Reactive postural adjustment in response to predictable and unpredictable perturbations in healthy adults: A comparison between swayback, hyperlordotic and erect postures.

BACKGROUND: Promoting an erect posture in standing has been advocated to offer superior protection to the spine when compared to hyperlordotic and swayback postures. RESEARCH QUESTION: Do postural adjustments towards external perturbation differ between erect, hyperlordotic and swayback postures? If so, which posture offers better protection to lumbar spine? METHODS: Forty-four healthy adults received top-down perturbations under unpredictable (without visual-and-auditory input) and predictable (with visual-and-auditory input) conditions in three simulated postures: erect, hyperlordotic, and swayback. Postural adjustments namely the centre of pressure parameters, joint angle onsets, and neuromuscular responses measured by muscle onsets and co-contraction between muscle pairs upon the perturbation were compared using the two-way repeated measures ANOVA. Post-hoc analysis with Bonferroni correction was conducted to identify the between-posture differences for the respective postural adjustment parameters. RESULTS: Path length, ellipse area and average velocity of centre of pressure were significantly greater under unpredictable condition as compared to predictable condition (p < 0.001). Significant between-posture difference was detected in centre of pressure path length (p < 0.035), pelvic tilt onset (p < 0.038) and all muscle co-contraction indexes (p < 0.001). Post-hoc analysis revealed significantly smaller centre of pressure path length in erect posture as compared to hyperlordotic and swayback postures (p < 0.01) under unpredictable conditions. Significantly greater co-contraction indexes of lumbar multifidus and erector spinae, and internal oblique and lumbar multifidus were found in hyperlordotic as compared to erect and swayback postures (p < 0.05). SIGNIFICANCE: Compared to erect posture, adoption of hyperlordotic and swayback postures altered the contributions of the active and passive subsystems of the spine that regulates postural control upon external perturbations. Such differences in neuromuscular control may lessen the capacity of the human spine to withstand loading and shear forces. Prospective studies are required to validate if habitually adopted hyperlordotic and swayback postures contribute to an earlier/ higher prevalence of spinal dysfunctions.

The impacts of physical activity on psychological and behavioral problems, and changes in physical activity, sleep and quality of life during the COVID-19 pandemic in preschoolers, children, and adolescents: A systematic review and meta-analysis.

Background: The COVID-19 pandemic has greatly affected the level of physical activity (PA). However, little is known about its effect on health outcomes. Methods: Articles without language restrictions published from the database inception through March 16, 2022, were retrieved using the CINAHL Complete, Cochrane Library, EMBASE, Medline, PubMed, and PsycINFO databases. High-quality articles assessing the effect of PA on psychological and behavioral problems. Additionally, PA, QoL, and/or sleep problems before and during the pandemic were included. Articles without data regarding PA or involving non-general populations were excluded. The PRISMA and MOOSE guidelines were followed. Data quality of the selected articles was assessed using the Newcastle-Ottawa Scale and GRADE approach. Data were pooled using a random-effects model and sensitivity analysis if heterogenicity was high (I 2 ≥ 50%). The relationship between PA and psychological and behavioral problems; and changes in PA, QoL, and sleeping patterns before and during the pandemic in preschoolers, children, and adolescents were investigated. A meta-analysis was conducted; odds ratios (ORs), mean differences (MD), and standardized MDs (SMDs) were calculated. Results: Thirty-four articles involving 66,857 participants were included. The results showed an overall significant protective effect between PA and psychological and/or behavioral problems (OR = 0.677; 95% CI = 0.630, 0.728; p-value <0.001; I 2 = 59.79%). This relationship was also significant in the subgroup analysis of children (OR = 0.690; 95% CI = 0.632, 0.752; p-value <0.001; I 2 = 58.93%) and adolescents (OR = 0.650; 95% CI = 0.570, 0.741; p-value <0.001; I 2 = 60.85%); however, no data on the relationship in preschoolers were collected. In addition, the overall time spent on PA significantly decreased by 23.2 min per day during the COVID-19 pandemic (95% CI = -13.5, -32.9; p-value <0.001; I 2 = 99.82%). Moreover, the results showed an overall significant decrease in QoL (SMD = -0.894, 95% CI = -1.180, -0.609, p-value <0.001, I 2 = 96.64%). However, there was no significant difference in sleep duration during the COVID-19 pandemic (MD = 0.01 h per day, 95% CI = -0.027, 0.225; p-value = 0.125; I 2 = 98.48%). Conclusion: During the pandemic, less PA was contributed to poor QoL and sleep quality. However, increases in PA are associated with reduced occurrences of psychological and behavioral problems. Implementing recovery plans to address the health effect of the pandemic is essential.

Effect of muscle fatigue of the thoracic erector spinae on neuromuscular control when performing the upper extremity functional tasks in people with adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) disrupts spinal alignment and increases the intrinsic demand for active stabilization to maintain postural stability. Understanding the paraspinal muscle fatigability and its effects on spinal alignment and kinematics informs the importance of paraspinal muscle endurance for postural stability. This study aims to investigate the effects of fatigue of thoracic erector spinae on the spinal muscle activity and spinal kinematics in individuals with scoliosis. Spinal muscle activity, posture and mobility measured by electromyography and surface tomography were compared between 15 participants with scoliosis and 15 age- and gender-matched healthy controls during unilateral shoulder flexion and abduction with and without holding a 2-kg weight and performed before and after a fatigue task (prone isometric chest raise). No between-groups difference was found for the spinal extensor endurance. Erector spinae activity at the convex side of AIS group was significantly higher than that at their concave side and than that of healthy controls during shoulder elevations, regardless of the fatigue status. Significant decreases in translational and rotational mobility were found at convex side of AIS group during weighted abduction tasks after fatigue. In contrast, a significant increase in rotational mobility was demonstrated at convex side of AIS participants during weighted flexion tasks after fatigue. Our results revealed a comparable level of spinal extensor endurance between individuals with or without AIS. The increase in muscle activation post-fatigue provides no additional active postural stability but may increase the risk of back pain over the convex side in individuals with scoliosis. Findings highlight imbalances in muscles and the potential implications in optimising neuromuscular activation and endurance capacity in the rehabilitation for AIS patients. Future research is needed to investigate if endurance training of the convex-sided back extensors could optimize the impaired neuromuscular control in the AIS patients.

The Effectiveness of Coaching the Australian Recommended Fundamental Overarm Throwing Skill Criteria for Less-Skilled Adolescents.

Purpose: The aim of this study was to investigate the effects of coaching the Australian recommended fundamental overarm throwing skill criteria for less-skilled adolescents on movement competency using three-dimensional (3D) motion analysis. Methods: Less-skilled non-sports-active and skilled sports-active pupils were assigned to FMS Group (n = 97) and Sports Group (n = 129), respectively. Demographic, anthropometric, whole-body kinematic (discrete and time-series angular displacement and angular velocity data), motor coordination (segmental sequencing) and motor performance (maximum ball release speed) were analyzed. Baseline data were compared using independent T-tests and Chi-Square tests; interaction effects were assessed using repeated-measure ANOVAs. Changes in time-series kinematic data were analyzed by comparing the areas enclosed by the 95% confidence intervals. Results:There was merely a modest improvement in motor competency for the less-skilled pupils. The FMS group significantly acquired 13/75 discrete kinematic variables (p < .01) and four movement patterns but not motor coordination (p = .469) and motor performance (p = .756). Prior to the intervention, the pupils acquired 4/7 recommended skill criteria. The descriptions of another three criteria were not appropriate with no improvement in motor coordination and performance. Two new skills were identified and improved after the FMS intervention. Conclusions: The recommended skill criteria for children were not developmentally and age-appropriate for early adolescents. The use of quantitative 3D motion data provided a more precise and developmentally applicable fundamental overarm throwing criteria than content validated skill criteria. The recommended skill criteria should be modified to facilitate teachers and coaches for effective education.

Ultrasound-guided dry needling versus traditional dry needling for patients with knee osteoarthritis: A double-blind randomized controlled trial.

OBJECTIVE: To compare the effect of ultrasound (US)-guided dry needling (DN) with traditional DN in the treatment of pain and dysfunction for patients with knee osteoarthritis (KOA). DESIGN: A double-blind, randomized controlled trial. METHODS: Patients (25 male and 65 female), age 50-80 years diagnosed with KOA were recruited and randomly assigned to one of three groups in a 1:1:1 ratio for intervention: real US-guided DN with exercise therapy (G1), placebo US-guided DN with exercise therapy (G2), and exercise therapy solely (G3). G1 and G2 were blinded to the application of real or placebo US guidance by turning the monitor of US imaging out-of-view from participants' vantage points. The effectiveness of blinding was evaluated by asking the participants whether they had received real-US guided DN. The responses were assessed by Chi-square test. Visual Analogue Scale (VAS), Knee injury, and Osteoarthritis Outcome Score (KOOS) subscales (KOOS-pain, KOOS-symptoms, KOOS-quality-of-life (QoL)) were collected at baseline, 4 weeks, and 8 weeks by a blinded assessor. Data were analyzed by mixed model analysis of variance (ANOVA) with Bonferroni correction. RESULTS: Eighty-four participants (61.26±5.57 years) completed the study. G1 achieved significant improvement in VAS at 8 weeks compared to G2 and G3 (G1 vs. G2: MD = -15.61, 95% CI [-25.49, -5.51], p = 0.001; G1 vs. G3: MD = -19.90, 95% CI [-29.71, -10.08], p< 0.001). G1 achieved significant improvement in KOOS-pain at 8 weeks compared to G2 and G3 (G1 vs. G2: MD = 9.76, 95% CI [2.38, 17.14], p = 0.006; G1 vs. G3: MD = 9.48, 95% CI [2.31, 16.66], p = 0.010). KOOS-symptoms and KOOS-QoL were not statistically significant between groups. G2 had no significant difference of the perceptions as G1 with p = 0.128. G2 were successfully blinded to placebo US-guided DN. CONCLUSION: US-guided DN with exercise therapy may be more effective than traditional DN with exercise therapy or exercise therapy alone in reduce pain of KOA.

Cardiac cephalgia: a diagnostic headache.

A 73-year-old man presented with a 6-month history of exertional headaches. Exercise tolerance test demonstrated progressive ischaemic changes concomitant with worsening headache. Cardiac cephalgia was diagnosed and his symptoms resolved after coronary artery bypass surgery. Cardiac cephalgia may occasionally present as exertional headache without chest symptoms.

Interleukin-6 as a predictor of symptom resolution in psychological distress: a cohort study.

BACKGROUND: Elevated levels of interleukin-6 (IL-6) have been associated with the development of common mental disorders, such as depression, but its role in symptom resolution is unclear. METHOD: We examined the association between IL-6 and symptom resolution in a non-clinical sample of participants with psychological distress. RESULTS: Relative to high IL-6 levels, low levels at baseline were associated with symptom resolution at follow-up [age- and sex-adjusted risk ratio (RR) = 1.15, 95% confidence interval (CI) 1.06-1.25]. Further adjustment for covariates had little effect on the association. Symptomatic participants with repeated low IL-6 were more likely to be symptom-free at follow-up compared with those with repeated high IL-6 (RR = 1.21, 95% CI 1.03-1.41). Among the symptomatic participants with elevated IL-6 at baseline, IL-6 decreased along with symptom resolution. CONCLUSIONS: IL-6 is potentially related to the mechanisms underlying recovery from symptoms of mental ill health. Further studies are needed to examine these mechanisms and to confirm the findings in relation to clinical depression.

Use of self-administered instruments to assess psychiatric disorders in older people: validity of the General Health Questionnaire, the Center for Epidemiologic Studies Depression Scale and the self-completion version of the revised Clinical Interview Schedule.

BACKGROUND: Diagnosis of depressive disorder using interviewer-administered instruments is expensive and frequently impractical in large epidemiological surveys. The aim of this study was to assess the validity of three self-completion measures of depressive disorder and other psychiatric disorders in older people against an interviewer-administered instrument. METHOD: A random sample stratified by sex, age and social position was selected from the Whitehall II study participants. This sample was supplemented by inclusion of depressed Whitehall II participants. Depressive disorder and other mental disorders were assessed by the interviewer-administered structured revised Clinical Interview Schedule (CIS-R) in 277 participants aged 58-80 years. Participants also completed a computerized self-completion version of the CIS-R in addition to the General Health Questionnaire (GHQ) and the Center for Epidemiologic Studies Depression Scale (CES-D). RESULTS: The mean total score was similar for the interviewer-administered (4.43) and self-completion (4.35) versions of the CIS-R [95% confidence interval (CI) for difference -0.31 to 0.16]. Differences were not related to sex, age, social position or presence of chronic physical illness. Sensitivity/specificity of self-completion CIS-R was 74%/98% for any mental disorder and 75%/98% for depressive episode. The corresponding figures were 86%/87% and 78%/83% for GHQ and 77%/89% and 89%/86% for CES-D. CONCLUSIONS: The self-completion computerized version of the CIS-R is feasible and has good validity as a measure of any mental disorder and depression in people aged ≥ 60 years. GHQ and CES-D also have good criterion validity as measures of any mental disorder and depressive disorder respectively.

Exploring the pattern and neural correlates of neuropsychological impairment in late-life depression.

BACKGROUND: Neuropsychological impairment is a key feature of late-life depression, with deficits observed across multiple domains. However, it is unclear whether deficits in multiple domains represent relatively independent processes with specific neural correlates or whether they can be explained by cognitive deficits in executive function or processing speed. METHOD: We examined group differences across five domains (episodic memory; executive function; language skills; processing speed; visuospatial skills) in a sample of 36 depressed participants and 25 control participants, all aged ≥ 60 years. The influence of executive function and processing speed deficits on other neuropsychological domains was also investigated. Magnetic resonance imaging correlates of executive function, processing speed and episodic memory were explored in the late-life depression group. RESULTS: Relative to controls, the late-life depression group performed significantly worse in the domains of executive function, processing speed, episodic memory and language skills. Impairments in executive function or processing speed were sufficient to explain differences in episodic memory and language skills. Executive function was correlated with anisotropy of the anterior thalamic radiation and uncinate fasciculus; processing speed was correlated with anisotropy of genu of the corpus callosum. Episodic memory was correlated with anisotropy of the anterior thalamic radiation, the genu and body of the corpus callosum and the fornix. CONCLUSIONS: Executive function and processing speed appear to represent important cognitive deficits in late-life depression, which contribute to deficits in other domains, and are related to reductions in anisotropy in frontal tracts.

Beat-frequency adjustable Er3+-doped DBR fiber laser for ultrasound detection.

A compact low beat-frequency dual-polarization distributed Bragg reflector (DBR) fiber laser whose beat frequency can be varied, for high-frequency ultrasound detection has been proposed and experimentally demonstrated. The laser was fabricated in small birefringent commercial erbium-doped fiber. It operated in a robust single-longitude mode with output power of more than 1 mW and high signal-to-noise ratio better than 60 dB. Induced birefringence to the fiber during the UV inscription process is small (~10(-7)) and consequently the laser beats at a low frequency of ~20 MHz which is at least one order of magnitude smaller than previously reported results, making frequency down-conversion unnecessary. The beat frequency can be adjusted by controlling the side-exposure time of the UV light irradiating the gain cavity, providing a simple approach to multiplex a large number of DBR fiber lasers of different frequencies in series using frequency division multiplexing (FDM) technique. The proposed DBR fiber laser is also temperature insensitive, making it a good candidate for hydrophone applications.

Single tilted Bragg reflector fiber laser for simultaneous sensing of refractive index and temperature.

A type of fiber laser, called tilted Bragg reflector fiber laser (TBR-FL), is proposed and its application in simultaneous sensing of surrounding refractive index (SRI) and temperature is demonstrated. This FL is formed by a pair of wavelength and tilt-angle matched tilted fiber Bragg gratings (TFBGs) that acted both as a resonant cavity and sensing element. A unique spectral feature of the TBR-FL is the presence of grating tilt-induced cladding modes spectrum that does not appear in other type of FL, which provides an extra sensing mechanism. By employing a simple experimental setup with the discrete wavelet transform as the demodulation technique, simultaneously sensing of SRI and temperature are achieved by measuring and analyzing the wavelet coefficients shifts of the laser output and averaged cladding modes.

Fourier analysis for hydrostatic pressure sensing in a polarization-maintaining photonic crystal fiber.

We measured the hydrostatic pressure dependence of the birefringence and birefringent dispersion of a Sagnac interferometric sensor incorporating a length of highly birefringent photonic crystal fiber using Fourier analysis. Sensitivity of both the phase and chirp spectra to hydrostatic pressure is demonstrated. Using this analysis, phase-based measurements showed a good linearity with an effective sensitivity of 9.45 nm/MPa and an accuracy of ±7.8 kPa using wavelength-encoded data and an effective sensitivity of -55.7 cm(-1)/MPa and an accuracy of ±4.4 kPa using wavenumber-encoded data. Chirp-based measurements, though nonlinear in response, showed an improvement in accuracy at certain pressure ranges with an accuracy of ±5.5 kPa for the full range of measured pressures using wavelength-encoded data and dropping to within ±2.5 kPa in the range of 0.17 to 0.4 MPa using wavenumber-encoded data. Improvements of the accuracy demonstrated the usefulness of implementing chirp-based analysis for sensing purposes.

Multiplexing technique using amplitude-modulated chirped fiber Bragg gratings.

We propose a new multiplexing technique using amplitude-modulated chirped fiber Bragg gratings that have an identical center Bragg wavelength. Each grating is inscribed with a unique amplitude modulation that allows them to be multiplexed with complete overlapping within a certain bandwidth. To demodulate the multiplexed signal, the discrete wavelet transform is employed. Concurrently, a wavelet denoising technique is used to reduce the noise. This proposed multiplexing technique has been verified through strain measurements. Experimental results showed that for strains applied up to 1250 microepsilon the absolute error and cross-talk are within +/-20 microepsilon and 16 microepsilon, respectively. A strain resolution of 4 microepsilon is obtained.

Simultaneous demodulation technique for a multiplexed fiber Fizeau interferometer and fiber Bragg grating sensor system.

We propose a demodulation technique for a multiplexed fiber Fizeau interferometer (FFI) and fiber Bragg grating (FBG) sensor system using the discrete wavelet transform with signal processing enhancements. This simple and flexible demodulation technique determines the cavity length of FFI and the Bragg wavelength of FBG simultaneously and is especially suited for quasi-static measurements. We demonstrate this demodulation technique by performing some strain measurements, and a strain resolution of 1.0 microepsilon and an accuracy of 2.6 microepsilon are obtained. The maximum cross-talk of the sensor system is 6% of the applied strains.

Are HIV/AIDS services in Leeds, UK, able to meet the needs of asylum seekers?

BACKGROUND: The Yorkshire and Humberside region of England ranks second only to London for reception of those seeking asylum in the UK. Human immunodeficiency virus (HIV) prevalence amongst asylum seekers is likely to mirror that in the country of origin. In 2001, the city of Leeds received 1100 asylum seekers, including dependents. Many of these were from areas with high seroprevalence of HIV, and HIV-infected asylum seekers require medical and social support. Are the current services for HIV-infected persons in Leeds appropriate and adequate for this new patient group? Provision of sexual health services for this client group needs to be evaluated. OBJECTIVES: To determine whether existing HIV/acquired immunodeficiency syndrome (AIDS) services in Leeds meet the needs of HIV-positive asylum seekers. METHODS: This was a qualitative study using semi-structured interviews. Seven service providers and 14 HIV-positive patients at Leeds Centre for Sexual Health, six of whom were asylum seekers, took part in the study. RESULTS: Asylum seekers and UK residents were equally satisfied with HIV/AIDS services at Leeds Centre for Sexual Health. Other agencies such as the Health Access Team and Terrence Higgins Trust had different strengths that provided valuable support for this client group. Unmet needs of asylum seekers were identified, such as specialist services for torture victims and educational opportunities. In areas of asylum seeker dispersal with increased case loads, this methodology may inform development of client-centred care networks.