Relationship with bone age In recent years, it is believed that the occurrence of growing pains is related to the delayed development of bone age. A study found that 80.8% of children with growing pains have delayed development of bone age compared with children of the same age, mostly pre-school children aged 4-6 years old, and the degree of pain is positively correlated with the number of bone age, and the pain of those who have increased their bone age is significantly reduced compared with that of the former when they return to the clinic after 1 year. Relationship with microcirculation of the lower limbs Some studies have found that children with growing pains have different degrees of microcirculation disorders, which are mainly manifested in the reduction of capillary diameter, abnormal morphology of collaterals, reduction in the number of collaterals, and obvious peri-collaterals exudation, and the degree of microcirculation disorders and the degree of deterioration of the disease are positively correlated. The study highly suggests that microcirculation disorder may be involved in the pathogenesis of growing pains, but its mechanism of action is still unclear. Relationship with overactivity Some foreign scholars have suggested that the symptoms of growing pains are similar to joint overactivity syndrome, which suggests that the occurrence of growing pains may also be related to overactivity. Long-term over-activity or overloading causes muscle fatigue, joint capsule laxity, and accumulation of local metabolic waste causing pain.