a common problem that severely impacts the quality of your life. It can limit your ability to be active. It can cause you to miss work. Many different causes may lead to pain in your neck.

This is a common neck injury. It happens when your neck jerks back and forth quickly and violently. Your spine bends past its normal range of motion. This can injure the vertebrae of your cervical spine. It can damage the supporting ligaments and muscles in your neck.

When your wrist is bent too far, this can injure bands of tissue called "ligaments." Ligaments connect the bones of your hand to each other. They also connect the bones of your hand to the bones of your forearm.