FootFAST screening tool for overuse injury risk: Psychometric properties of its three visual assessments of function.
Baxter, Marian Louise
Lower limb overuse injuries are common in the military, and their causes are multifactorial. Both internal factors such as anthropometrics and body mass index, and external factors such as equipment use and weapons carriage, have been implicated in the development of such injuries because of their potential detriment to efficient gait biomechanics. Visual assessments of function have been used as a method of assessing such injurious biomechanics, and are commonplace in the clinical environment. Despite the prevalence of their use, the psychometric properties of such tests have not been investigated extensively. This is an issue, as a minimum level of reliability and validity needs to be reached to ensure practises are justified. A recently developed visual assessment of function, FootFAST, had not been investigated in such a way. FootFAST was designed to be used with populations such as the military, and specifically aims to predict lower limb overuse injury risk. FootFAST comprises three visual assessments of function- hindfoot angle assessment, single leg stance and heel raise. The standard intervention method utilised with FootFAST, the shoe-inserted foot orthotic, had not been rigorously investigated in the population of interest, the military. Thus, the effectiveness of orthoses, and the justification of their continued use was uncertain. In order to address the issues outlined, the current thesis aimed to answer five research questions, which were: 1. What is the current evidence of the clinical effectiveness of orthoses in reducing target injuries in the population of interest: the military? 2. What is the current evidence for psychometric properties of clinical assessment tools for injury risk identification in the lower limb? 3. What is the inter-rater reliability of the three tests within the FootFAST screening protocol? 4. What is the intra-rater reliability of the three tests within the FootFAST screening protocol? 5. What is the criterion based validity of the three tests within the FootFAST screening protocol? In order to answer these questions, the thesis used a multi-method approach and is reported in a hybrid structure. To answer question one, a systematic review including meta-analysis of current literature was completed. It was found that current evidence did not support the continued use of orthoses as an en-masse intervention for the prevention of lower limb overuse injuries in the military. The second question was addressed by a narrative review of current literature which investigated inter-rater reliability, intra-rater reliability and/or validity of a visually-based, functional assessment. It was found that the popularity of visual assessments of function greatly outweighed current knowledge, and in some cases, the results question their continued use in a clinical environment. In order to address the final three research questions, a feasibility study was conducted which then informed the methodological choices and powering of the main research study. The results of the main study, which included eighteen assessors (comprised of sports medicine practitioners, physiotherapists, and New Zealand army medics) and eighteen participants, indicated that two out of the three tests within FootFAST were suitable for continued use in their current form. More research is needed in this area in order to address the issues identified within the thesis.
Advisor: McBride, David; Hendrick, Paul; Cury-Ribeiro, Daniel; Milosavljevic, Stephan
Degree Name: Doctor of Philosophy
Degree Discipline: Preventive and Social Medicine
Publisher: University of Otago
Keywords: Psychometric; FootFAST; reliability; validity; functional screening test; overuse injury; chronic injury
Research Type: Thesis