Torticollis of infancy: the reliability of visual estimation in the assessment of cervical spine active rotation and head tilt by physiotherapists and the impact of clinical experience on that reliability.

Abstract

Introduction: Torticollis is a clinical sign of asymmetric neck posture. In infancy, the most common causes are muscular in nature and can be classified as Congenital Muscular Torticollis or Postural Torticollis. Assessment of neck function is essential for diagnosis and management of torticollis. A systematic review demonstrated a paucity of reliable and valid measurement tools, in particular for the assessment of postural side-flexion (head tilt) and active neck rotation, in the upright position. Furthermore, most physiotherapists commonly use visual estimation in clinical practice, which has not been adequately tested for reliability in this population. Aims and objectives: This study aimed to examine the reliability of visual estimation for the assessment of head tilt and active neck rotation in the upright position, on infants with torticollis by physiotherapists. A further aim was to examine the impact of the physiotherapists’ clinical experience on their reliability. Methods: This was an observational (reliability) study, which involved the recruitment of 31 infants and 26 physiotherapists. Videos were taken of the infants’ head position in the frontal plane (anterior view) and active neck rotation (lateral view). Using a secure online portal, they were observed and rated by the physiotherapists on two occasions, at least one week apart. Inter-rater and intra-rater reliability was calculated using the intra-class correlation coefficient (ICC) and Standard Error of Measurement (SEM). The relationship between physiotherapists’ clinical experience (using three different criteria) and intrarater reliability was analysed using a Pearson product-moment correlation coefficient. Results: Overall, inter-rater reliability was good (mean ICC: 0.68 ± 0.20, 0.13 - 0.98; mean SEM: 5.1° ± 2.1°, 1-12°). Rotation videos had better reliability (mean ICC: 0.79 ± 0.14), in comparison to head tilt videos (mean ICC: 0.58 ± 0.20). Intra-rater reliability was excellent (mean ICC: 0.85 ± 0.09, 0.55 to 0.94) for both head tilt (mean ICC: 0.84 ± 0.08) and rotation (mean ICC: 0.85 ± 0.09). There was no correlation between intra-rater reliability and clinical experience. Conclusions and implications: Visual estimation has excellent intra-rater reliability and good inter-rater reliability in the assessment of head tilt and active neck rotation in the upright position for infants with torticollis. In both cases, assessment of rotation was more reliable than that of head tilt. Using an ICC value of ≥0.7 for a test to be clinically acceptable, inter-rater reliability of head tilt was found to be unacceptable. There was a wide variation in reliability and no correlation was found between reliability and clinical experience. Therefore, it is recommended that physiotherapists test their own reliability if possible, and that an alternative tool for the assessment of head tilt be explored.