Gillette Gait Index as a gait analysis summary measure: comparison with qualitative visual assessments of overall gait

Machine learning approach to gait deviation prediction based on isokinetic data acquired from biometric sensors

BACKGROUND

Analyzing gait deviation is one of the crucial factors during the diagnosis and treatment of children with Cerebral Palsy (CP). The typical diagnostic procedure requires an expensive and complicated three-dimensional gait analysis system based on visual sensors. In this work, we focus on predicting well-known gait pathology scores using only information collected from the BS4P, the affordable isokinetic dynamometer. Using such equipment, it is possible to determine gait pathological indices such as the gait deviation index (GDI) or the Gillette gait index (GGI).

RESEARCH QUESTION

Are there correlations between the results of examining patients with CP on the Biodex Pro 4 device and the gait quality metrics (GDI and GGI)?

METHODS

The isokinetic data acquired from biometric sensors (74 records) were analyzed using big data methods. We used several Machine Learning methods to find the correlation between gait deviation and isokinetic data: Adaptive Boosting Regression, K-nearest Neighbor, Decision Tree Regression, Random Forest Regression, and Gradient Boost Regression.

RESULTS

In this paper, we provided a detailed comparison of different machine learning regression models in predicting gait quality in patients with CP based only on the data gathered from affordable Biodex 4 Pro device. The best result was obtained using the gradient boosting regression model with Mean Absolute Percentage Error of 6%. However, it was not possible to precisely predict the GGI index using this method.

SIGNIFICANCE

The results obtained showed promising results in the evaluation of gait index scores, which gives the possibility of diagnosing patients with CP without the use of expensive optometric systems. Evaluating gait metrics using the approach proposed in this paper could be very helpful for both physicians and physiotherapists in assessing the condition of patients with CP, as well as other diseases related to gait problems.

Three decades of gait index development: A comparative review of clinical and research gait indices

BACKGROUND

A wide variety of indices have been developed to quantify gait performance markers and associate them with their respective pathologies. Indices scores have enabled better decisions regarding patient treatments and allowed for optimized monitoring of the evolution of their condition. The extensive range of human gait indices presented over the last 30 years is evaluated and summarized in this narrative literature review exploring their application in clinical and research environments.

METHODS

The analysis will explore historical and modern gait indices, focusing on the clinical efficacy with respect to their proposed pathology, age range, and associated parameter limits. Features, methods, and clinically acceptable errors are discussed while simultaneously assessing indices advantages and disadvantages. This review analyses all indices published between 1994 and February 2021 identified using the Medline, PubMed, ScienceDirect, CINAHL, EMBASE, and Google Scholar databases.

FINDINGS

A total of 30 indices were identified as noteworthy for clinical and research purposes and another 137 works were included for discussion. The indices were divided in three major groups: observational (13), instrumented (16) and hybrid (1). The instrumented indices were further sub-divided in six groups, namely kinematic- (4), spatiotemporal- (5), kinetic- (2), kinematic- and kinetic- (2), electromyographic- (1) and Inertial Measurement Unit-based indices (2).

INTERPRETATION

This work is one of the first reviews to summarize observational and instrumented gait indices, exploring their applicability in research and clinical contexts. The aim of this review is to assist members of these communities with the selection of the proper index for the group in analysis.

Gait profile score and gait variable scores in spina bifida

Quantitative data assessment on the basis of three-dimensional gait analysis has been routinely used in the evaluation of pathological gait of children with cerebral palsy. However, a similar quantitative methodology has not been applied for spina bifida patients in whom atypical gait patterns are thought to correlate with various levels of neurological paralysis. The purpose of this study is to investigate the differences among gait patterns in spina bifida between different levels of neurological lesions using quantitative methods: Gait profile score (GPS) and gait variable scores (GVS), scoring subject's gait deviation from a reference. In this cross-sectional study, 22 children with spina bifida (11 women, 11 men; mean age 9.4 years, SD 3.8 years, range 3-17 years), were examined using three-dimensional gait analysis from 2008 to 2018. Physical examination allowed for classification of each of the 44 limbs as either L4, L5 or S1 and comparison with the GPS and GVS using a linear mixed model. GPS and the GVS of the pelvis and hip range of motion in the coronal plane were significantly higher in the L4 group than in the L5 and S1 groups (GPS, P = 0.041, P = 0.003, respectively; GVS of pelvis, P = 0.001, P = 0.001; GVS of hip, P < 0.001, P < 0.001) GVS (foot progression angle) was significantly lower in the S1 group than in L4 and L5 groups (P < 0.001, P = 0.037). We found that GPS and GVS enable us to quantitatively assess the differences among gait patterns between different neurological levels. The scoring tool showed the potential for detecting individual neurological changes.

Evaluation of movement and brain activity

Clinical neurophysiology studies can contribute important information about the physiology of human movement and the pathophysiology and diagnosis of different movement disorders. Some techniques can be accomplished in a routine clinical neurophysiology laboratory and others require some special equipment. This review, initiating a series of articles on this topic, focuses on the methods and techniques. The methods reviewed include EMG, EEG, MEG, evoked potentials, coherence, accelerometry, posturography (balance), gait, and sleep studies. Functional MRI (fMRI) is also reviewed as a physiological method that can be used independently or together with other methods. A few applications to patients with movement disorders are discussed as examples, but the detailed applications will be the subject of other articles.

Three-Dimensional Gait Analysis in Children Undergoing Gastrocsoleus Lengthening for Equinus Secondary to Cerebral Palsy

Background and Objectives: Equinus is the most common deformity in children with cerebral palsy, and surgical lengthening of the gastrocsoleus muscle-tendon unit is the most commonly performed operation for children with cerebral palsy. Treatment outcomes of orthopaedic surgery can be measured objectively with three-dimensional gait analysis. This study examined the quality of evidence for gastrocsoleus lengthening surgery based on objective measures. Materials and Methods: A search was performed with Medline, Embase and PubMed from 1990 to 25 August 2020 using the keywords "cerebral palsy", "equinus", "surgery" and "gait analysis". Only studies of gastrocsoleus lengthening surgery using three-dimensional gait analysis were included, yielding 34 studies. Results: Fourteen studies reported swing phase kinematics and all studies reported a significant improvement. Rates of recurrent equinus and calcaneus were reported in 21 studies and varied widely based on follow-up period and surgical technique. Conclusions: Poor study quality and marked variability in study samples and interventions made comparison difficult. Future studies should consider prospective design, controls or comparison groups and more detailed breakdowns of outcomes by cerebral palsy subtype, sagittal gait pattern, and equinus type in order to allow more rigorous treatment recommendations to be made.

Relationship Between Observational Wisconsin Gait Scale, Gait Deviation Index, and Gait Variability Index in Individuals Poststroke

OBJECTIVE

To compare results of the observational Wisconsin Gait Scale (WGS) and global gait indexes such as Gait Deviation Index (GDI) and Gait Variability Index (GVI), constituting an objective method of assessing gait, and taking into account parameters identified during 3-dimensional gait analysis (3DGA).

DESIGN

A validation study.

SETTING

Rehabilitation clinic.

PARTICIPANTS

A total of 50 individuals poststroke and 50 individuals without stroke and without gait disorders (N=100).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Gait was evaluated using the WGS. GDI and GVI values were acquired using a movement analysis system. The global gait indexes GDI and GVI were determined based on the kinematic and spatiotemporal parameters, respectively.

RESULTS

The study showed statistically significant correlations between the parameters of GDI affected leg and WGS total score (R=-0.87), GVI affected leg and WGS total score (R=-0.93), GVI unaffected leg and WGS total score (R=-0.88), GVI affected/unaffected leg and the total score in the assessment of spatiotemporal parameters on the WGS (R=-0.81) as well as GDI affected leg and the total score in the assessment of kinematics parameters on the WGS (R=-0.85). All correlations were strong (0.7<|R|<0.9) or very strong (0.9<|R|<1).

CONCLUSIONS

WGS scores have a strong or very strong correlation with GDI and GVI. The WGS may be recommended as a substitute tool to be used when 3DGA is unavailable, as it is a useful ordinal scale, enabling simple and accurate observational assessment of gait in patients poststroke, with effectiveness that is comparable to the GDI and GVI.

Normal and pathological gait classification LSTM model

Computer vision-based clinical gait analysis is the subject of permanent research. However, there are very few datasets publicly available; hence the comparison of existing methods between each other is not straightforward. Even if the test data are in an open access, existing databases contain very few test subjects and single modality measurements, which limit their usage. The contributions of this paper are three-fold. First, we propose a new open-access multi-modal database acquired with the Kinect v.2 camera for the task of gait analysis. Second, we adapt to use the skeleton joint orientation data to calculate kinematic gait parameters to match golden-standard MOCAP systems. We propose a new set of features based on 3D low-limbs flexion dynamics to analyze the symmetry of a gait. Third, we design a Long-Short Term Memory (LSTM) ensemble model to create an unsupervised gait classification tool. The results show that joint orientation data provided by Kinect can be successfully used in an inexpensive clinical gait monitoring system, with the results moderately better than reported state-of-the-art for three normal/pathological gait classes.

The Multifeature Gait Score: An accurate way to assess gait quality

PURPOSE

This study introduces a novel way to accurately assess gait quality. This new method called Multifeature Gait Score (MGS) is based on the computation of multiple parameters characterizing six aspects of gait (temporal, amplitude, variability, regularity, symmetry and complexity) quantified with one inertial sensor. According to the aspects described, parameters were aggregated into partial scores to indicate the altered aspect in the case of abnormal patterns. In order to evaluate the overall gait quality, partial scores were averaged to a global score.

METHODS

The MGS was computed for 3 groups namely: healthy adult (10 subjects), sedentary elderly (11 subjects) and active elderly (20 subjects). Data were gathered from an inertial sensor located at the lumbar region during two sessions of 12m walking.

RESULTS

The results based on ANOVA and Tukey tests showed that the partial scores with the exception of those which describe the symmetry aspect were able to discriminate between groups (p<0.05). This significant difference was also confirmed by the global score which shows a significantly lower value for the sedentary elderly group (3.58 ±1.15) compared to the healthy adults (5.19 ±0.84) and active elderly (4.82 ±1.26). In addition, the intersession repeatability of the elaborated global score was excellent (ICC = 0.93, % SEM = 10.81).

CONCLUSION

The results obtained support the reliability and the relevance of the MGS as a novel method to characterize gait quality.

Reliability and validity of Edinburgh visual gait score as an evaluation tool for children with cerebral palsy

Assessment of gait abnormalities in cerebral palsy (CP) is challenging, and access to instrumented gait analysis is not always feasible. Therefore, many observational gait analysis scales have been devised. This study aimed to evaluate the interobserver reliability, intraobserver reliability, and validity of Edinburgh visual gait score (EVGS). Video of 30 children with spastic CP were reviewed by 7 raters (10 children each in GMFCS levels I, II, and III, age 6-12 years). Three observers had high level of experience in gait analysis (10+ years), two had medium level (2-5 years) and two had no previous experience (orthopedic fellows). Interobserver reliability was evaluated using percentage of complete agreement and kappa values. Criterion validity was evaluated by comparing EVGS scores with 3DGA data taken from the same video visit. Interobserver agreement was 60-90% and Kappa values were 0.18-0.85 for the 17 items in EVGS. Reliability was higher for distal segments (foot/ankle/knee 63-90%; trunk/pelvis/hip 60-76%), with greater experience (high 66-91%, medium 62-90%, no-experience 41-87%), with more EVGS practice (1st 10 videos 52-88%, last 10 videos 64-97%) and when used with higher functioning children (GMFCS I 65-96%, II 58-90%, III 35-65%). Intraobserver agreement was 64-92%. Agreement between EVGS and 3DGA was 52-73%. We believe that having EVGS as part of the standardized gait evaluation is helpful in optimizing the visual scoring. EVGS can be a supportive tool that adds quantitative data instead of only qualitative assessment to a video only gait evaluation.

Analysis of gait in rats with olivocerebellar lesions and ability of the nicotinic acetylcholine receptor agonist varenicline to attenuate impairments

Studies have demonstrated that administration of the neuronal nicotinic receptor agonist varenicline to rats with olivocerebellar lesions attenuates balance deficits on a rotorod and balance beam, but the effects of this drug on gait deficits have not been investigated. To accomplish this, male Sprague-Dawley rats were trained to walk on a motorized treadmill at 25 and 35 cm/s and baseline performance determined; both temporal and spatial gait parameters were analyzed. A principal component analysis (PCA) was used to identify the key components of gait, and the cumulative gait index (CGI) was calculated, representing deviations from prototypical gait patterns. Subsequently, animals either remained as non-lesioned controls or received injections of 3-acetylpyridine (3-AP)/nicotinamide to destroy the climbing fibers innervating Purkinje cells. The gait of the non-lesioned group was assessed weekly to monitor changes in the normal population, while the gait of the lesioned group was assessed 1 week following 3-AP administration, and weekly following the daily administration of saline or varenicline (0.3, 1.0, or 3.0mg free base/kg) for 2 weeks. Non-lesioned animals exhibited a 60-70% increased CGI over time due to increases in temporal gait measures, whereas lesioned animals exhibited a nearly 3-fold increased CGI as a consequence of increases in spatial measures. Following 2 weeks of treatment with the highest dose of varenicline (3.0mg free base/kg), the swing duration of lesioned animals normalized, and stride duration, stride length and step angle in this population did not differ from the non-lesioned population. Thus, varenicline enabled animals to compensate for their impairments and rectify the timing of the gait cycle.

Automated classification of neurological disorders of gait using spatio-temporal gait parameters

OBJECTIVE

Automated pattern recognition systems have been used for accurate identification of neurological conditions as well as the evaluation of the treatment outcomes. This study aims to determine the accuracy of diagnoses of (oto-)neurological gait disorders using different types of automated pattern recognition techniques.

METHODS

Clinically confirmed cases of phobic postural vertigo (N = 30), cerebellar ataxia (N = 30), progressive supranuclear palsy (N = 30), bilateral vestibulopathy (N = 30), as well as healthy subjects (N = 30) were recruited for the study. 8 measurements with 136 variables using a GAITRite(®) sensor carpet were obtained from each subject. Subjects were randomly divided into two groups (training cases and validation cases). Sensitivity and specificity of k-nearest neighbor (KNN), naive-bayes classifier (NB), artificial neural network (ANN), and support vector machine (SVM) in classifying the validation cases were calculated.

RESULTS

ANN and SVM had the highest overall sensitivity with 90.6% and 92.0% respectively, followed by NB (76.0%) and KNN (73.3%). SVM and ANN showed high false negative rates for bilateral vestibulopathy cases (20.0% and 26.0%); while KNN and NB had high false negative rates for progressive supranuclear palsy cases (76.7% and 40.0%).

CONCLUSIONS

Automated pattern recognition systems are able to identify pathological gait patterns and establish clinical diagnosis with good accuracy. SVM and ANN in particular differentiate gait patterns of several distinct oto-neurological disorders of gait with high sensitivity and specificity compared to KNN and NB. Both SVM and ANN appear to be a reliable diagnostic and management tool for disorders of gait.

Reported outcomes of lower limb orthopaedic surgery in children and adolescents with cerebral palsy: a mapping review

AIM

Lower limb surgery is often performed in ambulatory children with cerebral palsy (CP) to improve walking ability. This mapping review reports on outcome measures used in the published literature to assess surgical results, determine range and frequency of use, and map each measure to the International Classification of Functioning, Disability and Health.

METHOD

A mapped review of literature published between 1990 and 2011 was carried out to identify papers reporting the outcomes of lower limb orthopaedic surgery in ambulatory children with CP, aged 0 to 20 years.

RESULTS

A total of 229 published papers met the inclusion criteria. Thirty-two outcome measures with known psychometric properties were reported in the 229 papers. Twenty measures assess impairments in body structure and function and were used in 91% of studies. Ten measures assess restrictions in activity and participation and were used in 9% of papers. Two measures assessed quality of life. Since 1997, 29% of papers have used the Gross Motor Function Classification System to describe participants.

INTERPRETATION

The body of literature evaluating outcomes of lower limb orthopaedic surgery in CP is small but increasing. There is a need to develop a suite of outcome measures that better reflect outcomes across the International Classification of Functioning, Disability and Health, including activity and participation.

Gait analysis and the cumulative gait index (CGI): Translational tools to assess impairments exhibited by rats with olivocerebellar ataxia

Deviations from 'normal' locomotion exhibited by humans and laboratory animals may be determined using automated systems that capture both temporal and spatial gait parameters. Although many measures generated by these systems are unrelated and independent, some may be related and dependent, representing redundant assessments of function. To investigate this possibility, a treadmill-based system was used to capture gait parameters from normal and ataxic rats, and a multivariate analysis was conducted to determine deviations from normal. Rats were trained on the treadmill at two speeds, and gait parameters were generated prior to and following lesions of the olivocerebellar pathway. Control (non-lesioned) animals exhibited stable hindlimb gait parameters across assessments at each speed. Lesioned animals exhibited alterations in multiple hindlimb gait parameters, characterized by significant increases in stride frequency, braking duration, stance width, step angle, and paw angle and decreases in stride, stance, swing and propulsion durations, stride length and paw area. A principal component analysis of initial hindlimb measures indicated three uncorrelated factors mediating performance, termed Rhythmicity, Thrust and Contact. Deviation in the performance of each animal from the group mean was determined for each factor and values summed to yield the cumulative gait index (CGI), a single value reflecting variation within the group. The CGI for lesioned animals increased 2.3-fold relative to unlesioned animals. This study characterizes gait alterations in laboratory rats rendered ataxic by destruction of the climbing fiber pathway innervating Purkinje cells and demonstrates that a single index can be used to describe overall gait impairments.

Identification of gait patterns in individuals with cerebral palsy using multiple correspondence analysis

Great importance has been placed on the development of gait classification in cerebral palsy (CP) to assist clinicians. Nevertheless, gait classification is challenging within this group because the data is characterized by a high-dimensionality and a high-variability. Thus, the aim of this study was to analyze without a priori, a database of clinical gait analysis (CGA) of CP patients, using multiple correspondence analysis (MCA). A retrospective search, including biomechanical and clinical parameters was done between 2006 and 2012. One hundred and twenty two CP patients were included in this study (51 females and 71 males, mean age ± SD: 14.2 ± 7.5 years). Sixteen biomechanical spatio-temporal and kinematic parameters were included in the analysis. This data was transformed by a fuzzy window coding based on the distribution of each parameter in three modalities: low, average and high. Afterward, a MCA was used to associate parameters and to define classes. From this, seven most explicative gait parameters used to characterize gait of CP patients were identified: maximal hip extension, hip range, knee range, maximal knee flexion at initial contact, time of peak knee flexion, and maximal ankle dorsiflexion in stance phase and in swing phase. Moreover, four main profiles of CP patients have been defined from the multivariate approach: an apparent equinus gait group (the most similar of the control group with diplegic and hemiplegic patients with a GMFCS 1), a true equinus gait group (the youngest group with diplegic and some hemiplegic patients with a GMFCS 1), a crouch gait group (the oldest group with a majority of diplegic and rare hemiplegic patients with a GMFCS 2) and a jump knee gait group (the greatest level of global spasticity of the lower limbs with a majority of diplegic and rare hemiplegic patients with a GMFCS 2). Thus, this study showed the feasibility of the MCA in order to characterize and classify a large database of CP patients.

Gait and participation outcomes in adults with cerebral palsy: a series of case studies using mixed methods

BACKGROUND

There is a paucity of information on long-term outcomes of adults with cerebral palsy (CP) who received orthopedic interventions in childhood. Clinical effectiveness research requires assessment of outcomes that account for personal and environmental factors that may mediate the effects of treatment, in addition to body structures & function, activity, and participation.

OBJECTIVE/HYPOTHESIS

The purpose of this study is to provide a descriptive analysis of characteristics associated with gait and participation outcomes in a series of case studies of adults with CP.

METHODS

Participants had follow up gait analysis and clinical evaluation in adulthood and assessment of outcomes with the FIM instrument, the SF-36 Health survey, the Canadian Occupational Performance Measure, and semi-structured questions.

RESULTS

Twenty-two out of 26 participants (mean age = 25 years; GMFCS level I (n = 9); II (n = 3); III (n = 11); IV (n = 3)) maintained or improved childhood gait abilities, with levels of participation in society similar to age matched peers. Higher level of severity and personal choices impacted gait abilities in the four who declined. Majority of participants lost range of motion in hip flexion and knee extension, had pain, reported a fitness program, and increased in weight status. Personal factors and environmental factors played a role in both gait and participation outcomes.

CONCLUSION

Promotion of fitness activities and social advocacy are warranted for adults with CP. Clinical effectiveness research of long-term impact of orthopedic interventions should account for treatment effects on body structures & function, activity, participation, and modifying effects of personal, and environmental factors.

Does gender influence the long-term outcome of single-event multilevel surgery in spastic cerebral palsy?

This study compared the long-term outcome of single-event multilevel surgery in spastic diplegic cerebral palsy (CP) on the basis of sex. We hypothesized that boys would have a worse outcome than girls. Thirty-four children (19 boys and 15 girls) with diplegic spastic CP and a minimal follow-up of 10 years were included. The Gillette Gait Index was the main outcome measure. We found no differences in surgical treatment, and both groups initially benefited from the surgery. However, although girls maintained the enhanced level of walking, walking ability in boys deteriorated constantly. Such a finding suggests that sex might have an important influence on treatment outcomes in children with CP.

Gait parameters in a reference sample of healthy Spanish schoolchildren: multivariate descriptive statistics and asymmetries observed in left and right cycles

INTRODUCTION

Instrumental gait analysis is an emerging technology used increasingly to evaluate motor disorders in children. Normal reference data is necessary in order to evaluate patients, but there are few reference resources for the Spanish paediatric population.

OBJECTIVE

We aim to describe the values of 16 clinically relevant gait variables in healthy Spanish schoolchildren, and identify any linear associations or left-right asymmetries.

SUBJECTS AND METHODS

The values of 16 gait variables were determined in schoolchildren (n=27, aged 5-13 years) using instrumental gait analysis. We analysed asymmetries for each variable (Student's t-test for dependent samples) and calculated their confidence intervals (95% of the standardised difference in right and left means [SMD]). Values and associations between variables were represented using a heat map.

RESULTS

Our project presents normal values tables for 16 variables in the gait cycle. Significant asymmetries were detected in the mean values for minimum hip flexion (SMD: 0.25 95% CI, 0.11-0.39) and peak hip abduction in swing (SMD: -1.05 95% CI: -1.71--0.27). Functional associations among gait variables are present.

CONCLUSIONS

We present a reference dataset for Spanish school-aged children in which left-right asymmetries and functional associations may be observed for different variables.

Use of gait summary measures with lower limb amputees

Gait summary measures have been developed as a convenient method to communicate overall gait pathology. These measures are primarily used in the context of paediatric cerebral palsy and their use remains largely untested in other disability groups. This study assessed the suitability of gait summary measures for use with lower limb amputees. Modified (m) versions of three published gait summary measures were investigated - the Gillette Gait Index (mGGI), the Gait Deviation Index (mGDI) and the Gait Profile Score (mGPS) in conjunction with the Movement Analysis Profile (MAP). Twenty unilateral lower limb amputees underwent three-dimensional gait analysis. All measures reported significant differences between levels of amputation on the prosthetic limb. The mGGI and mGPS detected significant differences between the levels of amputation on the intact side, but the mGDI did not. All gait summary measures were moderately to strongly correlated with leg-length normalised self-selected walking speed and strong correlations were reported between all measures. The MAP exposed common strategies in amputee gait and showed that sagittal hip and knee kinematics contributed predominantly to overall gait deviation in this population group. The mGGI, mGDI and mGPS identified, quantified and stratified gait pathology, indicating that any of the gait measures investigated in this study can be applied as outcome measures in research and case management in lower limb amputees.

Single-event multilevel surgery in children with spastic diplegia: a pilot randomized controlled trial

BACKGROUND

Single-event multilevel surgery is considered the standard of care to improve gait and functioning of children with spastic diplegic cerebral palsy. However, the evidence base is limited. This pilot study is the first randomized controlled trial of single-event multilevel surgery, to our knowledge.

METHODS

Nineteen children (twelve boys and seven girls with a mean age of nine years and eight months) with spastic diplegia were enrolled. Eleven children were randomized to the surgical group and eight, to the control group. The control group underwent a program of progressive resistance strength training. The randomized phase of the trial concluded at twelve months. The control group then exited the study and progressed to surgery, whereas the surgical group continued to be followed in a prospective cohort study. The primary outcome measures were the Gait Profile Score (GPS) and the Gillette Gait Index (GGI). Secondary outcome measures were gross motor function (Gross Motor Function Measure-66 [GMFM-66]), functional mobility (Functional Mobility Scale [FMS]), time spent in the upright position, and health-related quality of life (Child Health Questionnaire [CHQ]).

RESULTS

A total of eighty-five surgical procedures were performed, with a mean of eight procedures per child (standard deviation, four). The surgical group had a 34% improvement in the GPS and a 57% improvement in the GGI at twelve months. The control group had a small nonsignificant deterioration in both indices. The between-group differences for the change in the GPS (-5.5; 95% confidence interval, -7.6 to -3.4) and the GGI (-218; 95% confidence interval, -299 to -136) were highly significant. The differences between the groups with regard to the secondary outcome measures were not significant at twelve months. At twenty-four months after surgery, there was a 4.9% increase in the GMFM-66 score and improvements in the FMS score, time spent in the upright position, and the physical functioning domain of the CHQ in the surgical group.

CONCLUSIONS

This study provides Level-II evidence that single-event multilevel surgery improves the gait of children with spastic diplegic cerebral palsy twelve months after surgery. Improvements in other domains, including gross motor function and quality of life, were not observed until twenty-four months after surgery.

Use of the Gait Deviation Index for the assessment of gastrocnemius fascia lengthening in children with Cerebral Palsy

Gait analysis (GA) is widely used for clinical evaluations and it is recognized as a central element in the quantitative evaluation of gait, in the planning of treatments and in the pre vs. post intervention evaluations in children with Cerebral Palsy (CP). Otherwise, GA produces a large volume of data and there is the clinical need to provide also a quantitative measure of the patient's overall gait. Starting from this aim some global indexes were proposed by literature as a summary measure of the patient's gait, such as the Gait Deviation Index (GDI). While validity of the GDI is demonstrated for the evaluation of the functional limitation of CP patients, no studies have evaluated with the GDI the pre vs. post surgery gait condition in children with CP. The aim of our study was therefore to investigate the effectiveness of the GDI in the quantification of gait changes occurring after surgical intervention (gastrocnemius fascia lengthening for the correction of equinus foot deformity) in patients with CP. 19 children with CP were evaluated pre-operatively (PRE session) and about 1 year (POST: mean 13.1 ± 5.1 months) after gastrocnemius fascia lengthening using 3D GA. From GA data the GDI was computed. The results evidenced that the GDI value in the PRE session was 70.4 ± 14.8, showing a moderate global disturbance of the gait patterns of the patients. After the surgical treatment a significant improvement of the GDI mean value was found (82.9 + 7.4; p < 0.05; CG ≥ 100) with an improvement of 18% respect to the PRE session. A strong correlation (ρ = 0.83; p<0.05) existed between the GDI value in the PRE session and the percentage of improvement. Our results demonstrated that GDI seems to be an appropriate outcome measure for the evaluation of the effects of surgical treatment in CP.

Examination of the child with cerebral palsy

This article describes the balanced combination of medical history, detailed physical examination, functional assessment, imaging, observational gait analysis, computerized gait analysis, and assessment of patient and family goals that are necessary to prepare treatment plans and accurately assess outcomes of treatment of children with cerebral palsy.

Movement deviation profile: a measure of distance from normality using a self-organizing neural network

We introduce the Movement Deviation Profile (MDP), which is a single curve showing the deviation of an individual's movement from normality. Joint angles, recorded from typically developing children over one gait cycle, were used to train a self-organizing map (SOM) which then generated MDP curves for patients with gait problems. The mean MDP over the gait cycle showed a high correlation (r(2) = .927) with the Gait Deviation Index (GDI), a statistically significant difference between groups of patients with a range of functional levels (Gillette Functional Assessment Questionnaire Walking Scale 7-10) and a trend of increasing values for patients with cerebral palsy through hemiplegia I-IV, diplegia, triplegia, and quadriplegia. The small difference between the MDP and GDI can be explained by the SOM's method of operation comparing biomechanical patterns to the nearest abstract reference pattern, and its flexibility to compensate for temporal shifts in movement data. The MDP is an alternative method of processing complex biomechanical data, potentially supporting clinical interpretation. The electronic addendum accompanying this article is a standalone program, which can be used to calculate the MDP from gait data, and can also be used in other applications where the deviation of multi-channel temporal data from a reference is required.

Botulinum toxin A treatment in toddlers with cerebral palsy

AIMS

In this study the aim was to evaluate the effect of botulinum toxin A (BoNT-A) treatment on muscle tone, contracture development and gait pattern in young children with cerebral palsy (CP).

METHOD

Fifteen children with spastic CP (mean age = 16 months) were included in a randomized control study. All received a daily stretching programme and children in the BoNT-A group additionally received two injections, 6 months apart in the gastrocnemius muscle. Outcomes were assessed at baseline, and after 1 and 3.5 years. A 3D gait-analysis was performed at 5 years of age.

RESULTS

Plantarflexor muscle tone in the BoNT-A group was significantly reduced after 3.5 years, while the muscle tone at the ankle and knee in the control group remained unchanged. The change-score in knee-flexion muscle tone between the groups was significantly different after 3.5 years. The knee joint ROM was significantly increased at 1 year in the BoNT-A group but reduced at the knee and ankle joints in the control group after 3.5 years. No group differences were found for gait analysis, GMFM-66 or PEDI.

CONCLUSION

Early treatment of BoNT-A in children with spastic CP may decrease muscle tone and decelerate contracture development after 3.5 years. The effect on gait development remains inconclusive.

Gillette Gait Index in adults

Gillette Gait Index (GGI) is a very useful tool to assess gait abnormalities. However, it seems that it has only been validated in children with cerebral palsy. Nevertheless, the parameters used to compute GGI are not specific to children population. Our aim is to demonstrate that GGI could also be used to evaluate adults gait abnormalities. 44 adults (25 healthy and 19 pathological) participated to this study. Pathological subjects had a diagnosis of central nervous system pathology (6 with spinal cord injury and 13 with brain injury). We first, compared the kinematic parameter values of our healthy adult group to healthy children group in previous studies. It appears that those parameters' variability is a bit lower in adults, which makes the GGI more sensitive. Moreover, the GGI in adults is too much dependent on one parameter among the 16 proposed by Schutte et al. (2000), the "Time of Peak Flexion". Finally, the Edinburgh Visual Gait Score (EVGS) is correlated to GGI in children. To emphasize the relevance of GGI in adults, we have evaluated the correlation between EVGS and GGI in our pathological group. Those two parameters are indeed highly correlated. All these results allow us to conclude that the GGI computed with the 15 remaining parameters is a useful tool to assess gait abnormalities in adults.

Walking abilities of young adults with cerebral palsy: changes after multilevel surgery and adolescence

Although there is some evidence to support the efficacy of single event multilevel surgery (SEMLS) in the short term for improving walking abilities in children with cerebral palsy (CP), long term effects are not known. It is hypothesized: (1) SEMLS improves walking abilities; (2) in young adulthood abilities deteriorate beyond pre-operative status; (3) walking abilities deteriorate from adolescence to young adulthood and are associated with weight status increase. Twenty-three young adults (mean age 25.5 years, range 20-36) with spastic CP Gross Motor Functional Classification Scale Level II (n=11) or III (n=12) returned for follow up three dimensional gait analysis (3DGA). Gillette Gait Index (GGI) was used as a general indicator of walking abilities. Eleven subjects had 3DGA prior to multilevel orthopedic surgery and 12 subjects had 3DGA after the age of 10 with no interventions in the interim. GGI(s) were graphed over time. Ten of 11 subjects (91%) who had multilevel surgery either improved (n=6) or maintained pre-operative walking abilities (n=4) based on GGI. Ten of 12 subjects (83%) who had 3DGA after the age of 10 but no interventions in the interim maintained (n=8) or improved (n=2) walking abilities. No associations were found between declines in walking abilities and increased weight status. After SEMLS, walking abilities in young adulthood were comparable to pre-operative status. A decline in walking abilities was not observed from adolescence to young adulthood.

Can clinical gait analysis guide the management of ambulant children with bilateral spastic cerebral palsy?

BACKGROUND

The role of clinical gait analysis in the management of ambulant children with bilateral spastic cerebral palsy (BSCP) is controversial. We hypothesized that gait analysis would allow us to differentiate between children with BSCP who would benefit from surgical intervention and those in whom surgery was not indicated.

METHODS

We reviewed the outcome in 3 groups of children with BSCP referred for treatment recommendations based on gait analysis by looking at changes in the popliteal angle (PA), Gillette Gait Index (GGI), and minimum knee flexion in single support (MKFS) on a subsequent gait analysis. We identified 15 children in whom surgical intervention was not thought to be needed (SNR group) and 15 children who had multilevel surgery recommended but not performed (SND group). We randomly selected and reviewed 15 children referred during the study period who had multilevel surgery recommended and performed following gait analysis (OP group) for comparison.

RESULTS

The initial PA, MKFS, and GGI were greater in the OP and SND groups compared with the SNR group. Popliteal angle did not change between analyses in the SNR and SND groups and decreased in the OP group (P = 0.004). Minimum knee flexion in single support remained similar between analyses in the SNR group, increased in the SND group (P < 0.0001), and decreased in the OP group (P < 0.0001). The GGI remained similar in the SNR and SND groups but decreased in the OP group (P = 0.0002). The number of children in the SND group showing an increase of more than 10% in the GGI between analyses (8/15) was greater than that in the OP group (0/15) (P = 0.0022). The PA, MKFS, and GGI contributed significantly to the treatment recommendations (P = 0.0013, P = 0.0045, P = 0.0054, respectively), which were not affected by age and Gross Motor Functional Classification System level.

CONCLUSIONS

Gait analysis helped us to distinguish children with BSCP who would benefit from surgery from those in whom nonoperative management was appropriate, and its routine clinical use is encouraged in the management of these children.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

The Gait Deviation Index: a new comprehensive index of gait pathology

This article describes a new multivariate measure of overall gait pathology called the Gait Deviation Index (GDI). The first step in developing the GDI was to use kinematic data from a large number of walking strides to derive a set of mutually independent joint rotation patterns that efficiently describe gait. These patterns are called gait features. Linear combinations of the first 15 gait features produced a 98% faithful reconstruction of both the data from which they were derived and 1000 validation strides not used in the derivation. The GDI was then defined as a scaled distance between the 15 gait feature scores for a subject and the average of the same 15 gait feature scores for a control group of typically developing (TD) children. Concurrent and face validity data for the GDI are presented through comparisons with the Gillette Gait Index (GGI), Gillette Functional Assessment Questionnaire Walking Scale (FAQ), and topographic classifications within the diagnosis of Cerebral Palsy (CP). The GDI and GGI are strongly correlated (r(2)=0.56). The GDI scales with FAQ level, distinguishes levels from one another, and is normally distributed across FAQ levels six to ten and among TD children. The GDI also scales with respect to clinical involvement based on topographic CP classification in Hemiplegia Types I-IV, Diplegia, Triplegia and Quadriplegia. The GDI offers an alternative to the GGI as a comprehensive quantitative gait pathology index, and can be readily computed using the electronic addendum provided with this article.

Does sex influence outcome in ambulant children with bilateral spastic cerebral palsy?

To investigate the effect of sex on the phenotype of bilateral spastic cerebral palsy (CP) we reviewed the gait analysis data of 116 children (78 males, mean age 8 y 1 mo [SD 3 y 1 mo] and 38 females, mean age 8 y 9 mo [3 y 1 mo]) with bilateral spastic CP (Gross Motor Function Classification System [GMFCS] Levels I [four males, six females]; II [41 males, 19 females]; III [26 males, 12 females]; and IV [7 males, 1 female]) who had been referred for gait analysis to inform treatment. Although there were no differences between males and females in terms of gestational age, chronological age, or GMFCS level, males were more likely to have had nonoperative intervention before the referral (p=0.024), had a greater degree of knee flexion in stance phase when walking (p=0.003), and had a higher Gillette Gait Index (p<0.001) when compared with females. Males were also more likely to have surgery recommended on the basis of gait analysis (p<0.001). Sex seems to influence the development of the musculoskeletal system and mobility in ambulant children with bilateral spastic CP, and this may need to be considered when planning intervention or when assessing the outcome of intervention.