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A Standardized Method for Measurement of Elbow Kinesthesia
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Angular acceleration and angular jerk of elbow extension-flexion movement as parameters for discriminating a

Mamoru Igarashi, Hideki Oyama, Shin-ichi Izumi

    No to Hattatsu = Brain and Development
    |July 17, 2018
    PubMed

    Insights

    Researchers studied infant movement changes using angular acceleration and jerk measurements. These metrics effectively track the evolving strength of spontaneous arm movements in premature infants.

    Area of Science:

    • Neonatal development
    • Biomechanics
    • Infant motor control

    Background:

    • Spontaneous movements are crucial for infant motor development.
    • Quantifying changes in movement patterns requires precise measurement techniques.
    • Early infancy is a critical period for observing motor transformations.

    Purpose of the Study:

    • To evaluate the root mean square (RMS) of angular acceleration and angular jerk.
    • To use these metrics to express the transformation of spontaneous movements in early infancy.
    • To analyze changes in upper limb movements in premature infants.

    Main Methods:

    • Utilized a three-dimensional motion analyzer (Fastrak system) to capture upper right limb movements.
    • Measured 15 premature infants (36-56 weeks post-menstrual age) every 4 weeks.
    • Calculated RMS of angular acceleration and jerk at the elbow, analyzing data in three developmental terms.

    Main Results:

    • A significant decrease in RMS of angular acceleration was observed between term I (36-40 weeks PMA) and term II (44-48 weeks PMA).
    • Significant reductions in RMS of angular jerk were found between term I and both term II and term III (52-56 weeks PMA).
    • These findings indicate a developmental decrease in the intensity of spontaneous movements.

    Conclusions:

    • RMS of angular acceleration and angular jerk are valuable quantitative measures.
    • These metrics effectively express changes in the strength of spontaneous elbow movements.
    • The study highlights quantifiable shifts in motor control during early infant development.

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