Repeatability of Gait Deviations in Children With Cerebral Palsy

Three-dimensional gait analysis (3DGA) is the 'gold standard' for measurement and description of gait. Gait variability can arise from intrinsic and extrinsic factors and may vary between walking conditions. This study aimed to define the inter-trial (intrinsic) and inter-session (extrinsic) repeatability in gait analysis data of children with CP who were walking in four conditions, namely barefoot or with ankle-foot orthosis, and overground or treadmill.

With a prevalence of two to three per 1000 live births, Cerebral Palsy (CP) is the most common motor disability of childhood. Improving disturbed gait in ambulatory children with CP is an important treatment goal because it is associated with functional independence and participation of children in the society. It is a common practice to prescribe ankle-foot orthoses (AFO) for ambulatory children to improve their gait, prevent secondary deformities, provide an improved base of support, and compensate for muscle weakness.

Three-dimensional gait analysis (3DGA) is the 'gold standard' for measurement and description of gait. However, gait variability can arise from intrinsic (i.e., caused by the person's natural gait variability) and extrinsic (i.e., methodological sources, such as marker placement errors) factors and may vary between walking conditions. Follow-up and/or pre- and post-intervention 3DGA's are used to determine the treatment for these children with CP. So, it is important to know when differences between 3DGA's can be seen as 'true differences' or when the difference can be explained by intrinsic/extrinsic gait variability.

The purpose of the current study is to quantify the repeatability of gait in children with CP. Therefore, the repeatability between two 3DGA's that are performed at the Clinical Motion Analysis Laboratory (CMAL) of UZ Leuven will be assessed, following the standard 3DGA procedure that is applied at CMAL for routine clinical follow-up.

On the first test day, subjects will first receive a standard clinical examination preceding the clinical overground 3DGA that is planned as a routine clinical follow-up at the CMAL, extended with an additional 3DGA on the treadmill. The treadmill gait laboratory and overground gait laboratory are across the hall from each other, which makes it possible for the subject to walk from one to the other gait laboratory in just a minute.

On the second test day, a repeated 3DGA overground and on the treadmill will be performed by the same clinician. This involved clinical assessor is well-trained to perform 3GDA in children with CP.

Between the measurements, a period from 1 - 14 days is foreseen. The combinations of repeated gait trials per test day, and the repeated test days, with involvement of only one assessor, facilitates the distinction between intrinsic and extrinsic variability.

Eligibility Criteria:
Inclusion Criteria:

* Gross Motor Function Classification System (GMFCS) level I - III
* CP (bilateral \& unilateral)
* Age: 6 - 17 years
* Prescribed AFO by the medical team (as part of the standard care)

Exclusion Criteria:

* Severe contractures or spasticity, which makes it impossible to wear a conventional AFO
* Cognitive or visual impairment that hinder them to understand instructions
* Previous surgery on bones and/or muscles of the legs in the last 12 months prior to assessment
* Presence of ataxia or dystonia