Acute lymphoblastic leukemia is the most common type of cancer in children diagnosed between the ages of two and five. After cancer treatment, children suffer from fatigue and exhaustion, and thus a decrease in daily physical activity. In addition, lack of physical activity and sports causes a decrease in strength and mobility and affects coordination of movements, proprioceptive perception and balance, which can lead to the occurrence of many injuries. In addition, physical inactivity in children who have survived cancer increases the risk of cardiovascular diseases or causes overweight and obesity. In addition, the separation of children with cancer from their peers harms social, emotional, physical and school indicators of quality of life. The aim of the project is to determine the impact of 12 weeks of buddy-movement therapy on the psychomotor and social development of pediatric cancer patients in remission. The investigators expect a significant improvement in the motor skills of pediatric oncology patients in remission, specifically in fine and gross motor skills, in coordination of both hands, in body coordination, in strength and dexterity. The investigators also assume that after the introduction of 12-week buddy-movement therapy, there will be a significant improvement in the quality of life of pediatric oncology patients in remission, specifically in emotional functioning, in social functioning, in physical functioning and in school functioning. Furthermore, it is anticipated that after the introduction of 12-week buddy-movement therapy, the study will notice significant differences in motor skills between the experimental and control groups. It is also assumed that after the introduction of 12-week buddy-movement therapy, significant differences in quality of life between the experimental and control groups will be observed. The research will involve pediatric oncology patients in remission aged 5 to 12 years with acute lymphoblastic leukemia - ALL, who are treated at the Department of Pediatric Hematology and Oncology of the National Institute of Children's Diseases (NÚDCH). The research participants will undergo an entry and exit examination, including body mass index (BMI; kg/m\^2) calculated from weight (kg), height (m), waist circumference (cm), hip circumference (cm), psychomotor examination using the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition, and quality of life measured by the Pediatric Quality of Life Inventory. They will be divided into a control and experimental group, with the experimental group undergoing a 12-week Buddy-movement therapy focused on the development of psychomotor skills and socialization of participants using Buddy peer support.