Stenosing tenosynovitis often presents with a painful and swollen thumb with limited range of motion, or a ring finger or middle finger with similarly limited motion. There is often a feeling of catching when the thumb is flexed. In the ring and middle fingers, often a nodule can be felt when you press the area of the hand where the palm meets the finger.

The most common manifestation of infectious tenosynovitis is in the flexor tendons of the fingers, though infections of other tendon sheaths have been reported as well. The four cardinal signs of infectious flexor tenosynovitis are tenderness to touch along the flexor aspect of the finger, symmetric enlargement of the affected finger, the finger being held in slight flexion at rest, and severe pain with passive extension. Fever may also be present but is uncommon.

Stenosing tenosynovitis (also known as trigger finger or trigger thumb) is a painful condition caused by the inflammation (tenosynovitis) and progressive restriction of the superficial and deep flexors fibrous tendon sheath adjacent to the A1 pulley at a metacarpal head. Repetitive forceful compression, tensile stress, and resistive flexion, causes inflammation, swelling, and microtrauma, that results in thickening (commonly a nodular formation) of the tendon distal to the pulley and stenosis of the tendon sheath leading to a painful digital base, limitation of finger movements, triggering, snapping, locking, and deformity progressively.

Patients report a popping sound at the proximal interphalangeal joint (PIP), morning stiffness with/without triggering, delayed and sometimes painful extension of the digit, and when more advanced, a locking position that requires manipulation to extend the affected finger. This condition more commonly affects the middle and ring fingers (occasionally the thumb), and the flexor rather than extensor tendons in the hand.

In rheumatic trigger finger (or in diabetes), more than one finger may be involved. Cases of stenosing peroneal tenosynovitis, have been reported where the patient presents with pain over the lateral malleolus, both with active and passive range of motion and no physical of radiographic evidence of instability.

Trigger fingers is a common disorder characterized by catching, snapping or locking of the involved finger flexor tendon, associated with dysfunction and pain. It is a sub-set of stenosing tenosynovitis.

A disparity in size between the flexor tendon and the surrounding retinacular pulley system, most commonly at the level of the first annular (A1) pulley, results in difficulty flexing or extending the finger and the "triggering" phenomenon. The label of trigger finger is used because when the finger unlocks, it pops back suddenly, as if releasing a trigger on a gun.

Tenosynovitis is the inflammation of the fluid-filled sheath (called the synovium) that surrounds a tendon, typically leading to joint pain, swelling, and stiffness. Tenosynovitis can be either infectious or noninfectious. Common clinical manifestations of noninfectious tenosynovitis include de Quervain tendinopathy and stenosing tenosynovitis (more commonly known as trigger finger)

Bicipital tenosynovitis is tendinitis or inflammation of the tendon and sheath lining of the biceps muscle. It is often the result of many years of small tears or other degenerative changes in the tendon first manifesting in middle age, but can be due to a sudden injury. Calcification of the tendon, and osteophytes ("bone spurs") in the intertubercular groove can be apparent on x-rays. The condition (which can also occur in dogs) is commonly treated with physical therapy and cortisone and/or surgery.

Lameness is most commonly caused by pain, but may also be the result of neuromuscular disease or mechanical restriction. Lameness itself is a clinical sign, and not a diagnosis.

Symptoms are pain at the radial side of the wrist, spasms, tenderness, occasional burning sensation in the hand, and swelling over the thumb side of the wrist, and difficulty gripping with the affected side of the hand. The onset is often gradual. Pain is made worse by movement of the thumb and wrist, and may radiate to the thumb or the forearm.

Diagnosis is made almost exclusively by history and physical examination alone. More than one finger may be affected at a time, though it usually affects the index, thumb, middle, or ring finger. The triggering is usually more pronounced late at night and into the morning, or while gripping an object firmly.

Knee pain is pain in or around the knee.

The knee joint consists of an articulation between four bones: the femur, tibia, fibula and patella. There are four compartments to the knee. These are the medial and lateral tibiofemoral compartments, the patellofemoral compartment and the superior tibiofibular joint. The components of each of these compartments can suffer from repetitive strain, injury or disease.

Running long distance can cause pain to the knee joint, as it is high-impact exercise.

Common deformities of the knee include:

- Genu varum

- Genu valgum

- Genu recurvatum (Knee hyperextension)

- Knee flexion deformity

- Bipartite patella

De Quervain syndrome, is a tenosynovitis of the sheath or tunnel that surrounds two tendons that control movement of the thumb.

Lameness is an abnormal gait or stance of an animal that is the result of dysfunction of the locomotor system. In the horse, it is most commonly caused by pain, but can be due to neurologic or mechanical dysfunction. Lameness is a common veterinary problem in racehorses, sport horses, and pleasure horses. It is one of the most costly health problems for the equine industry, both monetarily for the cost of diagnosis and treatment, and for the cost of time off resulting in loss-of-use.

Typically, Dupuytren's contracture first presents as a thickening or nodule in the palm, which initially can be with or without pain. Later in the disease process, there is painless increasing loss of range of motion of the affected fingers. The earliest sign of a contracture is a triangular “puckering” of the skin of the palm as it passes over the flexor tendon just before the flexor crease of the finger, at the metacarpophalangeal (MCP) joint. Generally, the cords or contractures are painless, but, rarely, tenosynovitis can occur and produce pain. The most common finger to be affected is the ring finger; the thumb and index finger are much less often affected. The disease begins in the palm and moves towards the fingers, with the metacarpophalangeal (MCP) joints affected before the proximal interphalangeal (PIP) joints.

In Dupuytren's contracture, the palmar fascia within the hand becomes abnormally thick, which can cause the fingers to curl and can impair finger function. The main function of the palmar fascia is to increase grip strength; thus, over time, Dupuytren's contracture decreases a person's ability to hold objects. People may report pain, aching and itching with the contractions. Normally, the palmar fascia consists of collagen type I, but in Dupuytren sufferers, the collagen changes to collagen type III, which is significantly thicker than collagen type I.

People with severe involvement often show lumps on the back of their finger joints (called “Garrod's pads”, “knuckle pads”, or “dorsal Dupuytren nodules”) and lumps in the arch of the feet (plantar fibromatosis or Ledderhose disease). In severe cases, the area where the palm meets the wrist may develop lumps. Severe Dupuytren disease may also be associated with frozen shoulder (adhesive capsulitis of shoulder), Peyronie's disease of the penis, increased risk of several types of cancer, and risk of early death, but more research is needed to clarify these relationships.

Some examples of symptoms experienced by patients with RSI are aching, pulsing pain, tingling and extremity weakness, initially presenting with intermittent discomfort and then, with a higher degree of frequency.

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.

A repetitive strain injury (RSI) is an "injury to the musculoskeletal and nervous systems that may be caused by repetitive tasks, forceful exertions, vibrations, mechanical compression, or sustained or awkward positions".

Septic arthritis, also known as joint infection or infectious arthritis, is the invasion of a joint by an infectious agent resulting in joint inflammation. Symptoms typically include redness, heat, and pain in a single joint associated with a decreased ability to move the joint. Onset is usually rapid. Other symptoms may include fever, weakness, and headache. Occasionally more than one joint may be involved.

Causes include bacteria, viruses, fungi, and parasites. Risk factors include an artificial joint, prior arthritis, diabetes, and poor immune function. Most commonly joints becomes infected via the blood but may also become infected via trauma or an infection around the joint. Diagnosis is generally based on aspirating joint fluid and culturing it. White blood cells of greater than 50,000 mm or lactate greater than 10 mmol/l in the joint fluid also makes the diagnosis likely.

Initial treatment typically include antibiotics such as vancomycin, ceftriaxone, or ceftazidime. Surgery may also be done to clean out the joint. Without early treatment long term joint problems may occur. Septic arthritis occurs in about 5 people per 100,000 each year. It occurs more commonly in older people. With treatment about 15% of people die while without 66% die.

Because lesions to different areas of the median nerve produce similar symptoms, clinicians perform a complete motor and sensory diagnosis along the nerve course. Decreased values of nerve conduction studies are used as indicators of nerve compression and may aid in determining the localization of compression.

Palpation above the elbow joint may reveal a bony consistency. Radiography images may show an abnormal bony spur outgrowth (supracondyloid process) just proximal to the elbow joint. Attached fibrous tissue (Struthers' ligament) may compress the median nerve as it passes underneath the process. This is also known as supracondylar process syndrome. Compression at this point may also occur without the bony spur; in this case, aponeurotic tissue found at the location of where Struthers' ligament should be is responsible for the compression.

If patients mention reproduction of symptoms to the forearm during elbow flexion of 120–130 degrees with the forearm in maximal supination, then the lesion may be localized to the area underneath the lacertus fibrosus (also known as bicipital aponeurosis). This is sometimes misdiagnosed as elbow strain and medial or lateral epicondylitis.

A lesion to the upper arm area, just proximal to where motor branches of forearm flexors originate, is diagnosed if the patient is unable to make a fist. More specifically, the patient's index and middle finger cannot flex at the MCP joint, while the thumb usually is unable to oppose. This is known as hand of benediction or Pope’s blessing hand. Another test is the bottle sign—the patient is unable to close all their fingers around a cylindrical object.

Carpal tunnel syndrome (CTS) is caused by compression of the median nerve as it passes under the carpal tunnel. Nerve conduction velocity tests through the hand are used to diagnosis CTS. Physical diagnostic tests include the Phalen maneuver or Phalen test and Tinel's sign. To relieve symptoms, patients may describe a motion similar to "shaking a thermometer", another indication of CTS.

Pronator teres syndrome (also known as pronator syndrome) is compression of the median nerve between the two heads of the pronator teres muscle. The Pronator teres test is an indication of the syndrome—the patient reports pain when attempting to pronate the forearm against resistance while extending the elbow simultaneously. The physician may notice an enlarged pronator teres muscle. Tinel's sign the area around the pronator teres heads should be positive. The key to discerning this syndrome from carpal tunnel syndrome is the absence of pain while sleeping. More recent literature collectively diagnose median nerve palsy occurring from the elbow to the forearm as pronator teres syndrome.

In uncooperative patients, the skin wrinkle test offers a pain-free way to identify denervation of the fingers. After submersion in water for 5 minutes, normal fingers will become wrinkled, whereas denervated fingers will not.

In "Ape hand deformity", the thenar muscles become paralyzed due to impingement and are subsequently flattened. This hand deformity is not by itself an individual diagnosis; it is seen only after the thenar muscles have atrophied. While the adductor pollicis remains intact, the flattening of the muscles causes the thumb to become adducted and laterally rotated. The opponens pollicis causes the thumb to flex and rotate medially, leaving the thumb unable to oppose. Carpal tunnel syndrome can result in thenar muscle paralysis which can then lead to ape hand deformity if left untreated. Ape hand deformity can also be seen in the hand of benediction deformity.

The Anterior Interosseus Nerve (AIN), a branch of the median nerve, only accounts for the movement of the fingers in hand and does not have any sensory capabilities. Therefore, the AIN syndrome is purely neuropathic. AINS is considered as an extremely rare condition because it accounts for less than 1% of neuropathies in the upper limb. Patients suffering from this syndrome have impaired distal interphalangeal joint, because of which they are unable to pinch anything or make and "OK" sign with their index finger and thumb. The syndrome can either happen from pinched nerve, or even dislocation of the elbow.

Individuals affected by RS3PE typically have repeated episodes of inflammation of the lining of their synovial joints and swelling of the end portion of the limbs. The arms and hands are more commonly affected than the legs and feet. Both sides are usually involved though RS3PE can affect only one side in certain cases.

Septic arthritis most commonly causes pain, swelling, and warmth at the affected joint. Therefore, those affected by septic arthritis will often refuse to use the extremity and prefer to hold the joint rigidly. Fever is also a symptom; however, it is less likely in older patients.

The most common joint affected is the knee. Hip, shoulder, wrist, or elbow joints are less commonly affected. Spine, sternoclavicular, and sacroiliac joints can also be involved; however, the most common cause of arthritis in these joints is intravenous drug use.

Usually only one joint is effected. More than one joint can be involved if bacteria are seeded through the bloodstream.

Remitting seronegative symmetrical synovitis with pitting edema (abbreviated RS3PE or sometimes RSPE) is a rare syndrome identified by symmetric polyarthritis, synovitis, acute pitting edema (swelling) of the back of the hands and/or feet, and a negative serum rheumatoid factor. If no underlying disorder can be identified (idiopathic RS3PE), this entity has an excellent prognosis and responds well to treatment.

RS3PE typically involves the joints of the extremities, specifically the metacarpophalangeal and proximal interphalangeal joints, wrists, shoulders, elbows, knees and ankles.

It is more common in older adults, with the mean age between 70 and 80 years in most studies.

It occurs more often in men than in women with a 2:1 ratio.

It is unknown how common this condition is.

Symptoms of JIA are often nonspecific initially, and include lethargy, reduced physical activity, and poor appetite. The first manifestation, particularly in young children, may be limping. Children may also become quite ill, presenting with flu-like symptoms that persist. The cardinal clinical feature is persistent swelling of the affected joint(s), which commonly include the knee, ankle, wrist, and small joints of the hands and feet. Swelling may be difficult to detect clinically, especially for joints such as those of the spine, sacroiliac joints, shoulder, hip, and jaw, where imaging techniques such as ultrasound or MRI are very useful.

Pain is an important symptom. Morning stiffness that improves later in the day is a common feature (this implies inflammatory-type joint pain versus mechanical-type joint pain). Late effects of arthritis include joint contracture (stiff, bent joint due to fibrosis) and joint damage. Children with JIA vary in the degree to which they are affected by particular symptoms. Symptoms may also differ between sexes, affecting girls and boys differently among different geographic locations. This is predicted to be due to biological differences in different geographic regions. Children may also have swollen joints (inflammatory swelling, or in chronic arthritis due to synovial proliferation and thickening, and periarticular soft-tissue swelling).

Eye disease: JIA is associated with inflammation in the front of the eye (specifically iridocyclitis, a form of chronic anterior uveitis), which affects about one child in five who has JIA, most commonly girls. This complication is usually asymptomatic and can be detected by an experienced optometrist or ophthalmologist using a slit lamp. Later slit lamp features include synechiae. Most children with JIA are enrolled in a regular slit lamp screening program, as poorly controlled chronic anterior uveitis may result in permanent eye damage, including blindness.

Growth disturbance: Children with JIA may have reduced overall rate of growth, especially if the disease involves many joints or other body systems. Paradoxically, individually affected large joints (such as the knee) may grow faster, due to inflammation-induced increased blood supply to the bone growth plates situated near the joints. This can result in leg length discrepancy, and also deformities such as genu valgum. Asymmetrical growth can also affect other bones e.g. discrepancy in digit length. Marked differences in bone age (skeletal maturation) may be seen.