Health monitoring of young children with Down syndrome: A parent-report study

© 2019 John Wiley & Sons Ltd.Background: Children with Down syndrome have an increased risk of serious health conditions, particularly in early childhood. Published guidelines promote the identification and monitoring of health issues and adherence could reduce health inequalities, yet there is limited research about the extent to which health monitoring occurs as recommended. This study aimed to investigate the health monitoring of children with Down syndrome aged 0–5 years in the UK. Materials and Methods: Twenty-four parents of children with Down syndrome with a mean age of 32 months (10–65 months) participated. They completed a questionnaire about their child's healthcare usage, diagnoses of health conditions and whether health checks had been completed at birth and since birth. The results of the questionnaires were charted and compared to the schedule of checks produced by the Down Syndrome Medical Interest Group UK. Results: Children with Down syndrome had high usage of health services and reported significant health issues. There was high adherence to published guidelines for the majority of health checks at birth, although 38% of children had not received all recommended checks. Not all health domains had been monitored since birth for all children, particularly breathing and blood (excluding thyroid). With the potential exception of sleep apnoea, diagnosed conditions appeared to be monitored. Conclusions: This study suggests that health monitoring after birth and screening for nondiagnosed health conditions is variable for children with Down syndrome. Further research should examine convergence of these findings with medical records and clinicians' experiences across the UK.Peer reviewedFinal Accepted Versio

Effects of gravitational forces on single joint arm movements in humans

We have examined the kinematics and muscle activation patterns of single joint elbow movements made in the vertical plane. Movements of different amplitudes were performed during a visual, step-tracking task. By adjusting shoulder position, both elbow flexion and extension movements were made under three conditions: (a) in the horizontal plane, (b) in the vertical plane against gravity, and (c) in the vertical plane with gravity. Regardless of the gravitational load, all movements were characterized by time symmetric velocity profiles. In addition, no differences were found in the relationships between movement duration, peak velocity, and movement amplitude in movements with or against gravity. The pattern of muscle activation was influenced however, by the gravitational load. Both flexion and extension movements made with gravity were characterized by a reciprocally organized pattern of muscle activity in which phasic agonist activity was followed by phasic antagonist activity. Flexion and extension movements made against gravity were characterized by early phasic antagonist activity occurring at about the same time as the initial agonist burst. These findings suggest that EMG patterns are modified in order to preserve a common temporal structure in the face of different gravitational loads.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46567/1/221_2004_Article_BF00239600.pd

Do we use a priori knowledge of gravity when making elbow rotations?

In this study, we aim to investigate whether motor commands, emanating from movement planning, are customized to movement orientation relative to gravity from the first trial on. Participants made fast point-to-point elbow flexions and extensions in the transverse plane. We compared movements that had been practiced in reclined orientation either against or with gravity with the same movement relative to the body axis made in the upright orientation (neutral compared to gravity). For each movement type, five rotations from reclined to upright orientation were made. For each rotation, we analyzed the first trial in upright orientation and the directly preceding trial in reclined orientation. Additionally, we analyzed the last five trials of a 30-trial block in upright position and compared these trials with the first trials in upright orientation. Although participants moved fast, gravitational torques were substantial. The change in body orientation affected movement planning: we found a decrease in peak angular velocity and a decrease in amplitude for the first trials made in the upright orientation, regardless of whether the previous movements in reclined orientation were made against or with gravity. We found that these decreases disappeared after participants familiarized themselves with moving in upright position in a 30-trial block. These results indicate that participants used a general strategy, corresponding to the strategy observed in situations with unreliable or limited information on external conditions. From this, we conclude that during movement planning, a priori knowledge of gravity was not used to specifically customize motor commands for the neutral gravity condition

Unconstrained three-dimensional reaching in Rhesus monkeys

To better understand normative behavior for quantitative evaluation of motor recovery after injury, we studied arm movements by non-injured Rhesus monkeys during a food-retrieval task. While seated, monkeys reached, grasped, and retrieved food items. We recorded three-dimensional kinematics and muscle activity, and used inverse dynamics to calculate joint moments due to gravity, segmental interactions, and to the muscles and tissues of the arm. Endpoint paths showed curvature in three dimensions, suggesting that maintaining straight paths was not an important constraint. Joint moments were dominated by gravity. Generalized muscle and interaction moments were less than half of the gravitational moments. The relationships between shoulder and elbow resultant moments were linear during both reach and retrieval. Although both reach and retrieval required elbow flexor moments, an elbow extensor (triceps brachii) was active during both phases. Antagonistic muscles of both the elbow and hand were co-activated during reach and retrieval. Joint behavior could be described by lumped-parameter models analogous to torsional springs at the joints. Minor alterations to joint quasi-stiffness properties, aided by interaction moments, result in reciprocal movements that evolve under the influence of gravity. The strategies identified in monkeys to reach, grasp, and retrieve items will allow the quantification of prehension during recovery after a spinal cord injury and the effectiveness of therapeutic interventions

Active Drumming Experience Increases Infants' Sensitivity to Audiovisual Synchrony during Observed Drumming Actions

In the current study, we examined the role of active experience on sensitivity to multisensory synchrony in six-month-old infants in a musical context. In the first of two experiments, we trained infants to produce a novel multimodal effect (i.e., a drum beat) and assessed the effects of this training, relative to no training, on their later perception of the synchrony between audio and visual presentation of the drumming action. In a second experiment, we then contrasted this active experience with the observation of drumming in order to test whether observation of the audiovisual effect was as effective for sensitivity to multimodal synchrony as active experience. Our results indicated that active experience provided a unique benefit above and beyond observational experience, providing insights on the embodied roots of (early) music perception and cognition

Joint stiffness and gait pattern evaluation in children with Down syndrome.

Hypotonia, ligament laxity and motor alterations are characteristic for patients with Down syndrome (DS). The purpose of this study was the evaluation of typical gait pattern of subjects with Down syndrome and the quantification of their joint stiffness, connected with ligament laxity and hypotonia, as a possible compensation. 98 children with DS (mean age: 11.7 years; range: 6–15 years) and 30 healthy children (control group (CG); mean age: 11 years; range: 5– 13 years) underwent full 3D gait analysis at self-selected speed. Subjects with DS walked with more hip flexion during the whole gait cycle, knee flexion in stance phase, a limitation of the knee range of motion, and plantarflexion of the ankle at initial contact. Ankle power was limited as evident in terminal stance and pre-swing, represented by a low propulsive capacity at push-off, too. Hip joint stiffness was increased in general in patients with DS versus normal subjects while ankle joint stiffness revealed a lower value instead

Joint stiffness and gait pattern evaluation in children with Down syndrome

Hypotonia, ligament laxity and motor alterations are characteristic for patients with Down syndrome (DS). The purpose of this study was the evaluation of typical gait pattern of subjects with Down syndrome and the quantification of their joint stiffness, connected with ligament laxity and hypotonia, as a possible compensation. 98 children with DS (mean age: 11.7 years; range: 6-15 years) and 30 healthy children (control group (CG); mean age: 11 years; range: 5-13 years) underwent full 3D gait analysis at self-selected speed. Subjects with DS walked with more hip flexion during the whole gait cycle, knee flexion in stance phase, a limitation of the knee range of motion, and plantarflexion of the ankle at initial contact. Ankle power was limited as evident in terminal stance and pre-swing, represented by a low propulsive capacity at push-off, too. Hip joint stiffness was increased in general in patients with DS versus normal subjects while ankle joint stiffness revealed a lower value instead