title: Development of infant reaching behaviors: kinematic changes in touching and hitting.
abstract: This longitudinal study investigated the development of reaching in typical infants, from age 4 to 8 months, and described the pattern of hand kinematics underlying changes in the characteristics of infants' actions while reaching for a target. Thirteen infants were followed biweekly. Two reaching behaviors emerged during the infants' free interactions with the target, touching and hitting. Changes over time were documented for the number of movement units, straightness index, distance, peak velocity and time to peak velocity of the hand for touches and hits. We observed increases in the numbers of touches and hits and changes in hand kinematics over time; the distance traveled by the hand was greater for hitting compared to touching. These kinematic changes were specific to the movement patterns that infants adopted to reach to the target.
authors.affiliation: Physical Therapy Department, Graduate Program in Rehabilitation Sciences, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Rejane Vale
authors.initials: RV
authors.lastname: Gonçalves
authors.forename: Elyonara Mello
authors.initials: EM
authors.lastname: Figueiredo
authors.forename: Camila Bretas
authors.initials: CB
authors.lastname: Mourão
authors.forename: Enrico Antônio
authors.initials: EA
authors.lastname: Colosimo
authors.forename: Sérgio Teixeira
authors.initials: ST
authors.lastname: Fonseca
authors.forename: Marisa Cotta
authors.initials: MC
authors.lastname: Mancini
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D002657:Child Development / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D014110:Touch / Q000502:physiology*
keywords: Action; Infant; Kinematics; Motor development; Reaching