Smart jumpsuit creates growth charts for infants’ gross motor development

Researchers at the University of Helsinki and HUS Helsinki University Hospital have built normative growth charts for infants’ gross motor development from measurements made in the children’s own homes. In the study, 92 typically developing infants between the ages of 4 and 19 months wore the MAIJU smart jumpsuit during free play, producing 580 measurements and 1,227 hours of data, from lying on the floor to walking fluently.

Until now, the development of a child’s movement abilities could only be assessed by eye, either through parental reports or through an assessment carried out by a professional. Both are strongly subjective and qualitative.

Alongside the anatomical growth charts for height, weight and head circumference, it is now possible to build functional growth charts. That has long been hoped for.” 

Professor Leena Haataja, University of Helsinki and HUS

The MAIJU jumpsuit has four movement sensors, one in each limb. A fully automatic deep-learning model analyses the data second by second and identifies the child’s postures and movements. From these, the researchers derived 220 different motor metrics and computed a normative growth chart for each of them.

The charts were then tested on a separate group of 39 children who were in neurological developmental follow-up for various clinical reasons. Altogether 121 of the 220 motor metrics were significantly different in the infants with abnormal neurological development.

Development is gradual, not a series of leaps

The results also give a more detailed picture of how early development typically proceeds. Motor skills did not appear in sudden jumps in the way that developmental milestone assessments assume.

“Development is for the most part a gradual shift towards a growing repertoire of skills, which are interwoven with the child’s broader neurocognitive and social development,” highlights Professor Sampsa Vanhatalo of the University of Helsinki and HUS.

Motor development matters because it is closely connected with cognitive, communicative and social development. It is also one of the few aspects of early development that can be compared across countries and cultures.

The same measurement works in a Finnish and a Malawian home

Because the measurement is made in the child’s own home environment by the parents, and analysed automatically, results from different parts of the world can be compared directly. The research group is currently compiling a comparison between Finland and Malawi.

“Gross motor performance is one of the few things through which a child’s neurological development can be assessed in much the same way anywhere in the world. There are thousands of wearable devices available, but we do not know of another one that can assess an infant’s motor performance quantitatively in this detail,” says Associate Professor Manu Airaksinen of the University of Helsinki and HUS.

“The effects of early treatments or therapies on the early neurodevelopment of an individual child have been very difficult to demonstrate with certainty. This method provides an objective tool for setting concrete, measurable targets and following them as the child develops,” Vanhatalo says.

The MAIJU system is presently a research tool and is not yet available as a medical device.