I am not aware of the source of what appear to be a biased opinions of the above comments. Today's reality is that many children and babies can respond very favorably to neuromuscular electrical stimulation. But whether any baby-toddler is a candidate to stimulation can only be determined by individual screening done by a competent PT or OT familiar with how, why, and when to add stimulation to the training program. Below is selected references published in peer-reviewed journals.
Solopova, I. A. Sukhotina, I. A. Zhvansky, D. S. et al. Effects of spinal cord stimulation on motor functions in children with cerebral palsy. Neurosci Lett. 2017;639:192-198. (mean age 9 yrs)
Musselman, K. E. Manns, P. Dawe, J. et al. The Feasibility of Functional Electrical Stimulation to Improve Upper Extremity Function in a Two-year-old Child with Perinatal Stroke: A Case Report. Phys Occup Ther Pediatr. 2017; 10.1080/01942638.2016.1255291
Lazzari, R. D. Politti, F. Belina, S. F. et al. Effect of Transcranial Direct Current Stimulation Combined With Virtual Reality Training on Balance in Children With Cerebral Palsy: A Randomized, Controlled, Double-Blind, Clinical Trial. 2016; 10.1080/00222895.2016.1204266 (mean age 7 yrs 6 month)
Karabay, I. Dogan, A. Ekiz, T. et al. Training postural control and sitting in children with cerebral palsy: Kinesio taping vs. neuromuscular electrical stimulation. Complement Ther Clin Pract 2016;24:67-72. (mean age ??)
Pool, D. Valentine, J. Bear, N. et al. The orthotic and therapeutic effects following daily community applied functional electrical stimulation in children with unilateral spastic cerebral palsy: a randomised controlled trial. BMC Pediatr 2015;15: 10.1186/s12887-015-0472-y (mean age 10 yrs 3 month)