[A technological platform for cerebral palsy - the ICT4Rehab project]. / Une plate-forme technologique liée à la paralysie cérébrale - le projet ICT4Rehab.

The musculoskeletal system (MSS) is essential to allow us performing every-day tasks, being able to have a professional life or developing social interactions with our entourage. MSS pathologies have a significant impact on our daily life. It is therefore not surprising to find MSS-related health problems at the top of global statistics on professional absenteeism or societal health costs. The MSS is also involved in central nervous conditions, such as cerebral palsy (CP). Such conditions show complex etiology that complicates the interpretation of the observable clinical signs and the establishment of a wide consensus on the best practices to adopt for clinical monitoring and patient follow-up. These elements justify the organization of fundamental and applied research projects aiming to develop new methods to help clinicians to cope with the complexity of some MSS disorders. The ICT4Rehab project (www.ict4rehab.org) developed an integrated platform providing tools that enable easier management and visualization of clinical information related to the MSS of CP patients. This platform is opened to every interested clinical centre.

Prevalence of cerebral palsy and factors associated with cerebral palsy subtype: A population-based study in Belgium.

AIM: To report on the prevalence, neuroimaging patterns, and function of children with cerebral palsy (CP) in Belgium for birth years 2007-2012, and identify distinctive risk indicators and differences in outcome between CP subtypes. METHODS: Antenatal and perinatal/neonatal factors, motor and speech function, associated impairments, and neuroimaging patterns were extracted from the Belgian Cerebral Palsy Register. Prevalence was estimated per 1000 (overall, ante/perinatal, spastic, dyskinetic CP) or 10,000 (post-neonatal, ataxic CP) live births. Multinomial logistic regression analyses were performed to ascertain the effects of antenatal/perinatal/neonatal factors and neuroimaging patterns on the likelihood of dyskinetic or ataxic CP relative to spastic CP, and test the likelihood of the occurrence of impaired motor and speech function and associated impairments in dyskinetic or ataxic CP relative to spastic CP. RESULTS: In total, 1127 children with CP were identified in Belgium. The birth prevalence of overall CP was 1.48 per 1000 live births. The likelihood of dyskinetic CP increases if the child was born to a mother aged ≥35 years, mechanically ventilated, and had predominant grey matter injury, while an increased likelihood of ataxic CP is associated with ≥2 previous deliveries. Children with dyskinetic and ataxic CP are more likely to function with impairments in motor, speech, and intellectual abilities. CONCLUSION: Distinctive risk indicators and differences in outcome between CP subtypes were identified. These factors can be incorporated into clinical practice to facilitate early, accurate, and reliable classification of CP subtype, and may lead to individually tailored neonatal care and other (early) intervention options.

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.

The Contribution of Decreased Muscle Size to Muscle Weakness in Children With Spastic Cerebral Palsy.

Muscle weakness is a common clinical symptom in children with spastic cerebral palsy (SCP). It is caused by impaired neural ability and altered intrinsic capacity of the muscles. To define the contribution of decreased muscle size to muscle weakness, two cohorts were recruited in this cross-sectional investigation: 53 children with SCP [median age, 8.2 (IQR, 4.1) years, 19/34 uni/bilateral] and 31 children with a typical development (TD) [median age, 9.7 (IQR, 2.9) years]. Muscle volume (MV) and muscle belly length for m. rectus femoris, semitendinosus, gastrocnemius medialis, and tibialis anterior were defined from three-dimensional freehand ultrasound acquisitions. A fixed dynamometer was used to assess maximal voluntary isometric contractions for knee extension, knee flexion, plantar flexion, and dorsiflexion from which maximal joint torque (MJT) was calculated. Selective motor control (SMC) was assessed on a 5-point scale for the children with SCP. First, the anthropometrics, strength, and muscle size parameters were compared between the cohorts. Significant differences for all muscle size and strength parameters were found (p ≤ 0.003), except for joint torque per MV for the plantar flexors. Secondly, the associations of anthropometrics, muscle size, gross motor function classification system (GMFCS) level, and SMC with MJT were investigated using univariate and stepwise multiple linear regressions. The associations of MJT with growth-related parameters like age, weight, and height appeared strongest in the TD cohort, whereas for the SCP cohort, these associations were accompanied by associations with SMC and GMFCS. The stepwise regression models resulted in ranges of explained variance in MJT from 29.3 to 66.3% in the TD cohort and from 16.8 to 60.1% in the SCP cohort. Finally, the MJT deficit observed in the SCP cohort was further investigated using the TD regression equations to estimate norm MJT based on height and potential MJT based on MV. From the total MJT deficit, 22.6-57.3% could be explained by deficits in MV. This investigation confirmed the disproportional decrease in muscle size and muscle strength around the knee and ankle joint in children with SCP, but also highlighted the large variability in the contribution of muscle size to muscle weakness.

Validity and Reproducibility of Inertial Physilog Sensors for Spatiotemporal Gait Analysis in Patients With Stroke.

Spatiotemporal gait analysis can provide quantitative information to assess treatment outcomes in stroke survivors. Therefore, clinicians need a portable, easy-to-use and low-cost tool that accurately and reliably measures spatiotemporal gait parameters. This paper examined the concurrent validity and reproducibility of the Gait Up gait analysis package for the spatiotemporal gait analysis in subacute stroke survivors. Twenty-five subacute stroke survivors participated in two walking tests. Spatiotemporal gait parameters were synchronously measured by 2 foot-worn inertial sensors (Physilog) and three-dimensional motion capturing (Vicon). Intraclass correlation coefficients, standard errors of measurement, smallest detectable changes, limits of agreement, and the Bland-Altman plots were calculated for the paretic and non-paretic side. After removing a consistent outlier (i.e., data of the paretic side of subject 36 who dragged his foot), agreement between both devices was good to excellent for paretic and non-paretic gait cycle time, cadence, stride length, stride velocity, and double support and moderate for paretic and non-paretic stance and swing. The Bland-Altman plots supported these findings. Test-retest reliability was good to excellent for most parameters, except paretic stance and swing. In conclusion, the Gait Up gait analysis package is a valid and reliable tool to measure paretic and non-paretic gait cycle time, cadence, stride length, and stride velocity in subacute patients with stroke, who do not exhibit severe dragging of the paretic foot. However, the algorithm should be improved for the analysis of paretic stance and swing phase.

The influence of the use of ankle-foot orthoses on thorax, spine, and pelvis kinematics during walking in children with cerebral palsy.

BACKGROUND: To improve gait function in children with cerebral palsy, ankle-foot orthoses are often prescribed. However, until now, little attention has been devoted to the effect of ankle-foot orthoses on the postural control during walking in children with cerebral palsy. OBJECTIVES: The aim was to compare the differences in thorax, spine, and pelvis movements in children with cerebral palsy during walking barefoot and walking with ankle-foot orthoses. STUDY DESIGN: Clinical study with an intra subject design. METHODS: A total of 15 children (12 boys and 3 girls; mean age, 8 ± 2 years) with bilateral spastic cerebral palsy (12 with Gross Motor Function Classification System I and 3 with Gross Motor Function Classification System II) performed a full-body three-dimensional gait analysis. Differences in the range of motion of the thorax, spine, and pelvis during walking barefoot and walking with bilateral ankle-foot orthoses were analyzed (SPSS v20, paired-samples t-test). RESULTS: Children with cerebral palsy showed a significantly larger range of motion of the thorax (flexion/extension, lateral bending, and rotation) and the spine (lateral bending) during walking with ankle-foot orthoses compared to walking barefoot. No significant differences were found in the range of motion of the pelvis between these two conditions. CONCLUSION: It can be concluded that wearing ankle-foot orthoses influences the postural control during walking in children with bilateral spastic cerebral palsy. Due to the increased range of motions, the movement pattern of the trunk diverges from the typically developing children. Clinical relevance Wearing ankle-foot orthoses not only gives more stability at the pelvis and ankle joint but also influences trunk motion. In order of the level of core stability of the child, compensations can be either seen in the lower back or the upper trunk. Clinicians should be aware of these compensations and should evaluate postural control in a more detailed evaluation.

Bilateral, Misalignment-Compensating, Full-DOF Hip Exoskeleton: Design and Kinematic Validation.

A shared design goal for most robotic lower limb exoskeletons is to reduce the metabolic cost of locomotion for the user. Despite this, only a limited amount of devices was able to actually reduce user metabolic consumption. Preservation of the natural motion kinematics was defined as an important requirement for a device to be metabolically beneficial. This requires the inclusion of all human degrees of freedom (DOF) in a design, as well as perfect alignment of the rotation axes. As perfect alignment is impossible, compensation for misalignment effects should be provided. A misalignment compensation mechanism for a 3-DOF system is presented in this paper. It is validated by the implementation in a bilateral hip exoskeleton, resulting in a compact and lightweight device that can be donned fast and autonomously, with a minimum of required adaptations. Extensive testing of the prototype has shown that hip range of motion of the user is maintained while wearing the device and this for all three hip DOFs. This allowed the users to maintain their natural motion patterns when they are walking with the novel hip exoskeleton.

Thorax and pelvis kinematics during walking, a comparison between children with and without cerebral palsy: A systematic review.

BACKGROUND: Dysfunctional postural control and pathological thorax and pelvis motions are often observed in children with cerebral palsy (CP) and can be considered as an indicator of diminished dynamic stability. OBJECTIVE: The aim of this study was to identify the differences between children with CP and typically developing children in three-dimensional thorax and pelvis kinematics during walking. METHODS: Three electronic databases were searched by using different combinations of keywords. The methodological quality of the studies was assessed by two researchers with the Strobe quality checklist. RESULTS: Ten studies (methodological quality: 32% to 74%) with in total 259 children with CP and 220 typically developing children (mean age: 7.6 to 13.6 year) were included. Compared to typically developing children, children with bilateral CP showed an increased range of motion of the thorax, pelvis and spine during walking. The results of the children with unilateral CP were less clear. CONCLUSION: In general, children with bilateral CP showed larger movement amplitudes of the trunk compared to children without CP. This increase in movement amplitudes could influence the dynamic stability of the body during walking. In children with unilateral CP, the results were less obvious and further research on this topic is required.

Validity and test-retest reliability of the Stride Analyzer in people with knee osteoarthritis.

INTRODUCTION: Subjects with knee osteoarthritis walk differently compared to healthy subjects. Managing these gait alterations has been proven effective for reducing pain and increasing function. The Stride Analyzer is a low cost gait analysis tool but its clinimetric properties have not been investigated yet in subjects with symptomatic knee osteoarthritis. The aim of this study was to investigate the reliability and validity of the SA compared with the Gold standard (Vicon) in persons with knee OA. METHODS: Fifteen subjects with symptomatic knee osteoarthritis were instructed to walk at a self-selected speed in a gait laboratory. Temporospatial (TS) gait parameters were recorded simultaneously by the Stride Analyzer and by a 16-camera-infrared optoelectronic motion capturing system (Vicon). Validity and test-retest reliability of the Stride Analyzer were examined by Bland-Altman plots, intra-class correlation coefficients (ICC) and the standard error of measurement (SEM). RESULTS: Test-retest analyses showed good agreement for all TS parameters with ICC values ranging from 0.805 (single limb support right) to 0.949 (velocity) and SEM% values ranging from 0.78% (stance phase right (% of gait cycle)) to 4.52% (double limb support right (% of gait cycle)). Good agreement between Stride Analyzer and Vicon was found for the following TS parameters: velocity (z=1.01), cadence (z=-0.85), stride length (z=1.63) and gait cycle (z=0.86). All other gait parameters showed lower ICC values (<0.689). INTERPRETATION: Our results suggest that the Stride Analyzer can be used in the clinical field to perform gait analysis in subjects with symptomatic knee osteoarthritis.

Effect of supporting 3D-garment on gait postural stability in children with bilateral spastic cerebral palsy.

BACKGROUND: Children with cerebral palsy show dysfunctional postural control which interferes with their functional performance and daily-life activities. OBJECTIVE: The aim of the study was to identify the effect of a 3D supporting garment on trunk postural control and interjoint coordination during gait in children with bilateral cerebral palsy. METHODS: We analyzed tridimensional trunk motion, trunk-thigh and interjoint coordination in 15 4-10 year-old children with bilateral spastic cerebral palsy (GMFCS I or II) and 16 4-10 year-old typically developing children while walking with or without a supporting garment. RESULTS: We found significantly changes in the coordination between trunk and lower limbs in children with cerebral palsy. Step velocity and cadence both increased significantly in children with cerebral palsy but in controls, the cadence remained unaltered. Interjoint coordination between hip-knee and knee-ankle was altered during the stance phase only in the subgroup of children with cerebral palsy without any limitations in ankle joint passive range of motion. CONCLUSION: 3D supporting garments improve trunk-thigh and lower limb interjoint coordination in walking in children with bilateral cerebral palsy.

Influence of botulinum toxin therapy on postural control and lower limb intersegmental coordination in children with spastic cerebral palsy.

Botulinum toxin injections may significantly improve lower limb kinematics in gait of children with spastic forms of cerebral palsy. Here we aimed to analyze the effect of lower limb botulinum toxin injections on trunk postural control and lower limb intralimb (intersegmental) coordination in children with spastic diplegia or spastic hemiplegia (GMFCS I or II). We recorded tridimensional trunk kinematics and thigh, shank and foot elevation angles in fourteen 3-12 year-old children with spastic diplegia and 14 with spastic hemiplegia while walking either barefoot or with ankle-foot orthoses (AFO) before and after botulinum toxin infiltration according to a management protocol. We found significantly greater trunk excursions in the transverse plane (barefoot condition) and in the frontal plane (AFO condition). Intralimb coordination showed significant differences only in the barefoot condition, suggesting that reducing the degrees of freedom may limit the emergence of selective coordination. Minimal relative phase analysis showed differences between the groups (diplegia and hemiplegia) but there were no significant alterations unless the children wore AFO. We conclude that botulinum toxin injection in lower limb spastic muscles leads to changes in motor planning, including through interference with trunk stability, but a combination of therapies (orthoses and physical therapy) is needed in order to learn new motor strategies.

Effect of ankle-foot orthoses on gait in typically developing children: Developmental trend in segmental coordination.

OBJECTIVE: As orthoses, and particularly ankle-foot orthoses, are widely used in the management of children with motor disorders, including cerebral palsy, we aimed to study their effect in normal children in order to add to normative gait data, which are essential for diagnosing, understanding and treating abnormal gait patterns. DESIGN: We analyzed the effect of ankle-foot orthoses on classical gait parameters and lower limb segments coordination patterns in typically developing children in two age groups reflecting different neuromaturational/developmental situations. We recorded 3D kinematic gait patterns in 9 children (4-5 years) and 11 children (9-10 years) walking barefoot or wearing bilateral solid ankle-foot orthoses maintaining the ankle joint angle at a neutral position. RESULTS: Ankle-foot orthoses induced little change in cadence, step length, step width or walking velocity in younger children, though they altered intralimb coordination through the gait cycle. In older children, walking velocity was reduced, shank elevation amplitude increased, while lower limb coordination changed less significantly. In this age group, ankle-foot orthoses significantly reduced the variability of coordinative strategies. CONCLUSION: Ankle-foot orthoses affect the gait pattern in children with a typical development at different levels in younger and older subjects, but the resulting changes are minimal.