Towards a diagnostic tool for neurological gait disorders in childhood combining 3D gait kinematics and deep learning.

Gait abnormalities are frequent in children and can be caused by different pathologies, such as cerebral palsy, neuromuscular disease, toe walker syndrome, etc. Analysis of the "gait pattern" (i.e., the way the person walks) using 3D analysis provides highly relevant clinical information. This information is used to guide therapeutic choices; however, it is underused in diagnostic processes, probably because of the lack of standardization of data collection methods. Therefore, 3D gait analysis is currently used as an assessment rather than a diagnostic tool. In this work, we aimed to determine if deep learning could be combined with 3D gait analysis data to diagnose gait disorders in children. We tested the diagnostic accuracy of deep learning methods combined with 3D gait analysis data from 371 children (148 with unilateral cerebral palsy, 60 with neuromuscular disease, 19 toe walkers, 60 with bilateral cerebral palsy, 25 stroke, and 59 typically developing children), with a total of 6400 gait cycles. We evaluated the accuracy, sensitivity, specificity, F1 score, Area Under the Curve (AUC) score, and confusion matrix of the predictions by ResNet, LSTM, and InceptionTime deep learning architectures for time series data. The deep learning-based models had good to excellent diagnostic accuracy (ranging from 0.77 to 0.99) for discrimination between healthy and pathological gait, discrimination between different etiologies of pathological gait (binary and multi-classification); and determining stroke onset time. LSTM performed best overall. This study revealed that the gait pattern contains specific, pathology-related information. These results open the way for an extension of 3D gait analysis from evaluation to diagnosis. Furthermore, the method we propose is a data-driven diagnostic model that can be trained and used without human intervention or expert knowledge. Furthermore, the method could be used to distinguish gait-related pathologies and their onset times beyond those studied in this research.

Lack of Proprioceptive Strategy Modulation Leads to At-Risk Biomechanics for Anterior Cruciate Ligament in Healthy Athletes.

INTRODUCTION: Anterior cruciate ligament (ACL) injuries are frequent in handball, and altered sensory integration may contribute to increased injury risk. Recent evidence showed that proprioceptive postural control strategies differ among athletes. The aim of this study was to evaluate the relationship between proprioceptive strategy and biomechanics during side-cutting maneuvers. METHODS: A total of 47 handball players performed anticipated and unanticipated cutting tasks. Their postural proprioceptive strategy was then characterized according to the perturbation of the center of pressure displacement generated by the muscle vibration on a firm and foam surface. Individuals able to reweight proprioception from ankle to lumbar signals according to the stability of the support were defined as flexible. Conversely, athletes maintaining an ankle-steered strategy on foam surface were characterized as rigid. Statistical parametric mapping analysis was used to compare pelvic and lower limb side-cutting kinematics, kinetics, and EMG activity from seven muscles 200 ms before and after initial contact (IC) using a two-way ANOVA (group-condition). RESULTS: Twenty athletes (11 females and 9 males, 18.5 yr) were characterized as flexible and 20 athletes (12 females and 8 males, 18.9 yr) as rigid. No interaction between condition and proprioceptive profile was observed. More ipsilateral pelvic tilt before IC and lower vastus lateralis (VL) activity immediately after IC was observed during CUT ant . When comparing proprioceptive strategy, rigid individuals exhibited less preactivity of the semitendinosus ( P < 0.001) and higher VL activity ( P = 0.032). Conversely, rigid showed higher gluteus medius preactivity ( P < 0.05) and higher VL activity 100 ms after IC ( P < 0.001). Ankle was also more internally rotated before and during the stance phase ( P < 0.05) among rigid athletes. CONCLUSIONS: Rigid handball players exhibited at-risk determinants for anterior cruciate ligament injuries during side-cutting maneuvers.

Quantitative gait analysis and prediction using artificial intelligence for patients with gait disorders.

Quantitative Gait Analysis (QGA) is considered as an objective measure of gait performance. In this study, we aim at designing an artificial intelligence that can efficiently predict the progression of gait quality using kinematic data obtained from QGA. For this purpose, a gait database collected from 734 patients with gait disorders is used. As the patient walks, kinematic data is collected during the gait session. This data is processed to generate the Gait Profile Score (GPS) for each gait cycle. Tracking potential GPS variations enables detecting changes in gait quality. In this regard, our work is driven by predicting such future variations. Two approaches were considered: signal-based and image-based. The signal-based one uses raw gait cycles, while the image-based one employs a two-dimensional Fast Fourier Transform (2D FFT) representation of gait cycles. Several architectures were developed, and the obtained Area Under the Curve (AUC) was above 0.72 for both approaches. To the best of our knowledge, our study is the first to apply neural networks for gait prediction tasks.

Comparison of Various Smoothness Metrics for Upper Limb Movements in Middle-Aged Healthy Subjects.

BACKGOUND: Metrics for movement smoothness include the number of zero-crossings on the acceleration profile (N0C), the log dimensionless jerk (LDLJ), the normalized averaged rectified jerk (NARJ) and the spectral arc length (SPARC). Sensitivity to the handedness and movement type of these four metrics was compared and correlations with other kinematic parameters were explored in healthy subjects. METHODS: Thirty-two healthy participants underwent 3D upper limb motion analysis during two sets of pointing movements on each side. They performed forward- and backward-pointing movements at a self-selected speed to a target located ahead at shoulder height and at 90% arm length, with and without a three-second pause between forward and backward movements. Kinematics were collected, and smoothness metrics were computed. RESULTS: LDLJ, NARJ and N0C found backward movements to be smoother, while SPARC found the opposite. Inter- and intra-subject coefficients of variation were lowest for SPARC. LDLJ, NARJ and N0C were correlated with each other and with movement time, unlike SPARC. CONCLUSION: There are major differences between smoothness metrics measured in the temporal domain (N0C, LDLJ, NARJ), which depend on movement time, and those measured in the frequency domain, the SPARC, which gave results opposite to the other metrics when comparing backward and forward movements.

Technical Feasibility of Supervision of Stretching Exercises by a Humanoid Robot Coach for Chronic Low Back Pain: The R-COOL Randomized Trial.

Adherence to exercise programs for chronic low back pain (CLBP) is a major issue. The R-COOL feasibility study evaluated humanoid robot supervision of exercise for CLBP. Aims are as follows: (1) compare stretching sessions between the robot and a physiotherapist (control), (2) compare clinical outcomes between groups, and (3) evaluate participant perceptions of usability and satisfaction and therapist acceptability of the robot system. Prospective, randomized, controlled, single-blind, 2-centre study comparing a 3-week (3 hours/day, 5 days/week) physical activity program. Stretching sessions (30 minutes/day) were supervised by a physiotherapist (control) or the robot. Primary outcome: daily physical activity time (adherence). Secondary outcomes: lumbar pain, disability and fear and beliefs, participant perception of usability (system usability scale) and satisfaction, and physiotherapist acceptability (technology acceptance model). Clinical outcomes were compared between groups with a Student t-test and perceptions with a Wilcoxon test. Data from 27 participants were analysed (n = 15 control and n = 12 robot group). Daily physical activity time did not differ between groups, but adherence declined (number of movements performed with the robot decreased from 82% in the first week to 72% in the second and 47% in the third). None of the clinical outcomes differed between groups. The median system usability scale score was lower in the robot group: 58 (IQR 11.8) points vs. 87 (IQR 9.4) in the control group at 3 weeks (p < 0.001). Median physiotherapist rating of the technology acceptance model was <3 points, suggesting a negative opinion of the robot. In conclusion, adherence to robot exercise reduced over time; however, lumbar pain, disability, or fear and beliefs did not differ between groups. The results of the participant questionnaires showed that they were willing to use such a system, although several technical issues suggested the KERAAL system could be improved to provide fully autonomous supervision of physical activity sessions.

Validity and reliability of video analysis to evaluate ankle proprioceptive reintegration during postural control.

BACKGROUND: The ability to dynamically reintegrate proprioceptive signals after they have been perturbated is impaired in certain pathologies. Evaluation of proprioceptive reintegration is useful for clinical practice but currently requires expensive laboratory tools. We developed a simple method, accessible to clinicians. RESEARCH QUESTION: Is two-dimensional (2D) video analysis of earlobe displacement a valid and reliable tool for the evaluation of ankle proprioceptive reintegration following muscle vibration? METHODS: Thirty-eight healthy individuals underwent vibration of the triceps surae while standing on a force plate (FP). Anterior (sagittal plane) earlobe displacement ('overshoot') was recorded at vibration cessation using 2D video analysis and rated by 3 blind examiners. Correlation analysis was performed between earlobe and center of pressure displacement (dCoP, recorded with the FP) to determine validity. Intra and interrater reliability were determined by calculation of the intraclass correlation coefficient (ICC), change in the mean (CiM), standard error of measurement (SEM) and the minimal detectable change (MDC). RESULTS AND SIGNIFICANCE: Strong positive correlations (r = 0.82-0.94, p < .001) were found between video and FP data. Intra- and interrater reliability were excellent (ICC from 0.99 to 1.00 and from 0.90 to 0.97 respectively). For intrarater analysis, the CiM was 0.01 cm, SEM were 0.27 cm (95% CI: 0.23-0.33) and 3.43% (95% CI: 2.92-4.20) and the MDC was 0.74 cm. For interrater reliability, the CiM ranged from - 0.81-0.55 cm, the SEM from 0.61 to 1.12 cm and the MDC from 1.69 to 3.10 cm. 2D video analysis of anterior (sagittal) earlobe displacement is therefore a valid and reliable method to assess postural recovery following muscle vibration. This simple method could be used by clinicians to evaluate the ability of the central nervous system to reintegrate proprioceptive signals from the ankle. Further studies are needed to assess its validity in individuals with proprioceptive impairment.

Proprioceptive postural control strategies differ among non-injured athletes.

Postural control during complex tasks requires adequate sensory integration and somaesthetic reweighting: suboptimal postural strategies can lead to injury. We assessed the ability of healthy athletes to reweight somaesthetic signals during postural perturbations on different surfaces. Thirty-five young (16 ± 1 years), healthy, elite handball players participated in this cross-sectional study. Proprioceptive reweighting was evaluated via vibration of the triceps surae and lumbar muscles on firm and foam surfaces. Postural variables and the electromyographic activity of the gluteus medius (GM), semitendinosus (ST) and fibularis longus (FL) were recorded during the PRE (10 s), VIBRATION (20 s) and POST (20 s) periods. Ankle proprioception was predominantly used on the firm compared to foam support. However, two opposing behaviours were observed: a "rigid" strategy in which reliance on ankle proprioception increased on the foam, and a "plastic" strategy that involved a proximal shift of proprioceptive reliance (p < 0.001). The plastic strategy was associated with a more effective recovery of balance after vibration cessation (p < 0.05). ST activation was higher during POST in the rigid strategy and did not return to the PRE level (p < 0.05) whereas it did in the plastic strategy. Proprioceptive strategies for postural control are highly variable and future studies should evaluate their contribution to injury.

Dissociating Sensorimotor Recovery and Compensation During Exoskeleton Training Following Stroke.

The quality of arm movements typically improves in the sub-acute phase of stroke affecting the upper extremity. Here, we used whole arm kinematic analysis during reaching movements to distinguish whether these improvements are due to true recovery or to compensation. Fifty-three participants with post-acute stroke performed ∼80 reaching movement tests during 4 weeks of training with the ArmeoSpring exoskeleton. All participants showed improvements in end-effector performance, as measured by movement smoothness. Four ArmeoSpring angles, shoulder horizontal (SH) rotation, shoulder elevation (SE), elbow rotation, and forearm rotation, were recorded and analyzed. We first characterized healthy joint coordination patterns by performing a sparse principal component analysis on these four joint velocities recorded during reaching tests performed by young control participants. We found that two dominant joint correlations [SH with elbow rotation and SE with forearm rotation] explained over 95% of variance of joint velocity data. We identified two clusters of stroke participants by comparing the evolution of these two correlations in all tests. In the "Recoverer" cluster (N = 19), both joint correlations converged toward the respective correlations for control participants. Thus, Recoverers relearned how to generate smooth end-effector movements while developing joint movement patterns similar to those of control participants. In the "Compensator" cluster (N = 34), at least one of the two joint correlations diverged from the corresponding correlation of control participants. Compensators relearned how to generate smooth end-effector movements by discovering various new compensatory movement patterns dissimilar to those of control participants. New compensatory patterns included atypical decoupling of the SE and forearm joints, and atypical coupling of the SH rotation and elbow joints. There was no difference in clinical impairment level between the two groups either at the onset or at the end of training as assessed with the Upper Extremity Fugl-Meyer scale. However, at the start of training, the Recoverers showed significantly faster improvements in end-effector movement smoothness than the Compensators. Our analysis can be used to inform neurorehabilitation clinicians on how to provide movement feedback during practice and suggest avenues for refining exoskeleton robot therapy to reduce compensatory patterns.

Additional, Mechanized Upper Limb Self-Rehabilitation in Patients With Subacute Stroke: The REM-AVC Randomized Trial.

Background and Purpose: Additional therapy may improve poststroke outcomes. Self-rehabilitation is a useful means to increase rehabilitation time. Mechanized systems are usual means to extend time for motor training. The primary aim was to compare the effects of self-rehabilitation using a mechanized device with control self-exercises on upper extremity impairment in patients with stroke. Methods: Phase III, parallel, concealed allocation, randomized controlled, multicenter trial, with 12-month follow-up. Patients aged 18 to 80 years, 3 weeks to 3 months poststroke with a Fugl-Meyer Assessment score of 10 to 40 points, were randomized to the Exo or control groups. All undertook two 30-minute self-rehabilitation sessions/day, 5 days/wk for 4 weeks in addition to usual rehabilitation. The Exo group performed games-based exercises using a gravity-supported mechanical exoskeleton (Armeo Spring). The control group performed stretching plus basic active exercises. Primary outcome was change in upper extremity Fugl-Meyer Assessment score at 4 weeks. Results: Two hundred fifteen participants were randomly allocated to the Exo group (107) or the control group (108). Mean age (SD), 58.3 (13.6) years; mean time poststroke, 54.8 (22.1) days; and mean baseline Fugl-Meyer Assessment score, 26.1 (9.5). There was no between-group difference in mean change in Fugl-Meyer Assessment score following the intervention: 13.3 (9.0) in the Exo group and 11.8 (8.8) in the control group (P=0.22). There were no significant between-group differences in changes for any of the other outcomes at any time point (except for perception of the self-rehabilitation). There was no between-group difference in cost utility at 12 months. Conclusions: In patients with moderate-to-severe impairment in the subacute phase of stroke, the purchase and use of complex devices to provide additional upper limb training may not be necessary: simply educating patients to regularly move and stretch their limbs appears sufficient. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01383512.

No pain, no gain? Children with cerebral palsy and their experience with physiotherapy.

OBJECTIVES: Recent studies have shown that physiotherapy can induce pain in children and young adults with cerebral palsy (CP). There is a lack of knowledge of children's pain experiences during therapy sessions and the specific causes of pain. The main objective of this study was to better understand the experience of children and young adults with CP during physiotherapy sessions and to analyse the coping strategies used by children and therapists. METHODS: Qualitative study with focus groups. Eighteen children/young adults with CP who experienced pain during physiotherapy were interviewed, using focus groups as a source of data collection in a phenomenological perspective. Data collection and analysis were consecutive to ensure that the data saturation point was reached. The transcripts were coded manually using thematic analysis. First, interesting features of the verbatim were coded, then codes were collated into potential themes and then the themes were checked to ensure they worked in relation to the coded extracts. Multiple coding was performed by 3 different researchers, and results were merged at each step. RESULTS: This study confirmed that among the 18 children interviewed (mean [SD] age 13.17 [4.02] years, 10 girls), physiotherapy, particularly stretching, induced pain. Participants reported that the experience of pain led to a dislike of physiotherapy, although some believed that the pain was necessary to show that the treatment was effective. The use of distraction techniques and the relationship with the physiotherapist were key elements associated with the perception and experience of pain. CONCLUSIONS: This study confirmed that patients with CP experience pain during physiotherapy. Stretching seems to be the main source of pain. Beliefs and practices regarding the concept of pain show that physiotherapists need training in this field.

A new deep learning-based method for the detection of gait events in children with gait disorders: Proof-of-concept and concurrent validity.

The stance and swing phases of the gait cycle are defined by foot strike (FS) and foot off (FO). Accurate determination of these events is thus an essential component of 3D motion recordings processing. Several methods have been developed for the automatic detection of these events (based on the heuristics of 3D marker position, velocity and acceleration), however the results may be inaccurate due to the high variability that is intrinsic to pathological gait. For this reason, gait events are still commonly determined manually, which is a tedious process. Here we propose a new application (DeepEvent) of a long short term memory recurrent neural network for the automatic detection of gait events. The 3D position and velocity of the markers on the heel, toe and lateral malleolus were used by the network to determine FS and FO. The method was developed from 10526 FS and 9375 FO from 226 children. DeepEvent predicted FS within 5.5 ms and FO within 10.7 ms of the gold standard (automatic determination using force platform data) and was more accurate than common heuristic marker trajectory-based methods proposed in the literature and another deep learning method. A sensitivity analysis showed that DeepEvent mainly used the toe and heel markers (z-axis (longitudinal) position and velocity) at the beginning and end of gait cycle to predict FS, and the toe marker (x-axis (anterior/posterior) velocity and z-axis position and velocity) at around 60% of the gait cycle to predict FO.

Effects of gleno-humeral joint centre mislocation on gleno-humeral kinematics and kinetics.

The gleno-humeral (GH) rotation centre is typically estimated using predictive or functional methods, however these methods may lead to location errors. This study aimed at determining a location error threshold above which statistically significant changes in the values of kinematic and kinetic GH parameters occur. The secondary aims were to quantify the effects of the direction of mislocation (X, Y or Z axis) of the GH rotation centre on GH kinematic and kinetic parameters. Shoulder flexion and abduction movements of 11 healthy volunteers were recorded using a standard motion capture system (Vicon, Oxford Metrics Ltd, Oxford, UK), then GH kinematic and kinetic parameters were computed. The true position of the GH rotation centre was determined using a low dose x-ray scanner (EOS™ imaging, France) and this position was transferred to the motion data. GH angles and moments were re-computed for each position of the GH rotation centre after errors of up to ± 20 mm were added in increments of ± 5 mm to each axis. The three-dimensional error range was 5 mm to 34.65 mm. GH joint angle and moment values were significantly altered from 10 mm of three-dimensional error, and from 5 mm of error on individual axes. However, errors on the longitudinal and antero-posterior axes only caused very small alterations of GH joint angle and moment values respectively. Future research should develop methods of GH rotation centre estimation that produce three-dimensional location errors of less than 10 mm to reduce error propagation on GH kinematics and kinetics.

Correction to: Dissociating motor learning from recovery in exoskeleton training post-stroke.

The original article [1] contained an error whereby the co-author, Karima Bakhti's name was displayed incorrectly.

Dissociating motor learning from recovery in exoskeleton training post-stroke.

BACKGROUND: A large number of robotic or gravity-supporting devices have been developed for rehabilitation of upper extremity post-stroke. Because these devices continuously monitor performance data during training, they could potentially help to develop predictive models of the effects of motor training on recovery. However, during training with such devices, patients must become adept at using the new "tool" of the exoskeleton, including learning the new forces and visuomotor transformations associated with the device. We thus hypothesized that the changes in performance during extensive training with a passive, gravity-supporting, exoskeleton device (the Armeo Spring) will follow an initial fast phase, due to learning to use the device, and a slower phase that corresponds to reduction in overall arm impairment. Of interest was whether these fast and slow processes were related. METHODS: To test the two-process hypothesis, we used mixed-effect exponential models to identify putative fast and slow changes in smoothness of arm movements during 80 arm reaching tests performed during 20 days of exoskeleton training in 53 individuals with post-acute stroke. RESULTS: In line with our hypothesis, we found that double exponential models better fit the changes in smoothness of arm movements than single exponential models. In contrast, single exponential models better fit the data for a group of young healthy control subjects. In addition, in the stroke group, we showed that smoothness correlated with a measure of impairment (the upper extremity Fugl Meyer score - UEFM) at the end, but not at the beginning, of training. Furthermore, the improvement in movement smoothness due to the slow component, but not to the fast component, strongly correlated with the improvement in the UEFM between the beginning and end of training. There was no correlation between the change of peaks due to the fast process and the changes due to the slow process. Finally, the improvement in smoothness due to the slow, but not the fast, component correlated with the number of days since stroke at the onset of training - i.e. participants who started exoskeleton training sooner after stroke improved their smoothness more. CONCLUSIONS: Our results therefore demonstrate that at least two processes are involved in in performance improvements measured during mechanized training post-stroke. The fast process is consistent with learning to use the exoskeleton, while the slow process independently reflects the reduction in upper extremity impairment.

From childhood to adulthood: health care use in individuals with cerebral palsy.

AIM: To analyse the health care usage of individuals with cerebral palsy (CP) as a function of age and ambulatory status. METHOD: In total, 970 self-administered questionnaires relating to health care usage were sent, via a clinical network of professionals and institutions, to children and adults with CP in Brittany, France. Frequency of use of different aspects of health care were analysed as a function of age and ambulatory status. Multivariate logistic regression evaluated differences in the frequency of each health care type with age; the transition from childhood to adulthood was specifically analysed. RESULTS: The response rate was 53% (282 adults, 230 children). Use of medication (particularly psychotropic and analgesic) increased with age, while physical-types of health care (rehabilitation, physical medicine and rehabilitation follow-up, and equipment) decreased with age, independently of ambulatory status. Use of other treatments, such as botulinum toxin injections, was not influenced by age. The provision of rehabilitation was particularly affected by the period of transition. INTERPRETATION: Although health care needs change naturally in adulthood, the large decrease in usage of specific types of rehabilitation after the transition to adulthood suggested individuals had difficulty accessing this type of health care after childhood. These results provide objectives for the development of patient-centred, transitional consultations, and longitudinal studies. WHAT THIS PAPER ADDS: Use of medication, particularly psychotropic and analgesic drugs, increased with age in individuals with cerebral palsy. Use of orthoses, physical medicine and rehabilitation physician follow-up, and rehabilitation decreased with age. Transition from childhood to adulthood involved significant changes in health care usage.

Medication, rehabilitation and health care consumption in adults with cerebral palsy: a population based study.

OBJECTIVE: To evaluate medication, rehabilitation and healthcare consumption in adults with CP as a function of Gross Motor Function Classification System (GMFCS) level. DESIGN: Questionnaire-based cross-sectional study. SETTING: Brittany, a French county. SUBJECTS: Adults with cerebral palsy. INTERVENTIONS: Questionnaires relating to drugs, orthotic devices, mobility aids, rehabilitation and medical input were sent to 435 members of a unique regional French network dedicated to adults with cerebral palsy. The questionnaire was completed by the participant or a helper if necessary. RESULTS: Of the 282 responders, 7.8% had a GMFCS level of I, 14.2% II, 17.7% III, 29.1% IV and 31.2% V. Participants consumed a large amount of healthcare. Almost three-quarters took orally administered drugs, of which antispastic and antiepileptic drugs were among the most frequent. Nearly all patients had at least one type of rehabilitation, 87.2% had physiotherapy, 78% used at least one mobility aid and 69.5% used at least one orthotic device. The frequency of numerous inputs increased with GMFCS level. Specificities were found for each GMFCS level, e.g. participants with GMFCS level IV and V had a high level of medical input and a greater use of trunk-supporting devices, antireflux and laxative. Profiles could be established based on GMFCS levels. CONCLUSIONS: Adults with cerebral palsy use a large amount of drugs, mobility aids, orthotic devices, rehabilitation and medical input. Healthcare is targeted at cerebral palsy-related issues. GMFCS is a determinant of healthcare consumption and thus a useful tool for clinical practice to target care appropriately.

Does muscle coactivation influence joint excursions during gait in children with and without hemiplegic cerebral palsy? Relationship between muscle coactivation and joint kinematics.

BACKGROUND: The theoretical role of muscle coactivation is to stiffen joints. The aim of this study was to assess the relationship between muscle coactivation and joint excursions during gait in children with and without hemiplegic cerebral palsy. METHODS: Twelve children with hemiplegic cerebral palsy and twelve typically developing children underwent gait analysis at three different gait speeds. Sagittal hip, knee, and ankle kinematics were divided into their main components corresponding to joint excursions. A coactivation index was calculated for each excursion from the electromyographic envelopes of the rectus femoris/semitendinosus, vastus medialis/semitendinosus, or tibialis anterior/soleus muscles. Mixed linear analyses of covariance modeled joint excursions as a function of the coactivation index and limb. FINDINGS: In typically developing children, increased coactivation was associated with reduced joint excursion for 8 of the 14 linear models (hip flexion, knee loading, knee extension in stance, knee flexion in swing, ankle plantarflexion from initial contact to foot-flat, ankle dorsiflexion in stance and in swing). Conversely, ankle plantarflexion excursion at push-off increased with increasing tibialis anterior/soleus coactivation. In the involved limbs of the children with cerebral palsy, knee loading, ankle plantarflexion at push off, and ankle dorsiflexion in swing decreased, while hip extension increased, with increasing muscle coactivation. INTERPRETATION: The relationships between muscle coactivation and joint excursion were not equally distributed in both groups, and predominant in typically developing children. The results suggest that excessive muscle coactivation is not a cause of stiff-knee gait in children with hemiplegic cerebral palsy, but appears to be related to spastic drop foot.

Impact of Injection-Guiding Techniques on the Effectiveness of Botulinum Toxin for the Treatment of Focal Spasticity and Dystonia: A Systematic Review.

OBJECTIVE: To conduct a systematic review of the impact of different injection-guiding techniques on the effectiveness of botulinum toxin type A (BoNT-A) for the treatment of focal spasticity and dystonia. DATA SOURCES: MEDLINE via PubMed, Academic Search Premier, PASCAL, The Cochrane Library, Scopus, SpringerLink, Web of Science, EM Premium, and PsycINFO. STUDY SELECTION: Two reviewers independently selected studies based on predetermined inclusion criteria. DATA EXTRACTION: Data relating to the aim were extracted. Methodological quality was graded independently by 2 reviewers using the Physiotherapy Evidence Database assessment scale for randomized controlled trials (RCTs) and the Downs and Black evaluation tool for non-RCTs. Level of evidence was determined using the modified Sackett scale. DATA SYNTHESIS: Ten studies were included. Seven were randomized. There was strong evidence (level 1) that instrumented guiding (ultrasonography [US], electrical stimulation [ES], electromyogram [EMG]) was more effective than manual needle placement for the treatment of spasmodic torticollis, upper limb spasticity, and spastic equinus in patients with stroke, and spastic equinus in children with cerebral palsy. Three studies provided strong evidence (level 1) of similar effectiveness of US and ES for upper and lower limb spasticity in patients with stroke, and spastic equinus in children with cerebral palsy, but there was poor evidence or no available evidence for EMG or other instrumented techniques. CONCLUSIONS: These results strongly recommend instrumented guidance of BoNT-A injection for the treatment of spasticity in adults and children (ES or US), and of focal dystonia such as spasmodic torticollis (EMG). No specific recommendations can be made regarding the choice of instrumented guiding technique, except that US appears to be more effective than ES for spastic equinus in adults with stroke.

Changes in muscle activity in typically developing children walking with unilaterally induced equinus.

BACKGROUND: Distinguishing changes in lower limb muscle activation during gait caused by abnormal motor control or adaptations to the presence of a fixed equinus remains a challenge. The objective of this study was to determine a threshold degree of equinus at which changes in muscle activity occur and to characterize adaptive patterns of muscle activity in typically developing children walking with unilateral induced equinus. METHODS: Ten typically developing children were included. A customized orthosis was fitted to the right ankle. Five conditions of dorsiflexion limitation were evaluated: 10° dorsiflexion, 0°, 10°, 20° of plantar flexion and maximum plantar flexion. Muscle activity of the rectus femoris, vastus lateralis, hamstring, tibialis anterior and soleus muscles of both limbs was recorded. FINDINGS: Significant changes in muscle activation and co-activation occurred from 10° of plantar flexion in the orthosis limb and from maximum plantar flexion in the contralateral limb. Soleus activation occurred prematurely in terminal swing and increased with the degree of equinus. Tibialis anterior activation was increased during initial and midswing and was decreased during terminal swing. From the -20° condition, hamstring activation was increased during the loading response. Vastus lateralis and rectus femoris activation was increased during stance phase. Similar changes in tibialis anterior and soleus activation occurred on the contralateral side. Changes in co-activation occurred in the soleus/tibialis anterior muscle pair in both limbs. INTERPRETATION: This study provides indications regarding changes in muscle activity during simulation of equinus gait which should be helpful for therapeutic decision making.

Validity and reliability of 3D marker based scapular motion analysis: a systematic review.

Methods based on cutaneous markers are the most popular for the recording of three dimensional scapular motion analysis. Numerous methods have been evaluated, each showing different levels of accuracy and reliability. The aim of this review was to report the metrological properties of 3D scapular kinematic measurements using cutaneous markers and to make recommendations based on metrological evidence. A database search was conducted using relevant keywords and inclusion/exclusion criteria in 5 databases. 19 articles were included and assessed using a quality score. Concurrent validity and reliability were analyzed for each method. Six different methods are reported in the literature, each based on different marker locations and post collection computations. The acromion marker cluster (AMC) method coupled with a calibration of the scapula with the arm at rest is the most studied method. Below 90-100° of humeral elevation, this method is accurate to about 5° during arm flexion and 7° during arm abduction compared to palpation (average of the 3 scapular rotation errors). Good to excellent within-session reliability and moderate to excellent between-session reliability have been reported. The AMC method can be improved using different or multiple calibrations. Other methods using different marker locations or more markers on the scapula blade have been described but are less accurate than AMC methods. Based on current metrological evidence we would recommend (1) the use of an AMC located at the junction of the scapular spine and the acromion, (2) the use of a single calibration at rest if the task does not reach 90° of humeral elevation, (3) the use of a second calibration (at 90° or 120° of humeral elevation), or multiple calibrations above 90° of humeral elevation.