Abstract
The aim of this commentary is to present characteristics of an "unidentified psychological barrier," which we previously have speculated to be associated with vestibular underachievement, an overlooked part for the understanding of the resistance to physical activity as well as in the assessments and interventions of developmental coordination disorder (DCD). Furthermore, we will discuss the importance of its identification and how to push knowledge forward. A delayed or partly absent sensorimotor development for an otherwise healthy infant might be a substantial sign of an underachieving vestibular system. It is time to act and to take sensorimotor immaturities seriously. In order to come to terms with DCD including physical inactivity there is a need for a grounded approach to sensorimotor development, not the least as a complement to already established 'treatment' methods.