Joint flexibility problems and the impact of its operationalisation

BACKGROUND: Dissatisfaction is being voiced with the generally used way joint flexibility problems are defined (operationalised), i.e. as a range of motion (ROM) one or more degrees lower than normative ROM of healthy subjects. Other, specifically more function-related operationalisations have been proposed. The current study evaluated the effect of applying different operationalisations of joint flexibility problems on its prevalence. METHOD: ROM data of 95 joints affected by burns of 23 children were used, and data on 18 functional activities (Burn Outcome Questionnaire (BOQ)). Five methods were used to operationalise joint flexibility problems: (1) ROM below normative ROM, (2) ROM below normative ROM minus 1SD, (3) ROM below normative ROM minus 2SD, (4) ROM below functional ROM, and (5) a score of 2 or more on the Likert Scale (BOQ). RESULTS: Prevalence of joint flexibility problems on a group level ranged from 13 to 100% depending on the operationalisation used. Per joint and movement direction, prevalence ranged from 40% to 100% (Method 1) and 0% to 80% (Methods 2-4). 18% of the children received '2' on the Likert Scale (Method 5). CONCLUSION: The operationalisation of joint flexibility problems substantially influences prevalence, both on group and joint level. Changing to a function-related operationalisation seems valuable; however, international consensus is required regarding its adoption. TRIAL REGISTRATION: The study is registered in the National Academic Research and Collaborations Information System of the Netherlands (OND1348800)