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.

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

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.

In tennis players, about 39.7% have reported current or previous problems with their elbow. Less than one quarter (24%) of these athletes under the age of 50 reported that the tennis elbow symptoms were "severe" and "disabling," while 42% were over the age of 50. More women (36%) than men (24%) considered their symptoms severe and disabling. Tennis elbow is more prevalent in individuals over 40, where there is about a four-fold increase among men and two-fold increase among women. Tennis elbow equally affects both sexes and, although men have a marginally higher overall prevalence rate as compared to women, this is not consistent within each age group, nor is it a statistically significant difference.

Playing time is a significant factor in tennis elbow occurrence, with increased incidence with increased playing time being greatery for respondents under 40. Individuals over 40 who played over two hours doubled their chance of injury. Those under 40 increased it 3.5 fold compared to those who played less than two hours per day.

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.

Workers in certain fields are at risk of repetitive strains. Most occupational injuries are musculoskeletal disorders, and many of these are caused by cumulative trauma rather than a single event. Miners and poultry workers, for example, must make repeated motions which can cause tendon, muscular, and skeletal injuries.

One way to prevent this injury from occurring is to be informed and educated about the risks involved in hurting your wrist and hand. If patients do suffer from median nerve palsy, occupational therapy or wearing a splint can help reduce the pain and further damage. Wearing a dynamic splint, which pulls the thumb into opposition, will help prevent an excess in deformity. This splint can also assist in function and help the fingers flex towards the thumb. Stretching and the use of C-splints can also assist in prevention of further damage and deformity. These two methods can help in the degree of movement the thumb can have. While it is impossible to prevent trauma to your arms and wrist, patients can reduce the amount of compression by maintaining proper form during repetitive activities. Furthermore, strengthening and increasing flexibility reduces the risk of nerve compression.

Another factor of tennis elbow injury is experience and ability. The proportion of players who reported a history of tennis elbow had an increased number of playing years. As for ability, poor technique increases the chance for injury much like any sport. Therefore, an individual must learn proper technique for all aspects of their sport. The competitive level of the athlete also affects the incidence of tennis elbow. Class A and B players had a significantly higher rate of tennis elbow occurrence compared to class C and novice players. However, an opposite, but not statistically significant, trend is observed for the recurrence of previous cases, with an increasingly higher rate as ability level decreases.

Other ways to prevent tennis elbow:

- Decrease the amount of playing time if already injured or feeling pain in outside part of the elbow.

- Stay in overall good physical shape.

- Strengthen the muscles of the forearm: (pronator quadratus, pronator teres, and supinator muscle)—the upper arm: (biceps, triceps)—and the shoulder (deltoid muscle) and upper back (trapezius). Increased muscular strength increases stability of joints such as the elbow.

- Like other sports, use equipment appropriate to your ability, body size, and muscular strength.

- Avoid any repetitive lifting or pulling of heavy objects (especially over your head)

Vibration dampeners (otherwise known as "gummies") are not believed to be a reliable preventative measure. Rather, proper weight distribution in the racket is thought to be a more viable option in negating shock.

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.

The international debate regarding the relationship between CTS and repetitive motion in work is ongoing. The Occupational Safety and Health Administration (OSHA) has adopted rules and regulations regarding cumulative trauma disorders. Occupational risk factors of repetitive tasks, force, posture, and vibration have been cited.

The relationship between work and CTS is controversial; in many locations, workers diagnosed with carpal tunnel syndrome are entitled to time off and compensation.

Some speculate that carpal tunnel syndrome is provoked by repetitive movement and manipulating activities and that the exposure can be cumulative. It has also been stated that symptoms are commonly exacerbated by forceful and repetitive use of the hand and wrists in industrial occupations, but it is unclear as to whether this refers to pain (which may not be due to carpal tunnel syndrome) or the more typical numbness symptoms.

A review of available scientific data by the National Institute for Occupational Safety and Health (NIOSH) indicated that job tasks that involve highly repetitive manual acts or specific wrist postures were associated with incidents of CTS, but causation was not established, and the distinction from work-related arm pains that are not carpal tunnel syndrome was not clear. It has been proposed that repetitive use of the arm can affect the biomechanics of the upper limb or cause damage to tissues. It has also been proposed that postural and spinal assessment along with ergonomic assessments should be included in the overall determination of the condition. Addressing these factors has been found to improve comfort in some studies. A 2010 survey by NIOSH showed that 2/3 of the 5 million carpal tunnel cases in the US that year were related to work. Women have more work-related carpal tunnel syndrome than men.

Speculation that CTS is work-related is based on claims such as CTS being found mostly in the working adult population, though evidence is lacking for this. For instance, in one recent representative series of a consecutive experience, most patients were older and not working. Based on the claimed increased incidence in the workplace, arm use is implicated, but the weight of evidence suggests that this is an inherent, genetic, slowly but inevitably progressive idiopathic peripheral mononeuropathy.

A pulled elbow, also known as a radial head subluxation, is when the ligament that wraps around the radial head slips off. Often a child will hold their arm against their body with the elbow slightly bent. They will not move the arm as this results in pain. Touching the arm, without moving the elbow, is usually not painful.

A pulled elbow typically results from a sudden pull on an extended arm. This may occur when lifting or swinging a child by the arms. The underlying mechanism involves slippage of the annular ligament off of the head of the radius followed by the ligament getting stuck between the radius and humerus. Diagnosis is often based on symptoms. Xrays may be done to rule out other problems.

Prevention is by avoiding potential causes. Treatment is by reduction. Moving the forearm into a palms down position with straitening at the elbow appears to be more effect than moving it into a palms up position followed by bending at the elbow. Following a successful reduction the child should return to normal within a few minutes. A pulled elbow is common. It generally occurs in children between the ages of 1 and 4 years old, though it can happen up to 7 years old.

This injury has also been reported in babies younger than six months and in older children up to the preteen years. There is a slight predilection for this injury to occur in girls and in the left arm. The classic mechanism of injury is longitudinal traction on the arm with the wrist in pronation, as occurs when the child is lifted up by the wrist. There is no support for the common assumption that a relatively small head of the radius as compared to the neck of the radius predisposes the young to this injury.

Among the causes of ulnar neuropathy are the following-

Much more commonly, ulnar neuropathy is caused by overuse of the triceps muscle and repetitive stress combined with poor ergonomics. Overused and hypertonic triceps muscle causes inflammation in the tendon and adhesions with the connective tissue surrounding that tendon and muscle. These in turn impinge on or trap the ulnar nerve. Ulnar neuropathy resulting from repetitive stress is amenable to massage and can usually be fully reversed without cortisone or surgery.

Center for Occupational and Environmental Neurology , Baltimore, MD has this to say:

“Repetitive Strain Injuries (RSI) refers to many different diagnoses of the neck/shoulder, arm, and wrist/hand area usually associated with work-related ergonomic stressors. Other terms used for Repetitive Strain Injuries are overuse syndrome, musculoskeletal disorders, and cumulative trauma disorders. Some of the more common conditions under these headings include:

Cubital Tunnel Syndrome-compression of the ulnar nerve in the cubital tunnel at the elbow.”

Radial Tunnel Syndrome is caused by increased pressure on the radial nerve as it travels from the upper arm (the brachial plexus) to the hand and wrist.

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.

Most people relieved of their carpal tunnel symptoms with conservative or surgical management find minimal residual or "nerve damage". Long-term chronic carpal tunnel syndrome (typically seen in the elderly) can result in permanent "nerve damage", i.e. irreversible numbness, muscle wasting, and weakness. Those that undergo a carpal tunnel release are nearly twice as likely as those not having surgery to develop trigger thumb in the months following the procedure.

While outcomes are generally good, certain factors can contribute to poorer results that have little to do with nerves, anatomy, or surgery type. One study showed that mental status parameters or alcohol use yields much poorer overall results of treatment.

Recurrence of carpal tunnel syndrome after successful surgery is rare.

The etiology of the Galeazzi fracture is thought to be a fall that causes an axial load to be placed on a hyperpronated forearm. However, researchers have been unable to reproduce the mechanism of injury in a laboratory setting.

After the injury, the fracture is subject to deforming forces including those of the brachioradialis, pronator quadratus, and thumb extensors, as well as the weight of the hand. The deforming muscular and soft-tissue injuries that are associated with this fracture cannot be controlled with plaster immobilization.

The condition is called "Golfer's Elbow" because in making a golf swing this tendon is stressed, especially if a non-overlapping (baseball style) grip is used; many people, however, who develop the condition have never handled a golf club. It is also sometimes called "Pitcher's Elbow" due to the same tendon being stressed by the throwing of objects such as a baseball, but this usage is much less frequent. Other names are "Climber's Elbow" and "Little League Elbow": all of the flexors of the fingers and the pronators of the forearm insert at the medial epicondyle of the humerus to include: pronator teres, flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis, and palmaris longus; making this the most common elbow injury for rock climbers, whose sport is very grip intensive. The pain is normally caused due to stress on the tendon as a result of the large amount of grip exerted by the digits and torsion of the wrist which is caused by the use and action of the cluster of muscles on the condyle of the ulna.

Epicondylitis is much more common on the lateral side of the elbow (tennis elbow), rather than the medial side. In most cases, its onset is gradual and symptoms often persist for weeks before patients seek care. In golfer's elbow, pain at the medial epicondyle is aggravated by resisted wrist flexion and pronation, which is used to aid diagnosis. On the other hand, tennis elbow is indicated by the presence of lateral epicondylar pain precipitated by resisted wrist extension. Although the condition is poorly understood at a cellular and molecular level, there are hypotheses that point to apoptosis and autophagic cell death as causes of chronic lateral epicondylitis. The cell death may decrease the muscle density and cause a snowball effect in muscle weakness - this susceptibility can compromise a muscle's ability to maintain its integrity. So athletes, like pitchers, must work on preventing this cell death via flexibility training and other preventive measures.

Distal radius fractures are the most common fractures seen in adults, with incidence in females outnumbering incidence in males by a factor of 2-3. Men who sustain distal radius fractures are usually younger, generally in their fifth decade (vs. seventh decade in females). The elderly are more susceptible because of the osteopenia and osteoporosis commonly seen in this age group. The majority of these fractures are extra-articular (i.e. not involving the joint).

This is also a common injury in children which may involve the growth plate (Salter-Harris fracture).

In young adults, the injury is often severe as a greater force is necessary to produce the injury.

Radial dysplasia, also known as radial club hand or radial longitudinal deficiency, is a congenital difference occurring in a longitudinal direction resulting in radial deviation of the wrist and shortening of the forearm. It can occur in different ways, from a minor anomaly to complete absence of the radius, radial side of the carpal bones and thumb. Hypoplasia of the distal humerus may be present as well and can lead to stiffnes of the elbow. Radial deviation of the wrist is caused by lack of support to the carpus, radial deviation may be reinforced if forearm muscles are functioning poorly or have abnormal insertions. Although radial longitudinal deficiency is often bilateral, the extent of involvement is most often asymmetric.

The incidence is between 1:30,000 and 1:100,000 and it is more often a sporadic mutation rather than an inherited condition. In case of an inherited condition, several syndromes are known for an association with radial dysplasia, such as the cardiovascular Holt-Oram syndrome, the gastrointestinal VATER syndrome and the hematologic Fanconi anemia and TAR syndrome. Other possible causes are an injury to the apical ectodermal ridge during upper limb development, intrauterine compression, or maternal drug use (thalidomide).

Intersection syndrome is a painful condition that affects the lateral side of the forearm when inflammation occurs at the intersection of the muscle bellies of the abductor pollicis longus and extensor pollicis brevis cross over the extensor carpi radialis longus and the extensor carpi radialis brevis. These 1st and 2nd dorsal muscle compartments intersect at this location, hence the name. The mechanism of injury is usually repetitive resisted extension, as with rowing, weight lifting, or pulling.

Intersection syndrome is often confused with another condition called DeQuervain's syndrome, which is an irritation of the thumb-sided set of tendons at the wrist, called the first dorsal compartment.

Injuries to the arm, forearm or wrist area can lead to various nerve disorders. One such disorder is median nerve palsy. The median nerve controls the majority of the muscles in the forearm. It controls abduction of the thumb, flexion of hand at wrist, flexion of digital phalanx of the fingers, is the sensory nerve for the first three fingers, etc. Because of this major role of the median nerve, it is also called the eye of the hand. If the median nerve is damaged, the ability to abduct and oppose the thumb may be lost due to paralysis of the thenar muscles. Various other symptoms can occur which may be repaired through surgery and tendon transfers. Tendon transfers have been very successful in restoring motor function and improving functional outcomes in patients with median nerve palsy.

The theory is that the radial nerve becomes irritated and/or inflamed from friction caused by compression by muscles in the forearm.

Some speculate that Radial Tunnel Syndrome is a type of repetitive strain injury (RSI), but there is no detectable pathophysiology and even the existence of this disorder is questioned.

The term "radial tunnel syndrome" is used for compression of the posterior interosseous nerve, a division of the radial nerve, at the lateral intermuscular septum of arm, while "supinator syndrome" is used for compression at the arcade of Frohse.

The "radial tunnel" is the region from the humeroradial joint past the proximal origin of the supinator muscle. Some scientists believe the radial tunnel extends as far as the distal border of the supinator. The radial nerve is commonly compressed within a 5 cm region near the elbow, but it can be compressed anywhere along the forearm if the syndrome is caused by injury (e.g. a fracture that puts pressure on the radial nerve). The radial nerve provides sensation to the skin of posterior arm, posterior and lateral forearm and wrist, and the joints of the elbow, wrist and hand. The nerve also provides sensory branches that travel to the periosteum of the lateral epicondyle, the anterior radiohumeral joint, and the annular ligament. It provides motor function through innervation to most extensor muscles of the posterior arm and forearm. Therefore, it is extremely important in upper body extremity movement and can cause significant pain to patients presenting with radial tunnel syndrome. Unlike carpal tunnel syndrome, radial tunnel syndrome does not present tingling or numbness, since the posterior interosseous nerve mainly affects motor function.

This problem is often caused by: bone tumors, injury (specifically fractures of the forearm), noncancerous fatty tumors (lipomas), and inflammation of surrounding tissue.

Ulnar deviation, also known as ulnar drift, is a hand deformity in which the swelling of the metacarpophalangeal joints (the big knuckles at the base of the fingers) causes the fingers to become displaced, tending towards the little finger. Its name comes from the displacement toward the ulna (as opposed to radial deviation, in which fingers are displaced toward the radius). Ulnar deviation is likely to be a characteristic of rheumatoid arthritis, more than of osteoarthritis. Consideration should also be given to Pigmented Villonodular Synovitis, in the setting of ulnar deviation and metacarpophalangeal synovitis.

Ulnar deviation is also a physiological movement of the wrist, where the hand including the fingers move towards the ulna.

Ulnar deviation is a disorder in which flexion by ulnar nerve innervated muscles is intact while flexion on the median nerve side is not.

In regards to the pathophysiology of ulnar neuropathy:the axon, and myelin can be affected. Within the axon, fascicles to individual muscles could be involved, with subsequent motor unit loss and amplitude decrease. Conduction block means impaired transmission via a part of the nerve. Conduction block can mean myelin damage to the involved area, slowing of conduction or significant spreading out of the temporal profile of the response with axonal integrity is a hallmark of demyelination.