Objective: The ultrasonographic (US) findings of the sternoocleidomastoid muscles (SCM) in patients with congenital torticollis were studied to evaluate the correlation between the US findings and outcome of physical theraphy.

Method: We studied 52 patients diagnosed as congenital muscular torticollis. We evaluated the thickness, mass, echogenicity and echotexture of both SCM muscles. The US findings of the SCM muscles were divided into 5 grades according to the severity. The physical theraphy included heat theraphy and passive stretching of involved muscle. The outcomes of the treatment were evaluated by physical examination and follow-up US examination.

Results: Neck rotation of lesion site comparing to non-lesion site was improved significantly from 83.0⁑16.5% to 94.9⁑7.16% and lateral flexion from 77.9⁑18.1% to 90.5⁑12.4% after the treatment. In 20 US follow-up cases, thickness ratio of the involved SCM muscle decreased significantly from 177.8⁑46.2% to 158.3⁑83.1%. The therapeutic effect tends to be low with higher grades of the US findings. But, there were no significant statistical correlation between age and treatment outcome.

Conclusion: The US findings of the SCM muscles had a significant correlation with the outcome and the duration of treatment.