Several risk factors of CMC OA of the thumb are known. Each of these risk factors does not cause CMC OA by itself, but acts as a predisposing factor influencing the process of OA in some way. Risk factors include: female gender, suffering from obesity, repetitive heavy manual labor, familial predisposition and hormonal changes, such as menopause.

CMC OA is the most common form of OA affecting the hand. Dahaghin et al. showed that about 15% of women and 7% of men between 50 and 60 years of age suffer from CMC OA of the thumb. However, in about 65% of people older than 55 years, radiologic evidence of OA was present without any symptoms. Armstrong et al. reported a prevalence of 33% in postmenopausal women, of which one third was symptomatic, compared to 11% in men older than 55 years. This shows CMC OA of the thumb is significantly more prevalent in women, especially in postmenopausal women, compared to men.

About 25% of people over the age of 50 experience knee pain from degenerative knee diseases.

In the United States, more than US $3 billion is spent each year on arthroscopic knee surgeries that are known to be ineffective in people with degenerative knee pain.

In most people, ligaments (which are the tissues that connect bones to each other) are naturally tight in such a way that the joints are restricted to 'normal' ranges of motion. This creates normal joint stability. If muscular control does not compensate for ligamentous laxity, joint instability may result. The trait is almost certainly hereditary, and is usually something the affected person would just be aware of, rather than a serious medical condition. However, if there is widespread laxity of other connective tissue, then this may be a sign of Ehlers-Danlos syndrome.

Ligamentous laxity may also result from injury, such as from a vehicle accident. It can result from whiplash and be overlooked for years by doctors who are not looking for it, despite the chronic pain that accompanies the resultant spinal instability. Ligamentous laxity will show up on an upright magnetic resonance imaging (MRI), the only kind of MRI that will show soft tissue damage. It can be seen in standing stress radiographs in flexion, extension, and neutral views as well, and also digital motion X-ray, or DMX.

An advantage to having lax ligaments and joints is the ability to withstand pain from hyperextension; however, this is also a disadvantage as a lack of perceived pain can prevent a person from removing the ligament from insult, leading to ligament damage. This can also lead to death if you tear the wrong ligament. People with hypermobile joints (or "double-jointed" people), almost by definition, have lax ligaments.

SLAC and SNAC are both caused by injury, for example a fall on an extended hand. SLAC is caused by rupture of the scapholunate ligament, SNAC is caused by a scaphoid fracture which does not heal and because of that will develop in a non-union fracture. SLAC is more common than SNAC; 55% of the patients with wrist osteoarthritis has a SLAC wrist. Although they have a different underlying pathology, they both lead to abnormal wrist kinematics which will eventually lead to osteoarthritis of the wrist.

The exact cause is unclear. Proposed factors include wearing overly tight shoes, family history, and rheumatoid arthritis. Some state that footwear only worsens a problem caused by genetics.

About 1.8 million people go to the emergency department each year due to hand injuries.

The cause of de Quervain's disease is not established. Evidence regarding a possible relation with occupational risk factors is debated. A systematic review of potential risk factors discussed in the literature did not find any evidence of a causal relationship with occupational factors. However, researchers in France found personal and work-related factors were associated with de Quervain's disease in the working population; wrist bending and movements associated with the twisting or driving of screws were the most significant of the work-related factors. Proponents of the view that De Quervain syndrome is a repetitive strain injury consider postures where the thumb is held in abduction and extension to be predisposing factors. Workers who perform rapid repetitive activities involving pinching, grasping, pulling or pushing have been considered at increased risk. Specific activities that have been postulated as potential risk factors include intensive computer mouse use, trackball use, and typing, as well as some pastimes, including bowling, golf, fly-fishing, piano-playing, sewing, and knitting.

Women are affected more often than men. The syndrome commonly occurs during and after pregnancy. Contributory factors may include hormonal changes, fluid retention and—more debatably—lifting.

Hypermobility syndrome is generally considered to comprise hypermobility together with other symptoms, such as myalgia and arthralgia. It is relatively common among children and affects more females than males.

Current thinking suggests four causative factors:

- The shape of the ends of the bones—Some joints normally have a large range of movement, such as the shoulder and hip. Both are ball and socket joints. If a shallow rather than a deep socket is inherited, a relatively large range of movement will be possible. If the socket is particularly shallow, then the joint may dislocate easily.

- Protein deficiency or hormone problems—Ligaments are made up of several types of protein fibre. These proteins include elastin, which gives elasticity and which may be altered in some people. Female sex hormones alter collagen proteins. Women are generally more supple just before a period and even more so in the latter stages of pregnancy, because of a hormone called relaxin that allows the pelvis to expand so the head of the baby can pass. Joint mobility differs by race, which may reflect differences in collagen protein structure. People from the Indian sub-continent, for example, often have more supple hands than Caucasians.

- Muscle tone—The tone of muscles is controlled by the nervous system, and influences range of movement. Special techniques can change muscle tone and increase flexibility. Yoga, for example, can help to relax muscles and make the joints more supple. Please note that Yoga is not recommended by most medical professionals for people with Joint Hypermobility Syndrome due to likelihood of damage to the joints. Gymnasts and athletes can sometimes acquire hypermobility in some joints through activity.

- Proprioception—Compromised ability to detect exact joint/body position with closed eyes, may lead to overstretching and hypermobile joints.

Hypermobility can also be caused by connective tissue disorders, such as Ehlers-Danlos Syndrome (EDS) and Marfan syndrome. Joint hypermobility is a common symptom for both. EDS has numerous sub-types; most include hypermobility in some degree. When hypermobility is the main symptom, then EDS/hypermobility type is likely. People with EDS-HT suffer frequent joint dislocations and subluxations (partial/incomplete dislocations), with or without trauma, sometimes spontaneously. Commonly, hypermobility is dismissed by medical professionals as nonsignificant.

The following factors may be involved in causing this deformity:

- Inherent laxity of the knee ligaments

- Weakness of biceps femoris muscle

- Instability of the knee joint due to ligaments and joint capsule injuries

- Inappropriate alignment of the tibia and femur

- Malunion of the bones around the knee

- Weakness in the hip extensor muscles

- Gastrocnemius muscle weakness (in standing position)

- Upper motor neuron lesion (for example, hemiplegia as the result of a cerebrovascular accident)

- Lower motor neuron lesion (for example, in post-polio syndrome)

- Deficit in joint proprioception

- Lower limb length discrepancy

- Congenital genu recurvatum

- Cerebral palsy

- Multiple sclerosis

- Muscular dystrophy

- Limited dorsiflexion (plantar flexion contracture)

- Popliteus muscle weakness

- Connective tissue disorders. In these disorders, there are excessive joint mobility (joint hypermobility) problems. These disorders include:

- Marfan syndrome

- Ehlers-Danlos syndrome

- Benign hypermobile joint syndrome

- Osteogenesis imperfecta disease

Those who have loose ligaments in the legs and feet often mistakenly assume that they have flat feet. While their feet have an arch when not supporting weight, when stood upon, the arch will flatten. This is because the loose ligaments cannot support the arch in the way that they should. This can make walking and standing painful and tiring.

Pain will usually occur in the feet and lower legs, but can also spread to the back due to abnormal standing and walking habits. Wearing shoes that have good arch support can help minimize the discomfort. The underlying problem, however, is not solved by wearing shoes with arch supports or worsened by wearing shoes without arch support. There is currently no cure for the condition.

In addition, people with ligamentous laxity often have clumsy or deliberate gaits, owing to the body having to overcompensate for the greater amount of energy required to offset the weakened ligaments. The feet may be spread apart at a wide angle, and the knees may flex backwards slightly after each stride.

Those who have this disease may experience sprained ankles more frequently than other people.

While genu valgum is often a symptom of genetic disorders it can be caused by poor nutrition. A major contributor to genu valgum is obesity, and far less commonly calcium and vitamin d deficiencies.

Like many other joints throughout the human body, facets can experience natural degeneration from constant use. Over time, the cartilage within the joints can naturally begin to wear out, allowing it to become thin or disappear entirely which, in turn, allows the conjoining vertebrae to rub directly against one another with little or no lubricant or separation. A result of this rubbing is often swelling, inflammation or other painful symptoms.

Over time, the body will naturally respond to the instability within the spine by developing bone spurs, thickened ligaments or even cysts that can press up against or pinch the sensitive nerve roots exiting the spinal column.

While primarily caused through natural wear and tear, advanced facet syndrome can also occur as a result of injury to the spine, degenerative disease or lifestyle choices. These causes can include:

- An unexpected, traumatic event such as a car accident, significant fall or high impact sports injury.

- Osteoarthritis

- Spondylolisthesis

- Obesity

- Smoking

- Malnutrition

- Lack of physical exercise or daily activity

Joint hypermobility syndrome shares symptoms with other conditions such as Marfan syndrome, Ehlers-Danlos Syndrome, and osteogenesis imperfecta. Experts in connective tissue disorders formally agreed that severe forms of Hypermobility Syndrome and mild forms of Ehlers-Danlos Syndrome Hypermobility Type are the same disorder.[""]

Generalized hypermobility is a common feature in all these hereditary connective tissue disorders and many features overlap, but often features are present that enable differentiating these disorders.

The inheritance pattern of Ehlers-Danlos syndrome varies by type. The arthrochalasia, classic, hypermobility and vascular forms usually have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance occurs when one copy of a gene in each cell is sufficient to cause a disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new (sporadic) gene mutations. Such cases can occur in people with no history of the disorder in their family.

The dermatosparaxis and kyphoscoliosis types of EDS and some cases of the classic and hypermobility forms, are inherited in an autosomal recessive pattern. In autosomal recessive inheritance, two copies of the gene in each cell are altered. Most often, both parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder.

Arthritis of the hand is common in females. Osteoarthritis of the hand joints is much less common than rheumatoid arthritis. As the arthritis progresses, the finger gets deformed and lose its functions. Moreover, many patients with rheumatoid arthritis have this dysfunction present in both hands and become disabled due to chronic pain. Osteoarthritis is most common at the base of thumb and is usually treated with pain pills, splinting or steroid injections.

Carpal tunnel syndrome is a common disorder of the hand. This disorder results from compression of an important nerve in the wrist. Disorders like diabetes mellitus, thyroid or rheumatoid arthritis can narrow the tunnel and cause impingement of the nerve. Carpal tunnel syndrome also occurs in people who overuse their hand or perform repetitive actions like using a computer key board, a cashiers machine or a musical instrument. When the nerve is compressed, it can result in disabling symptoms like numbness, tingling, or pain in the middle three fingers. As the condition progresses, it can lead to muscle weakness and inability to hold objects. The pain frequently occurs at night and can even radiate to the shoulder. Even though the diagnosis is straightforward, the treatment is not satisfactory.

Dupuytren's contracture is another disorder of the fingers that is due to thickening of the underlying skin tissues of the palm. The disorder results in a deformed finger which appears thin and has small bumps on the surface. Dupuytren's contracture does run in families, but is also associated with diabetes, smoking, seizure recurrence and other vascular disorders. Dupuytren's does not need any treatment as the condition can resolve on its own. However, if finger function is compromised, then surgery may be required.

Ganglion cysts are soft globular structures that occur on the back of the hand usually near the junction of the wrist joint. These small swellings are usually painless when small but can affect hand motion when they become large. The cysts contain a jelly like substance and usually do disappear on their own. If the ganglion cyst is not bothersome, it should be left alone. Just removing the fluid from the cyst is not curative because fluid will come back in less than a week. Surgery is often done for large cysts but the results are poor. Recurrences are common, and there is always the possibility of nerve or joint damage.

Tendinitis is disorder when tendons of the hands become inflamed. Tendons are thick fibrous cords that attach small muscles of the hand to bones. A Tendon is useful for generation of power to bend or extend the finger. When repetitive action is performed, tendons often get inflamed and present with pain and difficulty for moving the finger. In most cases, tendinitis can be treated with rest, ice and wearing splints. In some cases, an injection of corticosteroid may help. Tendinitis is primarily a disorder from overuse but if not treated properly, can become chronic.

Trigger finger is a common disorder which occurs when the sheath through which tendons pass, become swollen or irritated. Initially, the finger may catch during movement but symptoms like pain, swelling and a snap may occur with time. The finger often gets locked in one position and it may be difficult to straighten or bend the finger. Trigger finger has been found to be associated with diabetes, gout and rheumatoid arthritis.

55% of facet syndrome cases occur in cervical vertebrae, and 31% in lumbar. Facet syndrome can progress to spinal osteoarthritis, which is known as spondylosis. Pathology of the C1-C2 (atlantoaxial) joint, the most mobile of all vertebral segments, accounts for 4% of all spondylosis.

Wrist osteoarthritis is a group of mechanical abnormalities resulting in joint destruction, which can occur in the wrist. These abnormalities include degeneration of cartilage and hypertrophic bone changes, which can lead to pain, swelling and loss of function. Osteoarthritis of the wrist is one of the most common conditions seen by hand surgeons.

Osteoarthritis of the wrist can be idiopathic, but it is mostly seen as a post-traumatic condition. There are different types of post-traumatic osteoarthritis. Scapholunate advanced collapse (SLAC) is the most common form, followed by Scaphoid Non-union Advanced collapse (SNAC). Other post-traumatic causes such as intra-articular fractures of the distal radius or ulna can also lead to wrist osteoarthritis, but are less common.

The most important factors of knee stability include:

- Ligaments of the knee: The knee joint is stabilized by four main ligaments:

- Anterior cruciate ligament (ACL). The ACL has an important role in stabilization of knee extension movement by preventing the knee from hyperextending.

- Posterior cruciate ligament (PCL)

- Medial collateral ligament (MCL)

- Lateral collateral ligament (LCL)

- Joint capsule or articular capsule (especially posterior knee capsule)

- Quadriceps femoris muscle

- Appropriate alignment of the femur and tibia (especially in knee extension position )

Though articular cartilage damage is not life-threatening, it does strongly affect one's quality of life. Articular cartilage damage is often the cause of severe pain, knee swelling, substantial reduction in mobility and severe restrictions to one's activities. Over the last decades, however, research has focused on regenerating damaged joints.

These regenerative procedures are believed to delay osteoarthritis of injuries on the articular cartilage of the knee, by slowing down the degeneration of the joint compared to untreated damage. According to Mithoefer "et al." (2006), these articular cartilage repair procedures offer the best results when the intervention takes place in the early stages of the cartilage damage.

Identified risk factors for plantar fasciitis include excessive running, standing on hard surfaces for prolonged periods of time, high arches of the feet, the presence of a leg length inequality, and flat feet. The tendency of flat feet to excessively roll inward during walking or running makes them more susceptible to plantar fasciitis. Obesity is seen in 70% of individuals who present with plantar fasciitis and is an independent risk factor.

Studies have suggested a strong association exists between an increased body mass index and the development of plantar fasciitis in the non-athletic population; this association between weight and plantar fasciitis has not been observed in the athletic population. Achilles tendon tightness and inappropriate footwear have also been identified as significant risk factors.

Carpometacarpal bossing (or metacarpal/carpal bossing) is a small, immovable mass of bone on the back of the wrist. The mass occurs in one of the joints between the carpus and metacarpus of the hand, called the carpometacarpal joints, where a small immovable protuberance occurs when this joint becomes swollen or bossed.

The joint between the index metacarpal and the capitate is a fibrous non-mobile joint. Some people have a gene that leads to this growth. It looks like arthritis (bone spurs on each side of the joint) on X-ray. It looks like a ganglion on the hand, but more towards the fingertips.

Plantar fasciitis is the most common type of plantar fascia injury and is the most common reason for heel pain, responsible for 80% of cases. The condition tends to occur more often in women, military recruits, older athletes, the obese, and young male athletes.

Plantar fasciitis is estimated to affect 1 in 10 people at some point during their lifetime and most commonly affects people between 40–60 years of age. In the United States alone, more than two million people receive treatment for plantar fasciitis. The cost of treating plantar fasciitis in the United States is estimated to be $284 million each year.

The carpometacarpal joint is usually found at the base of the second and third metacarpal bones at the point where they meet the small bones of the wrist.

Bosses are usually painless and will never cause more than a slight ache. They tend to be of manageable size, but on occasion the extensor tendons can slide over the bump, which can be annoying. Sometimes there is a ganglion cyst along with the boss.

Often, this condition will be mistaken for a ganglion cyst due to its location and external appearance.

Carpometacarpal boss is uncommon and there is not much scientific data. It is likely genetic as often present on both hands. There is no evidence that it is related to hand use.

Typically, this condition will begin to show itself in the 3rd or 4th decade.

The degree of genu valgum can be estimated by the , which is the angle formed by a line drawn from the anterior superior iliac spine through the center of the patella and a line drawn from the center of the patella to the center of the tibial tubercle. In women, the Q angle should be less than 22 degrees with the knee in extension and less than 9 degrees with the knee in 90 degrees of flexion. In men, the Q angle should be less than 18 degrees with the knee in extension and less than 8 degrees with the knee in 90 degrees of flexion. A typical Q angle is 12 degrees for men and 17 degrees for women.