The condition is usually seen in athletic individuals typically between 10–14 years of age. Following a strain or partial rupture of patellar ligament the patient develops a traction ‘tendinitis’ characterized by pain and point tenderness at the inferior (lower) pole of the patella associated with focal swelling.

Children with cerebral palsy are particularly prone to SLJ 4.

Achard syndrome is a syndrome consisting of arachnodactyly, receding lower jaw, and joint laxity limited to the hands and feet. Hypermobility and subluxations of the joints, increased lateral excursion of the patellas and other findings reflect the increased ligament laxity. It is clinically similar to Marfan syndrome.

Sinding-Larsen and Johansson syndrome, named after Swedish surgeon Sven Christian Johansson (1880-1959), and Christian Magnus Falsen Sinding-Larsen (1866-1930), a Norwegian physician, is an analogous condition to Osgood–Schlatter disease involving the patellar tendon and the lower margin of the patella bone, instead of the upper margin of the tibia, as is the case in Osgood-Schlatter. This variant was discovered in 1908, during a winter indoor Olympic qualifier event in Scandinavia. Sever's disease is a similar condition affecting the heel.

This condition called Sinding-Larsen and Johansson syndrome was described independently by Sinding-Larsen in 1921 and Johansson in 1922.

Individuals with Jefferson fractures usually experience pain in the upper neck but no neurological signs. The fracture may also cause damage to the arteries in the neck, resulting in lateral medullary syndrome, Horner's syndrome, ataxia, and the inability to sense pain or temperature.

In rare cases, congenital abnormality may cause the same symptoms as a Jefferson fracture.

Signs and symptoms of a dislocation or rotator cuff tear such as:

- Significant pain, which can sometimes be felt past the shoulder, along the arm.

- Inability to move the arm from its current position, particularly in positions with the arm reaching away from the body and with the top of the arm twisted toward the back.

- Numbness of the arm.

- Visibly displaced shoulder. Some dislocations result in the shoulder appearing unusually square.

- No bone in the side of the shoulder showing shoulder has become dislocated.

Pellegrine–Stieda syndrome (also called Stieda disease and Köhler–Pellegrine–Stieda disease) refers to the ossification of the superior part of the medial collateral ligament of the knee. It is a common incidental finding on knee radiographs. It is named for the Italian surgeon A. Pellegrini (b. 1877) and the German surgeon A. Stieda (1869–1945).

Grisel’s syndrome is a non-traumatic subluxation of the atlanto-axial joint caused by inflammation of the adjacent tissues. This is a rare disease that usually affects children. Progressive throat and neck pain and neck stiffness can be followed by neurologic symptoms such as pain or numbness radiating to arms (radiculopathies). In extreme cases, the condition can lead to quadriplegia and even death from acute respiratory failure. The condition often follows soft tissue inflammation in the neck such as in cases of upper respiratory tract infections, peritonsillar or retropharyngeal abscesses. Post-operative inflammation after certain procedures such as adenoidectomy can also lead to this condition in susceptible individuals such as those with Down's syndrome.

Pathophysiology of this disease consists of relaxation of the transverse ligament of the atlanto-axial joint.

Ulnar tunnel syndrome, also known as Guyon's canal syndrome or Handlebar palsy, is caused by entrapment of the ulnar nerve in the Guyon canal as it passes through the wrist. Symptoms usually begin with a feeling of pins and needles in the ring and little fingers before progressing to a loss of sensation and/or impaired motor function of the intrinsic muscles of the hand which are innervated by the ulnar nerve. Ulnar tunnel syndrome is commonly seen in regular cyclists due to prolonged pressure of the Guyon's canal against bicycle handlebars. Another very common cause of sensory loss in the ring and pink finger is due to ulnar nerve entrapment at the Cubital Tunnel near the elbow, which is known as Cubital Tunnel Syndrome.

Symptoms of gamekeeper's thumb are instability of the MCP joint of the thumb, accompanied by pain and weakness of the pinch grasp. The severity of the symptoms are related to the extent of the initial tear of the UCL (in the case of Skier's thumb), or how long the injury has been allowed to progress (in the case of gamekeeper's thumb).

Characteristic signs include pain, swelling, and ecchymosis around the thenar eminence, and especially over the MCP joint of the thumb. Physical examination demonstrates instability of the MCP joint of the thumb.

The patient will often manifest a weakened ability to grasp objects or perform such tasks as tying shoes and tearing a piece of paper. Other complaints include intense pain experienced upon catching the thumb on an object, such as when reaching into a pants pocket.

Symptoms include:

- The child stops using the arm, which is held in extension (or slightly bent) and palm down.

- Minimal swelling.

- All movements are permitted except supination.

- Caused by longitudinal traction with the wrist in pronation, although in a series only 51% of people were reported to have this mechanism, with 22% reporting falls, and patients less than 6 months of age noted to have the injury after rolling over in bed.

A strain is a type of acute injury that occurs to the muscle or tendon. Similar to sprains, it can vary in severity, from a stretching of the muscle or tendon to a complete tear of the tendon from the muscle. Some of the most common places that strains occur are in the foot, back of the leg (hamstring), or back.

A sprain is a type of acute injury which results from the stretching or tearing of a ligament. Depending on the severity of the sprain, the movement on the joint can be compromised since ligaments aid in the stability and support of joints. Sprains are commonly seen in vulnerable areas such as the wrists, knees, and ankles. They can occur from movements such as falling on an outstretched hand, or a twisting of the ankle or foot.

The severity of a sprain can also be classified:

Grade 1: Only some of the fibers in the ligament are torn, and the injured site is moderately painful and swollen. Function in the joint will be unaffected for the most part.

Grade 2: Many of the ligament fibers are torn, and pain and swelling is moderate. The functionality of the joint is compromised.

Grade 3: The soft tissue is completely torn, and functionality and strength on the joint is completely compromised. In most cases, surgery is needed to repair the damage.

Ulnar tunnel syndrome may be characterized by the location or zone within the Guyon's canal at which the ulnar nerve is compressed. The nerve divides into a superficial sensory branch and a deeper motor branch in this area. Thus, Guyon's canal can be separated into three zones based on which portion of the ulnar nerve are involved. The resulting syndrome results in either muscle weakness or impaired sensation in the ulnar distribution.

Zone 2 type syndromes are most common, while Zone 3 are least common.

The inferior glenohumeral ligament attaches to the glenoid labrum(cartilage which surrounds the "shoulder socket") at one end, and at the other end attaches to the anatomic neck of the humerus(the section of the humerus which is directly below the head of the humerus which rotates within the "shoulder socket"). In between these two attachment points the ligament droops down to give the appearance of a U, wherein(on the right side of the body), the left end of the U is its attachment to the humerus, and the right end is its attachment to the glenoid labrum. Excessive stress on the inferior glenohumeral ligament, often due to physical trauma, can cause the end attached to the humerus to detach and fall down, transforming the U-shaped appearance of the ligament into a J-shaped appearance called the "J" Sign. On the left side of the body—where it is the right side of the ligament which is attached to humerus— the U becomes a reverse "J" Sign. Imaging (MRI) is the best modality for diagnosis where the presence of the "J" sign on an MRI indicates that this detachment has occurred.

Clinical differential diagnosis of anterior shoulder instability include:

- Bankart lesions

- Anterior labroligamentous periosteal sleeve avulsions

- glenolabral articular disruption (GLAD) lesions

- HAGL

The triphalangeal thumb has a different appearance than normal thumbs. The appearance can differ widely; the thumb can be a longer thumb, it can be deviated in the radio-ulnar plane (clinodactyly), thumb strength can be diminished. In the case of a five fingered-hand it has a finger-like appearance, with the position in the plane of the four fingers, thenar muscle deficiency, and additional length. There is often a combination with radial polydactyly.

An unhappy triad (or terrible triad, "horrible triangle", O'Donoghue's triad or a "blown knee") is an injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, acute tears of the medial meniscus always present with a concomitant lateral meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.

While ligamentous laxity may be genetic and affect an individual from a very early age, it can also be the result of an injury. Injuries, especially those involving the joints, invariably damage ligaments either by stretching them abnormally or even tearing them.

Loose or lax ligaments in turn are not capable of supporting joints as effectively as healthy ones, making the affected individual prone to further injury as well as compensation for the weakness using other parts of the body. Afflicted individuals may improve over time and lose some of their juvenile hyperlaxity as they age. Individuals over age 40 often have recurrent joint problems and almost always suffer from chronic pain. Back patients with ligamentous laxity in the area of the spine may also experience osteoarthritis and disc degeneration.

In the case of extreme laxity, or hypermobility, affected individuals often have a decreased ability to sense joint position, which can contribute to joint damage. The resulting poor limb positions can lead to the acceleration of degenerative joint conditions. Many hypermobility patients suffer from osteoarthritis, disorders involving nerve compression, chondromalacia patellae, excessive anterior mandibular movement, mitral valve prolapse, uterine prolapse and varicose veins.

A Jefferson fracture is a bone fracture of the anterior and posterior arches of the C1 vertebra, though it may also appear as a three- or two-part fracture. The fracture may result from an axial load on the back of the head or hyperextension of the neck (e.g. caused by diving), causing a posterior break, and may be accompanied by a break in other parts of the cervical spine.

It is named after the British neurologist and neurosurgeon Sir Geoffrey Jefferson, who reported four cases of the fracture in 1920 in addition to reviewing cases that had been reported previously.

Gamekeeper's thumb (also known as skier's thumb or UCL tear) is a type of injury to the ulnar collateral ligament (UCL) of the thumb. The UCL may be torn, damaged or in some cases avulsed from its insertion site into the proximal phalanx of the thumb in the vast majority (approximately 90%) of cases. This condition is commonly observed among gamekeepers and Scottish fowl hunters, as well as athletes (such as volleyballers). It also occurs among people who sustain a fall onto an outstretched hand, frequently skiers.

Because of the high rate of associated ligamentous and meniscal injury, the presence of a Segond or reverse Segond fracture requires that these other pathologies must be specifically ruled out. Increasingly, reconstruction of the ACL is combined with reconstruction of the ALL when this associated pathology is present. It is often associated with an increased 'pivot shift' on physical exam.

Generally, triphalangeal thumbs are non-opposable. In contrast to most people with opposable thumbs, a person suffering from TPT cannot easily place his or her thumb opposite the other four digits of the same hand. The opposable thumb's ability to effortlessly utilize fingers in a "pinch" formation is critical in precision gripping. For the thumb to adequately grip, certain thumb criteria must be met (e.g. suitable position and length, stable joints and good thenar muscle strength). Because triphalangeal thumbs cannot easily oppose and do not possess many of the optimal qualities found in most opposable thumbs, they tend to cause the hand to be less effective in use and, therefore, prove to be more problematic in daily life.

Patients often complain of pain and instability at the joint. With concurrent nerve injuries, patients may experience numbness, tingling and weakness of the ankle dorsiflexors and great toe extensors, or a footdrop.

Patients often complain of pain and swelling over the medial aspect of the knee joint. They may also report instability with side-to-side movement and during athletic performance that involves cutting or pivoting.

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.