Kinematic and Qualitative Analysis of Lower-Extremity Movements in Preterm Infants With Brain Lesions

Abstract

The purposes of this study were to evaluate the effects of preterm birth, severe brain lesions, and postterm age on kicking movements of young infants and to compare the prognostic value of kinematic analysis of kicking with a qualitative assessment of infants' spontaneous movements. The subjects were 12 full-term infants without brain injury, 12 low-risk preterm infants without brain injury, and 11 preterm infants with severe brain lesions (periventricular leukomalacia). Videotape recordings of each infant's motor behavior in a supine position were made at 1 and 3 months postterm age. Kicking frequency, temporal organization of the kick cycle, coordination among different joints, and interlimb coordination were measured. A qualitative assessment for lower-extremity movements and a Gestalt judgment of general movement quality according to Prechtl's method were made from the same videotape recordings. Kinematic analysis showed only mild differences among the 3 groups of infants. Qualitative assessment of the lower-extremity movements, however, showed that preterm infants with brain lesions, and particularly those who later were found to have cerebral palsy, consistently had fewer segmental movements of the foot and abnormal general movements at both ages. The data suggest that the mechanisms responsible for kicking movements in newborns and young infants do not appear to be influenced by the extrauterine environment or by brain lesions, at least at the ages studied. Qualitative assessment of lower-extremity and general movements seems to be more appropriate for clinical purposes.