Identification of very young infants with motor dysfunction is inadequate in early intervention programs due to lack of clinical tools that are easily administered and highly prognostic for infants under 3 months of age. Observation and assessment of spontaneous movements is a promising tool for this population. Spontaneous movements are described as highly coordinated as well as variable and complex, and may differentiate between infants developing typically and those with movement disorders. Kinematic studies were used to quatitatively describe coordination of hip, knee, and ankle movements. Qualitative studies employed “gestalt” methodology to identify overall variability/complexity of movement. Clinicians often have difficulty observing and describing spontaneous movements due to the presence of both coordination and variability/complexity in young infants. With expanded specific descriptions of infant spontaneous lower extremity movements, new tools may become available for improved clinical identification of movement dysfunction in very young infants. The purpose of this study was to describe foot movements of eversion/inversion and abduction/adduction during spontaneous lower extremity movement in newborn (NB) and 3 month (3M) old infants. Movements were examined for spatial and temporal coordination of hip, knee, ankle and foot using joint pair correlation coefficients and phase lag computation. Twenty-four joint combinations were identified to assist in the clinical description of movement variation necessary for future adaptability of movement for function. Comparisons were made between ages on all measures to examine developmental changes.
