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The aim of this study was to investigate the effects of backpack load carriage on quiet standing postural control and limits of stability (LOS) of older adults. Fourteen older adults (65 [6] y) performed quiet standing and a forward, right, and left LOS test in 3 conditions, unloaded, stable, and unstable backpack loads while activity of 4 leg muscles was recorded. Stable and unstable loads decreased postural sway (main effect ηp² = .84, stable P < .001, unstable P < .001), mediolateral (main effect ηp² = .49, stable P = .002, unstable P = .018) and anterior--posterior (main effect ηp² = .64, stable P < .001, unstable P = .001) fractal dimension, and LOS distance (main effect ηp² = .18, stable P = .011, unstable P = .046) compared with unloaded. Rectus femoris (main effect ηp² = .39, stable P = .001, unstable P = .010) and gastrocnemius (main effect ηp² = .30, unstable P = .027) activity increased in loaded conditions during LOS and quiet standing. Gastrocnemius--tibialis anterior coactivation was greater in unstable load than stable loaded quiet standing (main effect ηp² = .24, P = .040). These findings suggest older adults adopt conservative postural control strategies minimizing the need for postural corrections in loaded conditions. Reduced LOS may also increase fall risk when carrying a load. However, there was no difference between unstable and stable loads for postural control variables. [ABSTRACT FROM AUTHOR]

The present study examined the predicted positive and linear relationship (Iwanaga, 1995a, 1995b) between exercise heart rate and music tempo preference. Initially, 128 undergraduate students (M age = 20.0 years, SD = 0.9) were surveyed to establish their three favorite music artists. A separate experimental group of 29 undergraduates (M age = 20.3 years, SD = 1.2) selected the music of a single artist from the three highest-rated artists from the earlier survey. They reported their preference for slow, medium, and fast tempo selections from each artist for three treadmill walking conditions at 40%, 60%, and 75% maximal heart rate reserve. A mixed-model 3 x 3 x 2 (Exercise Intensity x Music Tempo x Gender) analysis of variance was used to analyze the data. Results indicated there was no three-way interaction for music preference. There was, however, a significant (p less than 0.05) two-way interaction for Exercise Intensity x Music Tempo (partial [Eta][squared] = 0.09) and a significant (p less than 0.05) main effect for music tempo, with large differences evident between preference for medium versus slow tempo and fast versus slow tempo music at all exercise intensities (partial [Eta][squared] = 0.78). Participants reported a preference for both medium and fast tempo music at low and moderate exercise intensities and for fast tempo music at high intensity. Only partial support was found for the expected linear relationship between exercise intensity and music tempo preference. (Contains 1 table and 1 figure.)

Anxiety and balance and postural control are linked via common neural pathways, such as the parabrachial nucleus network. A laboratory‐based model of general anxiety disorder (GAD) using the CO2 challenge, has potential to be used to observe this relationship, potentially mimicking subjective, autonomic, and neuropsychological features of GAD. The current feasibility study used the CO2 challenge to explore postural control changes in healthy adults. It was predicted that during the CO2 condition, participants would show increased postural sway path length and decreased sway stability, compared with a normal air breathing condition. To assess this, heart and breathing rate, quiet standing postural sway path length, sway dynamic stability, and subjective measures of emotion were measured either before and after or during and after the inhalation conditions. Results demonstrated that CO2 inhalation led to both an increase in sway path length and reduced sway stability compared to the air breathing conditions; the effect on sway path lasted after the inhalation of CO2 had ceased. Additionally, replication of HR and subjective measures of emotion were observed when comparing air and CO2 conditions. This provides experimental evidence that CO2 inhalation can affect balance, suggestive of shared mechanisms between anxiety and balance performance, as well as indicating that the CO2 model of GAD is suitable to look at changes in balance performance in healthy adults. Future use of this model to explore factors that can reduce the influence of GAD on balance would be beneficial as would a more detailed exploration of the neural pathways associated with the associated comorbidity. This feasibility study demonstrates the potential of using the CO2 challenge model as an experimental tool to better understand the relationship between anxiety and balance disorders. We evidenced increased path sway and stability as the result of 7.5% CO2 inhalation induced anxiety state. Furthermore, increased heart rate and poorer self‐reported mood state due to the CO2 inhalation, corroborate previous findings of generalised anxiety disorder symptomology in this model. [ABSTRACT FROM AUTHOR]

The minimal important change and analogous terms (MIC) can provide a measure of change in health outcome variables that is associated with a level of importance for participant/patient. This review explores the availability of the MIC for different balance measures used with older adults in research and clinical settings. PubMed, ProQuest and Web of Science search engines were used and based on the inclusion and exclusion criteria, 11 studies were deemed suitable for data extraction and analysis. The results demonstrated that MIC is available for the following balance-associated tests: Berg Balance Scale, Timed Up and Go, Short Physical Performance Battery, BESTest and the Tinetti test. A range of MIC values were shown, reflective of different older adult health conditions, calculation methods and anchors used. It was also evident that the responsiveness of the test was not always available or appropriately determined, questioning the validity of the MIC value published. Greater research is needed to establish MIC for balance measurements for use with older adults with different health conditions, preferably using objective measures such as falls. The calculation of such statistics will improve the evaluation of intervention effectiveness. [ABSTRACT FROM AUTHOR]

Back pain is associated with activity such as walking or assembly line work that involves upper-body movement. However, no single study has explored the effect of these tasks on back pain, spinal angles and balance in an older adult female population. This study investigated changes in back pain, postural sway, upper-, lower- and full-spine angle and EMG activation of trunk muscles following 30 minutes of walking and a modified quiet standing task. Fourteen older adult females (62 ± 11yrs) with low to moderate chronic back pain were recruited as participants. Findings demonstrated that following these activities, increased acute back pain and upper-spine flexion occur although acute back pain was not clinically significant; postural control and muscle activation remained unchanged. This suggests that walking and modified quiet standing can lead to subtle acute back pain in older females that could be due to an increased upper spinal flexion rather than muscle fatigue. Practitioner summary: Back pain and postural problems are common in older adults. Older adult female participants experienced increased back pain and greater upper-spine flexion following 30-minute walking and standing with trunk rotation, but the practical importance was less clear. However, balance was unaffected, suggesting no increase in fall risk. Abbreviations: CBP: chronic back pain; MQS: modified quiet standing; QS: quiet standing; RPE: rating of perceived exertion; TD: trapezius descendens; TT: trapezius transversalis; TA: trapezius ascendens; ESL: erector spinae longissimus; C7: seventh cervical vertebrae; T7: seventh thoracic vertebrae; T10: tenth thoracic vertebrae; T12: twelfth thoracic vertebrae; L2: second lumbar vertebrae; S2: second sacral vertebrae; AP: anterior-posterior; ML: medial-lateral; SWAYtot: total postural sway; M: mean [ABSTRACT FROM AUTHOR]

This study aimed to determine relationships between muscle quality, the ratio of muscle strength to muscle mass, and postural control and compare postural control of older adults with higher and lower muscle quality. Twenty-five older adults had leg muscle quality and postural control with eyes open and closed measured. Linear and non-linear postural control variables were calculated from center of pressure movements. There was a significant canonical correlation between muscle quality and sway complexity, but no relationship between muscle quality and sway magnitude. Higher muscle quality older adults had greater medio-lateral sway complexity than lower muscle quality older adults. These findings suggest that higher muscle quality relates to greater sway complexity in older adults, suggesting maintenance of muscle quality should be considered important to attenuate postural control declines. [ABSTRACT FROM AUTHOR]

This investigation measures the biomechanical response of four soccer players (age 24 (standard deviation: 0.82) years, weight 74.6 (standard deviation: 6.9) kg, footwear size 10) to the seasonal changes that occur to a natural turf playing surface. The surface was tested on two occasions where participants wore a pair of soccer boots with six screw-in studs (metal cleat) and a pair with 15 rubber moulded studs (moulded cleat) in a 2 × 2 surface-footwear design. While running (3.0 m/s ± 5%) and performing a 180° turn (consistent self-selected ± 5%), data were collected using Footscan pressure insoles (500 Hz, (RSscan, Belgium)). These data included peak impact force, peak impact force loading rate and the peak pressures and peak pressure loading rate at the medial and lateral heel and first and fifth metatarsals. Multiple two-way repeated measures analyses of variance were conducted on the data and p-values, effect size and confidence intervals determined. Intraclass correlation coefficients were also used to determine the reliability of data during the turning movement. Study findings demonstrate that greater pressure magnitudes were experienced on the harder turf surfaces when running (p < 0.05) which may contribute to the greater risk of injury seen in the literature, The study results also show that the reliability of selected data collected during the 180° turning motion was good to excellent. For some measures of loading, particularly during turning, a larger confirmatory investigation is needed with sufficient statistical power to support these findings. [ABSTRACT FROM AUTHOR]

Gender diversity is increasingly recognized as a critical element in corporate management. However, existing research on its impact on firm performance demonstrates inconsistency in a global context. This study employs 1990 publicly listed Japanese companies from 2006 to 2023 and examines the effect of board gender diversity on firm performance in Japan. Findings from the fixed-effects regression model revealed a significant negative impact of board gender diversity on firm performance. This adverse correlation is more pronounced in smaller firms, those with greater leverage and reduced institutional ownership, and regulated and consumer-focused industries, particularly pre-COVID-19. The detrimental impact of board gender diversity on firm performance is transmitted via corporate social responsibility and firm innovation instead of board independence or CEO duality. Notably, the two-stage least squares estimation addresses potential endogeneity, employing an equal opportunity policy as an instrumental variable. Moreover, the robustness of our results is affirmed via the substitution of return on equity for return on assets as an indicator of firm performance. Lastly, our analysis does not reveal a U-shaped nonlinear relationship between board gender diversity and corporate performance. As Japan progressively promotes women's participation in corporate governance, this research bears significant implications for corporate leaders, investors, and policymakers in Japan. [ABSTRACT FROM AUTHOR]

This study mainly aims to test the impact of gender diversity on a firm's performance. Namely, the non-linear and the quantile impact on the listed companies in Palestine Exchange during the period 2010 to 2020. The study also aims to determine the impact of a firm's internal characteristics on gender diversity. The study uses instrument analysis, traditional panel models, and quantile regression to fulfil the aims. The results demonstrate the existence of a critical mass for the impact of gender diversity on firms' performance and that mass is about 30% for the ROA and 41% for the EPS. [ABSTRACT FROM AUTHOR]

The aim of this paper was to examine the effect of managerial/board gender diversity and corporate governance structure on firm performance in a Jordanian business environment—a developing economy that has a distinct environment from that of developed economies. The current study focuses on the unique context of an emerging economy (i.e., Jordan). Data were collected from nonfinancial companies listed on the Amman Stock Exchange from 2018 to 2020. Data analysis was carried out using the random-effects estimator, which was considered as the most suitable for this study. The results disclose that female representation on the board of executives of Jordanian companies had a positive but insignificant effect on corporate performance, as measured by the return on equity, indicating that this variable has no effect on the performance of firms in Jordan. Both family ownership and board size had negative significant effects on performance, but for the moderating effect, corporate governance structure had no effect on the relationship among CEO duality, institution ownership, government ownership, independent directors, and firm performance. The current study only focused on Jordanian industrial firms listed on ASE, thus rendering the findings nongeneralizable to other sectors and nations. Further investigations are urged to broaden the context of the study to achieve more enriched findings. Managers can use the findings to achieve a deeper understanding of the way governance structure affects firm performance. Additionally, regulators at the Jordan Securities Commission can attain valuable insight about the adequacy of the current regulations regarding the role of gender diversity and corporate governance structure in Jordan. The current study contributes to the literature concerning the effect of managerial gender diversity and corporate governance structure on performance. Furthermore, this investigation aims to fill the current research gap in the context of Jordan, which is an emerging economy in the Arab region that is under-represented in this field of research. [ABSTRACT FROM AUTHOR]