Idiopathic infantile asymmetry, proposal of a measurement scale

To evaluate the development of idiopathic infantile asymmetry and the efficacy of therapeutic interventions, spinal scoliosis can be quantified on the basis of radiographs. For obvious reasons, use of this technique is limited. Here we present a clinical method to describe and quantify infantile asymmetry. For item selection, spontaneous movements (SMs), reactive movements (RMs) and length differences were video recorded in 30 infants (median age 10 weeks, range 6–16) with variable degrees of asymmetry. Within these three categories, reactive movements elicited by head turns to the right and left side in the prone and supine position emerged as reliable parameters reflecting trunk convexity and cervical rotation deficits. Six-point scales were developed for both measurements and added to form final scales. Consistency and interobserver reliability were evaluated in another 20 infants (median age 9 weeks, range 6–15) with variable degrees of asymmetry. Statistical analysis indicated good reliability and consistency of the testing method with an intraclass correlation coefficient of 91.5% (Cronbach alpha 0.84). During the first months of life, idiopathic infantile asymmetry can be clinically assessed using a highly consistent and reliable measurement scale describing degrees of trunk convexity and cervical rotations deficit.