Cohen Efrat MPT; Boettcher, Kristi MPT; Maker, Tracy MPT; Phillips, Allyson MPT; Terrel, Leslie MPT; Nixon-Cave, Kim MS, PT, PCS; Shepard, Katherine PhD, PT, FAPTAPediatric Physical Therapy: Winter 1999 RESEARCH REPORT: PDF Only Free Abstract It is important to establish the validity of using standardized tests to determine differences in gross motor development among different cultures. This study examined whether the Peabody Developmental Motor Scales (PDMS) appropriately assesses the differences in the rate of gross motor skill development of children of African American and Hispanic ethnic backgrounds between the ages of zero and 24 months. Gross motor development of a convenience sample of 125 typically developing infants of African American and Hispanic backgrounds was tested using the PDMS. Raw scores were converted to standard scores. Comparison of gross motor scores with the normative data was made using z scores. Significant differences were found in both groups. The sample of children of African American background consistently achieved more gross motor skills at an earlier age than the established normal values (norms). The children of Hispanic background scored closer to the normative data in most skill categories. Therefore, it was concluded that to prevent erroneous conclusions when using pediatric evaluation tools such as the PDMS, clinicians need to consider the influences of culture on gross motor development. © 1999 Lippincott Williams & Wilkins, Inc.