The OxAFQ-C raw domain scores demonstrated good agreement between parents and children (Table 1). In this study's small convenience sample, little more can be inferred from these findings. The OxAFQ-C for children was developed as a site-specific (ankle/foot) instrument to provide an inexpensive and expedient method for assessing health status and evaluating outcomes from the child's perspective, aged between 5 and 16 years . This objective measure should be regularly used to assess the extent to which children are affected by foot and ankle problems.
The examiners displayed largely good intra-rater and inter-rater reliability for the FPI-6, Lunge test, the Beighton scale and the LLAS when applied to the sample population of children with a mean age 10.6 years. Intra-rater reliability results returned very good intraclass correlation results and small SEM for each measure. Rater 1 was the more experienced of the two raters and returned lower FPI-6 scores and also lower LLAS scores, indicating that experience and clinical exposure modulates assessment of flat feet and joint hypermobility within the lower limb.
Inter-rater reliability results, as categorised by the Portney and Watkins levels , were good for the FPI-6, the lunge test and the LLAS. The Beighton score was only slightly short of this cut-off level, and being upper limb dominant may be a less familiar clinical tool for podiatrists, especially podiatry students. Clinicians can feel confident in using the FPI-6, the lunge test and either hypermobility evaluation tool in a busy clinical setting.
This study confirms the reliability of the FPI-6 [12, 15, 24] and the LLAS  in the paediatric setting. Whilst widely used as an expedient measure of global joint hypermobility, the Beighton scale has not previously been examined for its reliability in children. Previous studies in adults have found the Beighton scale to yield good inter-rater reliability [21–23]. The lunge test [17, 28] has been demonstrated to be a reliable clinical tool for ankle joint range assessment in adults [17, 25], but has not been tested for reliability in the paediatric population until now.
Given the known relationships between foot posture and ankle range, ankle range and hypermobility, and foot posture and hypermobility it is pertinent to have identified the most useful measures for clinical assessment of these parameters. Often used in concert, the clinician and researcher can assuredly use the FPI-6, the lunge test, the Beighton scale and/or the LLAS for both baseline and monitoring purposes.
The LLAS has distinct advantages for use in the podiatry setting as it evaluates hypermobility in the lower limb and foot very specifically. The LLAS does take longer to administer than the briefer, and more global Beighton scale, but yields far greater information distal to the hips. The Beighton scale is a very quick and slightly coarser filter for hypermobility screening, and in one author's (AE) experience, is usefully used prior to the more specific LLAS.
This study had limitations, as the sample included children with a mean age of 10.6 (2.3) years were assessed for the purpose of assessing the reliability of the four clinical tools. Caution must be advised if using these measures in ages that are significantly less or more than 10 years, and especially in younger children, for whom very different results with clinical foot measures have been previously found . The clearly disparate examiner experience appears to affect results and must be noted in the assessment of both joint hypermobility and foot posture, where less experience may over-estimate extent.
Future research directions include the establishment of normative reference values across age groups for each of the four measures: the FPI-6, the lunge test, the Beighton scale and the LLAS. Such values already exist for the FPI-6 , so the assignation of normal values for the other three measures for healthy children and specific disease groups (e.g. cerebral palsy, Down's syndrome) would greatly assist both clinicians and research teams.