The frequency of obstetric palsy ranges from 0.5 to 3.0 cases per 1000 live births. The functional outcome disorders are determined by the nature of the damage and the number of damaged roots of the brachial plexus. There are 50 % of patients have complete recovery, 15 % have severe functional disorders of the upper limb, and 35 % have some limitation of the shoulder joint function. There are 3 variants of residual phenomena in children with obstetric palsy: paresis, paralysis, and co‑contraction. The article describes the mechanisms of nerve regeneration in children and adults, the pathogenesis of contractions and motor disorders in general in children with obstetric palsy, and modern methods of treatment of co‑contraction. This article will be useful for neurologists, rehabilitation specialists, and orthopedists.