Cervical Lateral Flexion Stretching Angles Applied During Physical Therapy in Infants With Congenital Muscular Torticollis: A Video-Based Observational Study

Objective: To quantify the cervical lateral flexion stretching angles attained and tolerated during routine physical therapy in infants aged 12 months or younger with congenital muscular torticollis (CMT), and to compare them between two therapeutic positions and across age groups.Methods: Infants with CMT were recorded once, at the first physical therapy session after diagnosis. Therapists stretched in both directions in supported forward-facing and supine positions. Angles were computed from video frames between the inter-pupillary and inter-glenohumeral vectors; the direction of flexion was determined visually from the recordings. The primary analysis used the therapeutic direction, lateral flexion away from the head tilt.Results: Eighty-two infants were analyzed. In the therapeutic direction the angle was greater in the supported forward-facing position (41.9±8.0°, n=79) than supine (31.7±9.1°, n=54); among 51 infants measured in both, the mean paired difference was 10.8° (95% confidence interval, 8.1–13.5; p<0.001; Cohen’s d=1.12). In exploratory comparisons, no difference was detected between the therapeutic and opposite directions (p=0.39, p=0.73) or across age groups (p>0.05). Inter-rater reliability of annotation was high (intraclass correlation coefficient, 0.98).Conclusion: A greater lateral flexion angle was attained in the supported forward-facing position than supine; exploratory analyses detected no difference across age groups or between stretching directions. These findings provide descriptive values for therapist-applied stretching in this cohort; their relationship with clinical outcomes and safety requires further study.