The cause of in-toeing can be differentiated based on the location of the disalignment. The variants are:

- Curved foot (metatarsus adductus)

- Twisted shin (tibial torsion)

- Twisted thighbone (femoral anteversion)

The tibia or lower leg slightly or severely twists inward when walking or standing.

In clubfoot one or both feet are rotated inwards and downwards. The affected foot, calf, and leg may be smaller than the other. In about half of those affected, both feet are involved. Most cases are not associated with other problems. Without treatment, people walk on the sides of their feet which causes issues with walking.

As with certain cases of flat feet, high arches may be painful due to metatarsal compression; however, high arches— particularly if they are flexible or properly cared-for—may be an asymptomatic condition.

People with pes cavus sometimes—though not always—have difficulty finding shoes that fit and may require support in their shoes. Children with high arches who have difficulty walking may wear specially-designed insoles, which are available in various sizes and can be made to order.

Individuals with pes cavus frequently report foot pain, which can lead to a significant limitation in function. The range of complaints reported in the literature include metatarsalgia, pain under the first metatarsal, plantar fasciitis, painful callosities, ankle arthritis, and Achilles tendonitis.

There are many other symptoms believed to be related to the cavus foot. These include shoe-fitting problems, lateral ankle instability, lower limb stress fractures, knee pain, iliotibial band friction syndrome, back pain and tripping.

Foot pain in people with pes cavus may result from abnormal plantar pressure loading because, structurally, the cavoid foot is regarded as being rigid and non-shock absorbent and having reduced ground contact area. There have previously been reports of an association between excessive plantar pressure and foot pathology in people with pes cavus.

On weightbearing projectional radiography, pes cavus can be diagnosed and graded by several features, the most important being medial peritalar subluxation, increased calcaneal pitch (variable) and abnormal "talar-1st metatarsal angle" (Meary's angle). Medial peritalar subluxation can be demonstrated by a medially rotated talonavicular coverage angle.

Clubfoot is a birth defect where one or both feet are rotated inwards and downwards. The affected foot, calf, and leg may be smaller than the other. In about half of those affected, both feet are involved. Most cases are not associated with other problems. Without treatment, people walk on the sides of their feet which causes issues with walking.

The exact cause is usually unclear. A few cases are associated with distal arthrogryposis or myelomeningocele. If one identical twin is affected there is a 33% chance the other one will be as well. Diagnosis may occur at birth or before birth during an ultrasound exam.

Initial treatment is most often with the Ponseti method. This involves moving the foot into an improved position followed by casting, which is repeated at weekly intervals. Once the inward bending is improved, the Achilles tendon is often cut and braces are worn until the age of four. Initially the brace is worn nearly continuously and then just at night. In about 20% of cases further surgery is required.

Clubfoot occurs in about one in 1,000 newborns. The condition is less common among the Chinese and more common among Maori. Males are affected about twice as often as females. Treatment can be carried out by a range of healthcare providers and can generally be achieved in the developing world with few resources.

Ankylosis or anchylosis (from Greek ἀγκύλος, bent, crooked) is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself.

When the structures outside the joint are affected, the term "false ankylosis" has been used in contradistinction to "true ankylosis", in which the disease is within the joint. When inflammation has caused the joint-ends of the bones to be fused together, the ankylosis is termed "osseous" or complete and is an instance of synostosis. Excision of a completely ankylosed shoulder or elbow may restore free mobility and usefulness to the limb. "Ankylosis" is also used as an anatomical term, bones being said to ankylose (or anchylose) when, from being originally distinct, they coalesce, or become so joined together that no motion can take place between them.

In 2014, there was a rare case of Ankylosis, wherein a six-year old girl was able to open her mouth only a couple millimeters after one of her jaw joints got fused. Liliana Cernecca was the patient's name. She underwent a surgery at King's College Hospital in London, during which her jaw was operated on and unlocked.She was said to be one of the youngest patients to have undergone this surgery.

Fibrous ankylosis is a fibrous connective tissue process which results in decreased range of motion. Symptoms present as bony ankylosis, in which osseous tissue fuses two bones together reducing mobility, which is why fibrous ankylosis is also known as false ankylosis.

Pathology may be the result of trauma, disease, chronic inflammation, or surgery.

Some research suggests fibrous ankylosis may precede the development of bony ankylosis

Amniotic band constriction (also known as "amniotic band syndrome", "ADAM complex", "Amniotic band sequence", "Congenital constriction bands" and "Pseudoainhum") is a congenital disorder caused by entrapment of fetal parts (usually a limb or digits) in fibrous amniotic bands while in utero.

Often, every joint in a patient with arthrogryposis is affected; in 84% all limbs are involved, in 11% only the legs, and in 4% only the arms are involved. Every joint in the body, when affected, displays typical signs and symptoms: for example, the shoulder (internal rotation); wrist (volar and ulnar); hand (fingers in fixed flexion and thumb in palm); hip (flexed, abducted and externally rotated, frequently dislocated); elbow (extension and pronation) and foot (clubfoot). Range of motion can be different between joints because of the different deviations. Some types of arthrogryposis like amyoplasia have a symmetrical joint/limb involvement, with normal sensations. The contractures in the joints can result in delayed walking development in the first 5 years, but severity of contractures do not necessarily predict eventual walking ability or inability.

Intelligence is normal to above normal in children with amyoplasia, but it is not known how many of these children have an above normal intelligence, and there is no literature available about the cause of this syndrome. There are a few syndromes like the Freeman-Sheldon and Gordon syndrome, which have craniofacial involvement. The amyoplasia form of arthrogryposis is sometimes accompanied with a midline facial hemangioma.

Arthrogryposis is not a diagnosis but a clinical finding, so this disease is often accompanied with other syndromes or diseases. These other diagnoses could affect any organ in a patient. There are a few slightly more common diagnoses such as pulmonary hypoplasia, cryptorchidism, congenital heart defects, tracheoesophageal fistulas, inguinal hernias, cleft palate, and eye abnormalities.

The constriction of appendages by amniotic bands may result in:

1. Constriction rings around the digits, arms and legs

2. Swelling of the extremities distal to the point of constriction (congenital lymphedema)

3. Amputation of digits, arms and legs (congenital amputation)

A strong relationship between ABS and clubfoot (also called "talipes") exists. A 31.5% of associated clubfoot deformity and ABS can be correlated with 20% occurring bilaterally. Other abnormalities found with ABS include: clubhands, cleft lip, and/or cleft palate, and hemangioma.

Decreased fetal movement could be a sign of a serious problem which may include ABS. It is rare but possible for the membrane to become wrapped around the placenta or the neck of the baby in the womb causing strangulation and death.

Some of the different types of AMC include:

- Arthrogryposis multiplex due to muscular dystrophy.

- Arthrogryposis ectodermal dysplasia other anomalies, also known as Cote Adamopoulos Pantelakis syndrome, Trichooculodermovertebral syndrome, syndrome and Alves syndrome.

- Arthrogryposis epileptic seizures migrational brain disorder.

- Arthrogryposis thoracic dystrophy, also known as Van Bervliet syndrome.

- Arthrogryposis like disorder, also known as Kuskokwim disease.

- Arthrogryposis-like hand anomaly and sensorineural deafness.

- Arthrogryposis multiplex congenita calcification.

- Arthrogryposis multiplex congenita distal (), also known as X-linked spinal muscular atrophy type 2

- Gordon Syndrome, also known as Distal Arthrogryposis, Type 2A.

- Arthrogryposis multiplex congenita, distal type 2B, also known as Freeman-Sheldon syndrome variant.

- Arthrogryposis multiplex congenita neurogenic type (). This particular type of AMC has been linked to the gene on locus 5q35. Arthrogryposis multiplex congenita pulmonary hypoplasia, also with a large number of synonyms.

- Arthrogryposis multiplex congenita whistling face, also known as Illum syndrome.

- Arthrogryposis multiplex congenita, distal type 1 ().

- Arthrogryposis ophthalmoplegia retinopathy, also known as Oculomelic amyoplasia.

- Arthrogryposis renal dysfunction cholestasis syndrome, also known as Syndrome.

Because collagen plays an important role in the development of the body, people with Kniest Dysplasia will typically have their first symptoms at birth. These symptoms can include:.

- Musculoskeletal Problems

- Short limbs

- Shortened body trunk

- Flattened bones in the spine

- kyphoscoliosis

- Scoliosis (Lateral curvature of the spine)

- Early development of arthritis

- Respiratory problems

- Respiratory tract infection

- Difficulty breathing

- Eye problems

- Severe myopia (near-sightedness)

- Cataract (cloudiness in the lens of the eye)

- Hearing problems

- progressive hearing loss

- ear infections

Most symptoms are chronic and will continue to worsen as the individual ages. It is essential to have regular checkups with general doctors, orthopedist, ophthalmologists, and/or otorhinolaryngologists. This will help to detect whether there are any changes that could cause concern.

A hygroma, or a false bursa, is a discrete, fluid-filled sac that can form on the joints of dogs in response to repeated pressure, such as that from sitting on a hard surface. It is treated by draining the fluid and may be prevented by providing padded bedding.

This condition is also characterized by an unusual clubfoot with twisting of the metatarsals, inward- and upward-turning foot, tarsus varus, and inversion adducted appearances. Furthermore, they classically present with scoliosis (progressive curvature of the spine), and unusually positioned thumbs (hitchhiker thumbs). About half of infants with diastrophic dysplasia are born with an opening in the roof of the mouth called a cleft palate. Swelling of the external ears is also common in newborns and can lead to thickened, deformed ears.

The signs and symptoms of diastrophic dysplasia are similar to those of another skeletal disorder called atelosteogenesis, type 2; however diastrophic dysplasia tends to be less severe.

Individuals with distal 18q- may have problems with reflux. Hernias have also been reported.

Due to changes in facial structures, infants, toddlers, and children with distal 18q- often have poor drainage from the middle ears, leading to a build-up of fluid. This can in turn lead to recurrent ear and sinus infections. Antibiotics are typically required to treat these infections. In addition, the diagnosis of ear infections in children with 18q- is frequently complicated by stenosis or atresia of the ear canals, a common finding in people with distal 18q-.

Orthopedic anomalies are commonly seen in people with proximal 18q-. Clubfoot, pes planus, and scoliosis have all been reported.

People with this condition are short-statured from birth, with a very short trunk and shortened limbs. Their hands and feet, however, are usually average-sized. Curvature of the spine (scoliosis and lumbar lordosis) may be severe and can cause problems with breathing. Changes in the spinal bones (vertebrae) in the neck may also increase the risk of spinal cord damage. Other skeletal signs include flattened vertebrae (platyspondyly), severe protrusion of the breastbone (pectus carinatum), a hip joint deformity in which the upper leg bones turn inward (coxa vara), and a foot deformity known as clubfoot.

Affected individuals have mild and variable changes in their facial features. The cheekbones close to the nose may appear flattened. Some infants are born with an opening in the roof of the mouth, which is called a cleft palate. Severe nearsightedness (high myopia) and detachment of the retina (the part of the eye that detects light and color) are also common.

Hypotonia is a common finding. Seizures are present in about half of individuals.

Evidence for ankylosis found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury. Ankylosis has been reported in dinosaur fossils from several species, including "Allosaurus fragilis", "Becklespinax altispinax", "Poekilopleuron bucklandii", and "Tyrannosaurus rex" (including the Stan specimen).

Spondyloepimetaphyseal dysplasia, Strudwick type is an inherited disorder of bone growth that results in dwarfism, characteristic skeletal abnormalities, and problems with vision. The name of the condition indicates that it affects the bones of the spine (spondylo-) and two regions near the ends of bones (epiphyses and metaphyses). This type was named after the first reported patient with the disorder. Spondyloepimetaphyseal dysplasia, Strudwick type is a subtype of collagenopathy, types II and XI.

The signs and symptoms of this condition at birth are very similar to those of spondyloepiphyseal dysplasia congenita, a related skeletal disorder. Beginning in childhood, the two conditions can be distinguished in X-ray images by changes in areas near the ends of bones (metaphyses). These changes are characteristic of spondyloepimetaphyseal dysplasia, Strudwick type.

People with the combination of Duane anomaly and radial ray malformations may have a variety of other signs and symptoms. These features include:

- Unusually shaped ears

- Hearing loss

- Heart and kidney defects

- A distinctive facial appearance

- An inward- and downward-turning foot (a clubfoot)

- Fused vertebrae.

This is characterized by hand and arm abnormalities. The following are specific characteristics:

- Malformed or absent (aplasia) thumb

- A thumb that looks more like a finger

- Partial or complete absence of a radius

- Shortening and radial deviation of the forearms

- Triphalangeal thumb

- Duplication of the thumb (preaxial polydactyly)

People with spondyloepiphyseal dysplasia are short-statured from birth, with a very short trunk and neck and shortened limbs. Their hands and feet, however, are usually average-sized. This type of dwarfism is characterized by a normal spinal column length relative to the femur bone. Adult height ranges from 0.9 meters (35 inches) to just over 1.4 meters (55 inches). Curvature of the spine (kyphoscoliosis and lordosis) progresses during childhood and can cause problems with breathing. Changes in the spinal bones (vertebrae) in the neck may also increase the risk of spinal cord damage. Other skeletal signs include flattened vertebrae (platyspondyly), a hip joint deformity in which the upper leg bones turn inward (coxa vara), and an inward- and downward-turning foot (called clubfoot). Decreased joint mobility and arthritis often develop early in life. Medical texts often state a mild and variable change to facial features, including cheekbones close to the nose appearing flattened, although this appears to be unfounded. Some infants are born with an opening in the roof of the mouth, which is called a cleft palate. Severe nearsightedness (high myopia) is sometimes present, as are other eye problems that can affect vision such as detached retinas. About one-quarter of people with this condition have mild to moderate hearing loss.