What is the GMFM? The Gross Motor Function Measure (GMFM) is a clinical measure designed and validatedto evaluate changes in the gross motor function in children with cerebral palsy (CP). There are two versions of the GMFM: the original 88-item measure (GMFM-88) andthe 66-item measure (GMFM-66). These items are administered in the same way-thedifference between the two versions simply concerns which of the items (from the fullpool of 88 possible items) are included in GMFM-66. There are three methods of administering the GMFM to obtain a GMFM-66 score. Allthree methods require the Gross Motor Ability Estimator (GMAE-2) scoring software toconvert the item data into a GMFM-66 score. Administration methods include the following:(1) GMFM-66: administer all 66 items; (2) GMFM-66-Item Sets (GMFM-66-IS): usea scoring algorithm to identify a subset of items to administer; and (3) GMFM-66 Basal &Ceiling (GMFM-66-B&C): use a basal/ceiling approach to identify a subset of items.Items on the GMFM-88 span aspects of what the World Health Organization's InternationalClassification of Functioning, Disability and Health refers to as gross motor'activity', ranging from activities such as lying and rolling to walking, running andjumping skills. The GMFM-66 consists of a subset of the 88 items that has been shown to be unidimensional.