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.