The development of grading criteria and investigation of single rater test-retest reliability of selected floor sitting postures

Abstract

Background and objectives The use of floor sitting postures may provide an alternative to regional orthopaedic examination for evaluation of the musculoskeletal system. No research has yet been conducted on the utility of evaluating floor sitting postures as an indicator of musculoskeletal function. The aims of this study were to: 1) develop grading criteria for floor sitting postures; 2) investigate single rater test-retest reliability of floor sitting postures between sessions.

Methods Part 1- Development of grading criteria: An iterative process of development and review was undertaken to select appropriate floor sitting postures; identify performance variables for each posture; describe and refine criteria of performance quality; and develop a grading scale to evaluate the quality of performance for each posture. Part 2- A repeated measures design was employed to investigate single rater test-retest reliability of the postures. A sample of 33 healthy participants (n=23F, n=10M) were recruited from the general population. Participants attended two sessions within a 7 to 14-day interval. Anatomical landmarks were marked on each participant with titanium dioxide and self-adhesive markers. Participants performed 3-trials of six defined floor sitting postures in each session. Postures were recorded using digital video in two views; anterior and lateral. Still frames for each posture were captured and analysed. Postural dimensions were measured on each frame. The mean of the postural dimensions for 3-trials of each session was used to analyse the reliability of posture between sessions.

Results Part 1- The final grading criteria included six variations of floor sitting postures. A grading system was developed using a 3-6 point ordinal scale. Part 2- Data from 25 participants (n=17F, n=8) was used for analysis by a single rater of test-retest reliability. Inter-session reliability was calculated for each posture dimension using intra-class correlation coefficients (ICC). Postural dimensions for four of the six postures demonstrated high reliability ranging from ‘very high’ (ICC = 0.87; 95% CI 0.71 to 0.94) to ‘nearly perfect’ (ICC = 0.97; 95% CI 0.94 to 0.99). The Straight Leg Sit postural angle of dorsiflexion demonstrated ‘low’ reliability (ICC = 0.67; 95% CI 0.25 to 0.85). The Low Kneel postural angle of hip flexion demonstrated ‘moderate reliability’ (ICC = 0.71; 95% CI 0.37 to 0.87).

Conclusion A set of grading criteria to evaluate the quality of a defined group of floor sitting postures was developed. Participants in this study demonstrated a reasonable level of consistency in achieving postures between two sessions over a 7 to 14-day period. Observer reliability of grading floor sitting postures was not part of this study and needs to be investigated to determine the clinical utility of the grading criteria.