Dupuytren’s disease has a high recurrence rate, especially when a person has so called Dupuytren’s diathesis. The term diathesis relates to certain features of Dupuytren's disease and indicates an aggressive course of disease.

The presence of all new Dupuytren’s diathesis factors increases the risk of recurrent Dupuytren’s disease by 71% compared with a baseline risk of 23% in people lacking the factors. In another study the prognostic value of diathesis was evaluated. They concluded that presence of diathesis can predict recurrence and extension. A scoring system was made to evaluate the risk of recurrence and extension evaluating the following values: bilateral hand involvement, little finger surgery, early onset of disease, plantar fibrosis, knuckle pads and radial side involvement.

Minimally invasive therapies may precede higher recurrence rates. Recurrence lacks a consensus definition. Furthermore, different standards and measurements follow from the various definitions.

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

In one study, those with stage 2 of the disease were found to have a slightly increased risk of mortality, especially from cancer.

Most hand injuries are minor and can heal without difficulty. However, any time the hand or finger is cut, crushed or the pain is ongoing, it is best to see a physician. Hand injuries when not treated on time can result in long term morbidity.

Antibiotics in simple hand injuries do not typically require antibiotics as they do not change the chance of infection.

Ice and elevation may help reduce pain and swelling, and allow the injury to begin to recover.

Severe sprains accompanied by significant pain and swelling may need to be immobilized.

To resolve the problem, the affected arm is moved in a way that causes the joint to move back into a normal position. The two main methods are hyperpronation and a combination of supination and flexion. Hyperpronation has a higher success rate and is less painful than a supination-flexion maneuver.

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.

In the US, the annual incidence of stress fractures in athletes and military recruits ranges from 5% to 30%, depending on the sport and other risk factors. Women and highly active individuals are also at a higher risk. The incidence probably also increases with age due to age-related reductions in bone mass density (BMD). Children may also be at risk because their bones have yet to reach full density and strength. The female athlete triad also can put women at risk as disordered eating and osteoporosis can cause the bones to be severely weakened.

The term jammed finger refers to finger joint pain and swelling from an impact injury. It's the most common injury in sports. This injury tends to be very painful, and immediate treatment will usually help heal the joint faster. Most jammed fingers heal relatively quickly, if no fracture occurs. If there is a fracture, however, the healing process will take longer; anywhere from one or two weeks to several months, and the methods of healing will become more in depth. Toes can become jammed as well, but not as often as fingers.

The Jersey Finger is a finger-related tendon injury that is common in athletics and can result in permanent loss of flexion of the end of the finger if not surgically repaired.

This injury often occurs in American football when a player grabs another player's jersey with the tips of one or more fingers while that player is pulling or running away.

The classically used Leddy and Packer Classification classifies Jersey finger tendon injuries based on the degree of tendon injury, retraction, and presence of a concomitant fracture.

Often, surgical pins are inserted into the injured digit to stabilize the bone and tendon in their proper alignment. Post surgical complications can include infection, pin failure and nail and joint deformity. Surgery is often accompanied by a rehabilitation protocol to strengthen the injured muscle and help the patient regain as much range of motion (ROM) as possible at the affected joint. The finger may never return normal extension ROM.

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.

Morton's neuroma (also known as Morton neuroma, Morton's metatarsalgia, Intermetatarsal neuroma and Intermetatarsal space neuroma.) is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces (between 2nd−3rd and 3rd−4th metatarsal heads), which results in the entrapment of the affected nerve. The main symptoms are pain and/or numbness, sometimes relieved by removing narrow or high-heeled footwear. Sometimes symptoms are relieved by wearing non-constricting footwear.

Some sources claim that entrapment of the plantar nerve because of compression between the metatarsal heads, as originally proposed by Morton, is highly unlikely, because the plantar nerve is on the plantar side of the transverse metatarsal ligament and thus does not come in contact with the metatarsal heads. It is more likely that the transverse metatarsal ligament is the cause of the entrapment.

Despite the name, the condition was first correctly described by a chiropodist named Durlacher, and although it is labeled a "neuroma", many sources do not consider it a true tumor, but rather a perineural fibroma (fibrous tissue formation around nerve tissue).

Webbed toes in humans are a purely cosmetic condition. This condition does not impair the ability to perform any activity, including walking, running, or swimming. Depending on the severity and structure of the webbing, there can be some minor consequences.

People with more severe webbed toes may have a slight disadvantage for activities that benefit from prehensile toes, due to the toes being unable to split or move laterally. Although not scientifically proven, some believe that this condition can possibly allow for a slight advantage, specifically, in athletics. Considering your big toe is a main source for balance, having your second and third toe webbed could virtually be seen as having two big toes. Thus, allowing for better balance in athletics such as running or dance.

Psychological stress may arise from the fear of negative reactions to this condition from people who do not have webbed toes, particularly in severe cases where the nails are stuck visibly close together. Many people with webbed toes can physically feel the toes touching under the fused skin, which can cause psychological discomfort. This is due to the nerves of each toe fully developing and independent muscles working. In other cases where the toes are partially webbed, the webbing holds the separate tips of the toes against one another and prevents the muscles from spreading the toes apart, causing the toes and sometimes nails to press together.

However a disadvantage would be a difficulty in wearing flip-flops or other such footwear in warm countries. People with webbed toes may be unable to wear Toe socks or Vibram FiveFingers shoes. Difficulty navigating rough terrain barefoot, such as rocks at a beach is also common. In some cases the toes grow at different lengths causing the toes to buckle or bend and many people with severe webbed toes experience cramping in these toes due to the muscles and ligaments being strained.

Golfer's elbow, or medial epicondylitis, is tendinosis of the medial epicondyle on the inside of the elbow. It is in some ways similar to tennis elbow, which affects the outside at the lateral epicondyle.

The anterior forearm contains several muscles that are involved with flexing the digits of the hand, and flexing and pronating the wrist. The tendons of these muscles come together in a common tendinous sheath, which originates from the medial epicondyle of the humerus at the elbow joint. In response to minor injury, or sometimes for no obvious reason at all, this point of insertion becomes inflamed.

Negative signs include no obvious deformities, erythema, signs of inflammation, or limitation of movement. Direct pressure between the metatarsal heads will replicate the symptoms, as will compression of the forefoot between the finger and thumb so as to compress the transverse arch of the foot. This is referred to as Mulder’s Sign.

There are other causes of pain in the forefoot. Too often all forefoot pain is categorized as neuroma. Other conditions to consider are capsulitis, which is an inflammation of ligaments that surrounds two bones, at the level of the joint. In this case, it would be the ligaments that attach the phalanx (bone of the toe) to the metatarsal bone. Inflammation from this condition will put pressure on an otherwise healthy nerve and give neuroma-type symptoms. Additionally, an intermetatarsal bursitis between the third and fourth metatarsal bones will also give neuroma-type symptoms because it too puts pressure on the nerve. Freiberg's disease, which is an osteochondritis of the metatarsal head, causes pain on weight bearing or compression.

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.”

Anterior tibial stress fractures can have a particularly poor prognosis and can require surgery. On radiographic imaging these stress fractures are referred to as the "dreaded black line." When compared to other stress fractures, anterior tibial fractures are more likely to progress to complete fracture of the tibia and displacement. Superior femoral neck stress fractures, if left untreated, can progress to become complete fractures with avascular necrosis, and should also be managed surgically. Proximal metadiaphyseal fractures of the fifth metatarsal (middle of the outside edge of the foot) are also notorious for poor bone healing. These stress fractures heal slowly with significant risk of refracture.

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.

The exact cause of the condition is unknown. In some cases, close family members may share this condition. In other cases, no other related persons have this condition. The scientific name for the condition is syndactyly, although this term covers both webbed fingers and webbed toes. Syndactyly occurs when apoptosis or programmed cell death during gestation is absent or incomplete. Webbed toes occur most commonly in the following circumstances:

- Syndactyly or Familial Syndactyly

- Down syndrome

It is also associated with a number of rare conditions, notably:

- Aarskog–Scott syndrome

- Acrocallosal syndrome

- Apert's syndrome

- Bardet-Biedl syndrome

- Carpenter syndrome

- Cornelia de Lange syndrome

- Edwards syndrome

- Jackson–Weiss syndrome

- Fetal hydantoin syndrome

- Miller syndrome

- Pfeiffer syndrome

- Smith-Lemli-Opitz syndrome

- Timothy syndrome

- Ectodermal Dysplasia

- Klippel-Feil Syndrome

Malformations of the upper extremities can occur In the third to seventh embryonic week. In some cases the TPT is hereditary. In these cases, there is a mutation on chromosome 7q36. If the TPT is hereditary, it is mostly inherited as an autosomal dominant trait, non-opposable and bilateral. The sporadic cases are mostly opposable and unilateral.

Triphalangeal thumb can occur in syndromes but it can also be isolated. The triphalangeal thumb can appear in combination with other malformations or syndromes.

Syndromes include:

- Holt-Oram syndrome

- Aase syndrome

- Blackfan-Diamond syndrome

- Townes-Brocks syndrome

Malformations include:

- Radial polydactyly

- Syndactyly

- Claw-like hand or foot

The reported incidence of constriction ring syndrome varies from 1/1200 and 1/15000 live births. The prevalence is equally in male and female.

Fetomaternal factors like prematurity, maternal illnes, low birth weight and maternal drug exposure are predisposing factors for the constriction ring syndrome.

No positive relationship between CRS and genetic inheritance has been reported.

There are many ways to acquire radial nerve palsy.

The term "Saturday Night Palsy" refers to an injury to the radial nerve in the spiral groove of the humerus caused while sleeping in a position that would under normal circumstances cause discomfort. It can occur when a person falls asleep while heavily medicated and/or under the influence of alcohol with the underside of the arm compressed by a bar edge, bench, chair back, or like object. Sleeping with the head resting on the arm can also cause radial nerve palsy.

Breaking the humerus and deep puncture wounds can also cause the condition.

Posterior interosseus palsy is distinguished from radial nerve palsy by the preservation of elbow extension.

Symptoms vary depending on the severity and location of the trauma; however, common symptoms include wrist drop (the inability to extend the wrist upward when the hand is palm down); numbness of the back of the hand and wrist, specifically over the first web space which is innervated by the radial nerve; and inability to voluntarily straighten the fingers or extend the thumb, which is performed by muscles of the extensor group, all of which are primarily innervated by the radial nerve. Loss of wrist extension is due to paralysis of the posterior compartment of forearm muscles; although the elbow extensors are also innervated by the radial nerve, their innervation is usually spared because the compression occurs below, distal, to the level of the axillary nerve, which innervates the long head of the triceps, and the upper branches of the radial nerve that innervate the remainder of the Triceps.

Oligodactyly (from the Ancient Greek "oligos" meaning "few" and δάκτυλος "daktylos" meaning "finger") is the presence of fewer than five fingers or toes on a hand or foot.

It is quite often incorrectly called "hypodactyly", but the Greek prefixes and are used for scales (e.g. in hypoglycaemia and hypercholesterolemia). This as opposed to or scales, where and should be used (e.g. in oligarchy and polygamy). Oligodactyly is therefore the opposite of polydactyly. Very rare, this medical condition usually has a genetic or familial cause.

Oligodactyly is sometimes a sign or symptom of several syndromes including Poland syndrome and Weyer Ulnar Ray Syndrome. It is a type of Dysmelia.

Ectrodactyly is an extreme instance of oligodactyly, involving the absence of one or more central digits of the hand or foot and is also known as split hand/split foot malformation (SHFM). The hands and feet of people with ectrodactyly are often described as "claw-like" and may include only the thumb and one finger (usually either the little finger, ring finger, or a syndactyly of the two) with similar abnormalities of the feet.

People with oligodactyly often have full use of the remaining digits and adapt well to their condition. They are not greatly hindered in their daily activities, if at all. Even those with the most extreme forms are known to engage in tasks that require fine control, such as writing and bootmaking as well as working as a cab driver.

Vadoma people of Zimbabwe have a high frequency of oligodactyly.