Congenital hypotonia is a symptom that may have a number of causes.

Determining these causes can tax the most astute physician. By using a few clinical criteria, congenital hypotonia can be divided into broad categories.

There is controversy over the usefulness of electromyography (EMG) in the examination of hypotonic infants. However in this study, the EMG diagnosis was identical to that obtained by muscle biopsy in 72.7% of cases in which biopsy was done. Therefore electromyography is a sensitive and noninvasive diagnostic tool of congenital hypotonia.