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Purpose: Muscle power is a component of muscular fitness and is proportional to its volume. Reduced muscular fitness in children is linked to negative health outcomes. Associations between muscle volume (MV) and power have not been examined in young children and could reveal important insights into early neuromuscular development. Method: Forty-four children (2-8 y) completed 3 tests of short-term muscular power: repeated anaerobic sprint test, vertical jump, and horizontal jump. MV was assessed using 3D ultrasound for 3 lower limb muscles (rectus femoris, medial gastrocnemius, and tibialis anterior) and summed for across legs. Associations between muscular power and summed MV were assessed using Pearson correlation (r). Sex-based differences in muscular power and MV were assessed using 1-way analysis of covariance. Results: Moderate-strong associations (r =.57 - .87) were found between muscular power and summed MV. No differences were found between boys and girls for height, weight, MV, or muscular power. Conclusions: Young children who have larger lower limb muscles perform better at tasks dependent on short-term muscular power, such as running and jumping, compared with children with smaller muscles. Sex-based differences in short-term muscular power do not exist in young children and reflect similar anthropometry, including lower limb MV. [ABSTRACT FROM AUTHOR]

This is the 85th annual report of the British Trust for Ornithology's Ringing Scheme, incorporating the report of the Nest Record Scheme and covering work carried out and data processed in 2021. In 2021, 105 Constant Effort Sites submitted data for the year. Long-term (1984–2020) declines in abundance were observed for five migrant, one partial migrant and five resident species, while long-term increases in abundance were recorded for two short-distance migrants and seven resident species. Ten species are exhibiting significant long-term declines in productivity, while only Chaffinch Fringilla coelebs shows a significant long-term increase. Long-term trends in survival indicate increases for 12 species and declines for seven. Short-term trends, which compare the current year to the five-year mean for 2016–20, show that the abundance of seven species increased significantly in 2021, with one species, Treecreeper Certhia familiaris, being recorded in higher numbers than in any previous year of CES monitoring. Significant decreases in abundance were recorded for four species. Productivity decreased significantly for seven migrant and 11 resident species in 2021, with six species recording their lowest breeding success since CES monitoring began; no species recorded a significant short-term increase. Significant changes in survival rate were observed for two species in 2021 compared to the five-year mean, with Song Thrush Turdus philomelos increasing and Chaffinch both declining and recording its lowest survival rate ever. The Garden CES trial continued in 2021, with 60 sites submitting data. The new winter ringing project also continued in 2021, with submissions received from 126 sites. The number of Retrapping Adults for Survival projects that were able to run and submit data in 2021 was 192, with data from one more project submitted too late to be included in this report and another four active projects unable to operate. In total, 60 species were monitored, with Starling Sturnus vulgaris (21 projects), House Sparrow Passer domesticus (20 projects), Pied Flycatcher Ficedula hypoleuca (19 projects), Reed Warbler Acrocephalus scirpaceus (nine projects) and Sand Martin Riparia riparia (nine projects) the species most studied. A total of 900 131 birds were ringed during the year, comprising 146 458 nestlings, 438 342 first-year birds, 291 127 adults (birds in their second calendar year or older) and 24 204 birds whose age could not be determined. In addition, there were 210 147 recaptures of ringed birds at or near the ringing site. In total, 42 328 recoveries (birds found dead, recaptured or resighted at least 5 km from the place of ringing) of BTO-ringed birds were reported in 2021. The Appendix highlights a selection of recoveries that have extended our knowledge of movements, as well as longevity records established during the year. A total of 41 096 NRS submissions were received in 2021. Mean laying dates for 2021 were significantly later than the average for 13 species and only one species significantly advanced its laying date. Five species displayed a significant change in fledglings per breeding attempt, with two recording increased productivity and three reduced productivity. Permits or licences to disturb breeding birds on Schedule 1 of the Wildlife and Countryside Act 1981 (as amended) were prepared and issued to 602 ringers and nest recorders in 2021. During 2021, 2588 marking endorsements, 868 sampling endorsements and 214 trapping endorsements were issued in the UK and overseas. [ABSTRACT FROM AUTHOR]

The primary of this study was to compare the volume, length, echo intensity, and growth rate of the medial gastrocnemius (MG) and tibialis anterior (TA) muscle of both limbs (more-involved and less-involved) in children with unilateral spastic cerebral palsy (USCP), with those of an age-matched typically developing (TD) group. A secondary aim in the USCP group was to explore the associations between these muscle parameters and discrete ankle positions during phase of gait. Muscle parameters were assessed using 3D ultrasound. Maximal ankle dorsiflexion in stance and swing during walking were determined from 2D video analysis. Group differences in muscle size and echo intensity were assessed using a two-way analysis of covariance (age-by-group), with the interaction term used to compare muscle growth rates. Associations between muscle parameters and maximal ankle dorsiflexion in stance and swing were assessed using backwards multiple linear regression analyses. The MG of both limbs in children with USCP had signs of impaired muscle development (smaller volume and length, higher echo intensity and lower growth rate). There was no evidence of impaired muscle development of TA between limbs or compared the TD children. Tibialis anterior volume, length, echo intensity and MG volume explained 66% and 83% of the variance in maximal ankle dorsiflexion position in the stance and swing phases of walking, respectively. Unlike the MG, the TA volume and growth rate in children with USCP are equivalent between limbs and compared to TD children. For the more-involved limb only, TA volume, length, and echo intensity appear associated with maximal ankle dorsiflexion during walking and represent important muscle parameters that could be targeted in with early exercise therapy. Tibialis anterior (TA) size and echogenicity appear normal in both limbs in young children with unilateral spastic cerebral palsy (USCP); findings that could indicate sufficient mechanical stimulus and muscle anabolism to maintain normal muscle growth. Tibialis anterior size and echogenicity are associated with maximal ankle dorsiflexion in both stance and swing phase of walking in young children with USCP; though such relations appear isolated to the more-involved limb. Early therapeutic interventions that target TA are likely to be successful in maintaining muscle size and may offset the negative effects of medial gastrocnemius atrophy in the development of fixed ankle equinus of the more-involved limb and improve ankle positioning during gait. [ABSTRACT FROM AUTHOR]

Muscle size is an important determinant of muscular fitness and health, and so it is important to have accurate estimates of actual muscle growth in children. This study compared actual versus age‐predicted growth rates of the medial gastrocnemius (MG) muscle in young children over a 12‐month period. Three‐dimensional ultrasound was used to measure MG length and volume in 50 children (mean ± standard deviation [SD] age = 70.3 ± 29.9 months) to establish age‐predicted muscle growth rates using a least‐squares linear regression. Twenty children (mean ± SD age = 78.5 ± 27.2 months) were followed up at 6 and 12 months to establish actual muscle growth of MG volume and length. These data were then compared to their age‐predicted muscle growth from the linear regression equation using paired t‐tests and Bland–Altman limits of agreement method. Age‐predicted MG growth significantly underestimated actual muscle growth for both volume and length at each timepoint. On average, actual muscle volume and length were 11.5% and 21.5% greater than the age‐predicted volume and length respectively. Caution is warranted when predicting future muscle size in young children based solely on age. [ABSTRACT FROM AUTHOR]

This study investigated reliability of freehand three-dimensional ultrasound (3DUS) measurement of in vivo human Achilles tendon (AT) moment arm. Sixteen healthy adults were scanned on 2 separate occasions by a single investigator. 3DUS scans were performed over the free AT, medial malleolus, and lateral malleolus with the ankle passively positioned in maximal dorsiflexion, mid dorsiflexion, neutral, mid plantar flexion and maximal plantar flexion. 3D reconstructions of the AT, medial malleolus, and lateral malleolus were created from manual segmentation of the ultrasound images and used to geometrically determine the AT moment arm using both a straight (straight ATMA) and curved (curved ATMA) tendon line-of-action. Both methods were reliable within- and between-session (intra-class correlation coefficients > 0.92; coefficient of variation < 2.5 %) and revealed that AT moment arm increased by ~ 7 mm from maximal dorsiflexion (~ 41mm) to maximal plantar flexion (~ 48 mm). Failing to account for tendon curvature led to a small overestimation (< 2 mm) of AT moment arm that was most pronounced in ankle plantar flexion, but was less than the minimal detectable change of the method and could be disregarded. [ABSTRACT FROM AUTHOR]

This is the 84th annual report of the British Trust for Ornithology's Ringing Scheme, incorporating the report of the Nest Record Scheme and covering work carried out and data processed in 2020. An analysis of Curlew Numenius arquata ringing records was carried out to investigate recent declines. Results showed that survival rates are high, so current population declines are more likely to have been driven by low productivity. To reverse the recent population declines, breeding success would need to increase and effective conservation strategies will be needed to maintain the high levels of survival. We examined the potential opportunities and challenges of using winter ringing records to produce survival estimates, as well as other outputs such as age ratios and recruitment, by analysing 2 641 352 encounter records from the winters of 2007/08 to 2017/18: winter-to-winter survival analyses on adult birds were undertaken, initially on 44 species. Results indicated that fortnightly ringing sessions should yield sufficient data to produce useful survival estimates. This research identified a number of potential analytical and methodological options for future development. Covid-19 restrictions limited the amount of fieldwork carried out in 2020; consequently, only 72 CE sites submitted data for the year. Long-term (1984–2019) declines in abundance were observed for five migrant, one partial migrant and four resident species while long-term increases in abundance were recorded for two short-distance migrants and six resident species. Six species are exhibiting significant long-term declines in productivity while only Chaffinch Fringilla coelebs shows a significant long-term increase. Long-term trends in survival indicate increases for 10 species and declines for nine. Short-term trends, which compare the current year to the five-year mean (2015–19), show that the abundance of 10 species increased significantly in 2020, with three species being recorded in higher numbers than in any previous year since CES monitoring began. Significant decreases in abundance were recorded for only two species. Productivity decreased significantly for one migrant and five resident species in 2020; no species recorded a significant increase. Productivity was lower in 2020 than in any previous CES year for Blue Tit Cyanistes caeruleus and Great Tit Parus major. Significant changes in survival rate were observed in two species in 2020 compared to the five-year mean, with Bullfinch Pyrrhula pyrrhula increasing and Blackbird Turdus merula decreasing. A new habitat was added to the suite of standard CES habitats in 2020 in the first year of a Garden CES trial. Submissions were received from 92 sites. A new winter ringing project was also launched in 2020, following a similar methodology to CES. Submissions were received from 111 sites. The number of Retrapping Adults for Survival projects that were able to run and submit data in 2020 was 146, from 200 that were registered. In total, 60 species were monitored, with Pied Flycatcher Ficedula hypoleuca (20 projects), Starling Sturnus vulgaris (19), House Sparrow Passer domesticus (18), Sand Martin Riparia riparia (10) and Reed Warbler Acrocephalus scirpaceus (eight) the species most studied. A total of 930 091 birds were ringed during the year, comprising 98 500 nestlings, 523 777 first-year birds, 278 157 adults (birds in their second calendar year or older) and 29 657 birds whose age could not be determined. In addition, there were 212 414 recaptures of ringed birds at or near the ringing site. In total, 42 987 recoveries (birds found dead, recaptured or resighted at least 5 km from the place of ringing) of BTO-ringed birds were reported in 2020. The Appendix highlights a selection of recoveries that have extended our knowledge of movements, as well as longevity records established during the year. A total of 23 928 NRS submissions were received in 2020, far fewer than usual due to Covid-19 restrictions being in place during the height of the nesting season. As the seasonality of nest records was biased towards the end of the breeding season, after Covid-19 restrictions had lifted, it was not possible to generate meaningful NRS trends for 2020. Permits or licences to disturb breeding birds on Schedule 1 of the Wildlife and Countryside Act 1981 (as amended) were prepared and issued to 611 ringers and nest recorders in 2020. During 2020, the use of special methods was authorised for 1182 marking projects and 146 trapping projects. [ABSTRACT FROM AUTHOR]

Purpose: Distal lower limb motor impairment impacts gait mechanics in individuals with cerebral palsy (CP), however, the contribution of impairments of muscle activation to reduced gross motor function (GMF) is not clear. This study aimed to investigate deficits in plantar flexion voluntary activation capacity in CP compared to typically developed (TD) peers, and evaluate relationships between voluntary activation capacity, strength and GMF.Methods: Fifteen ambulant individuals with spastic CP (23 ± 6 years, GMFCS I-III) and 14 TD (22 ± 2 years) people participated. Plantar- and dorsiflexion strength were assessed with a dynamometer. Voluntary activation capacity was assessed using the interpolated twitch technique via single twitch supramaximal tibial nerve stimulation. GMF was assessed using the timed upstairs test, 10 m walk test, muscle power sprint test and six-minute walk test.Results: Plantar- and dorsiflexion strength were 55.6% and 60.7% lower in CP than TD (p < 0.001). Although voluntary activation capacity was 17.9% lower on average for CP than TD (p = 0.039), 46.7% of individuals with CP achieved a sufficiently high activation to fall within one standard deviation of the TD mean. Plantar flexion voluntary activation capacity did not correlate with strength (R2 = 0.092, p = 0.314) or GMF measures in the high functioning CP group (GMFCS I-II).Conclusion: In contrast to previous research, plantar flexion activation capacity did not strongly predict weakness or reduced GMF. We propose that muscle size contributes more to weakness than voluntary activation capacity in high functioning individuals with CP and that relationships between muscle activation and functional capacity are complicated by effects at multiple joints. [ABSTRACT FROM AUTHOR]