Introduction: Infancy is the key period in human development. Disorders in the motor development during the first year of life may affect the body posture, motor patterns and functioning in the period of childhood. The study objective was to assess the correlation between motor development in the first year of life and angle of trunk rotation, lumbopelvic-hip complex mobility and occurrence of joint hypermobility in children aged 3-9.Material and methods: 120 healthy children aged 3 to 9 participated in the study. The study comprised a questionnaire and a clinical trial. The children in whom the questionnaire revealed abnormal motor development in the first year of life were included in the study group, and the other children were a control group. Then, a physiotherapist assessed the value of the trunk rotation angle with the use of a scoliometer, the lumbopelvic-hip complex mobility with the use of TPHA test, and the occurrence of joint hypermobility with the use of Beigthon test.Results: Children with abnormal motor development in the first year of life were characterised by a statistically significantly higher value of the trunk rotation angle in the thoracic section and they had a higher asymmetry of rotational movement of the lumbopelvic-hip complex, as well as higher values in the Beighton test.Conclusions: Abnormal motor development in the first year of life is a factor predisposing to increased values of the trunk rotation angle in the thoracic section, asymmetry of rotational movement of the lumbo-pelvic-hip complex, and joint hypermobility. Studies of other factors potentially leading to development of such disorders should be continued. Children with impaired development should be included in programmes of prophylaxis. children, posture, development