Nonlinear gait variability in young people after ACL reconstruction
Research type
Research Study
Full title
Reliability and validity of nonlinear gait variability measuring methods in young people following Anterior Cruciate Ligament reconstruction
IRAS ID
300673
Contact name
Adam Kennerley
Contact email
Sponsor organisation
Sheffield Hallam University, Research & Innovation Office
Duration of Study in the UK
1 years, 0 months, 1 days
Research summary
It is reported that approximately 1 in 4 young people who Return-to-Sport (RTS) following Anterior Cruciate Ligament Reconstruction surgery (ACLR) will suffer a re-injury. The exact cause of re-injury may be unclear, but it is apparent that current methods used to inform RTS readiness may be unsuitable.
Current time-based recommendations, functional subjective measures and objective performance measures are inaccurate, inconsistent and fail to differentiate between successful RTS and re-injury in young people. Biomechanical markers show potential in identifying re-injury risk in young people however, their association with RTS has yet to be established and implementing these into clinical-based practice is often unfeasible. Therefore, investigation into a valid, reliable and flexible measure may assist in the assessment of readiness to RTS following ACLR.
A possible solution is the assessment of movement variability. Variability is intrinsic to all biological systems and can be described as the normal variations that occur in motor performance across multiple repetitions of a task. Nonlinear analysis of movement variability quantifies the structure or the organisation of variations over time and can differentiate between a healthy and pathological or injured gait, where traditional linear measures (i.e. standard deviation) fail to.
One such nonlinear measure is Lyapunov Exponents (LyE) which can estimate the local dynamic stability of gait and quantify the complexity of structure in a time series. The application of LyE measures in ACLR patients does show promise however research remains in its infancy. Studies have yet to agree on a standardised methodology, making it difficult to compare results, and several key questions remain, which this study will aim to answer. For example, the discovery of a valid, reliable, and flexible method of measuring local dynamic stability in young people and the reliability of LyE calculation parameter choices including, algorithm, trial duration and kinematic gait variable.
REC name
London - Surrey Research Ethics Committee
REC reference
22/LO/0266
Date of REC Opinion
5 May 2022
REC opinion
Further Information Favourable Opinion