Comparing the Lower-Limb Muscle Activation Patterns of Simulated Walking Using an End-Effector-Type Robot with Real Level and Stair Walking in Children with Spastic Bilateral Cerebral Palsy.

Cerebral palsy is a neurologic disorder caused by lesions on an immature brain, often resulting in spasticity and gait abnormality. This study aimed to compare the muscle activation patterns of real level and stair walking with those of simulated walking using an end-effector-type robot in children with spastic cerebral palsy. The electromyographic activities of the vastus lateralis, biceps femoris, tibialis anterior and medial gastrocnemius of nine children with spastic bilateral cerebral palsy were measured during gait using a wireless surface EMG device. Morning walk was used for the simulated gait. Differences in the muscle activation patterns between the real and simulated gait conditions were analyzed. In the loading response, all four muscles showed reduced activity during two simulated conditions. In mid-stance, mGCM showed reduced activity during simulated conditions, whereas BFem showed greater activity during simulated level walking. In the swing phase, BFem and TAnt activity was reduced during the simulated conditions. The onset-offset of the VLat, BFem and TAnt activity was significantly delayed during simulated versus real level walking. No differences in activity onset-offset were observed between the simulated level and stair conditions. In conclusion, the robot-simulated gait showed differences in its muscle activation patterns compared with the real gait conditions, which must be considered for gait training using an end-effector-type robot.

The Effects of Wearing Facemasks during Vigorous Exercise in the Aspect of Cardiopulmonary Response, In-Mask Environment, and Subject Discomfort.

Non-pharmaceutical intervention such as wearing a mask during the pandemic of SARS-CoV-2 is one of the most important ways to prevent the spread of the virus. However, despite high effectiveness and easy to access, the biggest problem is 'discomfort'. The purpose of this study was to measure the changes of cardiopulmonary response and related factors affecting breathing discomfort when wearing a mask during vigorous exercise. Fifteen healthy male adults participated in this study. The experimental protocol consisted of three conditions: no mask; KF-94 mask; and sports mask. Each condition consisted of three stages: stage I, 2 m/s on even level; stage II, 2 m/s with 5° inclination; and stage III, 3 m/s on even level. Oxygen saturation (SaO2) and heart rate (HR), partial pressure of carbon dioxide (pCO2), energy expenditure index (EEI), in-mask temperature, humidity, and a five-point scale questionnaire to evaluate subjective discomfort were measured. The results show that there was a significantly higher discomfort score in mask conditions compared with no mask (p < 0.05) and only pCO2 change significantly related to subjective discomfort during exercise (p < 0.05). Moreover, the pCO2 washout was significantly disturbed when wearing a sports mask in stages 2 and 3, which was related to wearer subjective discomfort.

Gait Adaptation Is Different between the Affected and Unaffected Legs in Children with Spastic Hemiplegic Cerebral Palsy While Walking on a Changing Slope.

Walking on sloped surfaces requires additional effort; how individuals with spastic hemiplegic cerebral palsy (CP) manage their gait on slopes remains unknown. Herein, we analyzed the difference in gait adaptation between the affected and unaffected legs according to changes in the incline by measuring spatiotemporal and kinematic data in children with spastic hemiplegic CP. Seventeen children underwent instrumented three-dimensional gait analysis on a dynamic pitch treadmill at an incline of +10° to -10° (intervals of 5°). While the step length of the affected legs increased during uphill gait and decreased during downhill gait, the unaffected legs showed no significance. During uphill gait, the hip, knee, and ankle joints of the affected and unaffected legs showed increased flexion, while the unaffected leg showed increased knee flexion throughout most of the stance phase compared with the affected leg. During downhill gait, hip and knee flexion increased in the affected leg, and knee flexion increased in the unaffected leg during the early swing phase. However, the ankle plantar flexion increased during the stance phase only in the unaffected leg. Although alterations in temporospatial variables and joint kinematics occurred in both legs as the slope angle changed, they showed different adaptation mechanisms.

Evaluation of sitting and standing postural balance in cerebral palsy by center-of-pressure measurement using force plates: comparison with clinical measurements.

BACKGROUND: Center-of-pressure (CoP) measurements have been studied for assessing balance control. While CoP measurements using force plates have been used to assess standing balance in children with cerebral palsy (CP), it has not been assessed in a sitting position, which specifically reflects trunk postural control. RESEARCH QUESTION: The purpose of this study was to compare CoP measurements using force plates during both standing and sitting trials with the Pediatric Balance Scale (PBS) in children with spastic CP. METHODS: We recruited 26 children with spastic CP (7.8 ±â€¯3.4 years, 4-13 years) and used the PBS, a validated evaluation tool that measures static and dynamic balance control. We took CoP measurements using force plates during sitting and standing. For both trials, subjects stayed still for 10 s with their eyes open or closed. We calculated the CoP velocity, mediolateral (ML) and anteroposterior (AP) velocity, and ML and AP displacements of CoP. RESULTS AND SIGNIFICANCE: During standing trials, static PBS standing scores negatively correlated with more AP displacement and velocity than ML displacement and velocity (p < 0.05). During sitting trials, dynamic PBS sitting scores negatively correlated with ML displacement and velocity (p < 0.05). CoP parameters in the ML direction of the sitting position and CoP parameters in the AP direction of the standing position may better reflect the balance control in children with spastic CP.

Analysis of foot kinematics during toe walking in able-bodied individuals using the Oxford Foot Model.

Various neurological and musculoskeletal disorders can induce pathologic toe walking and lead to changes in foot kinematics. In this study, we analyzed the differences in foot kinematics between toe walking and heel-toe walking (HW) in able-bodied individuals. Twenty young healthy adults performed three gaits: HW, comfortable-height toe walking (CTW), and maximum-height toe walking (MTW). Oxford Foot Model was used for gait analysis. Toe walking showed increase of forefoot plantarflexion and hindfoot internal rotation compared to HW. Thus, our results may help distinguish the pathologic mechanism of the equinus gait in various disorders from the kinematic change of toe walking itself.

Overground Robot-Assisted Gait Training for Pediatric Cerebral Palsy.

The untethered exoskeletal robot provides patients with the freest and realistic walking experience by assisting them based on their intended movement. However, few previous studies have reported the effect of robot-assisted gait training (RAGT) using wearable exoskeleton in children with cerebral palsy (CP). This pilot study evaluated the effect of overground RAGT using an untethered torque-assisted exoskeletal wearable robot for children with CP. Three children with bilateral spastic CP were recruited. The robot generates assistive torques according to gait phases automatically detected by force sensors: flexion torque during the swing phase and extension torque during the stance phase at hip and knee joints. The overground RAGT was conducted for 17~20 sessions (60 min per session) in each child. The evaluation was performed without wearing a robot before and after the training to measure (1) the motor functions using the gross motor function measure and the pediatric balance scale and (2) the gait performance using instrumented gait analysis, the 6-min walk test, and oxygen consumption measurement. All three participants showed improvement in gross motor function measure after training. Spatiotemporal parameters of gait analysis improved in participant P1 (9-year-old girl, GMFCS II) and participant P2 (13-year-old boy, GMFCS III). In addition, they walked faster and farther with lower oxygen consumption during the 6-min walk test after the training. Although participant P3 (16-year-old girl, GMFCS IV) needed the continuous help of a therapist for stepping at baseline, she was able to walk with the platform walker independently after the training. Overground RAGT using a torque-assisted exoskeletal wearable robot seems to be promising for improving gross motor function, walking speed, gait endurance, and gait efficiency in children with CP. In addition, it was safe and feasible even for children with severe motor impairment (GMFCS IV).