scholarly journals Muscle Synergies in Children Walking and Running on a Treadmill

2021 ◽  
Vol 15 ◽  
Author(s):  
Margit M. Bach ◽  
Andreas Daffertshofer ◽  
Nadia Dominici
Keyword(s):  
Age Groups ◽  
Medial Gastrocnemius ◽  
Muscle Synergy ◽  
School Age Children ◽  
Muscle Synergies ◽  
Older Children ◽  
Temporal Shift ◽  
Double Support ◽  
Complex Motor ◽  
Locomotor Patterns

Muscle synergies reflect the presence of a common neural input to multiple muscles. Steering small sets of synergies is commonly believed to simplify the control of complex motor tasks like walking and running. When these locomotor patterns emerge, it is likely that synergies emerge as well. We hence hypothesized that in children learning to run the number of accompanying synergies increases and that some of the synergies’ activities display a temporal shift related to a reduced stance phase as observed in adults. We investigated the development of locomotion in 23 children aged 2–9 years of age and compared them with seven young adults. Muscle activity of 15 bilateral leg, trunk, and arm muscles, ground reaction forces, and kinematics were recorded during comfortable treadmill walking and running, followed by a muscle synergy analysis. We found that toddlers (2–3.5 years) and preschoolers (3.5–6.5 years) utilize a “walk-run strategy” when learning to run: they managed the fastest speeds on the treadmill by combining double support (DS) and flight phases (FPs). In particular the activity duration of the medial gastrocnemius muscle was weakly correlated with age. The number of synergies across groups and conditions needed to cover sufficient data variation ranged between four and eight. The number of synergies tended to be smaller in toddlers than it did in preschoolers and school-age children but the adults had the lowest number for both conditions. Against our expectations, the age groups did not differ significantly in the timing or duration of synergies. We believe that the increase in the number of muscle synergies in older children relates to motor learning and exploration. The ability to run with a FP is clearly associated with an increase in the number of muscle synergies.

Complex Motor Functions of the Preferred and Non-Preferred Hands in Brain-Damaged and Normal Children

1971 ◽  
Vol 33 (2) ◽  
pp. 671-675 ◽  
Author(s):  
Ralph M. Reitan
Keyword(s):  
School Age Children ◽  
Older Children ◽  
Normal Children ◽  
Early School ◽  
Complex Motor ◽  
Name Writing ◽  
Early School Age ◽  
The Difference ◽  
Age Range ◽  
The Brain

A previous study of early school-age children indicated that a brain-damaged group took more time in normal name-writing than did a group of normal children with both the preferred hand and the non-preferred hand. In addition, the difference between the 2 hands was greater for the brain-damaged children. These results could have been attributed at least in part, considering the age range of 6 to 8 yr., to lack of development of skill in name-writing. Therefore, the study was replicated using children in the 9- to 14-yr. age range since name-writing should have been a practiced and perhaps over-learned skill for older children. Groups were formed by matching pairs of brain-damaged and normal children for race, sex, and age. The results, found by applying converted scores derived from the study of younger children, confirmed the findings with younger children and permitted differentiation of the brain-damaged and normal groups with almost the same degree of accuracy achieved in the prior study. The results suggest that the findings are not due to lack of development of name-writing skill but instead reflect a difference in normal tempo, associated with brain damage, in a highly practiced, complex motor function.

scholarly journals Development of Asymmetric Vection for Radial Expansion or Contraction Motion: Comparison Between School-Age Children and Adults

i-Perception ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 204166951876119 ◽  
Author(s):  
Nobu Shirai ◽  
Shuich Endo ◽  
Shigehito Tanahashi ◽  
Takeharu Seno ◽  
Tomoko Imura
Keyword(s):  
Age Groups ◽  
School Age Children ◽  
School Age ◽  
Radial Expansion ◽  
Older Children ◽  
Contraction Flow ◽  
Younger Age ◽  
Cumulative Duration ◽  
Self Motion ◽  
Trial Participants

Vection is illusory self-motion elicited by visual stimuli and is more easily induced by radial contraction than expansion flow in adults. The asymmetric feature of vection was reexamined with 18 younger (age: 6–8 years) and 19 older children (age: 9–11 years) and 20 adults. In each experimental trial, participants observed either radial expansion or contraction flow; the latency, cumulative duration, and saturation of vection were measured. The results indicated that the latency for contraction was significantly shorter than that for expansion in all age-groups. In addition, the latency and saturation were significantly shorter and greater, respectively, in the younger or older children compared with the adults, regardless of the flow pattern. These results indicate that the asymmetry in vection for expansion or contraction flow emerges by school age, and that school-age children experience significantly more rapid and stronger vection than adults.

scholarly journals Accommodative Amplitude in School-Age Children

2017 ◽  
Vol 71 (5) ◽  
pp. 387-391
Author(s):  
Gatis Ikaunieks ◽  
Karola Panke ◽  
Madara Segliņa ◽  
Aiga Švede ◽  
Gunta Krūmiņa
Keyword(s):  
Visual Acuity ◽  
Age Groups ◽  
School Age Children ◽  
School Age ◽  
Older Children ◽  
Good Visual Acuity ◽  
Before And After ◽  
Near Work ◽  
Anatomical Parameters ◽  
Accommodative Amplitude

Abstract In children, intensive near-work affects the accommodation system of the eye. Younger children, due to anatomical parameters, read at smaller distance than older children and we can expect that the accommodation system of younger can be affected more than that of older children. We wanted to test this hypothesis. Some authors showed that the norms of amplitude of accommodation (AA) developed by Hofstetter (1950) not always could be applied for children. We also wanted to verify these results. A total of 106 (age 7-15) children participated in the study. Distance visual acuity was measured for all children and only data of children with good visual acuity 1.0 or more (dec. units) were analysed (73 children). Accommodative amplitude was measured before and after lessons using subjective push-up technique (with RAF Near Point Ruler). The results showed that the amplitude of accommodation reduced significantly (p < 0.05) during the day and decrease of AA was similar in different age groups (about ~0.70 D). Additional measurements are needed to verify that the observed changes in AA were associated with fatigue effect. The results showed lower accommodation values compared to average values calculated according to the Hofstetter equation (p < 0.05).

scholarly journals Nutrient Intake in Children 4–13 Years Old in Ibadan, Nigeria

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1741
Author(s):  
Marie Tassy ◽  
Alison L. Eldridge ◽  
Rasaki A. Sanusi ◽  
Oluwaseun Ariyo ◽  
AnuOluwapo Ogundero ◽  
...  
Keyword(s):  
Child Nutrition ◽  
Age Groups ◽  
School Age Children ◽  
Future Research ◽  
Older Children ◽  
Nutrient Intakes ◽  
Dietary Recall ◽  
Distribution Ranges ◽  
Research And Education ◽  
Ibadan Nigeria

The paucity of adequate data on dietary and nutrient intakes of school-age children is a barrier to addressing malnutrition and associated risks in Nigeria. This study included 955 children aged 4–13 years from Ibadan, Nigeria, using a stratified random sampling design. Information on family socio-demographic characteristics was reported, and child anthropometrics were measured. Dietary intake data were collected using a multi-pass 24 h dietary recall method; 20% of subjects completed a second 24 h recall to estimate usual nutrient intakes. Means and distributions of usual intakes of energy and nutrients as well as prevalence of inadequacy were estimated. Usual energy intake (kcal/day) was 1345 and 1590 for younger (4–8 years) and older (9–13 years) age groups, respectively. The macronutrient intakes of most children did not conform to Adequate Macronutrient Distribution Ranges (AMDRs), which were characterized by a higher proportion of energy from carbohydrates and lower proportion from total fats. Protein intake was largely within the AMDR. Compared to recommendations, over 60% of 4–8-year-old children had inadequate intakes of calcium, copper, iron, folate, and vitamins A, D, and E. There were more micronutrient inadequacies in the older children. This study identifies nutrition gaps and suggests future research and education to improve child nutrition in Nigeria.

scholarly journals Muscle synergy differences between voluntary and reactive backward stepping

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuaijie Wang ◽  
Gonzalo Varas-Diaz ◽  
Tanvi Bhatt
Keyword(s):  
Older Adults ◽  
Age Groups ◽  
Neuromuscular Control ◽  
Potential Effect ◽  
Muscle Synergy ◽  
Muscle Synergies ◽  
Limited Effect ◽  
Healthy Older Adults ◽  
Different Populations ◽  
Reactive Stepping

AbstractReactive stepping responses are essential to prevent falls after a loss of balance. It has previously been well described that both voluntary and reactive step training could improve the efficacy of reactive stepping in different populations. However, the effect of aging on neuromuscular control during voluntary and reactive stepping remains unclear. Electromyography (EMG) signals during both backward voluntary stepping in response to an auditory cue and backward reactive stepping elicited by a forward slip-like treadmill perturbation during stance were recorded in ten healthy young adults and ten healthy older adults. Using muscle synergy analysis, we extracted the muscle synergies for both voluntary and reactive stepping. Our results showed that fewer muscle synergies were used during reactive stepping than during voluntary stepping in both young and older adults. Minor differences in the synergy structure were observed for both voluntary and reactive stepping between age groups. Our results indicate that there is a low similarity of muscle synergies between voluntary stepping and reactive stepping and that aging had a limited effect on the structure of muscle synergies. This study enhances our understanding of the neuromuscular basis of both voluntary and reactive stepping as well as the potential effect of aging on neuromuscular control during balance tasks.

RTS,S/AS01, a vaccine targeting pre-erythrocytic stages of Plasmodium falciparum

2017 ◽  
Vol 1 (6) ◽  
pp. 533-537
Author(s):  
Lorenz von Seidlein ◽  
Borimas Hanboonkunupakarn ◽  
Podjanee Jittmala ◽  
Sasithon Pukrittayakamee
Keyword(s):  
Protective Efficacy ◽  
Age Groups ◽  
Sub Saharan Africa ◽  
Phase Iii ◽  
European Medicines Agency ◽  
Older Children ◽  
Pivotal Phase ◽  
Malaria Epidemiology ◽  
Maximum Benefit ◽  
Sub Saharan

RTS,S/AS01 is the most advanced vaccine to prevent malaria. It is safe and moderately effective. A large pivotal phase III trial in over 15 000 young children in sub-Saharan Africa completed in 2014 showed that the vaccine could protect around one-third of children (aged 5–17 months) and one-fourth of infants (aged 6–12 weeks) from uncomplicated falciparum malaria. The European Medicines Agency approved licensing and programmatic roll-out of the RTSS vaccine in malaria endemic countries in sub-Saharan Africa. WHO is planning further studies in a large Malaria Vaccine Implementation Programme, in more than 400 000 young African children. With the changing malaria epidemiology in Africa resulting in older children at risk, alternative modes of employment are under evaluation, for example the use of RTS,S/AS01 in older children as part of seasonal malaria prophylaxis. Another strategy is combining mass drug administrations with mass vaccine campaigns for all age groups in regional malaria elimination campaigns. A phase II trial is ongoing to evaluate the safety and immunogenicity of the RTSS in combination with antimalarial drugs in Thailand. Such novel approaches aim to extract the maximum benefit from the well-documented, short-lasting protective efficacy of RTS,S/AS01.

Perceptions of Stuttering of Different Age Groups

2019 ◽  
Vol 4 (6) ◽  
pp. 1311-1315
Author(s):  
Sergey M. Kondrashov ◽  
John A. Tetnowski
Keyword(s):  
Age Groups ◽  
School Age Children ◽  
Clinical Implications ◽  
School Age ◽  
Fourth Edition ◽  
Self Perception ◽  
Behavioral Measures ◽  
Self Rating ◽  
Comparison Results ◽  
Subject Pool

Purpose The purpose of this study was to assess the perceptions of stuttering of school-age children who stutter and those of adults who stutter through the use of the same tools that could be commonly used by clinicians. Method Twenty-three participants across various ages and stuttering severity were administered both the Stuttering Severity Instrument–Fourth Edition (SSI-4; Riley, 2009 ) and the Wright & Ayre Stuttering Self-Rating Profile ( Wright & Ayre, 2000 ). Comparisons were made between severity of behavioral measures of stuttering made by the SSI-4 and by age (child/adult). Results Significant differences were obtained for the age comparison but not for the severity comparison. Results are explained in terms of the correlation between severity equivalents of the SSI-4 and the Wright & Ayre Stuttering Self-Rating Profile scores, with clinical implications justifying multi-aspect assessment. Conclusions Clinical implications indicate that self-perception and impact of stuttering must not be assumed and should be evaluated for individual participants. Research implications include further study with a larger subject pool and various levels of stuttering severity.

Time-Based Prospective Memory in Schoolchildren

2011 ◽  
Vol 219 (2) ◽  
pp. 92-99 ◽  
Author(s):  
Babett Voigt ◽  
Ingo Aberle ◽  
Judith Schönfeld ◽  
Matthias Kliegel
Keyword(s):  
Primary School ◽  
Prospective Memory ◽  
Age Differences ◽  
Memory Retrieval ◽  
Primary Schools ◽  
School Age Children ◽  
School Age ◽  
Older Children ◽  
Strategic Monitoring ◽  
Primary School Age

The present study examined age differences in time-based prospective memory (TBPM) in primary school age children and tested the role of self-initiated memory retrieval and strategic time monitoring (TM) as possible developmental mechanisms. Fifty-four children were recruited from local primary schools (27 younger children, mean age = 7.2 ± 0.55 years, and 27 older children, mean age = 9.61 ± 0.71 years). The task was a driving game scenario in which children had to drive a vehicle (ongoing task) and to remember to refuel before the vehicle runs out of gas (TBPM task, i.e., the fuel gauge served as child-appropriate time equivalent). Fuel gauge was either displayed permanently (low level of self-initiation) or could only be viewed on demand by hitting a button (high level of self-initiation). The results revealed age-dependent TBPM differences with better performance in older children. In contrast, level of self-initiated memory retrieval did not affect TBPM performance. However, strategies of TM influenced TBPM, as more frequent time checking was related to better performance. Patterns of time checking frequency differed according to children’s age and course of the game, suggesting difficulties in maintaining initial strategic TM in younger children. Taken together, the study revealed ongoing development of TBPM across primary school age. Observed age differences seemed to be associated with the ability to maintain strategic monitoring.

scholarly journals Incidence of childhood injuries and modifiable household risk factors in rural Ghana: a multistage, cluster-randomised, population-based, household survey

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e039243
Author(s):  
Adam Gyedu ◽  
Barclay T Stewart ◽  
Easmon Otupiri ◽  
Kajal Mehta ◽  
Peter Donkor ◽  
...  
Keyword(s):  
Risk Factors ◽  
Protective Factor ◽  
Age Groups ◽  
Secondary Outcome ◽  
Older Children ◽  
Multilevel Regression ◽  
Sampling Weights ◽  
Effective Prevention ◽  
Childhood Injuries ◽  
Rural Ghana

ObjectiveWe aimed to describe the incidence of childhood household injuries and prevalence of modifiable household risk factors in rural Ghana to inform prevention initiatives.Setting357 randomly selected households in rural Ghana.ParticipantsCaregivers of children aged <5 years.Primary and secondary outcome measuresChildhood injuries that occurred within 6 months and 200 metres of the home that resulted in missed school/work, hospitalisation and/or death. Sampling weights were applied, injuries were described and multilevel regression was used to identify risk factors.ResultsCaregivers from 357 households had a mean age of 35 years (SD 12.8) and often supervised ≥2 children (51%). Households typically used biomass fuels (84%) on a cookstove outside the home (79%). Cookstoves were commonly <1 metre of the ground (95%). Weighted incidence of childhood injury was 542 per 1000 child-years. Falls (37%), lacerations (24%), burns (12%) and violence (12%) were common mechanisms. There were differences in mechanism across age groups (p<0.01), but no gender differences (p=0.25). Presence of older children in the home (OR 0.15, 95% CI 0.09 to 0.24; adjusted OR (aOR) 0.26, 95% CI 0.13 to 0.54) and cooking outside the home (OR 0.28, 95% CI 0.19 to 0.42; aOR 0.25, 95% CI 0.13 to 0.49) were protective against injury, but other common modifiable risk factors (eg, stove height, fuel type, secured cabinets) were not.ConclusionsChildhood injuries occurred frequently in rural Ghana. Several common modifiable household risk factors were not associated with an increase in household injuries. Presence of older children was a protective factor, suggesting that efforts to improve supervision of younger children might be effective prevention strategies.

Effects of Eye Color on the Accuracy of Ball Throwing of Elementary School Children

1989 ◽  
Vol 68 (1) ◽  
pp. 163-166 ◽  
Author(s):  
John Beer ◽  
Paula Fleming
Keyword(s):  
Elementary School ◽  
School Children ◽  
Elementary School Children ◽  
School Age Children ◽  
School Age ◽  
Older Children ◽  
Eye Color ◽  
Elementary School Age

Light-eyed individuals generally perform better at self-paced activities while dark-eyed individuals perform better at reactive activities. In throwing a ball at a target there were no differences between light- and dark-eyed elementary school-age children. Boys hit the target more times than did girls, and older children in upper grades hit the target more often than did younger children in lower grades.

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