There are several kinds of kyphosis (ICD-10 codes are provided):

- Postural kyphosis (M40.0), the most common type, normally attributed to slouching, can occur in both the old and the young. In the young, it can be called "slouching" and is reversible by correcting muscular imbalances. In the old, it may be a case of hyperkyphosis and called "dowager's hump". About one third of the most severe hyperkyphosis cases in older people have vertebral fractures. Otherwise, the aging body does tend towards a loss of musculoskeletal integrity, and hyperkyphosis can develop due to aging alone.

- Scheuermann's kyphosis (M42.0) is significantly worse cosmetically and can cause varying degrees of pain, and can also affect different areas of the spine (the most common being the midthoracic area). Scheuermann's kyphosis is considered a form of juvenile osteochondrosis of the spine, and is more commonly called Scheuermann's disease. It is found mostly in teenagers and presents a significantly worse deformity than postural kyphosis. A patient suffering from Scheuermann’s kyphosis cannot consciously correct posture. The apex of the curve, located in the thoracic vertebrae, is quite rigid. The patient may feel pain at this apex, which can be aggravated by physical activity and by long periods of standing or sitting. This can have a significantly detrimental effect on their lives, as their level of activity is curbed by their condition; they may feel isolated or uneasy amongst peers if they are children, depending on the level of deformity. Whereas in postural kyphosis, the vertebrae and discs appear normal, in Scheuermann’s kyphosis, they are irregular, often herniated, and wedge-shaped over at least three adjacent levels. Fatigue is a very common symptom, most likely because of the intense muscle work that has to be put into standing or sitting properly. The condition appears to run in families. Most patients who undergo surgery to correct their kyphosis have Scheuermann's disease.

- Congenital kyphosis (Q76.4) can result in infants whose spinal column has not developed correctly in the womb. Vertebrae may be malformed or fused together and can cause further progressive kyphosis as the child develops. Surgical treatment may be necessary at a very early stage and can help maintain a normal curve in coordination with consistent follow-ups to monitor changes. However, the decision to carry out the procedure can be very difficult due to the potential risks to the child. A congenital kyphosis can also suddenly appear in teenage years, more commonly in children with cerebral palsy and other neurological disorders.

- Nutritional kyphosis can result from nutritional deficiencies, especially during childhood, such as vitamin D deficiency (producing rickets), which softens bones and results in curving of the spine and limbs under the child's body weight.

- Gibbus deformity is a form of structural kyphosis, often a "sequela" to tuberculosis.

- Post-traumatic kyphosis (M84.0) can arise from untreated or ineffectively treated vertebral fractures.

Gibbus deformity is a form of structural kyphosis typically found in the upper lumbar and lower thoracic vertebrae, where one or more adjacent vertebrae become wedged. Gibbus deformity most often develops in young children as a result of spinal tuberculosis and is the result of collapse of vertebral bodies. This can in turn lead to spinal cord compression causing paraplegia.

In addition to tuberculosis, other possible causes of gibbus deformity include pathological diseases, hereditary and congenital conditions, and physical trauma to the spine that results in injury. Gibbus deformity may result from the sail vertebrae associated with cretinism (the childhood form of hypothyroidism), mucopolysaccharidosis (MPS), and certain congenital syndromes, including achondroplasia. Because most children with MPS I (Hurler Syndrome) also exhibit symptoms of a gibbus deformity, the latter can possibly be used to identify the former.

Gibbus deformity is included in a subset of structural kyphosis that is distinguished by a higher-degree angle in the spinal curve that is specific to these forms of kyphosis. Other conditions within this subset include Pott’s disease and Scheuermann kyphosis, but gibbus deformity is marked by an especially sharp angle. Viewed from behind, the resulting hunchback is more easily seen when bending forward. A kyphosis of >70° can be an indication of the need for surgery and these surgeries can be necessary for children as young as two years old, with a reported average of 8 years of age.

Scheuermann's disease is considered to be a form of juvenile osteochondrosis of the spine. It is found mostly in teenagers and presents a significantly worse deformity than postural kyphosis. Patients suffering with Scheuermann’s kyphosis cannot consciously correct their posture. The apex of their curve, located in the thoracic vertebrae, is quite rigid.

Scheuermann's disease is notorious for causing lower and mid-level back and neck pain, which can be severe and disabling. The sufferer may feel pain at the apex of the curve, which is aggravated by physical activity and by periods of standing or sitting; this can have a significantly detrimental effect to their lives as their level of activity is curbed by their disability. The sufferer may feel isolated or uneasy amongst their peers if they are children, depending on the level of deformity.

In addition to the pain associated with Scheuermann's disease, many sufferers of the disorder have loss of vertebral height, and depending on where the apex of the curve is, may have a visual 'hunchback' or 'roundback'. It has been reported that curves in the lower thoracic region cause more pain, whereas curves in the upper region present a more visual deformity. Nevertheless, it is typically pain or cosmetic reasons that prompt sufferers to seek help for their condition. In studies, kyphosis is better characterized for the thoracic spine than for the lumbar spine.

The seventh and tenth thoracic vertebrae are most commonly affected. It causes backache and spinal curvature. In very serious cases it may cause internal problems and spinal cord damage, but these cases are extremely rare. The curvature of the back decreases height, thus putting pressure on internal organs, wearing them out more quickly than the natural aging process; surgical procedures are almost always recommended in this case.

Kyphosis (from Greek κυφός "kyphos", a hump) is an abnormally excessive convex "kyphotic" curvature of the spine as it occurs in the cervical, thoracic and sacral regions. (Abnormal inward concave "lordotic" curving of the cervical and lumbar regions of the spine is called lordosis.) Kyphosis can be called roundback or Kelso's hunchback. It can result from degenerative diseases such as arthritis; developmental problems, most commonly Scheuermann's disease; osteoporosis with compression fractures of the vertebra; multiple myeloma or trauma. A normal thoracic spine extends from the 1st to the 12th vertebra and should have a slight kyphotic angle, ranging from 20° to 45°. When the "roundness" of the upper spine increases past 45° it is called kyphosis or "hyperkyphosis". Scheuermann's kyphosis is the most classic form of hyperkyphosis and is the result of wedged vertebrae that develop during adolescence. The cause is not currently known and the condition appears to be multifactorial and is seen more frequently in males than females.

In the sense of a deformity, it is the pathological curving of the spine, where parts of the spinal column lose some or all of their lordotic profile. This causes a bowing of the back, seen as a slouching posture.

While most cases of kyphosis are mild and only require routine monitoring, serious cases can be debilitating. High degrees of kyphosis can cause severe pain and discomfort, breathing and digestion difficulties, cardiovascular irregularities, neurological compromise and, in the more severe cases, significantly shortened life spans. These types of high-end curves typically do not respond well to conservative treatment and almost always warrant spinal fusion surgery, which can restore the body's natural degree of curvature.

Many with Scheuermann's disease often have an excessive lordotic curve in the lumbar spine; this is the body's natural way to compensate for the kyphotic curve above. Interestingly, many with Scheuermann's disease have very large lung capacities and males often have broad, barrel chests. Most people have forced vital capacity (FVC) scores above average. It has been proposed that this is the body's natural way to compensate for a loss of breathing depth.

Often patients have tight hamstrings, which, again, is related to the body compensating for excessive spinal curvature, though this is also debated (for example, some suggest the tightness of ligament is the initial cause of the growth abnormality). In addition to the common lordosis, it has been suggested that between 20–30% of patients with Scheuermann's Disease also have scoliosis, though most cases are negligible. In more serious cases, however, the combination is classified as a separate condition known as kyphoscoliosis.

Sprengel's deformity (also known as high scapula or congenital high scapula) is a rare congenital skeletal abnormality where a person has one shoulder blade that sits higher on the back than the other. The deformity is due to a failure in early fetal development where the shoulder fails to descend properly from the neck to its final position. The deformity is commonly associated with other conditions, most notably Klippel-Feil syndrome, congenital scoliosis including cervical scoliosis, fused ribs, the presence of an omovertebral bone and spina bifida. The left shoulder is the most commonly affected shoulder but the condition can be bilateral, meaning that both shoulders are affected. About 75% of all observed cases are girls. Treatment includes surgery in early childhood and physical therapy. Surgical treatment in adulthood is complicated by the risk of nerve damage when removing the omovertebral bone and when stretching the muscle tissue during relocation of the shoulder.

The scapula is small and rotated so that its inferior edge points toward the spine. There is a high correlation between Sprengel's deformity and the Klippel-Feil syndrome. Sometimes a bony connection is present between the elevated scapula and one of the cervical vertebrae, usually C5 or C6. This connection is known as the omovertebral bone.

Coxa vara is a deformity of the hip, whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees. This results in the leg being shortened, and the development of a limp. It is commonly caused by injury, such as a fracture. It can also occur when the bone tissue in the neck of the femur is softer than normal, causing it to bend under the weight of the body. This may either be congenital or the result of a bone disorder. The most common cause of coxa vara is either congenital or developmental. Other common causes include metabolic bone diseases (e.g. Paget's disease of bone), post-Perthes deformity, osteomyelitis, and post traumatic (due to improper healing of a fracture between the greater and lesser trochanter). Shepherd's Crook deformity is a severe form of coxa vara where the proximal femur is severely deformed with a reduction in the neck shaft angle beyond 90 degrees. It is most commonly a sequela of osteogenesis imperfecta, Pagets disease, osteomyelitis, tumour and tumour-like conditions (e.g. fibrous dysplasia).

Coxa vara can happen in cleidocranial dysostosis.

If a child is sickly, either with rickets or any other ailment that prevents ossification of the bones, or is improperly fed, the bowed condition may persist. Thus the chief cause of this deformity is rickets. Skeletal problems, infection, and tumors can also affect the growth of the leg, sometimes giving rise to a one-sided bow-leggedness. The remaining causes are occupational, especially among jockeys, and from physical trauma, the condition being very likely to supervene after accidents involving the condyles of the femur.

Coxa valga is a deformity of the hip where the angle formed between the head and neck of the femur and its shaft is increased, usually above 135 degrees. It is caused by a slipped epiphysis of the femoral head.

The differential diagnosis includes neuromuscular disorders (i.e. cerebral palsy, spinal dysraphism, poliomyelitis), skeletal dysplasias, and juvenile idiopathic arthritis.

The hallmark of the condition is a sunken appearance of the sternum. The most common form is a cup-shaped concavity, involving the lower end of the sternum; also a broader concavity involving the upper costal cartilages is possible. The lower-most ribs may protrude ("flared ribs"). Pectus excavatum defects may be symmetric or asymmetric.

People may also experience chest and back pain, which is usually of musculoskeletal origin.

In mild cases, cardiorespiratory function is normal, although the heart can be displaced and/or rotated. In severe cases, mitral valve prolapse may be present and physical capability may be limited due to base lung capacity being decreased.

Psychological symptoms manifest with feelings of embarrassment, social anxiety, shame, limited capacity for activities and communication, negativity, intolerance, frustration, and even depression.

Children until the age of 3 to 4 have a degree of Genu Varum. The child sits with the soles of the feet facing one another; the tibia and femur are curved outwards; and, if the limbs are extended, although the ankles are in contact, there is a distinct space between the knee-joints. During the first year of life, a gradual change takes place. The knee-joints approach one another; the femur slopes downward and inward towards the knee joints; the tibia become straight; and the sole of the foot faces almost directly downwards.

While these changes are occurring, the bones, which at first consist principally of cartilage, are gradually becoming ossified. By the time a normal child begins to walk, the lower limbs are prepared, both by their general direction and by the rigidity of the bones which form them, to support the weight of the body.

It is a congenital subluxation or dislocation of the ulna's distal end, due to malformation of the bones. Sometimes, minor abnormalities of other bone structures, often caused by disease or injury, such as a fracture of the distal end of the radius with upward displacement of the distal fragment. The deformity varies in degree from a slight protrusion of the lower end of the ulna, to complete dislocation of the inferior radio-ulnar joint with marked radial deviation of the hand. Severe deformities are associated with congenital absence or hypoplasia of the radius.

The male:female rate of this disorder is 1:4. The incidence is unknown, and there is no described racial predominance. Even though Madelung's Deformity is considered a congenital disorder, symptoms sometimes aren't seen until adulthood. In most cases, symptoms find their onset during midchildhood. At this age, the relatively slower growth of the ulnar and palmar part of the radius, leads to an increasingly progressive deformity. Pain and deformity are the main symptoms patients present with. Typical clinical presentation consists of a short forearm, anterior-ulnar bow of the radius and a forward subluxation of the hand on the forearm. As mentioned before, the severity of the disorder varies greatly, which also leads to a spectrum of presentation.

Madelung's deformity is usually characterized by malformed wrists and wrist bones and is often associated with Léri-Weill dyschondrosteosis. It can be bilateral (in both wrists) or just in the one wrist.

It has only been recognized within the past hundred years.

Characteristics are:

- A fibrous band instead of the fibula

- Short deformed leg

- Absence of the lateral part of the ankle joint (due to absence of the distal end of the fibula), and what is left is unstable; the foot has an equinovalgus deformity

- Possible absence of part of the foot requiring surgical intervention to bring the foot into normal function, or amputation.

- Possible absence of one or two toes on the foot

- Possible conjoined toes or metatarsals

Partial or total absence of fibula is among the most frequent limb anomalies. It is the most common long bone deficiency and is the most common skeletal deformity in the leg. It most often is unilateral (present only on one side). It may also present as bilateral (affecting both legs). Paraxial fibular hemimelia is the most common manifestation in which only the postaxial portion of the limb is affected. It is commonly seen as a complete terminal deficiency, where the lateral rays of the foot are also affected. Hemimelia can also be intercalary in which case the foot remains unaffected. Although the missing bone is easily identified, this condition is not simply a missing bone. Males are affected twice as often as females in most series.

Cubitus varus (varus means a deformity of a limb in which part of it is deviated towards the midline of the body) is a common deformity in which the extended forearm is deviated towards midline of the body.

Cubitus varus is often referred to as "Gunstock deformity", due to the crooked nature of the healing.

The "opposite" condition is cubitus valgus.

Clinodactyly (from the Ancient Greek κλίνειν ' meaning "to bend" and δάκτυλος ' meaning "digit") is a medical term describing the curvature of a digit (a finger or toe) in the plane of the palm, most commonly the fifth finger (the "little finger") towards the adjacent fourth finger (the "ring finger").

It is a fairly common isolated anomaly which often goes unnoticed, but also occurs in combination with other abnormalities in certain genetic syndromes.

Femoroacetabular Impingement (FAI), or hip impingement syndrome, may affect the hip joint in young and middle-aged adults and occurs when the ball shaped femoral head rubs abnormally or does not permit a normal range of motion in the acetabular socket. Damage can occur to the articular cartilage, or labral cartilage (soft tissue bumper of the socket), or both. Treatment options range from conservative to arthroscopic to open surgery.

Fibular hemimelia or longitudinal fibular deficiency is "the congenital absence of the fibula and it is the most common congenital absence of long bone of the extremities." It is the shortening of the fibula at birth, or the complete lack thereof. In humans, the disorder can be noted by ultrasound in utero to prepare for amputation after birth or complex bone lengthening surgery. The amputation usually takes place at six months with removal of portions of the legs to prepare them for prosthetic use. The other treatments which include repeated corrective osteotomies and leg-lengthening surgery (Ilizarov apparatus) are costly and associated with residual deformity.

In early skeletal development, a common physis serves the greater trochanter and the capital femoral epiphysis. This physis divides as growth continues in a balance that favors the capital epiphysis and creates a normal neck shaft angle (angle between the femoral shaft and the neck). The corresponding angle at maturity is 135 ± 7 degrees. Another angle used for the measurement of coxa vara is the cervicofemoral angle which is approximately 35 degrees at infancy and increases to 45 degrees after maturity.

An equinovalgus is a deformity of the human foot. It may be a flexible deformity or a fixed deformity. Equino- means plantarflexed (as in standing on one's toes), and valgus means that the base of the heel is rotated away from the midline of the foot (eversion) and abduction of foot. This means that the patient is placing his/her weight on the medial border of the foot, and the arch of the foot is absent, which distorts the foot's normal shape.

Equinovalgus mostly occurs due to tightness of plantar flexors (calf muscles) and peroneus group of muscles.

Instances in which the medial epicondyle of the distal humerus is malformed due to the initial fracture at the humeral endplate may result in subluxation (snapping) of the ulnar nerve over the medial epicondyle with active flexion and extension of the elbow. In such instances, conductance of the ulnar nerve may be compromised due to chronic irritation, potentially resulting in irreversible ulnar neuropathy.

Pectus excavatum is a congenital deformity of the anterior thoracic wall in which the sternum and rib cage grow abnormally. This produces a caved-in or sunken appearance of the chest. It can either be present at birth or not develop until puberty.

Pectus excavatum is sometimes considered to be cosmetic, but depending on the severity, it can impair cardiac and respiratory function and cause pain in the chest and back.

People with the condition may experience negative psychosocial effects, and avoid activities that expose the chest in some societies.

A foot deformity is a disorder of the foot that can be congenital or acquired.

Such deformities can include hammer toe, club foot, flat feet, pes cavus, etc.

The following factors may be involved in causing this deformity:

- Inherent laxity of the knee ligaments

- Weakness of biceps femoris muscle

- Instability of the knee joint due to ligaments and joint capsule injuries

- Inappropriate alignment of the tibia and femur

- Malunion of the bones around the knee

- Weakness in the hip extensor muscles

- Gastrocnemius muscle weakness (in standing position)

- Upper motor neuron lesion (for example, hemiplegia as the result of a cerebrovascular accident)

- Lower motor neuron lesion (for example, in post-polio syndrome)

- Deficit in joint proprioception

- Lower limb length discrepancy

- Congenital genu recurvatum

- Cerebral palsy

- Multiple sclerosis

- Muscular dystrophy

- Limited dorsiflexion (plantar flexion contracture)

- Popliteus muscle weakness

- Connective tissue disorders. In these disorders, there are excessive joint mobility (joint hypermobility) problems. These disorders include:

- Marfan syndrome

- Ehlers-Danlos syndrome

- Benign hypermobile joint syndrome

- Osteogenesis imperfecta disease