Aims: Our objective was to identify the most common variables used for infant reaching assessment, describe values of these variables across the first year of life, and identify methodological considerations and knowledge gaps for future research.
Methods: Studies were included if they met the following criteria: (1) assessed infant reaching in any position, (2) included a sample of infants with typical development: healthy, full-term, with no known impairments, (3) infants were under one year old at the first data collection, and (4) counted successful reaches resulting in object contact.
Results: We identified 6 commonly assessed kinematic reaching variables: frequency, duration, movement units, peak velocity, average velocity, and straightness index. Methodological inconsistencies limit our ability to interpret values of these variables across studies.
Conclusions: Eliminating inconsistencies in study design and data analysis methods is the next step to defining a normative reference standard for reaching development. Establishing a normative reference standard for reaching in the first year of life will be important for assessment of typical and atypical reaching development.
Keywords: Infant; kinematics; motor assessment; motor development; reaching.