Trunk mobility in the sagittal and horizontal planes: clinical methods to quantify movement in an elite surfing population

Question: What is the intra-rater reliability of two measures of thoracic ROM? Do elite surfers possess greater thoracic ROM than age- and gender-matched controls? 
Design: Clinical measurement intra-rater reliability (repeated measures) studies and matched cohort study. 
Participants: 30 participants (30.84 ± 10.96 years, female n =16, male n =14) to determine reliability of existing thoracic rotation measure; 27 participants (31.69 ± 11.52 years, female n = 15, male n = 12) to determine reliability of new method to assess thoracic mobility in the sagittal plane; 15 elite surfers (26.47 ± 4.59 years, male n =15) and 11 age- and gender-matched control participants (drawn from the reliability study) for thoracic ROM study. 
Outcome measures: Movement excursion distance, joint angles measured by an inclinometer. 
Results: Intra-rater reliability (within and between sessions) intraclass correlation coefficient (ICC) values ranged between 0.95 - 0.99 for thoracic ROM measures. There was no significant difference in sagittal plane thoracic ROM between groups; however the elite surfers had significantly greater rotation than the control participants (mean rotation 63.57° versus 40.80°, respectively, p < 0.001). 
Conclusion: The thoracic ROM measures have good intra-rater reliability. Elite surfers exhibit greater thoracic rotation ROM than matched controls. 
Key Practice Points:•Further research is warranted to assess the prognostic value of thoracic rotation ROM for surfing performance and injury risk.•The described thoracic ROM measures can be reliably used by a single clinician to assess changes and differences in thoracic ROM, but further research is required to assess their inter-rater reliability.