Load perturbation does not influence spontaneous movements in 3-month-old infants.

BACKGROUND The assessment of the quality of general movements (GMs) in young infants is a reliable and valid diagnostic tool for detecting brain dysfunction early in life. Of special interest is a type of GMs called fidgety movements (FMs) characteristic for 3- to 5-month-old infants. GMs are part of an infant's spontaneous motor repertoire and as such endogenously generated by the nervous system. Visual, acoustic and social stimuli hardly had any influence on FMs. AIM Our main purpose was to find out whether FMs are sensitive to load perturbation. STUDY DESIGN Spontaneous motility in supine position, with and without weighting was recorded on video and the data were semiquantitatively analysed. Weights were attached to the ankles and wrists of all four limbs; on one side of the body only; or without visual feedback of the weighted arm. SUBJECTS We studied 29 healthy infants with normal FMs at the age of 12 weeks. RESULTS Spontaneous motility remained symmetrical during all the experimental trails. Weighting had no influence on the quality or temporal organisation of FMs. CONCLUSION This study demonstrated that the mechanisms responsible for FMs in 3-month-old infants are all but impervious to weight perturbation, at least not with the loads studied. FMs is the stable and predominant motor pattern of this age.