Postural screening is conducted yearly for all children in Grade 5 through Grade 9. This is not a diagnostic service but does provide screening for postural problems prevalent in this age group which sometimes need medical attention. Postural screen¬ing is required by M.G.L. c. 71, sec. 57. It is the responsibility of the school to see that each child is screened and referred as appropriate unless the parent makes a written request for exemption on religious grounds.