Is 3-D gait analysis essential? By Professor James Wright: Introduction by Mr. Tim Theologis

Transversal Malalignment and Proximal Involvement Play a Relevant Role in Unilateral Cerebral Palsy Regardless the Subtype

Classification of gait disorders in cerebral palsy (CP) remains challenging. The Winters, Gage, and Hicks (WGH) is a commonly used classification system for unilateral CP regarding the gait patterns (lower limb kinematics) solely in the sagittal plane. Due to the high number of unclassified patients, this classification system might fail to depict all gait disorders accurately. As the information on trunk/pelvic movements, frontal and transverse planes, and kinetics are disregarded in WGH, 3D instrumented gait analysis (IGA) for further characterization is necessary. The objective of this study was a detailed analysis of patients with unilateral CP using IGA taking all planes/degrees of freedom into account including pelvic and trunk movements. A total of 89 individuals with unilateral CP matched the inclusion criteria and were classified by WGH. Subtype-specific differences were analyzed. The most remarkable findings, in addition to the established WGH subtype-specific deviations, were pelvic obliquity and pelvic retraction in all WGH types. Furthermore, the unclassified individuals showed altered hip rotation moments and pelvic retraction almost throughout the whole gait cycle. Transversal malalignment and proximal involvement are relevant in all individuals with unilateral CP. Further studies should focus on WGH type-specific rotational malalignment assessment (static vs. dynamic, femoral vs. tibial) including therapeutic effects and potential subtype-specific compensation mechanisms and/or tertiary deviations of the sound limb.

Gait event detection using kinematic data in children with bilateral spastic cerebral palsy

BACKGROUND

Ground reaction forces are the gold standard for detecting gait events, but they are not always applicable in cerebral palsy. Ghoussayni's algorithm is an event detection method based on the sagittal plane velocity of heel and toe markers. We aimed to evaluate whether Ghoussayni's algorithm, using two different thresholds, was a valid event detection method in children with bilateral spastic cerebral palsy. We also aimed to define a new adaptation of Ghoussayni's algorithm for detecting foot strike in cerebral palsy, and study the effect of event detection methods on spatiotemporal parameters.

METHODS

Synchronized kinematic and kinetic data were collected retrospectively from 16 children with bilateral spastic cerebral palsy (7 males and 9 females; age 8.9 ± 2.7 years) walking barefoot at self-selected speed. Gait events were detected using methods: 1) ground reaction forces, 2) Ghoussayni's algorithm with a threshold of 0.5 m/s, and 3) Ghoussayni's algorithm with a walking speed dependent threshold. The new adaptation distinguished how foot strikes were performed (heel and/or toe) comparing the timing when the foot markers velocities fell below the threshold. Differences between the three methods, and between spatiotemporal parameters calculated from the two Ghoussayni's thresholds were analyzed.

FINDINGS

There were statistically significant (P < 0.05) differences between methods 1 and 3, and between some spatiotemporal parameters calculated from methods 2 and 3. Ghoussayni's algorithm showed better performance for foot strike than for toe off.

INTERPRETATION

Ghoussayni's algorithm using 0.5 m/s is valid in children with bilateral spastic cerebral palsy. Event detection methods affect spatiotemporal parameters.

[Dynamic analysis of joint loading due to leg axis deformity in the frontal plane : Relevance of instrumented gait analysis]

BACKGROUND

Instrumented 3D gait analysis (IGA) has been established for the functional evaluation of orthopedic diseases. It can provide valuable additional information beyond conventional static radiographic diagnostics and, thus, contributes to treatment decisions and a successful surgical outcome. Regarding the assessment of leg axis deformities IGA is currently only used in a few specialized centers.

PRACTICE

This article describes the methods used by IGA and shows its benefit for the treatment of leg axis deformities of the knee in the frontal plane. In particular, the calculation of dynamic joint loads provides important insights regarding the development of degenerative joint deformities in the knee joint and, thus, complements the static assessment of the leg axis. A new treatment algorithm for guided growth intervention in children and adolescents by temporary epiphysiodesis is presented. IGA can be particularly useful for clinical decision-making in borderline cases. If there is a discrepancy between the static leg axis and dynamic knee joint loading, IGA can reveal potential compensatory mechanisms during walking.

The selective dorsal rhizotomy technique for spasticity in 2020: a review

This review looks at the advances in the surgical technique, selective dorsal rhizotomy, used for the management of spasticity in children.

Gait parameters in children with bilateral spastic cerebral palsy: a systematic review of randomized controlled trials

AIM

To identify the gait parameters used to assess gait disorders in children with bilateral spastic cerebral palsy (CP) and evaluate their responsiveness to treatments.

METHOD

A systematic search within PubMed, Web of Science, and Scopus (in English, 2000-2016) for randomized controlled trials of children with bilateral spastic CP who were assessed by instrumented gait analysis (IGA) was performed. Data related to participants and study characteristics, risk of bias, and outcome measures were collected. A list of gait parameters responsive to clinical interventions was obtained.

RESULTS

Twenty-one articles met the inclusion criteria. Eighty-nine gait parameters were identified, 56 of which showed responsiveness to treatments. Spatiotemporal and kinematic parameters were widely used compared to kinetic and surface electromyography data. The majority of responsive gait parameters were joint angles at the sagittal plane (flexion-extension).

INTERPRETATION

The IGA yields responsive outcome measures for the gait assessment of children with bilateral spastic CP. Spatiotemporal and kinematic (at sagittal plane) parameters are the gait parameters used most frequently. Further research is needed to establish the relevant gait parameters for each clinical problem.

WHAT THIS PAPER ADDS

Fifty-six responsive gait parameters for children with bilateral spastic cerebral palsy were identified. Most responsive gait parameters belong to joint angles time-series at sagittal plane. Spatiotemporal and kinematic parameters are widely used compared to kinetic and surface electromyography parameters.

Interobserver reliability in the interpretation of three-dimensional gait analysis in children with gait disorders

AIM

To assess interobserver reliability in the interpretation of three-dimensional gait analysis (3DGA) of children with gait disorders within a single institution.

METHOD

Seven experienced interpreters in our institution participated in a quality-assurance program reviewing one unique patient's 3DGA data every 3 months. Between 2014 and 2017, 15 patients' data were interpreted (14 with spastic cerebral palsy, 1 with myelodysplasia). Interpreters were asked to select 'yes', 'no', or 'indeterminate' from a list of problems and treatment recommendations. Kappa and percent agreement calculations were performed to evaluate consistency.

RESULTS

Average percentage agreement in problem identification and treatment recommendation was greater than 84 percent and 90 percent for all interpreters respectively. Average kappa for the 10 most consistently identified problems and recommended treatments were 0.69 and 0.59 respectively. Interpreter consistency was moderate or better for the most commonly performed operations at our institution (0.44-0.59). Sagittal plane abnormalities of the hip and knee had the highest consistency.

INTERPRETATION

When institutional differences in data collection and regional variations in management philosophies are removed, interobserver consistency in 3DGA interpretation is moderate to substantial for many commonly selected items. Identification of areas with poor consistency may help address underlying causes and improve data processes.

WHAT THIS PAPER ADDS

Consistency in three-dimensional gait analysis interpretation and treatment recommendation is high within a single institution. There is moderate or better consistency for most commonly identified problems and recommended treatments. Sagittal plane problem identification of the hip and knee have the highest consistency. Lower consistency is seen in areas with poor objective measures, such as dystonia and balance.

Retrospective Evaluation of Changes in Gait Patterns in Children and Adolescents With Cerebral Palsy After Multilevel Surgery

The purpose of this study was to retrospectively investigate changes in gait patterns after single-event multilevel surgery in children and adolescents with bilateral cerebral palsy. Three-dimensional instrumented pre- and postoperative gait data of 12 patients were compared to data of 12 healthy control subjects using principal component analysis to reduce the dimensionality of kinematic and kinetic gait data and detect gait differences. The differences between pre- and postoperative data and between postoperative data and data of control subjects were calculated using a linear mixed model. The results revealed 14 significant effects for pre- and postoperative waveforms and 11 significant effects for postoperative and control waveforms. Patients after single-event multilevel surgery walked with smaller internal foot progression angle throughout the gait cycle, lower knee flexion at initial swing, and earlier knee extension during terminal swing. Retained gait deviations included excessive pelvic tilt and internally rotated and flexed hips over the entire gait cycle. Contrary to our hypothesis, postoperative waveforms in the sagittal plane differed more from control waveforms than from preoperative waveforms. These results emphasize the importance of carefully planning further conservative therapy 2 years after single-event multilevel surgery.

Gait analysis in children with cerebral palsy

Cerebral palsy (CP) children present complex and heterogeneous motor disorders that cause gait deviations.

Clinical gait analysis (CGA) is needed to identify, understand and support the management of gait deviations in CP. CGA assesses a large amount of quantitative data concerning patients’ gait characteristics, such as video, kinematics, kinetics, electromyography and plantar pressure data.

Common gait deviations in CP can be grouped into the gait patterns of spastic hemiplegia (drop foot, equinus with different knee positions) and spastic diplegia (true equinus, jump, apparent equinus and crouch) to facilitate communication. However, gait deviations in CP tend to be a continuum of deviations rather than well delineated groups. To interpret CGA, it is necessary to link gait deviations to clinical impairments and to distinguish primary gait deviations from compensatory strategies.

CGA does not tell us how to treat a CP patient, but can provide objective identification of gait deviations and further the understanding of gait deviations. Numerous treatment options are available to manage gait deviations in CP. Generally, treatments strive to limit secondary deformations, re-establish the lever arm function and preserve muscle strength.

Additional roles of CGA are to better understand the effects of treatments on gait deviations.

Cite this article: Armand S, Decoulon G, Bonnefoy-Mazure A. Gait analysis in children with cerebral palsy. EFORT Open Rev 2016;1:448-460. DOI: 10.1302/2058-5241.1.000052.