Symmetry of limb poses in the crib

Abnormal motor development is an early marker for developmental and behavioral conditions (e.g., autism spectrum disorder (ASD), cerebral palsy, developmental coordination disorder). Asymmetry of posture and movement have been observed in children with ASD [1].

By measuring the levels of limb symmetry exhibited by infants, while lying on their back in the crib, this study has shown that infants that later went on to be diagnosed with ASD showed lower levels of symmetry [2].

The EMMA AI tool measures symmetry levels for both the upper limbs and lower limbs. The levels of symmetry indicate the percentage of frames in the crib video where the limbs were visible and the left/right side were in a symmetric pose (within 45 degrees of angle).

In the illustration above (extracted from [2]), the baby is displaying a symmetric pose on the left and an asymmetric pose on the right.

A dynamic view of this can be seen in the video in this previous post.

References

[1] Teitelbaum P, Teitelbaum O, Nye J, Fryman J, Maurer R. Movement analysis in infancy may be useful for early diagnosis of autism. Proc Natl Acad Sci. USA. 1998;95:13983-7.

[2] Esposito G, Venuti P, Maestro S, Muratori F. An exploration of symmetry in early autism spectrum disorders: An analysis of lying. Brain and Development: 31, (2), 131-138, 2009.