The effect of lower extremity selective voluntary motor control on interjoint coordination during gait in children with spastic diplegic cerebral palsy

Selective voluntary motor control influences knee joint torque, work and power in children with spastic cerebral palsy

BACKGROUND

Children with spastic cerebral palsy (CP) have damage to the corticospinal tracts that are responsible for selective motor control (SMC). Force, velocity and timing of joint movement are related biomechanical features controlled by the corticospinal tracts (CSTs) that are important for skilled movement.

RESEARCH QUESTION

Does SMC influence knee joint biomechanics in spastic CP?

METHODS

In this prospective study, relationships between SMC and knee biomechanics (peak torque, total work, average power) across a range of velocities (0-300 deg/s) were assessed using an isokinetic dynamometer in 23 children with spastic CP. SMC was assessed using Selective Control Assessment of the Lower Extremity (SCALE). Logistic and linear regression models were used to evaluate relationships between SCALE and biomechanical measures.

RESULTS

The ability to produce knee torque diminished with increasing velocity for both Low (0-4 points) and High (5-10 points) SCALE limb score groups (p < 0.01). More knees in the High group produced extension torque at 300 deg/s (p < 0.05) and flexion torque at 30, 90,180, 240 and 300 deg/s (p < 0.05). The ability to produce torque markedly decreased above 180 deg/s for Low group flexion. For knees that produced torque, significant positive correlations between SCALE limb scores and joint torque (0 and 120 deg/s), work (120 deg/s) and power (120 deg/s) were found (p < 0.05). Greater knee torque, work and power for the High group was found for the extensors at most velocities and the flexors for up to 120 deg/s (p < 0.05). Few Low group participants generated knee flexor torque above 120 deg/s limiting comparisons.

SIGNIFICANCE

Biomechanical impairments found for children with low SMC are concerning as skilled movements during gait, play and sport activities occur at high velocities. Differences in SMC should be considered when designing individualized assessments and interventions.

A coactivation strategy in anticipatory postural adjustments during voluntary unilateral arm movement while standing in individuals with bilateral spastic cerebral palsy

Individuals with bilateral spastic cerebral palsy (BSCP) reportedly has problems with anticipatory postural adjustments (APAs) while standing. However, the use of coactivation strategy in APAs in individuals with BSCP has conflicting evidence. Hence, this study aimed to investigate postural muscle activities in BSCP during unilateral arm flexion task in which postural perturbations occur in the sagittal, frontal, and horizontal planes. We included 10 individuals with BSCP with level II on the Gross Motor Function Classification System (BSCP group) and 10 individuals without disability (control group). The participants stood on a force platform and rapidly flexed a shoulder from 0° to 90° at their own timing. Surface electromyograms were recorded from the rectus femoris, medial hamstring, tibialis anterior, and medial gastrocnemius. The control group showed a mixture of anticipatory activation and inhibition of postural muscles, whereas the BSCP group predominantly exhibited anticipatory activation with slight anticipatory inhibition. Compared with the control group, the BSCP group tended to activate the ipsilateral and contralateral postural muscles and the agonist-antagonist muscle pairs. The BSCP group had a larger disturbance in postural equilibrium, quantified by the peak displacement of center of pressure during the unilateral arm flexion, than those without disability. Individuals with BSCP may use coactivation strategy, mainly the anticipatory activation of postural muscle activity, during a task that requires a selective postural muscle activity to maintain stable posture.

Three-Dimensional Instrumented Gait Analysis for Children With Cerebral Palsy: An Evidence-Based Clinical Practice Guideline

BACKGROUND

Children with cerebral palsy (CP) who walk have complex gait patterns and deviations often requiring physical therapy (PT)/medical/surgical interventions. Walking in children with CP can be assessed with 3-dimensional instrumented gait analysis (3D-IGA) providing kinematics (joint angles), kinetics (joint moments/powers), and muscle activity.

PURPOSE

This clinical practice guideline provides PTs, physicians, and associated clinicians involved in the care of children with CP, with 7 action statements on when and how 3D-IGA can inform clinical assessments and potential interventions. It links the action statement grades with specific levels of evidence based on a critical appraisal of the literature.

CONCLUSIONS

This clinical practice guideline addresses 3D-IGA's utility to inform surgical and non-surgical interventions, to identify gait deviations among segments/joints and planes and to evaluate the effectiveness of interventions. Best practice statements provide guidance for clinicians about the preferred characteristics of 3D-IGA laboratories including instrumentation, staffing, and reporting practices.Video Abstract: Supplemental digital content available at http://links.lww.com/PPT/A524.

Children with bilateral cerebral palsy use their hip joint to complete a step-up task

Performance in stair-climbing is largely associated with disruptions to mobility and community participation in children with cerebral palsy (CP). It is important to understand the nature of motor impairments responsible for making stairs a challenge in children with bilateral CP to clarify underlying causes of impaired mobility. In pediatric clinical populations, sensitive measurements of movement quality can be captured during the initial step of stair ascent. Thus, the purpose of this study was to quantify the lower limb joint moments of children with bilateral CP during the stance phases of a step-up task. Participants performed multiple stepping trials in a university gait laboratory. Outcome measures included extensor support moments (the sum of hip, knee, and ankle sagittal plane moments), hip abduction moments, and their timing. We recruited seven participants per group. We found that peak support and hip abduction moments were similar in the bilateral CP group compared to the typical development (TD) group. We also found that children with bilateral CP timed their peak moments closer together and increasingly depended on the hip joint to complete the task, especially in their more affected (MA) lower limb. Our investigation highlights some underlying causes that may make stair climbing a challenge for the CP population, including a loss of selective voluntary motor control (SVMC), and provides a possible treatment approach to strengthen lower limb muscles.

Improved Myelination following Camp Leg Power, a Selective Motor Control Intervention for Children with Spastic Bilateral Cerebral Palsy: A Diffusion Tensor MRI Study

BACKGROUND AND PURPOSE

Children with spastic cerebral palsy have motor deficits associated with periventricular leukomalacia indicating WM damage to the corticospinal tracts. We investigated whether practice of skilled lower extremity selective motor control movements would elicit neuroplasticity.

MATERIALS AND METHODS

Twelve children with spastic bilateral cerebral palsy and periventricular leukomalacia born preterm (mean age, 11.5 years; age range, 7.3-16.6 years) participated in a lower extremity selective motor control intervention, Camp Leg Power. Activities promoted isolated joint movement including isokinetic knee exercises, ankle-controlled gaming, gait training, and sensorimotor activities (3 hours/day, 15 sessions, 1 month). DWI scans were collected pre- and postintervention. Tract-Based Spatial Statistics was used to analyze changes in fractional anisotropy, radial diffusivity, axial diffusivity, and mean diffusivity.

RESULTS

Significantly reduced radial diffusivity (P < . 05) was found within corticospinal tract ROIs, including 28.4% of the left and 3.6% of the right posterior limb of the internal capsule and 14.1% of the left superior corona radiata. Reduced mean diffusivity was found within the same ROIs (13.3%, 11.6%, and 6.6%, respectively). Additionally, decreased radial diffusivity was observed in the left primary motor cortex. Additional WM tracts had decreased radial diffusivity and mean diffusivity, including the anterior limb of the internal capsule, external capsule, anterior corona radiata, and corpus callosum body and genu.

CONCLUSIONS

Myelination of the corticospinal tracts improved following Camp Leg Power. Neighboring WM changes suggest recruitment of additional tracts involved in regulating neuroplasticity of the motor regions. Intensive practice of skilled lower extremity selective motor control movements promotes neuroplasticity in children with spastic bilateral cerebral palsy.

Causal modelling demonstrates metabolic power is largely affected by gait kinematics and motor control in children with cerebral palsy

Metabolic power (net energy consumed while walking per unit time) is, on average, two-to-three times greater in children with cerebral palsy (CP) than their typically developing peers, contributing to greater physical fatigue, lower levels of physical activity and greater risk of cardiovascular disease. The goal of this study was to identify the causal effects of clinical factors that may contribute to high metabolic power demand in children with CP. We included children who 1) visited Gillette Children's Specialty Healthcare for a quantitative gait assessment after the year 2000, 2) were formally diagnosed with CP, 3) were classified as level I-III under the Gross Motor Function Classification System and 4) were 18 years old or younger. We created a structural causal model that specified the assumed relationships of a child's gait pattern (i.e., gait deviation index, GDI) and common impairments (i.e., dynamic and selective motor control, strength, and spasticity) with metabolic power. We estimated causal effects using Bayesian additive regression trees, adjusting for factors identified by the causal model. There were 2157 children who met our criteria. We found that a child's gait pattern, as summarized by the GDI, affected metabolic power approximately twice as much as the next largest contributor. Selective motor control, dynamic motor control, and spasticity had the next largest effects. Among the factors we considered, strength had the smallest effect on metabolic power. Our results suggest that children with CP may benefit more from treatments that improve their gait pattern and motor control than treatments that improve spasticity or strength.

Analysis of cerebral palsy gait based on movement primitives

BACKGROUND

Cerebral palsy is the most prevalent motor disorder among children. Despite extensive studies on motor modularity of gait of children with cerebral palsy, kinematic modularity of their gait has not been addressed which is the main goal of this study.

METHODS

The kinematics of the gait of 13 typical development children and 188 children with cerebral palsy was captured and analyzed, where the cerebral palsy children were grouped into True, Jump, Apparent, and Crouch. Non-negative matrix factorization method was used to extract the kinematic modulus of each group, which were then clustered to find their characteristic movement primitives. The movement primitives of groups were then matched based on the similarity of their activation profiles.

FINDINGS

The number of movement primitives was three for the Crouch group, four for the other cerebral palsy groups, and five for the typical development group. Compared to the typical development children, the kinematic modules and activations of the cerebral palsy groups involved higher variability and co-activation, respectively (P < 0.05). Three temporally matched movement primitives were shared by all groups, but with altered structures.

INTERPRETATION

The gait of children with cerebral palsy involved lower complexity and higher variability due to the reduced and inconsistent kinematic modularity. Three basic movement primitives were sufficient to prodcue the overall gait kinematics, as observed in the Crouch group. Other movement primitives, were responsible for providing smooth transitions between basic movement primitives, as seen in more complex gait patterns.

Selective motor control correlates with gross motor ability, functional balance and gait performance in ambulant children with bilateral spastic cerebral palsy

BACKGROUND

Selective motor control (SMC) is a fundamental component of typical human motion. As a result of brain damage, impaired SMC often leads to difficulties with coordination, balance, gait efficiency and symmetry.

RESEARCH QUESTION

What is the association between impaired SMC and lower limb motor ability, functional balance and gait performance in children with bilateral spastic cerebral palsy (CP)?

METHODS

Thirty-six children (aged 5-16 years) with spastic bilateral CP in Gross Motor Function Classification System (GMFCS) level I to II were included in this study. SMC was assessed using Selective Control Assessment of the Lower Extremity (SCALE). Gross motor function was assessed using Gross Motor Function Measure-88 items D and E dimension (GMFM-88 D&E). Functional balance was assessed using Pediatric Balance Scale (PBS) and Timed Up and Go Test (TUG). Gait quality was assessed using Edinburg Visual Gait Score (EVGS) and 10-Meter Walk Test (10MWT). Spearman's rank correlation analyses were used to determine the association between SMC and other factors.

RESULTS

Correlation analyses showed that SCALE was strongly positively correlated with GMFM-88 (D&E) (rs=0.756, p < 0.001), PBS (rs=0.769, p < 0.001), and height-normalized fast walking speed (rs=0.632, p < 0.001), and strongly negatively correlated with TUG (rs=-0.766, p < 0.001) and EVGS (rs=-0.893, p < 0.001).

SIGNIFICANCE

Lower extremity SMC deficits are associated with poor gross motor function and balance control, more severe overall gait deviations and decreased fast walking speed in children with bilateral spastic CP. Physical therapy should include interventions that promote selective motor control in order to improve overall functional ability.

Reliability and validity of the Turkish version of the Selective Control Assessment of the Lower Extremity (SCALE) in children with spastic cerebral palsy

PURPOSE

This study aims to translate the Selective Control Assessment of the Lower Extremity (SCALE) into Turkish language, assess its reliability and validity in children with spastic cerebral palsy.

MATERIALS AND METHODS

Fifty-two children with CP (mean age 9 years 8 months, range 4-18 years) included in this cross-sectional study. Intra- and interrater reliability was assessed by intraclass correlation coefficient (ICC). The SCALE was correlated with the Gross Motor Function Classification System (GMFCS), the Physician's Rating Scale (PRS), and Gross Motor Function Measurement (GMFM) to assess validity.

RESULTS

Intra- and interrater reliability of the SCALE were excellent (ICC > 0.75). SCALE and GMFCS (r = -0.786, p < 0.001), SCALE and PRS (r = 0.761, p < 0.001), SCALE and GMFM (r = 0.863, p < 0.001) were highly correlated. SCALE scores differed significantly between GMFCS levels and between types of spastic CP.

CONCLUSIONS

The Turkish version of the SCALE appears to be a valid and reliable tool to assess selective voluntary motor control of the lower limbs in children with spastic CP.IMPLICATIONS FOR REHABILITATIONThe Turkish version of the Selective Control Assessment of the Lower Extremity is a valid and reliable assessment for children with spastic CP.The SCALE scores differed significantly between Gross Motor Function Classification System levels I versus II and levels II versus III as well as between types of spastic CP.The current study suggests that the SCALE is a quick and easy outcome measure to assess selective motor control in patients with spastic CP.

Predicting Coordination Variability of Selected Lower Extremity Couplings during a Cutting Movement: An Investigation of Deep Neural Networks with the LSTM Structure

There are still few portable methods for monitoring lower limb joint coordination during the cutting movements (CM). This study aims to obtain the relevant motion biomechanical parameters of the lower limb joints at 90°, 135°, and 180° CM by collecting IMU data of the human lower limbs, and utilizing the Long Short-Term Memory (LSTM) deep neural-network framework to predict the coordination variability of selected lower extremity couplings at the three CM directions. There was a significant (p < 0.001) difference between the three couplings during the swing, especially at 90° vs the other directions. At 135° and 180°, t13-he coordination variability of couplings was significantly greater than at 90° (p < 0.001). It is important to note that the coordination variability of Hip rotation/Knee flexion-extension was significantly higher at 90° than at 180° (p < 0.001). By the LSTM, the CM coordination variability for 90° (CMC = 0.99063, RMSE = 0.02358), 135° (CMC = 0.99018, RMSE = 0.02465) and 180° (CMC = 0.99485, RMSE = 0.01771) were accurately predicted. The predictive model could be used as a reliable tool for predicting the coordination variability of different CM directions in patients or athletes and real-world open scenarios using inertial sensors.

Assessment of foot alignment and function for ambulatory children with cerebral palsy: Results of a modified Delphi technique consensus study

PURPOSE

The purpose of this study was to establish consensus for the assessment of foot alignment and function in ambulatory children with cerebral palsy, using expert surgeon's opinion through a modified Delphi technique.

METHODS

The panel used a five-level Likert-type scale to record agreement or disagreement with 33 statements regarding the assessment of foot alignment and function. Consensus was defined as at least 80% of responses being in the highest or lowest of two of the five Likert-type ratings. General agreement was defined as 60%-79% falling into the highest or lowest two ratings. There was no agreement if neither threshold was reached.

RESULTS

Consensus was achieved for 25 (76%) statements, general agreement for 4 (12%) statements, and lack of consensus for 4 (12%) of the statements. There was consensus that the functional anatomy of the foot is best understood by dividing the foot into three segments and two columns. Consensus was achieved concerning descriptors of foot segmental alignment for both static and dynamic assessment. There was consensus that radiographs of the foot should be weight-bearing. There was general agreement that foot deformity in children with cerebral palsy can be classified into three levels based on soft tissue imbalance and skeletal malalignment.

CONCLUSION

The practices identified in this study can be used to establish best care guidelines, and the format used will be a template for future Delphi technique studies on clinical decision-making for the management of specific foot segmental malalignment patterns commonly seen in children with cerebral palsy.

LEVEL OF EVIDENCE

V.

Motivating Selective Motor Control of Infants at High Risk of Cerebral Palsy Using an In-Home Kicking-Activated Mobile Task: A Pilot Study

OBJECTIVE

Decreased selective motor control limits gait function of children with spastic cerebral palsy (CP). Infants at high risk of CP demonstrate decreased selective motor control by 1 month of age. To motivate more selective hip-knee control, infants at high risk of CP participated in an in-home kicking-activated mobile task. The purpose of this study was to determine whether infants at high risk of CP and infants with typical development (TD) demonstrated increased selective hip-knee control during 2-minute intervals of the mobile task when they demonstrated learning of the association between their leg movement and mobile activation vs during 2-minute intervals when they did not demonstrate learning.

METHODS

Participants in this cohort study included 10 infants at high risk of CP based on neuroimaging and 11 infants with TD at 3.5 to 4.5 months of age. Each infant participated in the in-home kicking-activated mobile task for 8 to 10 min/d, 5 d/wk, for 6 weeks. Over 80,000 kicks were extracted and classified for each infant as occurring during 2-minute intervals of the task when the infant demonstrated learning vs not learning based on mobile activation time above baseline.

RESULTS

Infants demonstrated kicks with more selective hip-knee control during 2-minute intervals of the mobile task when they demonstrated learning compared with when they did not demonstrate learning for 4 of 6 weeks in the cohort at high risk of CP and for 2 of 6 weeks in the cohort with TD.

CONCLUSION

Participation in the in-home kicking-activated mobile task may motivate more selective hip-knee control of infants at high risk of CP.

IMPACT

This study is a first step toward developing an intervention to promote selective hip-knee control of infants at high risk of CP, with the ultimate goal of optimizing future walking function.

LAY SUMMARY

This study showed that playing with an in-home infant kicking-activated mobile may motivate infants at high risk of CP to produce more age-appropriate leg movements.

Selective Motor Control is a Clinical Correlate of Brain Motor Tract Impairment in Children with Spastic Bilateral Cerebral Palsy

BACKGROUND AND PURPOSE

Selective voluntary motor control is an important factor influencing gross motor function, interjoint coordination, and the outcome of hamstring-lengthening surgery in spastic cerebral palsy. Using DTI, we investigated whether selective voluntary motor control would show strong correlations with WM motor tract microstructure and whether selective voluntary motor control is more sensitive to global WM impairment than gross motor function.

MATERIALS AND METHODS

Children with spastic bilateral cerebral palsy born preterm and typically developing children were recruited. The Selective Control Assessment of the Lower Extremity (SCALE) and Gross Motor Function Measure (GMFM) were assessed in participants with cerebral palsy. Participants underwent brain MR imaging to collect DWI data. Tract-Based Spatial Statistics was used to analyze the WM for between-group differences and correlations with SCALE and GMFM. ROI analyses compared motor regions.

RESULTS

Twelve children with cerebral palsy (mean age, 11.5 years) and 12 typically developing children (mean age, 10.3 years) participated. Altered DTI outcomes were found throughout the whole brain for the cerebral palsy group. SCALE, developed to evaluate selective voluntary motor control in cerebral palsy, showed significant positive correlations with fractional anisotropy in more WM voxels throughout the whole brain and for motor regions, including the corticospinal tract and corpus callosum, compared with GMFM. A significant negative correlation between radial diffusivity and SCALE, but not GMFM, was found within the corpus callosum.

CONCLUSIONS

SCALE was a more sensitive clinical correlate of motor and whole-brain WM tract impairment in children with spastic bilateral cerebral palsy, suggesting greater anisotropy and myelination in these regions for those with higher selective voluntary motor control.

Determining the relationship between the impairment of selective voluntary motor control and gait deviations in children with cerebral palsy using simple video-based analyses

BACKGROUND

The impairment of selective voluntary motor control (SVMC) in children with cerebral palsy (CP) has been shown to correlate with their gait characteristics using complex 3D gait analysis systems (3DGA); however, this relationship has not been investigated using simple video-based observational gait analysis (VBOGA). The aim of this study was to determine the relationship between VBOGA and SVMC of the lower extremities in children with CP.

METHODS

Forty-two CP children 10.9 ± 5.7 years old with Gross Motor Function Classification System (GMFCS) levels I-III participated in the study. Their gait characteristics were assessed using the Edinburgh Visual Gait Score (EVGS), and selective voluntary motor control was tested using the Selective Control Assessment of the Lower Extremity (SCALE). Spearman's rho correlation test with Cohen's classification were used in the statistical analyses.

RESULTS

The GMFCS levels (r = 0.604, p < 0.001), foot clearance (r = -0.584. p < 0.001), and maximum ankle dorsiflexion (r =-0.567, p < 0.001) during the swing phase had strong correlations with total SCALE scores. There was also a moderate correlation between total SCALE scores and total EVGS (r =-0.494, p < 0.001), knee extension in the terminal swing phase (r = -0.353, p < 0.001), peak sagittal trunk position (r = -0.316, p < 0.005), and maximum lateral shift (r = -0.37, p < 0.001).

CONCLUSION

Impaired lower extremity SVMC was noticeably related to the foot and ankle movements in the swing phase and initial stance during walking as well as the total EVGS scores and sagittal and frontal trunk movements. The SCALE correlations with VBOGA were similar those observed in the complex 3DGA in the literature; therefore, we suggest that SVMC impairment of gait could be evaluated using simple VBOGA. These findings may help to tailor physical therapy programs for CP children to increase their motor control and walking quality.

Energetics of walking in individuals with cerebral palsy and typical development, across severity and age: A systematic review and meta-analysis

BACKGROUND

Individuals with cerebral palsy (CP) report physical fatigue as a main cause of limitation, deterioration and eventually cessation of their walking ability. A consequence of higher level of fatigue in individuals with CP leads to a less efficient and long-distance walking ability.

RESEARCH QUESTION

This systematic review investigates the difference in 1) walking energy expenditure between individuals with CP and age-matched typically developing (TD) individuals; and 2) energetics of walking across Gross Motor Function Classification System (GMFCS) levels and age.

METHODS

Five electronic databases (PubMed, Web of Science, CINAHL, ScienceDirect and Scopus) were searched using search terms related to CP and energetics of walking.

RESULTS

Forty-one studies met inclusion criteria. Thirty-one studies compared energy expenditure between CP and age-matched controls. Twelve studies correlated energy expenditure and oxygen cost across GMFCS levels. Three studies investigated the walking efficiency across different ages or over a time period. A significant increase of energy expenditure and oxygen cost was found in individuals with CP compared to TD age-matched individuals, with a strong relationship across GMFCS levels.

SIGNIFICANCE

Despite significant differences between individuals with CP compared to TD peers, variability in methods and testing protocols may play a confounding role. Analysis suggests oxygen cost being the preferred/unbiased physiological parameter to assess walking efficacy in CP. To date, there is a knowledge gap on age-related changes of walking efficiency across GMFCS levels and wider span of age ranges. Further systematic research looking at longitudinal age-related changes of energetics of walking in this population is warranted.

Infants born preterm and infants born full-term generate more selective leg joint movement during the scaffolded mobile task

Infants born very preterm (PT), prior to 32 weeks gestation, are at increased risk of developing cerebral palsy. Children with spastic cerebral palsy have impaired selective leg joint movement, which contributes to lifelong walking limitations. We investigated whether infants born PT generated more selective hip-knee joint movement (e.g., hip flexes as knee extends) while participating in a scaffolded mobile task. Infants born PT and infants born full-term (FT) at 4 months corrected age participated in a scaffolded mobile task for 2-3 consecutive days. The scaffolded mobile task required infants to raise their legs vertically over a virtual threshold. Three threshold heights (low, middle, and high) were used to test whether the middle and high heights encourage infants to move their legs more selectively. Fifteen infants born FT learned the task and showed more selective hip-knee movement at each of the three threshold heights on the day that they learned, compared with their baseline spontaneous kicking. Thirteen infants born PT learned the task and showed more selective hip-knee movement on their learning day, but only when the middle and high thresholds were used. The results show that the scaffolded mobile task effectively encouraged infants to generate more selective hip-knee joint movement.

Correlation between the Korean Version of the Trunk Control Measurement Scale and the Selective Control Assessment of the Lower Extremity Scores in Children with Cerebral Palsy

Background and Objectives: The purpose of this study was to investigate the correlation between the Korean version of the trunk control measurement scale (K-TCMS) and the selective control assessment of the lower extremity (SCALE). Through this, we tried to find out the effect of proximal stabilization on distal motor development. Materials and Methods: Fifty-one children with gross motor function classification system level I–III, diagnosed with cerebral palsy (CP), were studied. The K-TCMS was used to evaluate the body control ability of the children. SCALE was used to quantify selective voluntary motor control (SVMC). Results: Analysis of SCALE and K-TCMS showed a significant positive correlation in all items. Multiple regression analysis showed that the SCALE score decreased as age increased, and that it increased as the static sitting balance ability score and the dynamic sitting balance ability score of the K-TCMS increased significantly (p < 0.05). Conclusions: In children with cerebral palsy, there was a close correlation between trunk control and selective voluntary motor control of the lower extremities. Therefore, when trying to improve the lower extremity function of a child with cerebral palsy, a trunk control intervention should be considered.

Quantifying age-related differences in selective voluntary motor control in children and adolescents with three assessments

BACKGROUND

Neurophysiological development of selective voluntary motor control (SVMC) is assumed but has not been quantified objectively. We assessed SVMC with (i) clinical assessments, (ii) a combination of these assessments with surface electromyography (sEMG) and, (iii) a playful computer game. The aim of this study was to describe and compare age-related differences in SVMC, quantified with these tools, in neurologically intact children, adolescents, and adults.

METHODS

We measured upper and lower extremity SVMC with three assessments in 31 children and adolescents. A sample of 33 and 31 adults provided reference values for the upper and lower extremity assessments, respectively. The Selective Control of the Upper Extremity Scale (SCUES) or the Selective Control Assessment of the Lower Extremity (SCALE) were combined with simultaneous sEMG recordings. We quantified SVMC by a similarity index that compared an individual's muscle activation pattern with those of an adult reference group. The SVMC Assessgame required isolated joint movements to steer an avatar and quantified the accuracy of the selective movement and the extent of involuntary movements occurring in not involved joints.

RESULTS

Results from the conventional clinical assessments correlated low to moderately with age (SCUES: r = 0.55, p = 0.013; SCALE: r = 0.44, p = 0.001), while the correlation between the sEMG based similarity index and age was negligible (r ≤ 0.25). The outcomes of the Assessgame correlated highly with age (r ≥ 0.80, p ≤ 0.001). Older children and adolescents performed movements more accurately and with fewer involuntary movements compared to younger participants.

CONCLUSIONS

The tools assess and quantify SVMC differently, affecting the way they capture age-related differences in SVMC. Some assessments require reference values from neurologically intact children and adolescents to correctly classify impairments of SVMC in patients with neuromotor disorders.

In-Home Kicking-Activated Mobile Task to Motivate Selective Motor Control of Infants at High Risk of Cerebral Palsy: A Feasibility Study

OBJECTIVE

Children with spastic cerebral palsy (CP) have gait impairments resulting from decreased selective motor control, an inability to move the leg joints independently of one another, relying on excessive flexion or extension coupling across the 3 joints. Infants with white matter injury are at high risk of CP and have decreased selective motor control as early as 1 month corrected age. An in-home kicking-activated mobile task was developed to motivate more selective hip-knee control of infants at high risk of CP. The purposes of this study were to determine the feasibility of the in-home mobile task and to determine whether infants at high risk of CP and infants with typical development (TD) learn the association between their leg movements and mobile activation.

METHODS

Ten infants at high risk of CP based on neuroimaging and 11 infants with TD participated in this cohort study at 3.5 to 4.5 months corrected age. Each infant participated in the in-home kicking-activated mobile task for 8 to 10 min/d, 5 d/wk, for 6 weeks. Learning was assessed weekly based on an increase in the time that the infant demonstrated the reinforced leg actions when interacting with the kicking-activated mobile compared with spontaneous kicking.

RESULTS

With regard to feasibility, participation averaged 92% for infants at high risk of CP and 99% for infants with TD. With regard to learning, the group at high risk of CP demonstrated learning of the task for 2 of 6 weeks, whereas the group with TD demonstrated learning for all 6 weeks.

CONCLUSIONS

Infants at high risk of CP demonstrated learning of the kicking-activated mobile task but at a reduced amount compared with infants with TD. Further research is necessary to determine whether the kicking-activated mobile task has potential as an intervention to motivate more selective hip-knee control and improve walking outcomes of infants at high risk of CP.

IMPACT

This study investigated the feasibility of an in-home kicking-activated mobile task, a discovery learning task designed to motivate infants at high risk of CP to engage in the intensive task practice necessary to promote their learning abilities and selective motor control.

LAY SUMMARY

CP is a lifelong disorder of movement caused by abnormal development or early damage to the brain. If an in-home infant kicking-activated mobile task could be used to motivate certain types of age-appropriate leg movements of infants who are at high risk of CP, the task could help improve walking outcomes, which eventually could contribute to improving children's ability to participate in daily life. This study showed that infants at high risk of CP did learn the infant kicking-activated mobile task but at a much reduced amount compared with infants who are developing typically; so, this is a first step in determining whether the task has potential to motivate more age-appropriate leg movements in infants at high risk of cerebral palsy.

Brain Metabolism During A Lower Extremity Voluntary Movement Task in Children With Spastic Cerebral Palsy

Reduced selective voluntary motor control (SVMC) is a primary impairment due to corticospinal tract (CST) injury in spastic cerebral palsy (CP). There are few studies of brain metabolism in CP and none have examined brain metabolism during a motor task. Nine children with bilateral spastic CP [Age: 6-11 years, Gross Motor Function Classification System (GMFCS) Levels II-V] completed this study. SVMC was evaluated using Selective Control Assessment of the Lower Extremity (SCALE) ranging from 0 (absent) to 10 (normal). Brain metabolism was measured using positron emission tomography (PET) scanning in association with a selective ankle motor task. Whole brain activation maps as well as ROI averaged metabolic activity were correlated with SCALE scores. The contralateral sensorimotor and superior parietal cortex were positively correlated with SCALE scores (p < 0.0005). In contrast, a negative correlation of metabolic activity with SCALE was found in the cerebellum (p < 0.0005). Subsequent ROI analysis showed that both ipsilateral and contralateral cerebellar metabolism correlated with SCALE but the relationship for the ipsilateral cerebellum was stronger (R ² = 0.80, p < 0.001 vs. R ² = 0.46, p = 0.045). Decreased cortical and increased cerebellar activation in children with less SVMC may be related to task difficulty, activation of new motor learning paradigms in the cerebellum and potential engagement of alternative motor systems when CSTs are focally damaged. These results support SCALE as a clinical correlate of neurological impairment.

Is deep squat movement strategy related to floor-to-waist height lifting strategy: implications for physical employment testing

Generalised predictive tests may be viable screening tools to evaluate job candidate workability if movement strategy used in assessment is consistent with movement strategy used in work. This study investigated if deep squat (DS) kinematics could predict floor-to-waist height lifting kinematics. Participants performed three DS repetitions, and 10 lifts of both a 10 kg and 20 kg box. Whole body kinematics were collected to calculate knee, hip and low back angles, and coordination as measured by relative phase angles. Movement features of lower extremity control, including knee and hip angles and coordination, were significantly correlated (r = 0.43-0.85) between the DS and lifting. However, low back movement features, measures linked to injury risk, were not significantly correlated between the DS and lifting. These findings do not support the DS as a suitable movement screen to predict lifting strategy, specifically when considering low back control. Practitioner summary: This study investigated whether lifting strategy could be inferred from deep squat performance. Knee and hip movement strategies were associated between the deep squat and lifting. However, inconsistencies in low back control between the deep squat and lifting limit the deep squat's injury risk assessment potential.

Influence of impaired selective motor control on gait in children with cerebral palsy

PURPOSE

Spastic cerebral palsy (CP) is characterized by four neuromuscular deficits: weakness, short muscle-tendon unit, muscle spasticity and impaired selective motor control (SMC). We examined the influence of impaired SMC on gait in children with bilateral spastic CP. Delineating the influence of neuromuscular deficits on gait abnormalities can guide surgical and therapeutic interventions to reduce long-term debilitating effects of CP.

METHODS

The relationship between impaired SMC and gait was assessed using multivariate linear regression analysis of Selective Control Assessment of the Lower Extremity (SCALE) in relation to stance phase knee flexion and temporal-spatial gait parameters calculated using 3D kinematics for 57 children with bilateral spastic CP, ages seven to 11 years.

RESULTS

Mean SCALE values were 5.8 (0 to 10, sd 3.0) and 5.7 (0 to 10, sd 2.9) for right and left legs, respectively. Multivariate linear regression models, including right and left SCALE and height, significantly predicted right and left knee flexion at initial contact (R = 0.479, p = 0.003; R = 0.452, p = 0.007, respectively) and right and left knee flexion in midstance (R = 0.428, p = 0.013; R = 0.407, p = 0.022, respectively). The model significantly predicted right and left step length (R = 0.645, p = 0.000; R = 0.523, p = 0.001, respectively) and predicted gait velocity (R = 0.444, p = 0.008). The model including SCALE did not predict step width.

CONCLUSION

Results indicate impaired SMC predicts increased knee flexion at initial contact, and reduces step length and velocity. Understanding the influence of impaired SMC on gait can inform decisions regarding therapy and surgery, such as hamstring lengthening.

LEVEL OF EVIDENCE

Level II Retrospective Study.

Effects of personal and task constraints on limb coordination during walking: A systematic review and meta-analysis

BACKGROUND

In human behaviour, emergence of movement patterns is shaped by different, interacting constraints and consequently, individuals with motor disorders usually display distinctive lower limb coordination modes.

OBJECTIVES

To review existing evidence on the effects of motor disorders and different task constraints on emergent coordination patterns during walking, and to examine the clinical significance of task constraints on gait coordination in people with motor disorders.

METHODS

The search included CINHAL Plus, MEDLINE, HSNAE, SPORTDiscus, Scopus, Pubmed and AMED. We included studies that compared intra-limb and inter-limb coordination during gait between individuals with a motor disorder and able-bodied individuals, and under different task constraints. Two reviewers independently examined the quality of studies by using the Newcastle Ottawa Scale-cohort study.

FINDINGS

From the search results, we identified 1416 articles that studied gait patterns and further analysis resulted in 33 articles for systematic review and 18 articles for meta-analysis-1, and 10 articles for meta-analysis-2. In total, the gait patterns of 539 patients and 358 able-bodied participants were analysed in the sampled studies. Results of the meta-analysis for group comparisons revealed a low effect size for group differences (ES = -0.24), and a moderate effect size for task interventions (ES = -0.53), on limb coordination during gait.

INTERPRETATION

Findings demonstrated that motor disorders can be considered as an individual constraint, significantly altering gait patterns. These findings suggest that gait should be interpreted as functional adaptation to changing personal constraints, rather than as an abnormality. Results imply that designing gait interventions, through modifying locomotion tasks, can facilitate the emergent re-organisation of inter-limb coordination patterns during rehabilitation.

Selective motor control and gross motor function in bilateral spastic cerebral palsy

AIM

To investigate the relationship between selective motor control (SMC), muscle volume, and spasticity with gross motor function in adolescents and young adults with bilateral spastic cerebral palsy (CP).

METHOD

Eleven male participants with CP (mean age 15y 7mo, standard deviation 3y 6mo, range 12y 1mo-23y 1mo) in Gross Motor Function Classification System (GMFCS) levels I to IV took part in this cross-sectional study. Magnetic resonance imaging (MRI) of both lower limbs of all participants were acquired, from which 18 muscles were manually segmented and muscle volume calculated by a single assessor. Muscle volumes were normalized to body mass and averaged between limbs for each individual. SMC was assessed using Selective Control Assessment of the Lower Extremity (SCALE). Spasticity was assessed using the Modified Ashworth Scale (MAS), and gross motor functional ability was assessed using the Gross Motor Function Measure (GMFM-66).

RESULTS

GMFM-66 was strongly positively correlated to SCALE (r=0.901, p≤0.001) and lower limb muscle volume normalized to body mass (r=0.750, p=0.008). MAS was significantly correlated with GMFM-66 (r=-0.691, p=0.018).

INTERPRETATION

SMC is a major factor influencing gross motor function in individuals with CP. Lower limb muscle volume and spasticity also influence gross motor function.

WHAT THIS PAPER ADDS

Selective motor control is a major factor of gross motor function in adolescents and young adults with bilateral cerebral palsy (CP). Gross motor function is related to muscle size and level of spasticity in adolescents and young adults with bilateral CP.

Strength Training Effects on Muscle Forces and Contributions to Whole-Body Movement in Cerebral Palsy

Strength training is often prescribed for children with cerebral palsy (CP); however, links between strength gains and mobility are unclear. Nine children (age 14 ± 3 years; GMFCS I-III) with spastic CP completed a 6-week strength-training program. Musculoskeletal gait simulations were generated for four children to assess training effects on muscle forces and function. There were increases in isometric joint strength, but no statistical changes in fast-as-possible walking speed or endurance after training. The walking simulations revealed changes in muscle forces and contributions to body center of mass acceleration, with greater forces from the hip muscles during walking most commonly observed. A progressive strength-training program can result in isometric and dynamic strength gains in children with CP, associated with variable mobility outcomes.

Relationship between sensorimotor cortical activation as assessed by functional near infrared spectroscopy and lower extremity motor coordination in bilateral cerebral palsy

Background

Evaluation of task-evoked cortical responses during movement has been limited in individuals with bilateral cerebral palsy (CP), despite documented alterations in brain structure/function and deficits in motor control.

Objective

To systematically evaluate cortical activity associated with lower extremity tasks, and relate activation parameters to clinical measures in CP.

Methods

28 ambulatory participants (14 with bilateral CP and 14 with typical development) completed five motor tasks (non-dominant ankle dorsiflexion, hip flexion and leg cycling as well as bilateral dorsiflexion and cycling) in a block design while their sensorimotor cortex was monitored using functional near infrared spectroscopy (fNIRS), in addition to laboratory and clinical measures of performance.

Results

Main effects for group and task were found for extent of fNIRS activation (number of active channels; p < 0.001 and p = 0.010, respectively), magnitude of activation (sum of beta values; p < 0.001 for both), and number of active muscles (p = 0.001 and p < 0.001, respectively), but no group by task interactions. Collectively, subgroups with CP and especially those with greater impairments, showed higher extent and magnitude of cortical sensorimotor activation as well as higher amounts of concurrent activity in muscles not required for task performance. Magnitude of fNIRS activation during non-dominant dorsiflexion correlated with validated measures of selective control (r = −0.60, p = 0.03), as well as mobility and daily activity (r = −0.55, p = 0.04 and r = −0.52, p = 0.05, respectively) and self-reported gait function (r = −0.68, p = 0.01) in those with CP.

Conclusions

The association between higher activity in the sensorimotor cortex and decreased selectivity in cortical organization suggests a potential neural mechanism of motor deficits and target for intervention.

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First fNIRS comparison of a range of lower extremity tasks in children with and without bilateral CP.

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FNIRS showed a greater amount and extent of activation of sensorimotor cortices in CP.

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Greater activation correlated with a greater number of muscles involved in the task.

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fNIRS results correlated to clinical measures of motor control and function.

Dynamic spasticity determines hamstring length and knee flexion angle during gait in children with spastic cerebral palsy

BACKGROUND

Previous researchers reported that popliteal angle did not correlate well with knee angle during gait in individuals with spastic cerebral palsy (CP).

RESEARCH QUESTION

To determine if hamstring spasticity, as measured by Modified Tardieu Scale (MTS) at rest, is associated with knee flexion angle at initial contact and midstance during gait.

METHODS

Thirty ambulatory children (mean age 8.7 ± 2.4 years) diagnosed with spastic CP participated. The hamstrings' spasticity was assessed in the supine position with the MTS, measuring R1 (muscle reaction to passive fast stretch), R2 (passive range of motion), and R2-R1 (dynamic component of spasticity). We conducted 3-dimensional computerized gait analysis and calculated semimembranosus muscle-tendon length and lengthening velocity during gait using musculoskeletal modeling and inverse kinematic analysis by OpenSim. Pearson correlation coefficients were calculated to estimate the association of MTS with biomechanical parameters during gait.

RESULTS

Knee flexion angle at initial contact and maximal knee extension angle during stance phase significantly positively correlated with both R1 and ㅣR2 - R1ㅣ of MTS, but not with R2 angle. The length of semimembranosus at initial contact, end of swing, and minimal length during stance phase were strongly negatively associated with R1, rather than R2 or ㅣR2 - R1ㅣ angles.

SIGNIFICANCE

The R1 angle of MTS (muscle reaction to passive fast stretch) is more relevant correlate of knee flexion angle during gait than the R2 (passive range of motion).

γδT cells but not αβT cells contribute to sepsis-induced white matter injury and motor abnormalities in mice

BACKGROUND

Infection and sepsis are associated with brain white matter injury in preterm infants and the subsequent development of cerebral palsy.

METHODS

In the present study, we used a neonatal mouse sepsis-induced white matter injury model to determine the contribution of different T cell subsets (αβT cells and γδT cells) to white matter injury and consequent behavioral changes. C57BL/6J wild-type (WT), T cell receptor (TCR) δ-deficient (Tcrd ^-/-, lacking γδT cells), and TCRα-deficient (Tcra ^-/-, lacking αβT cells) mice were administered with lipopolysaccharide (LPS) at postnatal day (PND) 2. Brain myelination was examined at PNDs 12, 26, and 60. Motor function and anxiety-like behavior were evaluated at PND 26 or 30 using DigiGait analysis and an elevated plus maze.

RESULTS

White matter development was normal in Tcrd ^-/- and Tcrα ^-/- compared to WT mice. LPS exposure induced reductions in white matter tissue volume in WT and Tcrα ^-/- mice, but not in the Tcrd ^-/- mice, compared with the saline-treated groups. Neither LPS administration nor the T cell deficiency affected anxiety behavior in these mice as determined with the elevated plus maze. DigiGait analysis revealed motor function deficiency after LPS-induced sepsis in both WT and Tcrα ^-/- mice, but no such effect was observed in Tcrd ^-/- mice.

CONCLUSIONS

Our results suggest that γδT cells but not αβT cells contribute to sepsis-induced white matter injury and subsequent motor function abnormalities in early life. Modulating the activity of γδT cells in the early stages of preterm white matter injury might represent a novel therapeutic strategy for the treatment of perinatal brain injury.

Infant intralimb coordination and torque production: Influence of prematurity

The purpose of this study is to investigate changes in leg joint coordination, intersegmental dynamics, and their relation in infants born preterm (PT) during the first months of life. Kicking actions were analyzed of 11 infants born PT at 6 and 15-weeks corrected age (CA) using three-dimensional kinematics and kinetics; results were compared to the kicking actions of 10 infants born full-term (FT). Both groups changed from a predominately in-phase coordination at 6-weeks CA to a less in-phase coordination at 15-weeks CA, however, at 6-weeks CA, infants born PT demonstrated less in-phase coordination of their ankle joints with their hip and knee joints. Between groups and across ages, both groups demonstrated consistent net and partitioned joint torque profiles, however, at 6-weeks CA infants born PT demonstrated more complex patterns of torque components. In both groups, less in-phase hip-knee coordination was associated with reduced active knee muscle torque and increased passive knee torques, however, passive knee torques had a greater influence on the kicks of infants born PT at 6-weeks CA. At 6-weeks CA, infants born PT, compared to FT, generated kicks with less in-phase hip-knee coordination, hip excursion, hip angular velocity, and hip muscle torque impulse. By 15-weeks CA, differences resolved in all variables except hip muscle torque impulse. These results highlight a different trajectory of leg joint coordination and torque production for infants born PT compared to FT.

Spastic diparetic does not directly affect the capacity to ascend and descend access ramps: three-dimensional analysis

Abstract Introduction: Diplegic children have difficulties in gait and therefore ramps are used as strategies of accessibility. Objective: The present study investigated the influence of an inclined surface (ascending and descending) on the kinematic characteristics during gait of the diplegic group (DG) when compared to typically developing children of the control group (CG). Methods: Study participants included 20 children (10 with DG and 10 CG) matched by age, which were evaluated in three experimental conditions (horizontal and inclined ascending and inclined descending surfaces of 7º) through an optoelectronic imaging system. Results: Among the linear kinematic variables, only step width differed among groups, however, without influence of the surface. The foot height differed among the groups only in the descending phase, where DG had greater difficulty in raising the foot. The 3-dimensional gait analyses could not provide more evidences of differences in kinematics variables, especially in transverse plane, between DG and CG, but provide some evidence to support that hip range of motion (ROM) during the gait cycle, hip flexion-extension in initial contact, knee ROM and the 2nd anterior-posterior trunk peak amplitude of the DG were influenced on descent by their flexor pattern. Conclusion: The DG was most affected by the inclination plane than CG especially on descent. Although a hip and knee flexor pattern is evident for DG on inclination of 7º, this angle is accessible since it allows independent gait functional activity.

Selective voluntary motor control measures of the lower extremity in children with upper motor neuron lesions: a systematic review

AIM

Recovery and trainability of impaired selective voluntary motor control (SVMC) of the lower extremity in children with upper motor neuron lesions has received little attention. To facilitate an evidence-based debate about this topic, this review evaluates the evidence level of the psychometric properties of SVMC measures.

METHOD

MEDLINE, Embase, CINAHL, PsycINFO, Scopus, Cochrane and PEDro databases were systematically searched up to July 2016. Two independent raters scored the methodological quality in accordance to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. The overall level of evidence was scored according to Cochrane criteria.

RESULTS

We identified 3590 studies, of which 17 were included. COSMIN scores ranged from 'poor' to 'excellent' for studies investigating measurement properties of the Selective Motor Control test, modified Trost test, Gillette's Selective Motor Control test, Selective Control Assessment of the Lower Extremity (SCALE), kinematic measures, electromyography, and torque steadiness. Studies assessing the SCALE scored highest on COSMIN items. Evidence levels for SCALE's validity and reliability properties were moderate, while for the other SVMC measures these ranged from unknown to moderate. Responsiveness was not assessed.

INTERPRETATION

Further psychometric studies of SVMC measures are needed to provide a scientific contribution to the ongoing debate of SVMC trainability.

Real-time feedback to improve gait in children with cerebral palsy

Real-time feedback may be useful for enhancing information gained from clinical gait analysis of children with cerebral palsy (CP). It may also be effective in functional gait training, however, it is not known if children with CP can adapt gait in response to real-time feedback of kinematic parameters. Sixteen children with cerebral palsy (age 6-16; GMFCS I-III), walking with a flexed-knee gait pattern, walked on an instrumented treadmill with virtual reality in three conditions: regular walking without feedback (NF), feedback on hip angle (FH) and feedback on knee angle (FK). Clinically relevant gait parameters were calculated and the gait profile score (GPS) was used as a measure of overall gait changes between conditions. All children, except one, were able to improve hip and/or knee extension during gait in response to feedback, with nine achieving a clinically relevant improvement. Peak hip extension improved significantly by 5.1±5.9° (NF: 8.9±12.8°, FH: 3.8±10.4°, p=0.01). Peak knee extension improved significantly by 7.7±7.1° (NF: 22.2±12.0°, FK: 14.5±12.7°, p<0.01). GPS did not change between conditions due to increased deviations in other gait parameters. Responders to feedback were shown to have worse initial gait as measured by GPS (p=0.005) and functional selectivity score (p=0.049). In conclusion, ambulatory children with CP show adaptability in gait and are able to respond to real-time feedback, resulting in significant and clinically relevant improvements in peak hip and knee extension. These findings show the potential of real-time feedback as a tool for functional gait training and advanced gait analysis in CP.

Selective motor control correlates with gait abnormality in children with cerebral palsy

Children with bilateral cerebral palsy (CP) commonly have limited selective motor control (SMC). This affects their ability to complete functional tasks. The impact of impaired SMC on walking has yet to be fully understood. Measures of SMC have been shown to correlate with specific characteristics of gait, however the impact of SMC on overall gait pattern has not been reported. This study explored SMC data collected as part of routine gait analysis in children with bilateral CP. As part of their clinical assessment, SMC was measured with the Selective Control Assessment of the Lower Extremities (SCALE) in 194 patients with bilateral cerebral palsy attending for clinical gait analysis at a single centre. Their summed SCALE score was compared with overall gait impairment, as measured by Gait Profile Score (GPS). Score on SCALE showed a significant negative correlation with GPS (r_s=-0.603, p<0.001). Cerebral injuries in CP result in damage to the motor tracts responsible for SMC. Our results indicate that this damage is also associated with changes in the development of walking pattern in children with CP.

25 years of lower limb joint kinematics by using inertial and magnetic sensors: A review of methodological approaches

Joint kinematics is typically limited to the laboratory environment, and the restricted volume of capture may vitiate the execution of the motor tasks under analysis. Conversely, clinicians often require the analysis of motor acts in non-standard environments and for long periods of time, such as in ambulatory settings or during daily life activities. The miniaturisation of motion sensors and electronic components, generally associated with wireless communications technology, has opened up a new perspective: movement analysis can be carried out outside the laboratory and at a relatively lower cost. Wearable inertial measurement units (embedding 3D accelerometers and gyroscopes), eventually associated with magnetometers, allow one to estimate segment orientation and joint angular kinematics by exploiting the laws governing the motion of a rotating rigid body. The first study which formalised the problem of the estimate of joint kinematics using inertial sensors dates back to 1990. Since then, a variety of methods have been presented over the past 25 years for the estimate of 2D and 3D joint kinematics by using inertial and magnetic sensors. The aim of the present review is to describe these approaches from a purely methodological point of view to provide the reader with a comprehensive understanding of all the instrumental, computational and methodological issues related to the estimate of joint kinematics when using such sensor technology.

Relation of selective voluntary motor control of the lower extremity and extensor strength of the knee joint in children with spastic diplegia

[Purpose] The aim of this study was to investigate differences in selective voluntary motor control of the lower extremities by objective assessment and determine the relationship between selective voluntary motor control and knee extensor strength in children with spastic diplegia. [Subjects and Methods] Forty individuals who had spastic cerebral palsy, with Gross Motor Function Classification System levels ranging from I to III, were assessed using the Selective Control Assessment of the Lower Extremity and by testing the maximum knee extensor strength. The unaffected side was defined as the lower limb with the higher score, and the affected side was defined as the lower limb with the lower score. [Results] The Selective Control Assessment of the Lower Extremity score on the affected side had a lower average than that on the unaffected side. The scores showed a significant inverse correlation with the maximum knee extensor strength. [Conclusion] There was bilateral difference in the selective voluntary motor control of the lower extremities in children with spastic diplegia, and the selective voluntary motor control of the lower extremity was related to maximum knee extensor strength.

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.

Clinical motion analyses over eight consecutive years in a child with crouch gait: a case report

BACKGROUND

This case report provides a unique look at the progression of crouch gait in a child with cerebral palsy over an 8-year time period, through annual physical examinations, three-dimensional gait analyses, and evaluation of postural balance. Our patient received regular botulinum toxin-A injections, casting, and physical therapy but no surgical interventions.

CASE PRESENTATION

A white American boy with spastic diplegic cerebral palsy was evaluated annually by clinical motion analyses, including physical examination, joint kinematics, electromyography, energy expenditure, and standing postural balance tests, from 6 to 13 years of age. These analyses revealed that the biomechanical factors contributing to our patient's crouch gait were weak plantar flexors, short and spastic hamstrings, moderately short hip flexors, and external rotation of the tibiae. Despite annual recommendations for surgical lengthening of the hamstrings, the family opted for non-surgical treatment through botulinum toxin-A injections, casting, and exercise. Our patient's crouch gait improved between ages 6 and 9, then worsened at age 10, concurrent with his greatest body mass index, increased plantar flexor weakness, increased standing postural sway, slowest normalized walking speed, and greatest walking energy expenditure. Although our patient's maximum knee extension in stance improved by 14 degrees at 13 years of age compared to 6 years of age, peak knee flexion in swing declined, his ankles became more dorsiflexed, his hips became more internally rotated, and his tibiae became more externally rotated. From 6 to 9 years of age, our patient's minimum stance-phase knee flexion varied in an inverse relationship with his body mass index; from 10 to 13 years of age, changes in his minimum stance-phase knee flexion paralleled changes in his body mass index.

CONCLUSIONS

The motor deficits of weakness, spasticity, shortened muscle-tendon lengths, and impaired selective motor control were highlighted by our patient's clinical motion analyses. Overall, our patient's crouch gait improved mildly with aggressive non-operative management and a supportive family dedicated to regular home exercise. The annual clinical motion analyses identified changes in motor deficits that were associated with changes in the child's walking pattern, suggesting that these analyses can serve to track the progression of children with spastic cerebral palsy.

Selective Control of the Upper Extremity Scale: validation of a clinical assessment tool for children with hemiplegic cerebral palsy

AIM

The ability to determine the relationship between selective motor control and upper extremity function in children with unilateral cerebral palsy (CP), and to measure the functional outcome and efficacy of interventions designed to improve selective motor control, has been limited by the lack of an objective, validated tool. The primary objective of this study is to describe the development of a clinical tool entitled Selective Control of the Upper Extremity Scale (SCUES), and present evidence of its validity and reliability.

METHOD

Content validity was established through an expert panel (eight clinicians, mean and median of 17y of clinical experience, range 2-30y). Intra- and interrater reliability was determined by six occupational therapists who scored 10 participant studies. Construct validity of the SCUES was established by comparison to the spontaneous functional analysis section of the Shriners Hospitals Upper Extremity Evaluation, the Manual Ability Classification System, and the Box and Block test for 25 children with unilateral CP.

RESULTS

The content validity ratio values were greater than 0 (indicating >50% agreement) for 33 of the 34 items (97%), and equal or greater than 0.5 (indicating ≥75% agreement) for 26 of the 34 items (76%). Intrarater reliability was excellent (intraclass correlation coefficient [ICC] >0.75) for all segments and joints of the affected extremity. Interrater reliability was excellent for all segments and joints of the affected extremity except the shoulder (ICC=0.72). The SCUES was strongly correlated with the SHUEE (Spearman's rho=0.69, p=0.003). The SCUES was not correlated with the Manual Ability Classification System (rho=-0.24, p=0.369) or the Box and Block test (rho=0.47, p=0.066).

INTERPRETATION

Psychometric analysis of the SCUES revealed comparable validity to other accepted video-based clinical assessment tools for the upper extremity in children with CP.

Construct validity and reliability of the Selective Control Assessment of the Lower Extremity in children with cerebral palsy

AIM

Assessing impaired selective voluntary movement control in children with cerebral palsy (CP) has gained increasing interest. We investigated construct validity and intra- and interrater reliability of the Selective Control Assessment of the Lower Extremity (SCALE).

METHOD

Thirty-nine children (21 males, 18 females) with spastic CP, mean age 12 years 6 months [range 6y 11mo-19y 9mo], Gross Motor Function Classification System (GMFCS) levels I to IV, participated. Differences in SCALE scores were determined on joint levels and between patients categorized according to their limb distribution and GMFCS levels. SCALE scores were correlated with the Fugl-Meyer Assessment, Manual Muscle Test, and Modified Ashworth Scale. To determine reliability, the SCALE was applied once and recorded on video.

RESULTS

SCALE scores differed significantly between the less and more affected leg (p<0.001) and between most leg joints. Total SCALE scores differed significantly between GMFCS levels I and II. Correlations with Fugl-Meyer Assessment, Manual Muscle Test, and Modified Ashworth Scale were 0.88, 0.88, and -0.55 respectively. Intraclass correlation coefficients were all above 0.9, with the minimal detectable change below 2 points.

INTERPRETATION

The SCALE appears to be a valid and reliable tool to assess selective voluntary movement control of the legs in children with spastic CP.

Correlation between the selective control assessment of lower extremity and pediatric balance scale scores in children with spastic cerebral palsy

[Purpose] The purpose of this study was to investigate the correlation between the Selective Control Assessment of Lower Extremity (SCALE) and Pediatric Balance Scales (PBS) in children with spastic cerebral palsy and further to test whether the SCALE is a valid tool to predict the PBS. [Subjects and Methods] A cross-sectional study was conducted to evaluate the SCALE and PBS in 23 children (9 females, 14 males, GMFCS level I–III) with spastic cerebral palsy. [Results] Both the SCALE and PBS scores for children with spastic hemiplegia were significantly higher than those for children with spastic diplegia. The scores for SCALE items were low for distal parts. The PBS items that were difficult for the participants to perform were items 8, 9, 10, and 14 with the highest difficulty experienced for item 8 followed by items 9, 10, and 14. The correlation coefficient (0.797) between the SCALE and PBS scores was statistically significant. The correlations between each SCALE item and the PBS scores were also statistically significant. SCALE items were significantly correlated with two PBS dimensions (standing and postural change). [Conclusion] In SCALE assessment, more severe deficits were observed in the distal parts. Standing and postural changes in the PBS method were difficult for the participants to perform. The two tests, that is, the SCALE and PBS, were highly correlated. Therefore, the SCALE is useful to prediction of PBS outcomes and is also applicable as a prognostic indicator for treatment planning.

Cortical somatosensory reorganization in children with spastic cerebral palsy: a multimodal neuroimaging study

Although cerebral palsy (CP) is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities [magnetoencephalography (MEG), diffusion tensor imaging (DTI), and resting-state fMRI] whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP), three with hemiplegic CP (HCP), and three typically developing (TD) children. Somatosensory (SS)-evoked fields (SEFs) were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the pre-central and post-central gyri in both hemispheres. The sensorimotor resting-state networks (RSNs) were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50 ms, in all except one child, localized over the primary SS cortex (S1). In five CP children, abnormal somatotopic organization was observed in the affected (or more affected) hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Resting-state functional MRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal SS processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections.

Etiology of impaired selective motor control: emerging evidence and its implications for research and treatment in cerebral palsy

Selective motor control (SMC) impairment involves movement patterns dominated by flexor or extensor synergies that interfere with functional movements in children with cerebral palsy (CP). Emerging evidence on neural correlates of impaired SMC has important implications for etiology and for the treatment for children with CP. Early evidence on the microstructure of brain white matter assessed with diffusion tensor imaging in adult patients after stroke suggests that the rubrospinal tract may compensate for injury to the corticospinal tract. Furthermore, the observed changes on diffusion tensor imaging corresponded to the degree of SMC impairment. The rubrospinal tract may provide imperfect compensation in response to corticospinal tract injury, resulting in diminished SMC. Cortical mapping evidence in stroke patients indicates that loss of SMC is also associated with increased overlap of joint representation in the sensorimotor cortices. The severity of SMC impairment can be assessed with the recently developed Selective Control Assessment of the Lower Extremity, a validated observation-based measure designed for children with spastic CP. Recent advances in neuroimaging and assessment of SMC provide an opportunity to better understand the etiology and impact of impaired SMC, which may ultimately guide strategic treatment for children with CP.

Infant exploratory learning: influence on leg joint coordination

A critical issue in the study of infant development is to identify the processes by which task-specific action emerges from spontaneous movement. Emergent leg action has been studied by providing contingent reinforcement to specific leg movements using an overhead infant-activated mobile, however, there is limited information on the strategies used by infants to support the emergence of task-specific leg action from spontaneous movement. The purpose of this study is to (1) determine the ability of 3 month old infants to learn, through discovery, the contingency between leg action and mobile activation using a virtual threshold, and (2) identify strategies, defined by variance of the end-effectors (feet) and hip-knee joint coordination, used by infants that learned the contingency. Fourteen 3 month old infants participated in 2 sessions of mobile reinforcement on consecutive days. As a group, infants increased the percentage of mobile activation to meet performance criteria on Day 2, but did not meet memory or learning criteria across days. However, five infants learned the contingency based on individual learning criteria. When interacting with the mobile on Day 2 as compared to spontaneous kicking on Day 1, infants who learned the contingency, but not infants who did not learn the contingency, increased variance of the end-effectors (feet) in the vertical, task-specific direction and demonstrated less in-phase hip-knee joint coordination. An important discovery is that infants can discover this very specific contingency, suggesting that this movement behavior (action) can be shaped in future work. This may have implications for the rehabilitation of infants with atypical leg action.

NeuroGame Therapy to improve wrist control in children with cerebral palsy: a case series

OBJECTIVE

This case series examines the feasibility, specificity, and preliminary effectiveness of NeuroGame Therapy (NGT) for improving wrist control in four children with cerebral palsy (CP). NGT uses surface electromyographic (sEMG) signals routed through motivating computer games to improve motor control.

METHODS

Primary outcomes of NGT included feasibility (hours of play) and specificity (changes in sEMG activity during game play). Secondary outcomes included changes in co-contraction, range of motion, segmental alignment, and spontaneous upper extremity function following intervention.

RESULTS

Participants completed a mean of 8.8 hours of NGT over 5-6 weeks. Participants demonstrated dramatic improvement of the sEMG activity during game play. Several participants also showed improvements in range of motion, co-contraction, and spontaneous upper extremity function following NGT.

CONCLUSION

This case series provides evidence for the feasibility, specificity, and effectiveness of NGT. Future studies will pair NGT with functional practice to improve transfer of learning to daily activities.

Deficits in anticipatory inhibition of postural muscle activity associated with load release while standing in individuals with spastic diplegic cerebral palsy

This study aimed to determine whether individuals with spastic diplegic cerebral palsy (SDCP) have deficits in anticipatory inhibition of postural muscle activity. Nine individuals with SDCP (SDCP group, 3 female and 6 male, 13–24 yr of age) and nine age- and sex-matched individuals without disability (control group) participated in this study. Participants stood on a force platform, which was used to measure the position of the center of pressure (CoP), while holding a light or heavy load in front of their bodies. They then released the load by abducting both shoulders. Surface electromyograms were recorded from the rectus abdominis, erector spinae (ES), rectus femoris (RF), medial hamstring (MH), tibialis anterior (TA), and gastrocnemius (GcM) muscles. In the control group, anticipatory inhibition before load release and load-related modulation of the inhibition were observed in all the dorsal muscles recorded (ES, MH, and GcM). In the SDCP group, similar results were obtained in the trunk muscle (ES) but not in the lower limb muscles (MH and GcM), although individual differences were seen, especially in MH. Anticipatory activation of the ventral lower limb muscles (RF and TA) and load-related modulation of the activation were observed in both participant groups. CoP path length during load release was longer in the SDCP group than in the control group. The present findings suggest that individuals with SDCP exhibit deficits in anticipatory inhibition of postural muscles at the dorsal part of the lower limbs, which is likely to result in a larger disturbance of postural equilibrium.

Interjoint Coordination and the Personal Lift-Assist Device

It has been suggested that interjoint coordination may serve to reduce joint stress and muscular demand and to maintain balance during dynamic lifting tasks, thus having implications for safe lifting practices. Before recommending the use of an on-body ergonomic aid, the Personal Lift-Assist Device (PLAD), it is important to determine any effects this device may have on interjoint coordination. Principal component analyses were applied to relative phase angle waveforms, defining the hip–knee and lumbar spine–hip coordination of 15 males and 15 females during a repetitive lifting task. When wearing the PLAD, users lifted with more synchronous hip–knee and lumbar spine–hip coordination patterns (P< .01). Furthermore, increases in load caused less synchronized interjoint coordination at both the hip–knee and lumbar spine–hip during the up and down phases of the lift (P< .01) for all conditions. No significant main effects of sex or significant interactions were observed on any of the outcome variables.

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.

Lower-limb joint coordination pattern in obese subjects

The coordinative pattern is an important feature of locomotion that has been studied in a number of pathologies. It has been observed that adaptive changes in coordination patterns are due to both external and internal constraints. Obesity is characterized by the presence of excess mass at pelvis and lower-limb areas, causing mechanical constraints that central nervous system could manage modifying the physiological interjoint coupling relationships. Since an altered coordination pattern may induce joint diseases and falls risk, the aim of this study was to analyze whether and how coordination during walking is affected by obesity. We evaluated interjoint coordination during walking in 25 obese subjects as well as in a control group. The time-distance parameters and joint kinematics were also measured. When compared with the control group, obese people displayed a substantial similarity in joint kinematic parameters and some differences in the time-distance and in the coupling parameters. Obese subjects revealed higher values in stride-to-stride intrasubjects variability in interjoint coupling parameters, whereas the coordinative mean pattern was unaltered. The increased variability in the coupling parameters is associated with an increased risk of falls and thus should be taken into account when designing treatments aimed at restoring a normal locomotion pattern.