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Updated: Apr 23, 2026
Frame-by-Frame Video Analysis of Idiosyncratic Reach-to-Grasp Movements in Humans
Published on: January 15, 2018
Hand preference status and reach kinematics in infants
Eliza L Nelson1, George D Konidaris2, Neil E Berthier3
1Department of Psychology, Florida International University, United States.
Insights
Infant hand preference did not affect reach smoothness or straightness. However, infants without a clear hand preference showed faster left-hand speeds in a feeding task, suggesting subtle motor control differences.
Area of Science:
- Developmental Psychology
- Motor Control
- Infant Behavior
Background:
- Infants develop smoother, straighter reaches and slower movements in early life.
- This developmental period coincides with the emergence of hand preference.
Purpose of the Study:
- To investigate the relationship between infant hand preference and motor control development.
- To determine if hand preference influences reach kinematics (smoothness, straightness, speed).
Main Methods:
- Assessed hand preference in 53 infants (11-14 months) by observing object reaching.
- Recorded 3-D arm movements during grasp-to-place and grasp-to-eat tasks.
- Analyzed reach straightness, smoothness, and average speed based on preference group (right preference vs. no preference).
Main Results:
- No significant differences in reach straightness or smoothness were found between preference groups for either task.
- On the grasp-to-eat task, infants with no hand preference had faster average left-hand speeds compared to those with a right preference.
Conclusions:
- Infant hand preference status is not systematically linked to early motor control biases in arm movements.
- Subtle behavioral differences in hand use may exist, but do not appear to reflect underlying kinematic control differences at this age.
Abstract:
Infants show age-related improvements in reach straightness and smoothness over the first years of life as well as a decrease in average movement speed. This period of changing kinematics overlaps the emergence of handedness. We examined whether infant hand preference status is related to the development of motor control in 53 infants ranging from 11 to 14 months old. Hand preference status was assessed from reaching to a set of 5 objects presented individually at the infant's midline; infants were classified into 'right preference' or 'no preference' groups. Three-dimensional (3-D) recordings were made of each arm for reaches under two distinct conditions: pick up a ball and fit it into the opening of a toy (grasp-to-place task) or pick up a Cheerio® and consume it (grasp-to-eat task). Contrary to expectations, there was no effect of hand preference status on reach smoothness or straightness for either task. On the grasp-to-eat task only, average speed of the left hand differed as a function of hand preference status. Infants in the no preference group exhibited higher left hand average speeds than infants in the right preference group. Our results suggest that while behavioral differences in the use of the two hands may be present in some infants, these differences do not appear to be systematically linked to biases in motor control of the arms early in development.
