Accelerometer measurements of physical activity in pregnant adolescents

2019 Summer.Includes bibliographical references.In adult women, physical activity during pregnancy, assessed objectively with accelerometry, has been related to less excess gestational weight gain and better health outcomes for mother and child. Objectively-measured physical activity has not been reported in pregnant adolescents, and it is unclear to what extent accelerometers are feasible in this group of young women who are at very high-risk for social-emotional challenges and excess gestational weight gain. The main purpose of the current thesis project was to investigate the feasibility of using accelerometers to objectively quantify physical activity in pregnant adolescents. The second aim was to explore the associations of physical activity with pregnant adolescent health characteristics including pre-pregnancy body mass index (BMI; kg/m2), first-trimester weight (kg), depression symptoms, emotional eating, and loss-of-control eating. Participants were N = 28 15-19 year old patients, 12-18 weeks gestation, obtaining prenatal care at a multidisciplinary adolescent pregnancy clinic. Physical activity was assessed with GT3-X wrist-worn accelerometers for 7 days to assess average moderate-vigorous physical activity (MVPA) per day, percentage of time spent in MVPA, daily average sedentary bouts, percent of time spent sedentary, average step counts, and maximum step counts. Feasibility was determined as median days of wear time equal to or exceeding 4 out of 7 days (of≥10 hours of wear time per day). Adolescents reported pre-pregnancy weight/height to compute pre-pregnancy BMI; first-trimester weight was assessed from measured weight. Depression symptoms and emotional eating were assessed with validated self-report questionnaires. Presence of loss-of-control eating was evaluated by interview. In addition to reporting statistical significance (p < .05), strength of bivariate associations were described as moderate (r ≥ .40) and large (r ≥ .60), given the pilot nature of the study. Results indicated that the median days of valid wear was 5 days, and 59.3% of pregnant adolescents met criteria for valid wear. Adolescents who did not have valid accelerometer reported heavier pre-pregnancy BMI (28.63 ± 6.75 kg/m2 vs. 23.55 ± 5.21 kg/m2, p = .04), with no other significant differences. Among pregnant adolescents with valid data (N = 16), there was an inverse, moderate association of average MVPA per day with depression symptoms (r = -.44 p = .09). In conclusion, there were mixed results for the feasibility of accelerometry in pregnant adolescents. In order to increase wear time compliance in this population, particularly for heavier adolescents, more incentives are required. Finally, results from this study suggest that the connection between pregnant adolescents' physical activity and depression warrants exploration in future research

The Impact of Small Spinal Curves in Adolescents That Have Not Presented to Secondary Care:A Population-Based Cohort Study

Study Design: A prospective, population-based, birth cohort study. Objective: The aim of this study was to identify whether there is any hidden burden of disease associated with smaller spinal curves. Summary of Background Data: Adolescent idiopathic scoliosis is present in 3% to 5% of the general population. Large curves are associated with increased pain and reduced quality of life. However, no information is available on the impact of smaller curves, many of which do not reach secondary care. Methods: The Avon Longitudinal Study of Parents and Children (ALSPAC) recruited over 14,000 pregnant women from the Bristol area of South-West England between 1991 and 1992 and has followed up their offspring regularly. At age 15, presence or absence of spinal curvature ≥6 degrees in the offspring was identified using the validated dual-energy X-ray absorptiometry Scoliosis Measure on 5299 participants. At age 18, a structured pain questionnaire was administered to 4083 participants. Logistic regression was used to investigate any association between presence of a spinal curve at age 15 and self-reported outcomes at age 18 years. Results: Full data were available for 3184 participants. Two hundred two (6.3%) had a spinal curve ≥6 degrees and 125 (3.9%) had a curve ≥10 degrees (median curve size of 11 degrees). About 46.3% reported aches and pains that lasted for a day or longer in the previous month. About 16.3% reported back pain. Those with spinal curves were 42% more likely to report back pain than those without (odds ratio 1.42, 95% confidence interval 1.00–2.02, P = 0.047). Those with spinal curves had more days off school and were more likely to avoid activities that caused their pain. Conclusion Our results highlight that small scoliotic curves may be less benign than previously thought. Teenagers with small curves may not present to secondary care, but are nonetheless reporting increased pain, more days off school, and avoidance of activities. These data suggest that we should reconsider current scoliosis screening and treatment practices. Level of Evidence: 2 </p

Using self-reports of pain and other variables to distinguish between older women with back pain due to vertebral fractures and those with back pain due to degenerative changes

SUMMARY: Women with back pain and vertebral fractures describe different pain experiences than women without vertebral fractures, particularly a shorter duration of back pain, crushing pain and pain that improves on lying down. This suggests a questionnaire could be developed to identify older women who may have osteoporotic vertebral fractures. INTRODUCTION: Approximately 12 % of postmenopausal women have vertebral fractures (VFs), but less than a third come to clinical attention. Distinguishing back pain likely to relate to VF from other types of back pain may ensure appropriate diagnostic radiographs, leading to treatment initiation. This study investigated whether characteristics of back pain in women with VF are different from those in women with no VFs. METHODS: A case control study was undertaken with women aged ≥60 years who had undergone thoracic spinal radiograph in the previous 3 months. Cases were defined as those with VFs identified using the algorithm-based qualitative (ABQ) method. Six hundred eighty-three potential participants were approached. Data were collected by self-completed questionnaire including the McGill Pain Questionnaire. Chi-squared tests assessed univariable associations; logistic regression identified independent predictors of VFs. Receiver operating characteristic (ROC) curves were used to evaluate the ability of the combined independent predictors to differentiate between women with and without VFs via area under the curve (AUC) statistics. RESULTS: One hundred ninety-seven women participated: 64 cases and 133 controls. Radiographs of controls were more likely to show moderate/severe degenerative change than cases (54.1 vs 29.7 %, P = 0.011). Independent predictors of VF were older age, history of previous fracture, shorter duration of back pain, pain described as crushing, pain improving on lying down and pain not spreading down the legs. AUC for combination of these factors was 0.85 (95 % CI 0.79 to 0.92). CONCLUSION: We present the first evidence that back pain experienced by women with osteoporotic VF is different to back pain related solely to degenerative change

Assessing physical literacy with school-aged children in occupational therapy practice:An exploratory qualitative study

Introduction: Physical literacy (the physical, psychological, social and cognitive capacities needed for movement and physical activity) is arguably important to occupational therapy yet is not explicit within current practice. This study aimed to understand how occupational therapists can engage with the physical literacy concept. Method: Eight paediatric occupational therapists were recruited by purposive sampling. Participants completed up to three semi-structured interviews to understand perspectives on physical literacy, introduce a novel pictorial assessment and to seek feedback on the assessment after trialling. Interviews were transcribed verbatim and analysed using reflexive thematic analysis. Results: Sixteen interviews were conducted. Four themes were identified: ‘Foreign tongue’ (occupational therapists have an understanding of physical literacy but used different terminology); ‘Sounds very OT oriented’ (illustrating the connection between physical literacy and occupational therapy); ‘We need the child’s voice’ (measure highlights the child’s perspective); and ‘Contemporary, useful BUT not for all’ (measure had utility for some children but was dependant on child’s condition). Conclusion: Occupational therapists can apply the physical literacy construct to traditional models and core concepts. The assessment can be used in paediatric occupational therapy practice supported by clinical reasoning, although future tool iterations may need to accommodate some children with disability

Adaptive Dispersion Compensation for Remote Fiber Delivery of NIR Femtosecond Pulses

We report on remote delivery of 25 pJ broadband near-infrared femtosecond light pulses from a Ti:sapphire laser through 150 meters of single-mode optical fiber. Pulse distortion due to dispersion is overcome with pre-compensation using adaptive pulse shaping techniques, while nonlinearities are mitigated using an SF10 rod for the final stage of pulse compression. Near transform limited pulse duration of 130 fs is measured after the final compression.Comment: 3 pages, 4 figure

Calibration and Cross-Validation of Accelerometery for Estimating Movement Skills in Children Aged 8-12 Years

This study sought to calibrate triaxial accelerometery, worn on both wrists, waist and both ankles, during children’s physical activity (PA), with particular attention to object control motor skills performed at a fast and slow cadence, and to cross-validate the accelerometer cut-points derived from the calibration using an independent dataset. Twenty boys (10.1 ±1.5 years) undertook seven, five-minute bouts of activity lying supine, standing, running (4.5kmph−1) instep passing a football (fast and slow cadence), dribbling a football (fast and slow cadence), whilst wearing five GENEActiv accelerometers on their non-dominant and dominant wrists and ankles and waist. VO2 was assessed concurrently using indirect calorimetry. ROC curve analysis was used to generate cut-points representing sedentary, light and moderate PA. The cut-points were then cross-validated using independent data from 30 children (9.4 ± 1.4 years), who had undertaken similar activities whilst wearing accelerometers and being assessed for VO2. GENEActiv monitors were able to discriminate sedentary activity to an excellent level irrespective of wear location. For moderate PA, discrimination of activity was considered good for monitors placed on the dominant wrist, waist, non-dominant and dominant ankles but fair for the non-dominant wrist. Applying the cut-points to the cross-validation sample indicated that cut-points validated in the calibration were able to successfully discriminate sedentary behaviour and moderate PA to an excellent standard and light PA to a fair standard. Cut-points derived from this calibration demonstrate an excellent ability to discriminate children’s sedentary behaviour and moderate intensity PA comprising motor skill activity.N/

Trends in atmospheric evaporative demand in Great Britain using high-resolution meteorological data

Observations of climate are often available on very different spatial scales from observations of the natural environments and resources that are affected by climate change. In order to help bridge the gap between these scales using modelling, a new dataset of daily meteorological variables was created at 1 km resolution over Great Britain for the years 1961–2012, by interpolating coarser resolution climate data and including the effects of local topography. These variables were used to calculate atmospheric evaporative demand (AED) at the same spatial and temporal resolution. Two functions that represent AED were chosen: one is a standard form of potential evapotranspiration (PET) and the other is a derived PET measure used by hydrologists that includes the effect of water intercepted by the canopy (PETI). Temporal trends in these functions were calculated, with PET found to be increasing in all regions, and at an overall rate of 0.021 ± 0.021 mm day−1 decade−1 in Great Britain. PETI was found to be increasing at a rate of 0.019 ± 0.020 mm day−1 decade−1 in Great Britain, but this was not statistically significant. However, there was a trend in PETI in England of 0.023 ± 0.023 mm day−1 decade−1. The trends were found to vary by season, with spring PET increasing by 0.043 ± 0.019 mm day−1 decade−1 (0.038 ± 0.018 mm day−1 decade−1 when the interception correction is included) in Great Britain, while there is no statistically significant trend in other seasons. The trends were attributed analytically to trends in the climate variables; the overall positive trend was predominantly driven by rising air temperature, although rising specific humidity had a negative effect on the trend. Recasting the analysis in terms of relative humidity revealed that the overall effect is that falling relative humidity causes the PET to rise. Increasing downward short- and longwave radiation made an overall positive contribution to the PET trend, while decreasing wind speed made a negative contribution to the trend in PET. The trend in spring PET was particularly strong due to a strong decrease in relative humidity and increase in downward shortwave radiation in the spring