Congenital aplasia:
Many congenital deformities in children are caused by congenital aplasia. Some of these deformities may be found at birth, such as congenital talipes equino varus. Some appear later in youth, such as congenital scoliosis. Some bone tumors, such as multiple exostosis are related to genetic factors in pathogenesis.

Age:
There are different morbidities of bone and tendon diseases in different age periods. For example, poliomyelitis often occurs in infants and young children, osteochondrosis in young people, osteoarticular retrograde degeneration in middle-aged or old people.

Constitution:
Young and vigorous people with sound kidney qi and strong tendon and bones are not subject to tendon and bone diseases. If the constitution is weak, the liver and kidney are insufficient and the healthy qi is impaired, pathogens will take advantage of deficiency and invade the body, resulting in bone tuberculosis or bone carbuncle.

Nutritive condition:
Dystrophy may cause such metabolic osteopathies as rickets, osteomalacia, and osteoporosis.

Visceral dysfunction:
Tendon and bone are the external matches of the liver and the kidney. When visceral functions get disordered, the tendon and bone will lose their nourishment, hence disease, such as renal osteopathy, dysparathyroidism, hormonal bones necrosis, cerebral palsy, and neurogenic myophagism.
   
Invasion of six exogenous pathogenic factors:
Invasion of such six exogenous pathogenic factors as wind, cold and dampness may cause Bi-syndromes of tendon and bone.

Infection of pathogen:
Invasion of various pathogens such as bacteria and viruses may cause infectious diseases of tendon and bone and poliomyelitis.

Chronic strain:
It may cause various diseases of tendon and bone, such as retrograde articular degeneration and some occupation diseases.

Geographic factors:
In different regions, the geographic conditions climatic factors and dietary habits are different, and there are different common diseases. For example, some osteophathies like osteoarthrosis deformans endemica and fluorosis of bone are related to these factors.

Poison and radioactive rays:
Constant exposure to harmful substances like inorganic poisons (lead, zinc, phosphorus and chromium) and organic, poisons (benzene, chlorine and ethylene), and radioactive rays may cause injury of bone.