Test-Retest Reliability of Discrete Gait Parameters in Children With Cerebral Palsy

Repeatability and minimal detectable change including clothing effects for smartphone-based 3D markerless motion capture

OpenCap, a smartphone- and web-based markerless system, has shown acceptable accuracy compared to marker-based systems, but lacks information on repeatability. This study fills this gap by evaluating the intersession repeatability of OpenCap and investigating the effects of clothing on gait kinematics. Twenty healthy volunteers participated in a test-retest study, performing walking and sit-to-stand tasks with minimal clothing and regular street wear. Segment lengths and lower-limb kinematics were compared between both sessions and for both clothing conditions using the root-mean-square-deviation (RMSD) for entire waveforms and the standard error of measurement (SEM) and minimal detectable change (MDC) for discrete kinematic parameters. In general, the RMSD test-retest values were 2.8 degrees (SD: 1.0) for walking and 3.3 degrees (SD: 1.2) for sit-to-stand. The highest intersession variability was observed in the trunk, pelvis, and hip kinematics of the sagittal plane. SEM and MDC values were on average 2.2 and 6.0 degrees, respectively, for walking, and 2.4 and 6.5 degrees for sit-to-stand. Clothing had minimal effects on kinematics by adding on average less than one degree to the RMSD values for most variables. The segment lengths showed moderate to excellent agreement between both sessions and poor to moderate agreement between clothing conditions. The study highlights the reliability of OpenCap for markerless motion capture, emphasizing its potential for large-scale field studies. However, some variables showed high MDC values above 5 degrees and thus warrant further enhancement of the technology. Although clothing had minimal effects, it is still recommended to maintain consistent clothing to minimize overall variability.

Effectiveness of Neurodevelopmental Treatment and Sensory Integration Therapy on Gross Motor Function, Balance and Gait Parameters in Children With Spastic Diplegia

Background Spastic diplegic cerebral palsy is the type that is most frequently seen in clinical settings. Spastic diplegic children have trouble maintaining their balance, gait, and gross motor function. This study investigated the effects of the Neurodevelopmental Technique (NDT) and Sensory Integration Technique (SIT) on balance, gross motor function, and gait characteristics in children with spastic diplegia. Method The study's participants were 8 to 12 years old, with spastic diplegia, categorized into stages I to III of the Gross Motor Function Classification System. While individuals in group B underwent sensory integration therapy, group A's subjects received NDT for 45 minutes. Both groups received traditional physiotherapy for 15 minutes. The protocol was given for five days a week, continuously for four weeks. All 40 subjects underwent pre- and post-treatment assessments using the Gross Motor Function Measure-88 (GMFM-88), Paediatric Balance Scale, Gait Parameters, and Gross Motor Function Classification System. Results The trial involved 40 children, divided into two groups of 20 each. Statistical analysis demonstrated a substantial improvement in group B post-intervention (P>0.0001). The study's findings were drawn using the Chi-Square test, paired and unpaired t-tests, and SPSS Statistics for Windows, version 27.0 (IBM Corp., Armonk, USA).A p<0.05 and the GraphPad Prism version 7.0 (GraphPad Software, Boston, USA) were used. A total of 40 children completed the entire duration of treatment for a month. 20 subjects participated in group A (age range 8-12 years; mean age 10.3 years) and 20 subjects in group B (age range 8-12 years; mean age 10.25 years). The GMFM-88, which assesses motor function, reveals that the between-group comparison indicates a substantial difference of 7.95 (6.04-9.86) in favor of Group B, with a p-value of 0.0001, signifying statistical significance. Similarly, the Pediatric Balance Scale (PBS) outcomes significantly enhanced in both groups post-intervention. The comparison between groups yields a difference of 1.85 (1.11-2.59) in favor of Group B, with a p-value of 0.0001. Conclusion The study concluded that SIT has a positive impact on gait metrics, balance, and gross motor function in children with spastic diplegia.

Inter- and intra-rater reliability of new application software for computerised paediatric version of Wisconsin Gait Scale

The paediatric version of Wisconsin Gait Scale (WGS) is a reliable tool for gait assessment in children with spastic hemiplegic cerebral palsy (CP). We decided to develop a solution which will make it possible to objectify the descriptive paediatric version of the WGS, and which, consequently, will allow researchers/clinicians to more easily perform accurate assessment of gait patterns in patients. The aim of the study was to assess inter- and intra-rater reliability of new application software for computerised paediatric version of the WGS in children with hemiplegic CP. The study involved 31 children with hemiplegic CP. The app was designed using a model based on thematic categories of the paediatric WGS, and utilising auxiliary lines between specific points on the patient's body, and taking into account angular values, duration and length of the specific gait phases, in order to enable acquisition of quantitative data corresponding to the components of the WGS. The gait of the study participants was recorded, in series of videos. These provided material for three independent raters who reviewed the recordings twice and assessed the participants' gait using the app. After the evaluation was completed, the data were retrieved from the software. The new application software for the computerised paediatric WGS presents very good inter- and intra-rater reliability. Intra-class correlation coefficient (ICC) was very high in measurement 1 (ICC > 0.9) and 2 (ICC > 0.8), which reflects a very high degree of agreement between the three examiners; there was also high agreement for the specific examiners, between the two measurements (ICC > 0.9). The observational gait scale, objectified through the new software, and enabling computer-aided use of the paediatric WGS, presents practical advantages for examiners since it facilitates decisions taken in the process of WGS-based assessment in children with spastic hemiplegic CP.

Relationship between kinematic gait quality and caregiver-reported everyday mobility in children and youth with spastic Cerebral Palsy

BACKGROUND

3D gait analysis (3DGA) is a common assessment in Cerebral Palsy (CP) to quantify the extent of movement abnormalities. Yet, 3DGA is performed in laboratories and may thus be of debatable significance to everyday life.

AIM

The aim was to assess the relationship between kinematic gait abnormality and everyday mobility in ambulatory children and youth with spastic CP.

METHODS

73 paediatric and juvenile patients with uni- or bilateral spastic CP (N = 21 USCP, N = 52, BSCP, age: 4-20 y, GMFCS I-III) underwent a 3DGA, while the MobQues47 Questionnaire quantified caregiver-reported mobility. We calculated the Gait Profile Score (GPS), a metric that summarizes how far the lower limb joint angles during walking deviate from those of matched controls.

RESULTS

The GPS correlated well with indoor and outdoor mobility (rho = -0.69 and -0.70, both p < 0.001) and the relationships were not significantly different for USCP and BSCP. Still, mobility was lower in BSCP (p < 0.001) and more compromised outdoors (p = 0.002). Indoor mobility could be predicted by walking speed, GPS and age (adj. R² = 0.62). Outdoor mobility was best predicted by walking speed and GPS (adj. R² = 0.60). The additive explained variance by the GPS was even higher outdoors than indoors (17.1% vs. 11.4%).

CONCLUSIONS

Measuring movement deviations with 3DGA seems equally meaningful in uni- and bilaterally affected children and has considerable relevance for real-life ambulation, particurlarly outdoors, where children with spastic CP typically face greater difficulties. Therapeutic strategies that achieve faster walking and reduction of kinematic deviations may increase outdoor mobility.

Lower limb muscle fatigue after uphill walking in children with unilateral spastic cerebral palsy

Fatigue during walking is a common complaint in cerebral palsy (CP). The primary purpose of this study is to investigate muscle fatigue from surface electromyography (sEMG) measurements after a treadmill-based fatigue protocol with increasing incline and speed in children with CP with drop foot. The secondary purpose is to investigate whether changes in sagittal kinematics of hip, knee and ankle occur after fatigue. Eighteen subjects with unilateral spastic CP performed the protocol while wearing their ankle-foot orthosis and scored their fatigue on the OMNI scale of perceived exertion. The median frequency (MF) and root mean square (RMS) were used as sEMG measures for fatigue and linear mixed effects model were applied. The MF was significantly decreased in fatigued condition, especially in the affected leg and in the tibialis anterior and peroneus longus muscle. The RMS did not change significantly in fatigued condition, while the OMNI fatigue score indicated patients felt really fatigued. No changes in sagittal kinematics of hip, knee and ankle were found using statistical non-parametric mapping. In conclusion, the current fatigue protocol seems promising in inducing fatigue in a population with CP with drop foot and it could be used to expand knowledge on muscle fatigue during walking in CP.

Effectiveness of Pelvic Proprioceptive Neuromuscular Facilitation on Balance and Gait Parameters in Children With Spastic Diplegia

Background  Among several variants of Cerebral Palsy, Spastic Diplegic is encountered most commonly in clinical setups. A majority of children with Spastic Diplegia manifest themselves with a disturbance in the geometrical orientation of their pelvis, which imposes an effect on their functional capabilities like walking with independence. This research had an emphasis on the extraction of the efficacy of Pelvic Proprioceptive Neuromuscular Facilitation (PNF) Techniques on Balance and Gait Parameters in children suffering from Spastic Diplegia. Method Participants included in the study were between the age groups of 8 to 12 years who were diagnosed with Spastic Diplegia with an independent sitting and walking ability and who are coming in stages I to III according to Gross Motor Function Classification System. Subjects in group A were given Pelvic PNF techniques for 15 minutes on both sides along with Task-Oriented training for 30 minutes, six days a week and continuously for four weeks, while the subjects in group B were given only Task-Oriented activity for the same duration. The pre- and post-treatment assessments of all 40 subjects were gathered using the Paediatric Balance Scale, Palpation Meter device, and Gait Parameters. Results The study included 40 participants, which were segregated into two groups of 20 subjects in each group. Group A received Pelvic Proprioceptive Neuromuscular Facilitation with Task-Oriented Training, and group B received only Task-Oriented training activities. The contrast of pre- and post-treatment findings of both the groups revealed that group A reported a significant improvement in their outcomes (P>0.0001). Conclusion  The present study, which included 40 subjects, has generated evidence regarding the efficacy of Pelvic PNF on Balance and Gait Parameters in children with Spastic Diplegia.

The Short-Term Impact of Botulinum Neurotoxin-A on Muscle Morphology and Gait in Children with Spastic Cerebral Palsy

Children with spastic cerebral palsy (SCP) are often treated with intramuscular Botulinum Neurotoxin type-A (BoNT-A). Recent studies demonstrated BoNT-A-induced muscle atrophy and variable effects on gait pathology. This group-matched controlled study in children with SCP compared changes in muscle morphology 8-10 weeks post-BoNT-A treatment (n = 25, median age 6.4 years, GMFCS level I/II/III (14/9/2)) to morphological changes of an untreated control group (n = 20, median age 7.6 years, GMFCS level I/II/III (14/5/1)). Additionally, the effects on gait and spasticity were assessed in all treated children and a subgroup (n = 14), respectively. BoNT-A treatment was applied following an established integrated approach. Gastrocnemius and semitendinosus volume and echogenicity intensity were assessed by 3D-freehand ultrasound, spasticity was quantified through electromyography during passive muscle stretches at different velocities. Ankle and knee kinematics were evaluated by 3D-gait analysis. Medial gastrocnemius (p = 0.018, -5.2%) and semitendinosus muscle volume (p = 0.030, -16.2%) reduced post-BoNT-A, but not in the untreated control group, while echogenicity intensity did not change. Spasticity reduced and ankle gait kinematics significantly improved, combined with limited effects on knee kinematics. This study demonstrated that BoNT-A reduces spasticity and partly improves pathological gait but reduces muscle volume 8-10 weeks post-injections. Close post-BoNT-A follow-up and well-considered treatment selection is advised before BoNT-A application in SCP.

Physical therapy with hippotherapy compared to physical therapy alone in children with cerebral palsy: systematic review and meta-analysis

AIM

To compare the effects of physical therapy with hippotherapy versus physical therapy alone on the gross motor function of children and adolescents with cerebral palsy (CP).

METHOD

Electronic searches were conducted in January 2021. We included controlled trials of the gross motor function of children and adolescents with CP, aged 2 to 18 years. We extracted means, standard deviations, and changes from the baseline to the end of the intervention. We used the Cochrane Collaboration's tool modified by Effective Practice and Organization of Care (EPOC) to assess the methodological quality and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method to verify evidence synthesis. We conducted the meta-analysis using Revman 5.3.

RESULTS

A total of 315 individuals from six studies were included. Both groups received physical therapy including strength, aerobic, stretch, and mobility exercises, and neurodevelopmental treatment. Studies presented high risk of bias. Both therapies presented similar effects for Gross Motor Function Measure scores, cadence, stride length, and speed during gait. The level of evidence was very low. The change was greater for the physical therapy with hippotherapy group, but inferior to the smallest real difference or the minimal detectable change.

INTERPRETATION

Physical therapy with hippotherapy presented similar effects to physical therapy alone on the gross motor function of children and adolescents with CP. Future studies should include larger sample sizes and studies with low risk of bias.

Instrumented gait analysis for management of gait disorders in children with cerebral palsy: A scoping review

BACKGROUND

The use of Instrumented Gait Analysis (IGA) for the clinical management of individuals with cerebral palsy (CP) has increased in recent years. Previous systematic reviews have been completed to evaluate and summarize the evidence related to the efficacy of IGA in general. However, a focused summary of research studies on IGA for children with CP related gait disorders is needed.

RESEARCH QUESTION

The purpose of the current work was to perform a scoping review to describe and categorize the range of existing literature about IGA as applied to the clinical management of children with CP related gait disorders.

METHOD

A health sciences librarian developed a search strategy to include four key inclusion criteria of original research study, population included children with CP, study employed IGA, available in English. The available literature was organized into six study categories: reliability and validity, documentation of subgroups or model development, IGA for clinical decision making, effectiveness of treatments that depend on IGA, cost effectiveness, IGA used to evaluate the outcome of surgical, medical or rehabilitation treatment.

RESULTS

909 studies met the inclusion criteria and were placed into the six study categories. 14 % of studies were in reliability and validity, 33 % in subgroups or modeling, 2% in IGA for clinical decision making, 2% in treatments that depend on IGA, 1% in cost effectiveness, and 49 % of studies had IGA used as an outcome measure for treatment.

SIGNIFICANCE

This scoping review has documented the wide range, diversity and extent of original research studies investigating the use of IGA for the clinical management of children with CP related gait disorders. The large volume of studies provides a basis for future work to develop a CPG about the use of IGA for the clinical management of children with CP related gait disorders.

Within-Session Reliability and Minimum Detectable Differences for Discrete Lower-Extremity Angles and Moments During Walking

Differences in walking biomechanics between groups or conditions should be greater than the measurement error to be considered meaningful. Reliability and minimum detectable differences (MDDs) have not been determined for lower-extremity angles and moments during walking within a session, as needed for interpreting differences in cross-sectional studies. Thus, the purpose of this study was to determine within-session reliability and MDDs for peak ankle, knee, and hip angles and moments during walking. Three-dimensional gait analysis was used to record walking at 1.25 m/s (±5%) in 18 men, 18-50 years of age. Peak angles and moments were calculated for 2 sets of 3 trials. Intraclass correlation coefficients (3, 3) were used to determine within-session reliability. In addition, MDDs were calculated. Within-session reliability was good to excellent for all variables. The MDDs ranged from 0.9° to 3.6° for joint angles and 0.06 to 0.15 N·m/kg for joint moments. Within-session reliability for peak ankle, knee, and hip angles and moments was better than the between-session reliability reported previously. Overall, our MDDs were similar or smaller than those previously reported for between-session reliability. The authors recommend using these MDDs to aid in the interpretation of cross-sectional comparisons of lower-extremity biomechanics during walking in healthy men.

Evaluation of Individualized Functional Electrical Stimulation-Induced Acute Changes during Walking: A Case Series in Children with Cerebral Palsy

Functional electrical stimulation (FES) walking interventions have demonstrated improvements to gait parameters; however, studies were often confined to stimulation of one or two muscle groups. Increased options such as number of muscle groups targeted, timing of stimulation delivery, and level of stimulation are needed to address subject-specific gait deviations. We aimed to demonstrate the feasibility of using a FES system with increased stimulation options during walking in children with cerebral palsy (CP). Three physical therapists designed individualized stimulation programs for six children with CP to target participant-specific gait deviations. Stimulation settings (pulse duration and current) were tuned to each participant. Participants donned our custom FES system that utilized gait phase detection to control stimulation to lower extremity muscle groups and walked on a treadmill at a self-selected speed. Motion capture data were collected during walking with and without the individualized stimulation program. Eight gait metrics and associated timing were compared between walking conditions. The prescribed participant-specific stimulation programs induced significant change towards typical gait in at least one metric for each participant with one iteration of FES-walking. FES systems with increased stimulation options have the potential to allow the physical therapist to better target the individual's gait deviations than a one size fits all device.

Reliability and sources of variability of 3D kinematics and electromyography measurements to assess newly-acquired gait in toddlers with typical development and unilateral cerebral palsy

The aim was to 1) determine intersession and intertrial reliability and 2) assess three sources of variability (intersubject, intersession and intertrial) of lower limb kinematic and electromyographic (EMG) variables during gait in toddlers with typical development (TD) and unilateral cerebral palsy (UCP) (age <3 years, independent walking experience ≤6 months). Gait kinematics and surface EMG were recorded in 30 toddlers (19 TD and 11 UCP), during two, 3D-motion capture sessions. Standard error of measurement (SEM) between trials (gait cycles) of the same session and between sessions was calculated to assess reliability. Standard deviations (SD) between subjects, sessions and trials were calculated to estimate sources of variability. Sixty-four percent of kinematic SEM-values were acceptable (2°-5°). Frontal plane measurements were most reliable (SEM 2°-4.6°). In toddlers with UCP, EMG variables were most reliable for affected side, distal muscles. Intrinsic (intertrial and intersubject) variability was high, reflecting both motor immaturity and the high variability of toddler gait patterns. In toddlers with UCP, variability was amplified by motor impairment and delayed motor development. 3D gait analysis and surface EMG are partially reliable tools to study individual gait patterns in toddlers in clinical practice and research, although some variables must be interpreted with caution.

Test-retest reliability and minimal detectable change of ankle kinematics and spatiotemporal parameters in MS population

BACKGROUND

Many people with multiple sclerosis (pwMS) experience walking impairments often including foot drop, evident as either reduced dorsiflexion at initial contact and/or at the swing phase of the gait cycle. To measure even subtle differences in ankle kinematics, 3D gait analysis is considered a 'gold' standard. However, the psychometric properties of ankle kinematics in the MS population have not yet been examined.

OBJECTIVE

The aim of the study was to examine test-retest relative and absolute reliability of sagittal ankle kinematics and spatiotemporal parameters in two groups of pwMS with different levels of walking impairment.

METHODS

Two groups of pwMS underwent 3D gait analysis on two occasions 7-14 days apart. Group A consisted of 21 (14 female) people with Expanded Disability Status Scale (EDSS) 1-3.5 and group B consisted of 28 participants (14 female) with EDSS 4-6. The Intraclass Correlation Coefficient (ICC_2,2), standard error of measurement (SEM) and minimal detectable change (MDC_95%) were calculated for peak dorsiflexion (DF) in swing, ankle angle at initial contact (IC), gait profile score (GPS), walking speed, cadence and step length.

RESULTS

Both groups presented 'excellent' ICC values (>0.75) for DF in swing, IC and step length of most and least affected limbs, walking speed and cadence, with GPS for both limbs exhibiting 'fair' to 'good' ICCs (0.489-0.698). The MDC_95% values for all ankle kinematic parameters in group A were lower (1.9°-4.2°) than those in group B (2.2°-7.7°).

CONCLUSION

The present results suggest that ankle kinematic and spatiotemporal parameters derived from 3D gait analysis are reliable outcome measures to be used in the MS population. Further, this study provides indices of reliability that can be applied to both clinical decision making and in the design of studies aimed at treating foot drop in people with MS.

Reliability of single-day walking performance and physical activity measures using inertial sensors in children with cerebral palsy

BACKGROUND

There is a lack of objective and reliable tools to measure walking performance in children with cerebral palsy (CP).

OBJECTIVE

To evaluate the reliability of inertial measurement units (IMUs) measuring daily life walking performance and physical activity (PA) in children with CP and healthy controls.

METHODS

Algorithms were developed to analyse data collected with IMUs during 2 standard school days of the same week and 1 weekend day in 15 children with CP and 14 controls. Additionally, within a clinical trial, 10 children with CP were measured twice, on the same weekday 2 to 4 weeks apart. Relative and absolute reliabilities of PA (% time walking, standing, sitting/lying) and gait parameters (e.g., velocity, cadence) were evaluated by using the intraclass correlation coefficient (ICC) and minimal detectable change (MDC₉₅), comparing 2 school days of the same week, a school day with a weekend day, and the same weekday 2 to 4 weeks apart.

RESULTS

For the 15 children with CP (mean [SD] age 13.5 [3.4] years), ICCs were very high (0.70-0.98) when comparing gait parameters for 2 school days. ICCs were lower when comparing 2 school days for 14 control children (mean [SD] age 13.9 [3.0] years) and lowest when comparing a school day with a weekend day for both CP and control children. ICCs for PA were 0.90-0.91 when measuring the same weekday 2 to 4 weeks apart but were very low when comparing 2 school days of the same week or a school day with a weekend day. MDC₉₅ values were high for both groups and all comparisons but comparable with findings of in-lab studies of similar parameters.

CONCLUSIONS

Our IMU and algorithm setup appears to be a reliable tool to measure daily life gait parameters in children with CP when repeatedly measured on 2 school days. PA was also reliably assessed but when measuring the same school day some weeks apart. However, the high MDC₉₅ values question whether the setup can be used as a responsive outcome measure of interventions.

The effect of joint translation constraint on within-participant variability of kinematics and kinetics during running in cerebral palsy

BACKGROUND

Biomechanical data in cerebral palsy are inherently variable but no optimal model of translational joint constraint has been identified. The primary aim of this study was to determine which model of translational joint constraint resulted in the lowest within-participant variability of lower limb joint angles and moments. The secondary aim was to determine which model best distinguished known functional groups in Cerebral Palsy.

METHODS

Three models (three degrees of freedom, six degrees of freedom and six degrees of freedom with specified joint translation constraint) were applied to data from running trials of 40 children with cerebral palsy.

FINDINGS

Joint angle standard deviations were largest using the six degrees of freedom model and smallest using the constrained six degrees of freedom model (p < 0.050). For all joints in all planes of motion, joint moment standard deviations were largest using the six degrees of freedom model and smallest using the constrained six degrees of freedom model; standard deviations using the constrained model were smaller than the three degrees of freedom model by 10-30% of moment magnitude (0.01-0.03 Nm/kg; p < 0.001). The six degrees of freedom models distinguished functional subgroups with larger effect size than the three degrees of freedom model only for hip power generation in swing.

INTERPRETATION

A model with specified joint constraint minimized within-participant variability during running and was useful for detecting differences in functional capacity in cerebral palsy.

Validation of inertial measurement units with optical tracking system in patients operated with Total hip arthroplasty

Background

Patient reported outcome measurement (PROMs) will not capture in detail the functional joint motion before and after total hip arthroplasty (THA). Therefore, methods more specifically aimed to analyse joint movements may be of interest. An analysis method that addresses these issues should be readily accessible and easy to use especially if applied to large groups of patients, who you want to study both before and after a surgical intervention such as THA. Our aim was to evaluate the accuracy of inertial measurement units (IMU) by comparison with an optical tracking system (OTS) to record pelvic tilt, hip and knee flexion in patients who had undergone THA.

Methods

49 subjects, 25 males 24 females, mean age of 73 years (range 51–80) with THA participated. All patients were measured with a portable IMU system, with sensors attached lateral to the pelvis, the thigh and the lower leg. For validation, a 12-camera motion capture system was used to determine the positions of 15 skin markers (Oqus 4, Qualisys AB, Sweden). Comparison of sagittal pelvic rotations, and hip and knee flexion-extension motions measured with the two systems was performed. The mean values of the IMU’s on the left and right sides were compared with OTS data.

Results

The comparison between the two gait analysis methods showed no significant difference for mean pelvic tilt range (4.9–5.4 degrees) or mean knee flexion range (54.4–55.1 degrees) on either side (p > 0.7). The IMU system did however record slightly less hip flexion on both sides (36.7–37.7 degrees for the OTS compared to 34.0–34.4 degrees for the IMU, p < 0.001).

Conclusions

We found that inertial measurement units can produce valid kinematic data of pelvis- and knee flexion-extension range. Slightly less hip flexion was however recorded with the inertial measurement units which may be due to the difference in the modelling of the pelvis, soft tissue artefacts, and malalignment between the two methods or misplacement of the inertial measurement units.

Trial registration

The study has ethical approval from the ethical committee “Regionala etikprövningsnämnden i Göteborg” (Dnr: 611–15, 2015-08-27) and all study participants have submitted written approval for participation in the study.

Different reliability of instrumented gait analysis between patients with unilateral hip osteoarthritis, unilateral hip prosthesis and healthy controls

BACKGROUND

The gait pattern varies within the population and between patient groups with different musculoskeletal diseases. It also varies over time due to various reasons. Three-dimensional gait analysis (3DGA) is frequently used to measure these changes, but the precision of this methodology may vary.

METHODS

We primarily aimed to study the repeatability of hip motion measurements in patients with unilateral osteoarthritis (OA), patients with unilateral total hip arthroplasty (THA) and healthy controls. A secondary aim was to delineate any differences in hip motion during walking between these groups. Ten males and 10 females in each group were recruited. All patients underwent gait assessments using 3DGA recorded by 2 examiners. Data was analysed with comparison of variance and linear regression.

RESULTS

The variability of the extension-flexion recordings was smallest in healthy controls (SD < 7.7°), increased in patients with THA (SD < 11.1°) and was most pronounced in the OA patients (SD < 12.2°). The degree of hip extension-flexion turned out to be the variable that most effectively could separate the controls from the 2 patient groups and the patient groups from each other. One to 2 years after THA the gait pattern was improved but still differed comparing a group of THA from a group of healthy controls.

CONCLUSIONS

Patients with hip osteoarthritis showed the poorest repeatability between gait recordings collected by different examiners, as compared to patients operated with a THA and healthy controls. The walking pattern after THA still differed from healthy controls 1-2 years after the operation.

How to choose and interpret similarity indices to quantify the variability in gait joint kinematics

Repeatability and reproducibility indices are often used in gait analysis to validate models and assess patients in their follow-up. When comparing joint kinematics, their interpretation can be ambiguous due to a lack of understanding of the exact sources of their variations. This paper studied four indices (Root Mean Square Deviation, Mean Absolute Variability, Coefficient of Multiple Correlation, and Linear Fit Method) in relation to five confusing-factors: joints’ range of motion, sample-by-sample amplitude variability, offset, time shift and curve shape. A first simulation was conducted to test the mathematics behind each index. A second simulation tested the influence of the curve shape on the indices using a Fourier’s decomposition. The Coefficient of Multiple Correlation and the Linear Fit method Coefficients were independent from the range of motion. Different Coefficients of Multiple Correlation were found among different joints, leading to misinterpretation of the results. The Linear Fit Method coefficients should not be adopted when time shift increases. Root Mean Square Deviation and Mean Absolute Variability were sensitive to all the confusing-factors. The Linear Fit Method coefficients seemed to be the most suitable to assess gait data variability, complemented with Root Mean Square Deviation or Mean Absolute Variability as measurements of data dispersion.

Reliability of three-dimensional kinematic gait data in adults with spinal cord injury

Objectives

Three-dimensional gait analysis has been recommended as part of standardized gait assessment in people with spinal cord injury. The aim was to investigate inter- and intra-session reliabilities of gait kinematics in people with spinal cord injury.

Methods

Fifteen adults with spinal cord injury performed two test sessions on separate days. Six infrared cameras, 16 reflective markers and the Plug-in gait model were used. For each subject, five gait trials from both sessions were included. The Gait Profile Score and the Gait Variable Score were used as kinematic outcome measures. Reliability was assessed with intraclass correlation coefficient, standard error of measurement, minimal detectable change, and Bland-Altman plots.

Results

Inter-session intraclass correlation coefficient for all variables was >0.82 and standard error of measurement <1.8°, except for hip rotation. Intra-session reliability was found to be high (≥0.78) and slightly better than that for inter-session. Minimal detectable change for all variables was <4.7°, except for hip rotation.

Conclusions

The high inter- and intra-session reliabilities indicate small intrinsic variation of gait. Thus, three-dimensional gait analysis seems to be a reliable tool to evaluate kinematic gait in adults with spinal cord injury, but caution is warranted especially for hip rotation evaluation.

Predicting postoperative gait in cerebral palsy

In this work, postoperative lower limb kinematics are predicted with respect to preoperative kinematics, physical examination and surgery data. Data of 115 children with cerebral palsy that have undergone single-event multilevel surgery were considered. Preoperative data dimension was reduced utilizing principal component analysis. Then, multiple linear regressions with 80% confidence intervals were performed between postoperative kinematics and bilateral preoperative kinematics, 36 physical examination variables and combinations of 9 different surgical procedures. The mean prediction errors on test vary from 4° (pelvic obliquity and hip adduction) to 10° (hip rotation and foot progression), depending on the kinematic angle. The unilateral mean sizes of the confidence intervals vary from 5° to 15°. Frontal plane angles are predicted with the lowest errors, however the same performance is achieved when considering the postoperative average signals. Sagittal plane angles are better predicted than transverse plane angles, with statistical differences with respect to the average postoperative kinematics for both plane's angles except for ankle dorsiflexion. The mean prediction errors are smaller than the variability of gait parameters in cerebral palsy. The performance of the system is independent of the preoperative state severity of the patient. Even if the system is not yet accurate enough to define a surgery plan, it shows an unbiased estimation of the most likely outcome, which can be useful for both the clinician and the patient. More patients' data are necessary for improving the precision of the model in order to predict the kinematic outcome of a large number of possible surgeries and gait patterns.

Gait Deviation Index Correlates With Daily Step Activity in Children With Cerebral Palsy

OBJECTIVES

To examine the association between the Gait Deviation Index (GDI), a multivariate measure of overall gait impairment, and measures of both community walking performance and walking capacity within the clinic setting in ambulatory children with cerebral palsy.

DESIGN

Cross-sectional study.

SETTING

Gait analysis, 6-minute walk test (6MWT), and self-selected walking speed (WS) were conducted in laboratory and clinic settings. Activity monitoring was done in participants' community environment.

PARTICIPANTS

Children with cerebral palsy (N=55; age range, 6-18y) with Gross Motor Function Classification System levels I to III.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The GDI was derived from gait analysis data as a measure of overall gait impairment; an activity monitor was used to capture community walking performance, and the 6MWT and WS were the clinic-based measures of walking capacity.

RESULTS

Fifty-five children had a median GDI of 78.86 (range, 53.07-105.34). A moderate association was found between the GDI and daily step count (Spearman ρ=.58; 95% confidence interval [CI], .37-.74; P<.0001). Weaker associations were found between the GDI and 6MWT (Spearman ρ=.4718; 95% CI, .2283-.6597; P<.0003) and between the GDI and WS (Spearman ρ=.3949; 95% CI, .1368-.6028; P<.0028).

CONCLUSIONS

The GDI has a moderate association with daily step count, which suggests that interventions that positively change gait kinematics may also affect community walking performance. Although the GDI's deviation from the normal value provides valuable information, other measures are required to provide a complete picture of a child's walking capacity and performance.

Effects of a knee-ankle-foot orthosis on gait biomechanical characteristics of paretic and non-paretic limbs in hemiplegic patients with genu recurvatum

BACKGROUND

A knee-ankle-foot orthosis may be prescribed for the prevention of genu recurvatum during the stance phase of gait. It allows also to limit abnormal plantarflexion during swing phase. The aim is to improve gait in hemiplegic patients and to prevent articular degeneration of the knee. However, the effects of knee-ankle-foot orthosis on both the paretic and non-paretic limbs during gait have not been evaluated. The aim of this study was to quantify biomechanical adaptations induced by wearing a knee-ankle-foot orthosis, on the paretic and non-paretic limbs of hemiplegic patients during gait.

METHODS

Eleven hemiplegic patients with genu recurvatum performed two gait analyses (without and with the knee-ankle-foot orthosis). Spatio-temporal, kinematic and kinetic gait parameters of both lower limbs were quantified using an instrumented gait analysis system during the stance and swing phases of the gait cycle.

FINDINGS

The knee-ankle-foot orthosis improved spatio-temporal gait parameters. During stance phase on the paretic side, knee hyperextension was reduced and ankle plantarflexion and hip flexion were increased. During swing phase, ankle dorsiflexion increased in the paretic limb and knee extension increased in the non-paretic limb. The paretic limb knee flexion moment also decreased.

INTERPRETATION

Wearing a knee-ankle-foot orthosis improved gait parameters in hemiplegic patients with genu recurvatum. It increased gait velocity, by improving cadence, stride length and non-paretic step length. These spatiotemporal adaptations seem mainly due to the decrease in knee hyperextension during stance phase and to the increase in paretic limb ankle dorsiflexion during both phases of the gait cycle.

Test-retest reliability and minimal detectable change of the SmartWheel clinical protocol

OBJECTIVES

(1) To quantify the intra- and intersession reliability and minimal detectable change (MDC) of the SmartWheel clinical protocol (SCP) and (2) to compare the reliability of the SCP between experienced and naïve wheelchair users.

DESIGN

Test-retest study.

SETTING

Biomechanics laboratory.

PARTICIPANTS

Manual wheelchair users (WCUs) (n=10) with 1 to 32 years of wheeling experience and able-bodied (AB) naïve users (n=15).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Wheelchair propulsion parameters including average peak force, push frequency, push length, and velocity were measured according to the SCP but with 5 trials per session, for 2 sessions. WCUs and AB users were analyzed separately. Intraclass correlation coefficients ([ICC](2,1) and ICC(2,5)) were calculated to assess intrasession reliability. ICC(2,1) and MDC (with 95% confidence) were calculated for each SCP parameter using a single trial from each session and with the mean of 5 repeated measures to evaluate intersession reliability.

RESULTS

Intra- and intersession reliability for WCU parameters ranged from high to very high correlation (ICC range, .70-.99). For AB parameters, intrasession ICC(2,1) ranged from moderate to very high (ICC range, .50-.92), while intersession ICC(2,1) indicated low to very high correlation (ICC range, .25-.90). Estimates of standard error of measurement and MDC were provided for each parameter. For both WCUs and AB users, using the means from 5 trials increased intra- and intersession ICC and decreased MDC values. All MDC values were lower for WCUs compared with AB users.

CONCLUSIONS

The SCP is a reliable method for assessing propulsion parameters in WCUs, even if just 1 trial is taken per session. AB users showed lower intra- and intersession reliability compared with WCUs. Therefore, for AB users or individuals with minimal wheeling experience, averaging multiple trials is recommended for the SCP.

Reliability and Minimal Detectible Change values for gait kinematics and kinetics in healthy adults

Computerized assessment of gait is commonly used in both research and clinical settings to quantify gait mechanics and detect change in performance. Minimal Detectable Change values have only recently been reported, are only available for patient populations, and in many cases exceed 10°. Twenty nine healthy individuals underwent two biomechanical gait assessments separated by 5.6 (SD 2.2) days, with two raters for each session. All subjects walked at a self selected pace and three controlled velocities. ICC, SEM and MDC for kinematic and kinetic measures were calculated for interrater-intrasession, intrarater-intersession and interrater-intersession. ICC values were in the good to excellent range (r>0.75) for all kinematic and kinetic variables and all comparisons. MDC values were lower than previously published data for all similar comparisons. The results of the current study suggest that reliability is good to excellent across a range of controlled walking velocities and the introduction of a second rater does not appreciably impact ICC or MDC values. In young healthy adults changes in gait kinematics of greater than approximately 5° can be identified when comparing between sessions.

Tibialis anterior architecture, strength, and gait in individuals with cerebral palsy

INTRODUCTION

The relationship of tibialis anterior (TA) muscle architecture, including muscle thickness (MT), cross-sectional area (CSA), pennation angle (PA), and fascicle length (FL), to strength and ankle function was examined in ambulatory individuals with CP and unilateral foot drop.

METHODS

Twenty individuals with CP participated in muscle ultrasound imaging, unilateral strength testing, and three-dimensional gait analysis.

RESULTS

Muscle size (MT and CSA) was positively related to strength, fast gait velocity, and ankle kinematics during walking. Higher PA was related to a more dorsiflexed ankle position at initial contact and inversely with fast gait velocity. FL was related to strength, fast velocity, and step length at a self-selected speed.

CONCLUSIONS

Muscle architecture partially explains the degree of impairment in strength and ankle function in CP. Treatments to increase TA size and strength may produce some gait improvement, but other factors that may contribute to ankle performance deficits must be considered.

Transverse plane rotation of the foot and transverse hip and pelvic kinematics in diplegic cerebral palsy

External rotation of the foot associated with mid-foot break is a commonly observed gait abnormality in diplegic CP patients. Previous studies have shown a correlation between equinus and internal hip rotation in hemiplegic patients. This study aimed to determine if there was a correlation between the amount of transverse plane rotation in diplegic CP patients using kinematic data from standardised gait analysis. Lower limb data of 134 ambulant children with diplegic CP was analysed retrospectively determining the maximum change in foot, hip and pelvis rotation during loading response. Highly significant negative correlations (P=<0.001) were found between foot and hip movements and foot and pelvic movements. Equinus at initial contact diminished the foot:hip correlation while it enhanced the foot:pelvic correlation. There was less external rotation of the foot in equinus patients (P=0.012) and more external rotation of the pelvis in the equinus group (P=<0.001). This data reveal a correlation between transverse plane rotation at foot level to that at the hip and pelvis. The likely biomechanical explanation is relatively excessive transverse external rotation of the foot due to abnormalities such as mid-foot break. When under load, where the foot is fixed to the floor, internal rotation of the entire leg occurs. This is due to lever arm disease as a result of the relatively shortened foot and inefficiency of the plantar-flexion knee-extension couple. Equinus modulates the effect. When treating such patients, lever arm deformities at all levels must be considered to result in the best outcome and prevent recurrences.

Ankle range of motion is key to gait efficiency in adolescents with cerebral palsy

BACKGROUND

Gait in young people with cerebral palsy is inefficient and there is a lack of relevant indicators for monitoring the problem. In particular, the impact of gait kinematics on gait efficiency is not well documented. The aim of this study is to examine the relationship between gait efficiency, gait kinematics, lower limb muscle strength, and muscular spasticity in adolescents with cerebral palsy.

METHODS

Ten ambulatory adolescents with spastic cerebral palsy were recruited. The energy expenditure index during gait, gait kinematics, flexion and extension knee isometric muscle strength, and quadriceps spasticity were assessed.

FINDINGS

Energy expenditure index (1.5 (0.7) beats/m) was strongly correlated with the ankle and knee flexion/extension ranges of motion (r= -0.82, P<0.01 and r= -0.70, P<0.02, respectively) and also with maximal plantar flexion (r=0.74, P<0.05) during gait. Knee flexion strength was the only strength measurement correlated with energy expenditure index (r= -0.85; P<0.01).

INTERPRETATION

This study suggests that ankle and knee flexion/extension ranges of motion during gait are key kinematics factors in gait efficiency in adolescents with cerebral palsy.