Motor Assessment of the Developing Infant, 2nd Edition presents theories of infant motor development and discusses the unique challenges involved in assessing the motor skills of developing infants as compared to that of adults. It provides step-by-step instructions for using the Alberta Infant Motor Scale (AIMS) - a scale that measures infant gross motor skills. It also features a review of two current theories of motor development, line drawings and photographs of 58 gross motor skills, and a percentile graph to plot an infant's score and derive an estimate of his or her percentile ranking. Clinicians, researchers, and parents/caregivers have all reported satisfaction with both the ease of an AIMS assessment and the strong psychometric properties of the scale. Thus, the descriptors of the 58 motor items and the administration and scoring guidelines have stood the test of time and remain unchanged in this second edition.