The reliability and validity of the weight-bearing lunge test in a Congenital Talipes Equinovarus population (CTEV)

QUESTION: What is the intra and inter-rater reliability and concurrent validity of the weight-bearing lunge test within a Congenital Talipes Equinovarus population? DESIGN: Test retest design for reliability and validity. The measure was taken, following preconditioning of the participants, using distance from wall, angle at distal posterior tibia using a digital inclinometer and the iPhone level function, twice by each rater. The raters included a clinician, clinician in training and a parent/carer. OUTCOME MEASURES: Weight bearing lunge test as a measure of ankle dorsiflexion. RESULTS: Twelve children aged 5–10 years were eligible to participate and consented, along with their parents. Intra-reliability of distance measures for all raters were good to excellent (ICC clinician 0.95, ICC training clinician 0.98 and ICC parent 0.89). Intra-rater reliability of the iPhone for all raters was good (ICCs > 0.751) and good to excellent for the inclinometer (ICC clinician 0.87, ICC training clinician 0.90). Concurrent validity between the clinician’s and parents distance measure was also high with ICC of 0.899. Inter-rater reliability was excellent for distance measure (ICC = 0.948), good for the inclinometer (ICC = 0.801) and moderate for the iPhone (ICC = 0.68). Standard error of measurement ranged from 0.70–2.05, whilst the minimal detectable change ranged from 1.90–5.70. CONCLUSION: The use of the WBLT within this CTEV population has demonstrated good to excellent reliability and validity amongst clinicians, clinicians in training and parents/carers, supporting its use as an assessment measure of dorsiflexion range of motion. There is support for parents/carers to use the WBLT at home as a monitoring assessment measure which may assist with early detection of a relapse. TRIAL REGISTRATION: University of South Australia’s ethics committee (ID: 201397); Women’s and Children’s Hospital ethics committee (AU/1/4BD7310).