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Published on: June 1, 2015
Immediate Effect of Positioning Devices on Infant Leg Movement Characteristics
Crystal Jiang1, Joyce T de Armendi, Beth A Smith
1Division of Biokinesiology and Physical Therapy (Mss Jiang, Armendi, and Dr Smith), University of Southern California, Los Angeles.
Insights
Car seats significantly reduce infant leg movement quantity and acceleration compared to the supine position or gym. This highlights the immediate impact of positioning devices on infant motor development.
Area of Science:
- Developmental Pediatrics
- Infant Motor Development
- Biomechanics
Background:
- Infant positioning devices are commonly used for safety and comfort.
- Understanding the impact of these devices on infant movement is crucial for development.
- Limited research exists on the immediate effects of various positioning devices on leg kinematics.
Purpose of the Study:
- To investigate the immediate effects of constraining and encouraging positioning devices on infant leg movements.
- To compare leg movement characteristics in infants with typical development (TD) and those at-risk for developmental delay (AR).
Main Methods:
- Twenty-six infants (13 TD, 13 AR) were studied in three conditions: supine position, jungle gym, and car seat.
- Movement sensors on ankles measured acceleration and angular velocity.
- Analysis of variance (ANOVA) was used to compare leg movement quantity, peak acceleration, and peak rotation across groups and conditions.
Main Results:
- Infant leg movement quantity was significantly lower in the car seat condition compared to the supine position or gym.
- Average peak acceleration of leg movements was also significantly reduced in the car seat condition.
- No significant group effect or group-by-condition interaction was found for the measured movement characteristics.
Conclusions:
- Positioning devices, particularly car seats, exert an immediate influence on infant leg movement characteristics.
- The findings suggest that prolonged use of constraining devices may limit opportunities for natural leg movement.
- Long-term developmental effects of these positioning device-induced movement changes are currently unknown and warrant further investigation.
Purpose:
To determine the immediate effects of constraining or encouraging positioning devices on leg movement of infants with typical development (TD) and at-risk for developmental delay (AR).
Methods:
Twenty-six infants (13 TD, 13 AR) were placed in the supine position, a jungle gym, or a car seat. Movement sensors on infants' ankles measured acceleration and angular velocity. We calculated the number of leg movements, peak acceleration, and peak rotational rate of each leg movement. A 2 (group) × 3 (condition) analysis of variance with repeated measures on condition tested for a group effect, a condition effect, and a group by condition interaction for leg movement quantity, average peak acceleration, and average peak rotation.
Results:
Leg movement quantity and average peak acceleration were significantly lower for the car seat condition compared with the supine position or the gym.
Conclusions:
Positioning device use has an immediate effect on infant leg movement characteristics. Long-term effects remain unknown.
