Department of Paediatric Propaedeutics and Bone Metabolism Diseases;
Medical University of Lodz;
Lodz;
Poland;
Department of Paediatric Allergology;
Gastroenterology and Nutrition;
Medical University of Lodz;
Lodz;
Poland;
Children; Densitometry; Cerebral Palsy; Muscular Dystrophy; Myelomeningocele;