Age- and sex-related differences in trunk kinematics during walking in able-bodied adults.

INTRODUCTION: Trunk motion during walking acts as a biomarker for decreased mobility and can differ between sexes. Knowing how age and sex affect trunk motion and energy conservation can help clinicians decide when and in whom to intervene with physiotherapy to prolong functional mobility. METHODS: A large sample of 138 able-bodied males and females in the age-categories 20-39 years, 40-59 years, 60-69 years, 70-79 years, and 80-89 years received a full-body 3D gait analysis. A two-factor ANOVA was performed to examine the effect of age and sex and their interaction on 3D trunk kinematics and positive mechanical work of the lower limbs, head-arms-trunk (HAT) segment and whole body. RESULTS: A significant decrease in walking speed was only found in those above 80 years (~ .05 nm/s, p < .006), while changes in 3D trunk kinematics were observed earlier. From 60 years on, trunk rotations decreased (~ 2-3°, p < .05), from 70-year frontal pelvic motion (~ 4°, p < .001), and from the age of 80 years sagittal thorax motion (~ 1-6°, p < .05). There were only small aging effects for mechanical energy demands that were more pronounced in females, showing decreased of HAT contributions (p = .020). Furthermore, age-related differences in trunk kinematics are highly dependent on sex whereby age-related changes were observed sooner in females than males in all three planes of motion. CONCLUSIONS: Age-related differences in 3D trunk kinematics are observed from 60 years onward and increase with age. Age-related stiffening of the trunk did not seem to affect the body's total mechanical work. Importantly, our data did show a stark contrast between males and females, indicating that training to prolong mobility should be tailored to sex. Future research should include sex-matched data when examining normal age and pathologic gait decline.

Gait Stride Length Estimation Using Embedded Machine Learning.

INTRODUCTION: Spatiotemporal gait parameters, e.g., gait stride length, are measurements that are classically derived from instrumented gait analysis. Today, different solutions are available for gait assessment outside the laboratory, specifically for spatiotemporal gait parameters. Such solutions are wearable devices that comprise an inertial measurement unit (IMU) sensor and a microcontroller (MCU). However, these existing wearable devices are resource-constrained. They contain a processing unit with limited processing and memory capabilities which limit the use of machine learning to estimate spatiotemporal gait parameters directly on the device. The solution for this limitation is embedded machine learning or tiny machine learning (tinyML). This study aims to create a machine-learning model for gait stride length estimation deployable on a microcontroller. MATERIALS AND METHOD: Starting from a dataset consisting of 4467 gait strides from 15 healthy people, measured by IMU sensor, and using state-of-the-art machine learning frameworks and machine learning operations (MLOps) tools, a multilayer 1D convolutional float32 and int8 model for gait stride length estimation was developed. RESULTS: The developed float32 model demonstrated a mean accuracy and precision of 0.23 ± 4.3 cm, and the int8 model demonstrated a mean accuracy and precision of 0.07 ± 4.3 cm. The memory usage for the float32 model was 284.5 kB flash and 31.9 kB RAM. The int8 model memory usage was 91.6 kB flash and 13.6 kB RAM. Both models were able to be deployed on a Cortex-M4F 64 MHz microcontroller with 1 MB flash memory and 256 kB RAM. CONCLUSIONS: This study shows that estimating gait stride length directly on a microcontroller is feasible and demonstrates the potential of embedded machine learning, or tinyML, in designing wearable sensor devices for gait analysis.

Functional mobility in children and young adults with Dravet syndrome.

AIM: This cohort study aimed to describe functional mobility in Dravet syndrome, a developmental and epileptic encephalopathy. METHOD: Functional mobility was assessed in individuals (aged 3-25 years), diagnosed with Dravet syndrome, using the Functional Mobility Scale (FMS), Mobility Questionnaire 28 (MobQues28), and estimated walking distance. Secondary outcome variables were Gait Profile Score (GPS), walking velocity, age at independent walking, intellectual disability, seizure frequency, genetic variant type, and body mass index (BMI). RESULTS: Forty participants aged 3 years to 24 years 2 months (mean = 12 years 2 months) had a median MobQues28 of 79%, median scores of 5, 5, and 4 for the FMS 5 m, 50 m, and 500 m and a median estimated walking distance of 1 km to 3 km. Most difficulties were seen in walking up and down the stairs, walking over obstacles, kicking a ball, and running. MobQues28 scores showed a significant decrease (-6.6%, p = 0.016) in the age category of young adults (≥18 years). After correcting for age, MobQues28 was correlated to age at independent walking (-0.485, p = 0.002), GPS (-0.460, p = 0.003), and walking velocity (0.334, p = 0.038). Analysis of variance showed a significant effect of intellectual disability and BMI on MobQues28 (p = 0.029, p = 0.049). No effect of seizure frequency or genetic variant was found (p = 0.579, p = 0.337). INTERPRETATION: Functional mobility limitations were observed mainly in dual tasks and activities requiring stability, with limitations increasing from the age of 18 years. Age at independent walking, gait impairments, intellectual disability, and BMI can impact functional mobility in Dravet syndrome. WHAT THIS PAPER ADDS: Most limitations were seen in dual task activities and activities that required more stability. Deterioration in functional mobility occurred in young adults. The more gait impairments, the more functional mobility limitations. Age at independent walking, intellectual disability, and body mass index can impact functional mobility.

Instrumented strength assessment in typically developing children and children with a neural or neuromuscular disorder: A reliability, validity and responsiveness study.

The aim of this study was to determine the clinimetric properties, i.e., reliability, validity and responsiveness of an instrumented strength assessment in typically developing (TD) children and children with cerebral palsy (CP) and Duchenne muscular dystrophy (DMD). Force (N), torque (Nm) and normalized torque (Nm/kg) were defined for maximal voluntary isometric contractions (MVICs) of the lower limb muscles using a pre-established protocol. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and minimal detectable change (MDC) of TD children (n = 14), children with CP (n = 11) and DMD (n = 11) were used to evaluate intra-rater reliability for the three cohorts and the inter-rater intersession as well as inter-rater intrasession reliability for TD children. Construct validity was assessed by comparing MVICs in TD children (n = 28) to children with CP (n = 26) and to children with DMD (n = 30), using the Kruskal Wallis and post-hoc Mann-Whitney U tests. Responsiveness was investigated by assessing changes in MVICs following a strength intervention in CP (n = 26) and a 1 and 2 year follow-up study in DMD (n = 13 and n = 6, respectively), using the Wilcoxon Signed-Rank test. The overall intra-rater reliability, was classified as good to excellent for 65.1%, moderate for 27.0% and poor for 7.9% of the measures (47.6%, 76.2%, and 66.7% good-excellent; 28.6%, 23.8%, and 33.7% moderate; 23.8%, 0%, and 0% poor in TD, CP, and DMD, respectively), while ICC values for TD children were slightly lower for inter-rater intrasession reliability (38.1% good-excellent, 33.3% moderate and 26.6% poor) and for inter-rater intersession reliability (47.6% good-excellent, 23.8% moderate and 28.6% poor). Children with CP and DMD were significantly weaker than TD children (p < 0.001) and the majority of these strength differences exceeded the MDC. Children with CP significantly improved strength after training, with changes that exceeded the SEMs, whereas only limited strength decreases over time were observed in the DMD cohort. In conclusion, the investigated instrumented strength assessment was sufficiently reliable to confirm known-group validity for both cohorts and could detect the responsiveness of children with CP after a strength intervention. However, more research is necessary to determine the responsiveness of this assessment in children with DMD regarding their natural decline.

Strength measurements in patients with Dravet Syndrome.

BACKGROUND: Dravet Syndrome (DS) is a developmental and epileptic encephalopathy, characterized by drug resistant infantile onset seizures and cognitive and motor impairment. Walking problems progressively occur and crouch gait is frequently observed. Muscle weakness is hypothesized as contributing impairment. Yet, so far, no studies have performed strength measurements in patients with DS, most likely due to cognitive impairment. AIMS: To determine the feasibility and validity of strength measurements in the framework of gait analysis and to outline strength problems in patients with DS. METHODS: Manual muscle testing, dynamometry (hand grip strength and handheld dynamometry) and functional tests (underarm throwing, standing long jump, sit-to-stand, stair climbing) were performed in 46 patients with DS. Results were compared to age-related reference values from literature. RESULTS: Forty one percent (19/46) of the patients (aged 5.2-24.8 years, median: 15.8 years) accomplished all measurements and scored generally below the fifth percentile of norm values. The remaining 59% (27/46) was not able to complete all strength assessment due to cognitive, behavioural and motor difficulties. Handheld dynamometry seemed most sensitive and specific to detect isolated muscle strength. Validity of the functional tests was controversial, as motor proficiency, balance and coordination may interfere. CONCLUSION: Although measuring strength in patients with DS was challenging in the context of gait analysis, decreased muscle strength was observed in patients that could perform strength measurements. Handheld dynamometry is preferred over functional tests for future investigations of muscle strength and its interference with gait are required for better understanding of walking problems.

Foot-floor contact pattern in children and adults with Dravet Syndrome.

BACKGROUND: Dravet Syndrome (DS) is a developmental and epileptic encephalopathy characterized by severe drug-resistant seizures and associated with cognitive and motor impairments. Walking problems are frequently observed. As the foot plays a key role during walking, compromised foot function can be a feature of deviant gait. AIM: To investigate foot function in DS by characterizing foot-floor contact patterns using pedobarography. METHODS: A total of 31 children and adults were included in the DS group (aged 5.2-32.8 years, 17 female, 174 steps) and 30 in the control group (aged 6.0-32.9, 16 female, 180 steps). The foot-floor contact pattern was evaluated based on progression, length and smoothness (spectral arc length) of the center of pressure (CoP). Linear mixed models were used to identify differences between non-heel strikes and heel strikes and between the DS and control group. RESULTS: Fifteen participants with DS showed inconsistency in the type of foot-floor contact (heel strikes and non-heel strikes). Heel strikes of participants with DS had significantly reduced time of CoP under the hindfoot and increased time under the midfoot region compared to the control group. Significant time and age effects were detected. CONCLUSIONS AND IMPLICATIONS: Deviant foot-floor contact patterns were observed in DS. Possible gait immaturity and instability as well as implications for interventions are discussed.

The mechanics behind gait problems in patients with Dravet Syndrome.

BACKGROUND: Dravet Syndrome (DS) is a developmental and epileptic encephalopathy starting in infancy and characterised by treatment resistant epilepsy with cognitive impairment and progressive motor dysfunction. Walking becomes markedly impaired with age, but the mechanical nature of gait problems remains unclear. RESEARCH QUESTION: What are the kinetic strategies characterised in gait of patients with DS? METHODS: This case-control study compared 41 patients with DS aged 5.2-26.1 years (19 female, 22 male) to 41 typically developing (TD) peers. Three dimensional gait analysis (VICON) was performed to obtain spatiotemporal parameters, kinematics and kinetics during barefoot, level walking at self-selected walking velocity. The sagittal plane support moment was analysed using Statistical Parametric Mapping (SPM). Three DS subgroups were identified based on differences in kinetic strategies characterised by the net internal knee joint moments and trunk lean. Kinematic and kinetic time profiles of the subgroups were compared to the TD group (SPM t-test). Clinical characteristics from physical examination and parental anamnesis were compared between DS (sub)groups using non-parametric tests (Kruskal-Wallis, Wilcoxon rank-sum, Fisher's exact). RESULTS: Support moments in stance were significantly increased in the DS group compared to TD and strongly related to minimum knee flexion in midstance. Persistent internal knee extension moments during stance were detected in a subgroup of 27 % of the patients. A second subgroup of 34 % showed forward trunk lean and attained internal knee flexion moments. The remaining 39 % had neutral or backward trunk lean with internal knee flexion moments. Subgroups differed significantly in age and functional mobility. SIGNIFICANCE: Inefficient kinetic patterns suggested that increased muscle effort was needed to control lower limb stability. Three distinct kinetic strategies that underly kinematic deviations were identified. Clinical evaluation of gait should pay attention to knee angles, trunk lean and support moments.

Independent walking and cognitive development in preschool children with Dravet syndrome.

AIM: To investigate the relation between cognitive and motor development in preschool aged children with Dravet syndrome, in particular between the age of independent walking and cognitive development. METHOD: Results of cognitive and motor developmental assessments and the age of independent walking were retrieved retrospectively from the medical records of 33 children (17 males, 16 females; mean age at last evaluation 33.2mo, SD 8.2mo, range 9-48mo) diagnosed with Dravet syndrome. Cognitive and motor developmental age, derived from the Bayley Scales of Infant Development or through standardized neurodevelopmental assessment, were converted into cognitive and motor developmental quotients. Multiple test scores per child were included. RESULTS: A strong positive relation was found between cognitive and motor developmental quotient (Pearson r=0.854; p<0.001) in 20 children (slope=0.75; 95% CI: 0.54-0.95). A later age of independent walking was associated with a lower cognitive developmental quotient (28 children; p<0.001; slope=-1.01; 95% CI: -1.53 to -0.49). A higher cognitive developmental quotient was seen in children with an age at testing younger than 24 months. The cognitive developmental quotient of children with a delay in independent walking (>17.6mo) was significantly lower than those without a delay (p=0.006). INTERPRETATION: A strong relation exists between cognitive and motor development. Furthermore, the age of independent walking might be an important indicator of the development of children with Dravet syndrome. WHAT THIS PAPER ADDS: Cognitive and motor development are strongly related in children with Dravet syndrome. Later age of independent walking is associated with worse cognitive development in children with Dravet syndrome.

Motor functions.

Motor development includes the evolution from reflexive to voluntary and goal-directed motor actions. These motor actions are never performed in isolation but always in a varying physical environment, often requiring object and social interaction. For a child to function within this context, they require the ability to demonstrate skillful, efficient, and voluntary postures and movement patterns. Furthermore, these movement patterns or motor skills need to be performed in interaction with the environment and in response to diverse stimuli, an ability that is defined as praxis. In this chapter, definitions are provided for the different components of motor function, motor skills, and praxis. The close interaction between perception, cognition, and (motor) action is discussed. Furthermore, crucial periods of typical development of motor and praxis abilities are highlighted, by means of the metaphorical "mountain of motor development," that is rooted in the dynamic systems perspective on motor development, as a starting point. The chapter ends with a discussion on the evaluation of motor function and praxis, highlighting benefits, and possible pitfalls.

Age-related differences in interlimb coordination during typical gait: An observational study.

BACKGROUND: Arm movements during gait are known to alter with increasing age during the slow maturation phase (>3years). It is unclear whether coordination between the arms and legs (i.e. interlimb coordination), which is a measure of gait quality, shows a similar pattern. RESEARCH QUESTION: to investigate age-related differences in interlimb coordination during gait in typically developing children and adults. METHODS: In this observational study, 98 typically developing participants were divided into five age-groups: preschool children (G1; 2.9-5.9 years[n = 18]), children (G2; 6.0-9.9 years[n = 22]), pubertal children (G3; 10.0-13.9 years[n = 26]), adolescents (G4; 14.0-18.9 years[n = 14]) and adults (G5; 19.0-35.2 years[n = 18]). Participants walked barefoot at a self-selected walking speed along a 10-m walkway during three-dimensional total-body gait analysis. To examine interlimb coordination, mean continuous relative phase over the gait cycle (MRP) and its variability (sdMRP) were calculated for each combination of limb pairs in the sagittal plane. RESULTS: MRP increased towards more anti-phase coordination with increasing age in following limb pair combinations: left arm-right arm (median[interquartile range]; G1: 152.0°[126.6;160.7°]-G5: 171.5°[170.0;175.3°]), left arm-left leg (G1: 155.0°[131.3;167.6°]-G5: 170.8°[165.3;173.5°]) and right arm-right leg (G1: 155.7°[135.5;166.0°]-G5: 170.0°[166.4;173.5°]). MRP decreased towards more in-phase coordination from G1 to G5 in left arm-right leg (G1: 24.4°[15.3;45.8°]-G5: 10.5°[6.1;15.6°]) and right arm-left leg (G1: 25.0°[13.7;41.1°]-G5: 9.7°[5.2;16.8°]). sdMRP decreased from G1 to G5 for all limb pair combinations. SIGNIFICANCE: Interlimb coordination altered with increasing age. First, coordination between the legs and right arm-left leg appeared mature in G1 (aged 2.9-5.9 years). Next, coordination between the ipsilateral limbs seemed mature at 9.9 years, followed by a mature coordination between left arm-right leg at 13.9years. Coordination between the two arms showed ongoing differences until adulthood. These data provide an age-related framework and normative dataset to distinguish age-related differences from pathology in children with neuromotor disorders in clinical practice.

Trunk biomechanics during walking after sub-acute stroke and its relation to lower limb impairments.

BACKGROUND: Trunk function and lower limb strength seem to be the primary predictors for functional independence in acute stroke patients. Gaining a better understanding of their relationship during walking aids in the identification of intrinsic trunk control deficits and underlying lower limb deficits resulting in compensatory trunk movements. METHODS: Fifty-seven subjects with stroke and 57 age- and gender-matched subjects without disability were included. Participants underwent an instrumented gait analysis with a standard total body Plug-In-Gait model, a clinical examination of the lower limbs based on range of motion, strength, muscle tone and several clinical assessment scales such as the Trunk Impairment Scale, Tinetti test and Functional Ambulation Categories. Spatiotemporal parameters and joint angular time profiles were compared between healthy adults and stroke survivors with severe and mild to moderate lower limb impairments. Spm1d was used to compare the joint angular time profiles between groups. FINDINGS: Truncal deviations are present during hemiplegic walking, sub-acute stroke survivors walked with increased thoracic tilt, a neutral frontal position of the pelvis during stance, a pelvic hike during swing, and a more rotated position without crossing of the midline. Patients with more severe lower limb impairments had more pronounced deficits in truncal motion. INTERPRETATION: Setting accurate rehabilitation goals is of major importance during stroke, as well as understanding the underlying mechanisms and causes of the truncal impairments. Although more compensatory trunk deviations were seen in participants with severe lower limb impairments, they should not be considered as the sole contributor of trunk impairments during walking. Results of this study suggest that intrinsic trunk deficits during walking are also present after stroke.

Gait abnormalities in people with Dravet syndrome: A cross-sectional multi-center study.

OBJECTIVE: To quantify gait abnormalities in people with Dravet syndrome (DS). METHODS: Individuals with a confirmed diagnosis of DS were enrolled, and stratified according to knee flexion at initial contact (IC) and range of motion (ROM) during stance (atypical crouch: knee flexion >20° at IC and knee ROM >15° during stance; straight: knee flexion <20° at IC). A 1D ANOVA (α = 0.05) was used to test statistical differences among the joint kinematics and spatio-temporal parameters of the cohort and an age-matched control group. Clinical (neurological and orthopaedic evaluation) and anamnestic data (seizure type, drugs, genetic mutation) were collected; distribution between the two gait phenotypes was assessed with the Fisher exact test and, for mutation, with the chi-squared test (p < 0.05). Linear regression between maximum knee flexion and normalised walking speed was calculated. RESULTS: Seventy-one subjects were enrolled and evaluated with instrumented gait analysis. Fifty-two were included in final analysis (mean age 13.8 ± 7.3; M 26). Two gait patterns were detected: an atypical crouch gait (34.6%) with increased ankle, knee and hip flexion during stance, and reduced walking speed and stride length not associated with muscle-tendon retractions; and a pattern resembling those of healthy age-matched controls, but still showing reduced walking speed and stride length. No differences in clinical or anamnestic data emerged between the two groups. SIGNIFICANCE: Objectively quantified gait in DS shows two gait patterns with no clear-cut relation to clinical data. Kinematics abnormalities may be related to stabilization issues. These findings may guide rehabilitative and preventive measures.

Gait deviations in patients with dravet syndrome: A systematic review.

BACKGROUND: Dravet Syndrome is a rare developmental and epileptic encephalopathy characterised by epileptic seizures, cognitive impairment and motor disorders. Gait is markedly impaired and could benefit from targeted intervention to improve quality of life for patient and caregivers. OBJECTIVE: To establish the state of the art regarding gait deviations in patients with Dravet Syndrome. METHODS: A systematic search was performed in Pubmed, Web of Science, Science Direct and Embase. Studies that assessed gait deviations in patients diagnosed with Dravet Syndrome using clinical observation, video gait analysis or three dimensional (3D) gait analysis and reported gait characteristics, spatiotemporal or kinematic outcomes were included. Screening, quality assessment and data extraction were performed by independent reviewers. RESULTS: Out of a total of 478 citations, nine articles were included. The total study population had an age range from 2.5 to 47 years. Three studies used clinical observation, three studies video analysis and three studies 3D gait analysis. Crouch gait was observed in about half of the population next to a variety of other gait deviations such as parkinsonian and cerebellar gait. Other findings included abnormalities in spatiotemporal parameters and kinematics, passive knee extension deficits, skeletal malalignment and neurological signs. CONCLUSIONS: A variety of gait characteristics was observed with crouch gait being the most reported gait pattern. Inconsistency in methods and findings from clinical and instrumented evaluation impede thorough understanding of the causal mechanism and evolution behind these deviations. PROSPERO REGISTRATION NUMBER: CRD42017070370.

Motor development in children with Dravet syndrome.

AIM: The aim of this study is to describe the course of motor development in children with Dravet syndrome. METHOD: Forty-three participants (21 males, 22 females; mean age at last assessment 53.89mo±42.50mo) met the inclusion criteria of having a confirmed diagnosis of Dravet syndrome and presence of data on motor development. All data between 1985 and 2018 were derived retrospectively from their medical records. Gross motor milestones and motor age equivalents were used to describe motor development. Standardized neurodevelopmental assessment and the Bayley Scales of Infant Development defined the overall motor development. Peabody Developmental Motor Scales, Bruininks-Oseretsky Test of Motor Proficiency, and the Beery-Buktenica Developmental Test of Visual-Motor Integration were used to describe development in specific motor domains. RESULTS: Children with Dravet syndrome showed a delay in both sitting (seven out of 14) and walking independently (11 out of 25). Overall motor age equivalents revealed a delay in 29 out of 38 assessments (age 9-115mo). All assessments of children older than 2 years (16 out of 16) showed a delay. Gross motor delay was present in seven out of seven and fine motor delay in 10 out of 13 assessments (age 19-167mo). INTERPRETATION: Motor development is delayed in the majority of children with Dravet syndrome older than 2 years and increases with age. WHAT THIS PAPER ADDS: A delay in motor development is present in most children with Dravet syndrome older than 2 years. Large diversity in early gross motor milestones confirms heterogeneity in Dravet syndrome.

Desarrollo motor en niños con el síndrome de Dravet OBJETIVO: El objetivo de este estudio es describir el curso del desarrollo motor en los niños con síndrome de Dravet. METODOLOGÍA: Cuarenta y tres participantes (21 niños, 22 niñas; con edad promedio en la última evaluación de 53,89 meses ± 42,50 meses) cumplieron los criterios de inclusión: tener un diagnóstico confirmado de síndrome de Dravet y presentar datos de desarrollo motor. Todos los datos recogidos entre 1,985 y 2,018 fueron extraídos retrospectivamente de las historias clínicas. Los hitos de motricidad gruesa y las equivalencias de edad motora se utilizaron para describir el desarrollo motor. Evaluaciones del neurodesarrollo estandarizadas y la escala de desarrollo infantil Bayley definieron el desarrollo motor global. La escala de desarrollo motor Peabody, el test de competencia motora Bruininks-Oseretsky y el test de desarrollo de la integración visomotora Beery-Buktenica se utilizaron para describir el desarrollo en los dominios motores específicos. RESULTADOS: Los niños con el síndrome de Dravet mostraron un retraso tanto en sentarse (7 de 14) como en caminar de manera independiente (11 de 25). En conjunto, las edades motoras equivalentes revelaron un retraso en 29 de las 38 evaluaciones (edad de 9-115 meses). Todas las evaluaciones de niños mayores de 2 años (16 de 16) mostraron un retraso. El retraso de la motricidad gruesa estuvo presente en 7 de 7 evaluaciones y el retraso de la motricidad fina en 10 de 13 evaluaciones (edad 19-167 meses). INTERPRETACIÓN: El desarrollo motor está retrasado en la mayoría de los niños con síndrome de Dravet mayores de dos años y aumenta con la edad.

Desenvolvimento motor em crianças com síndrome de Dravet OBJETIVO: O objetivo deste estudo é descrever o curso do desenvolvimento motor em crianças com síndrome de Dravet. MÉTODO: Quarenta e três participantes (21 do sexo masculino, 22 do sexo feminino; média de idade na última avaliação 53,89m ± 42,50m) atenderam aos critérios de inclusão de ter um diagnóstico confirmado de síndrome de Dravet e a presença de dados sobre o desenvolvimento motor. Todos os dados entre 1985 e 2018 foram derivados retrospectivamente de seus registros médicos. Marcos motores globais e idade motora equivalente foram usados para descrever o desenvolvimento motor. Avaliação padronizada do neurodesenvolvimento e a Escala Bayley de Desenvolvimento Infantil definiram o desenvolvimento global. A Escala Peabody de Desenvolvimento Motor, o Teste de Proficiência Motora de Bruininks-Oseretsky, e o Teste Desenvolvimental de Beery-Buktenica para Integração Visuo-motora foram usados para descrever o desenvolvimento em domínios motores específicos. RESULTADOS: Crianças com síndrome de Dravet mostraram atraso no sentar (sete em 14) e no andar independente (11 em 25). A idade motora global equivalente revelou atraso em 29 de 38 avaliações (idade 9-115m). Todas as avaliações de crianças com mais de 2 anos (16 de 16) mostraram atraso. O atraso motor global estava presente em sete de sete, e motor fino em 10 de 13 avaliações (idade 19-167m). INTERPRETAÇÃO: O desenvolvimento motor é atrasado na maioria das crianças com síndrome de Dravet maiores do que 2 anos, e aumenta com a idade.

Age-related changes in arm motion during typical gait.

BACKGROUND: When toddlers learn to walk, they do so with a typical high guard position of the arms. As gait matures, children develop a reciprocal arm swing. So far, there have been no attempts to describe age-related changes of arm movements during walking after this first rapid development. RESEARCH QUESTION: The purpose of this study was to investigate age-related changes in arm movement during typical gait. METHODS: All participants (n = 102) received gait analysis using a full-body marker set (Plug-in Gait). Participants were divided into five age-groups: young children (G1: n = 20; 3.0-5.9y), children (G2: n = 24; 6.0-9.9y), pubertal children (G3: n = 26; 10.0-13.9y), adolescents (G4: n = 16; 14.0-18.9y) and adults (G5: n = 16; 19.0-35.2y). Age-related changes in arm movements were investigated by comparing continuous joint angular waveforms (spm1d) between all groups, as well as by comparing the mean joint angle and range of motion of the different joints between age-groups. RESULTS: The overall shape of movement patterns was comparable across all age groups. Nevertheless, with advancing age, consistency increased. At the shoulder, G1&2 showed a larger mean extension angle compared to older children and adults. The range of shoulder axial rotation was significantly larger in adults compared to all other age groups. In the youngest groups (G1-G2), an increased mean elbow flexion and mean wrist extension angle was found. SIGNIFICANCE: Determining an exact age of maturation of arm swing remains difficult as parameter specific adult-like values were not reached at the same age but should not be set before the age of ten to fourteen years for any parameter.

Age-related differences in muscle activity patterns during walking in healthy individuals.

OBJECTIVE: To examine how muscle activity over the entire gait cycle changes with increasing age. METHODS: Electromyography data of the erector spinae, rectus femoris, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius muscles were collected by an instrumented gait analysis during over ground walking in healthy adults aged between 20 and 89 years. Participants were categorized per decade (n = 105, 15 per decade, decades 3-9). Normalized integrated linear envelopes of the electromyographic signal were calculated for one stride. A one way ANOVA using spm1d statistics explored the differences between age groups, followed by a post hoc analysis. RESULTS: While initiation of decline commenced at the age of 60 for erector spinae and tibialis anterior, age-related changes are most pronounced after the age of 80. Concerning timing of muscle activity, subjects in decade 7-9 had prolonged activity and/or early activity of the erector spinae, vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius compared to other decades. Regarding amplitude of muscle activity, decreased peak amplitudes of the erector spinae, rectus femoris, vastus lateralis and gastrocnemius were observed in decades 7-9 compared to other decades. CONCLUSION: Both timing and amplitude of muscle activation patterns need to be considered to understand the aging process. Regarding the erector spinae, tibialis anterior and vastus lateralis, a decrease in muscle activation coincides with prolonged activity, compared to the gastrocnemius where decreased muscle activation is associated with early activation.

Effectiveness of additional trunk exercises on gait performance: study protocol for a randomized controlled trial.

BACKGROUND: Evidence is lacking concerning the effect of additional trunk rehabilitation on gait performance. Investigating gait performance by both clinical and biomechanical outcome measures might lead to new scientific insights into the importance of the trunk during gait rehabilitation in people suffering from stroke. This protocol was written according to the SPIRIT 2013 Statement. METHODS AND DESIGN: An assessor-blinded randomized controlled trial will be conducted in patients with impaired trunk control after stroke. A total of 60 patients will be randomly allocated to the control or the experimental group by means of sealed opaque envelopes. They will receive either 16 h of additional trunk exercises (experimental group) or cognitive exercises (controls) for 1 h a day, 4 days a week for 4 weeks. Patients will also receive 2 h of standard care consisting of physiotherapy and occupational therapy. Gait performance will be assessed clinically by the Tinetti Test and biomechanically by means of a full body gait analysis. In addition, the effect of the exercise protocol on the trunk itself and trunk activities of daily living will be assessed by the Trunk Impairment Scale and the Barthel Index. DISCUSSION: Despite the evidence demonstrating the importance of trunk control after stroke, studies about the effects of trunk rehabilitation on gait performance are inconsistent. In the current study, a more sophisticated treatment protocol will be used to enlarge therapeutic improvements, the relationship between clinical and biomechanical measures of gait performance can be investigated, and the sustainability of the effects of trunk exercises over time will be examined. Since clinical improvements are of greater importance to patients and physiotherapists, clinical assessment scales will be used as primary outcome measures. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02708888 . Registered on 2 March 2016.

Coordinating arms and legs on a hybrid rehabilitation tricycle: the metabolic benefit of asymmetrical compared to symmetrical arm movements.

PURPOSE: The most commonly used propulsion method for handcycling is moving the arms symmetrically. Previous studies indicated that during outdoor handcycling symmetrical arm movements are more efficient. During locomotor movements, however, arm movements are performed asymmetrically in combination with leg movements. We questioned which combination of arm and leg movements is more efficient during combined arm and leg cycling for stationary use. METHODS: Twenty-five able-bodied adults performed eight submaximal tests of 6 min on a hybrid handcycle at three incremental gears during four different conditions ('arms only' and 'arms & legs' with arms symmetrical and asymmetrical). Oxygen uptake (VO2), heart rate (HR) and Borg score (Borg) were assessed. RESULTS: Increasing workload resulted in significant increases in VO2 (16 W: 13.0 ± 2.4 ml kg(-1) min(-1), 31 W: 14.5 ± 2.9, 49 W: 15.5 ± 2.8; p < 0.001) and Borg (16 W: 7.7 ± 1.7 points, 31 W: 8.6 ± 1.9, 49 W: 9.5 ± 1.9; p < 0.001). During 'arms only', no differences were found in exercise intensity between symmetrical and asymmetrical movements. Contrarily, during 'arms & legs', both VO2 (p < 0.001) and Borg (p = 0.001) were significantly lower for the asymmetrical (VO2: 13.8 ± 2.6 ml kg(-1) min(-1), Borg: 8.1 ± 1.6 points) compared to the symmetrical condition (VO2: 14.9 ± 2.8, Borg: 9.1 ± 2.0). CONCLUSIONS: Results indicated that asymmetrical arm movements, especially in combination with leg movements, represented the most efficient condition on a stationary hybrid handcycle. The current results suggest that neural energy costs are lower when moving in the preferred (asymmetrical) coordination when no steering is required. These findings may have implications for stationary arm & leg cycling rehabilitation and tricycle adaptations in patients with spinal cord injury.

How can push-off be preserved during use of an ankle foot orthosis in children with hemiplegia? A prospective controlled study.

Several studies indicated that walking with an ankle foot orthosis (AFO) impaired third rocker. The purpose of this study was to evaluate the effects of two types of orthoses, with similar goal settings, on gait, in a homogeneous group of children, using both barefoot and shoe walking as control conditions. Fifteen children with hemiplegia, aged between 4 and 10 years, received two types of individually tuned AFOs: common posterior leaf-spring (PLS) and Dual Carbon Fiber Spring AFO (CFO) (with carbon fibre at the dorsal part of the orthosis). Both orthoses were expected to prevent plantar flexion, thus improving first rocker, allowing dorsiflexion to improve second rocker, absorbing energy during second rocker, and returning it during the third rocker. The effect of the AFOs was studied using objective gait analysis, including 3D kinematics, and kinetics in four conditions: barefoot, shoes without AFO, and PLS and CFO combined with shoes. Several gait parameters significantly changed in shoe walking compared to barefoot walking (cadence, ankle ROM and velocity, knee shock absorption, and knee angle in swing). The CFO produced a significantly larger ankle ROM and ankle velocity during push-off, and an increased plantar flexion moment and power generation at pre-swing compared to the PLS (<0.01). The results of this study further support the findings of previous studies indicating that orthoses improve specific gait parameters compared to barefoot walking (velocity, step length, first and second ankle rocker, sagittal knee and hip ROM). However, compared to shoes, not all improvements were statistically significant.

Do dynamic and static clinical measurements correlate with gait analysis parameters in children with cerebral palsy?

The present study documents the correlation between gait analysis data and clinical measurements and evaluates the combined predictive value of static and dynamic clinical measurements on gait data of children with cerebral palsy. Two hundred patients were evaluated using a set of measurements of range of motion (ROM), alignment, spasticity, strength and selectivity, and by three-dimensional gait analysis. Fair to moderate correlations were found between clinical measurements and gait data, the overall highest correlation being 0.60. Clinical data of strength and selectivity had the highest degree of significant correlations with gait data, compared to the ROM and spasticity. ROM, spasticity and strength measurements for the hip in the coronal plane and spasticity of rectus femoris most frequently showed fair to moderate correlations to gait data. Time and distance and EMG parameters mainly correlated with strength and selectivity parameters. Unexpectedly, alignment parameters only fairly correlated with hip rotation in stance. Multiple regression analysis revealed that adding dynamic clinical measurements (spasticity, strength and selectivity) to a static model (ROM) enhanced the link between clinical measurements and gait data. The variance of gait parameters was better explained by a combined model of static and dynamic clinical measurements, compared to a purely static model. However, R(2)-values were low. Gait analysis data cannot be sufficiently predicted by a combination of clinical measurements. The independence of the measurements supports the notion that both, clinical examination and gait analysis data provide important information for delineating the problems of children with CP.