Impaired balance is a significant risk factor for falls among older adults. The precise impact of lower-extremity muscles, including the proportion of muscle strength, on the performance of single-leg standing balance tests in older individuals is very interesting. The aim of this study is to examine the correlation between the knee extensor (KE), ankle plantar flexor (AP) muscle strength, and performance in single-leg standing balance tests in older females. Additionally, it aims to evaluate the combined proportion of KE and AP muscle strength in maintaining balance during single-leg standing. A total of 90 older females (mean age 67.83 ± 8.00 years) were recruited. All participants underwent maximum voluntary isometric contraction (MVIC) testing of the KE and AP muscles, as well as single-leg standing balance tests with eyes open (SSEO) and eyes closed (SSEC). To examine the influence of KE and AP muscle strength on balance performance, multiple regression analysis was conducted. Low correlations were found between SSEO and MVIC of KE and AP muscles, but moderate correlations were found with percentage of MVIC to body weight ratio (%MVIC/BW). The best model for SSEO included 0.99 times of the %MVIC/BW of AP and 0.66 times that of KE muscles as independent predictor variables (r = 0.682). In conclusion, AP muscle strength was found to have a greater impact on single-leg standing balance compared with KE muscle strength.

Post-COVID-19 pandemic, most universities changed their educational model from online courses to onsite learning, allowing students to attend regular face-to-face classes. These changes can cause stress in students, which affects physical fitness. The aim of this study was to investigate the relationship between stress levels and physical fitness in female university students. The participants were 101 female university students, 18–23 years of age. All participants completed the Suan Prung Stress Test-60 (SPST-60). The physical fitness test included body composition, cardiorespiratory fitness, as well as musculoskeletal fitness. Multiple linear regression analysis was used to determine the associations between SPST-60 scores and physical fitness. A p-value < 0.05 was considered statistically significant. We found a negative correlation between the sources of stress scores, here environment, and maximal oxygen consumption (β = −0.291; 95% CI, −0.551, −0.031). We also found that symptoms of stress scores in the parasympathetic and sympathetic nervous systems were positively associated with waist-hip circumference ratio (WHR) (β = 0.010; 95% CI, 0.002, 0.017 and β = 0.006; 95% CI, 0.000, 0.012, respectively). Moreover, the symptoms of stress, here emotion, were positively associated with the WHR (β = 0.005; 95 %CI, 0.001, 0.009) and negatively associated with upper extremity muscle strength (β = −0.005; 95% CI, −0.009, 0.000). The results of this study confirmed the associations between stress levels in the post-COVID-19 pandemic era and WHR, maximal oxygen consumption, and upper extremity muscle strength. As a result, stress reduction or prevention alternatives should be considered in order to maintain physical fitness and prevent stress disorders.

Background: Stress and sedentary lifestyles negatively impact the physical fitness of overweight and obese female university students. Physical activity has been shown to promote psychological as well as physical wellness. However, the effects of Surya Namaskar (SN) yoga on stress and physical fitness remain unclear. Objective: This study aimed to compare the physical fitness, anthropometric measures, and perceived stress between the SN yoga training program group and the control group. Methods: In a randomized controlled study, 44 overweight and obese female university students participated. For 8 weeks, the exercise group received training in SN yoga, whereas the control group was not permitted to participate in any form of exercise. At baseline and after 8 weeks of training, all participants completed the Thai Perceived Stress Scale-10 (T-PSS-10), and assessed the body mass index (BMI), waist–hip ratio, body fat percentage, maximum oxygen consumption (VO₂max), and muscle strength and flexibility. We used the dependent t-test or Wilcoxon sign rank test to examine the differences between the T-PSS-10 and physical fitness within each group. The statistical differences of all parameters between the two groups were compared using an independent t-test or a Mann–Whitney U test. A p-[ ] was considered statistically significant. Results: Compared to the baseline, the SN yoga group’s post-training period had a significant increase ([ ]) in forward back flexibility, hand grip strength, leg strength, and VO₂max, while a significant decrease ([ ]) in T-PSS-10 scores and BMI. In addition, we found a significant difference between the both groups in forward back flexibility and T-PSS-10 scores in the post-training period ([ ] and [ ], respectively). Conclusion: This study’s findings demonstrated that SN yoga is a useful exercise for enhancing overweight and obese female university students’ perceived stress scales and physical fitness.

(1) Background: The assessment of postural segment control in premature infants seems to be critical during the onset of upright gross motor development, especially sitting. Identifying correlations between postural segment control and the development of sitting milestones could help with promoting optimal gross motor movement. However, data on this topic in home-raised premature infants via longitudinal design are still limited. The purpose of this study was to examine relationships between postural segment control and sitting development through series assessments from the corrected age of 4 months until the early onset of independent sitting attainment. (2) Methods: 33 moderate-to-late premature infants were recruited. Their trunk segment control was assessed using the Segmental Assessment of Trunk Control (SATCo), and sitting development was examined by the Alberta Infant Motor Scale (AIMS). Relationships between SATCo and sitting scores were analysed using Spearman’s rank correlation (r_s). (3) Results: significant fair-to-good correlations between segmental trunk control and sitting scales were found from 4 months (r_s = 0.370–0.420, p < 0.05) to the age of independent sitting attainment (r_s = 0.561–0.602, p < 0.01). (4) Conclusion: relationships between the trunk segment control and sitting ability of moderate-to-late preterm infants were increased in accordance with age.

Objective: To assess postural stability, specifically center of body sway during single-leg standing balance, among individuals with and without forward head posture (FHP) during smartphone use. Methods: The research recruited 53 healthy smartphone users, aged 18–25, and categorized them into FHP group comprising 26 subjects and the normal (control) group with 27 subjects. Participants were assigned the task of maintaining balance while engaged in smartphone typing during single-leg standing. The experiment involved four specific conditions according to neck posture and stable of surface. The study meticulously quantified body center of pressure (COP) sway amplitudes using the Nintendo Wii Balance Board. Results: The research revealed that individuals with FHP exhibited significantly greater body sway compared to the control group when using smartphones. Notably, distinct variations were observed in path length sway, anteroposterior (AP), and mediolateral (ML) sway amplitude, particularly evident when maintaining flexed neck positions on a soft surface while engaged with smartphones. Conclusion: These findings strongly suggest that individuals with FHP encounter deteriorated postural stability during smartphone use, particularly in challenging head positions.

Background: The decline in lower limb muscle strength, one of the risk factors for falling in the older adults, puts older persons at an increased risk of falling. The assessment of the lower limb muscle strength is very important. Objective: The purpose of this study was to construct the equation for predicting knee extensor muscle strength based on demographic data and the results of the Five-Time Sit-to-Stand Test (FTSST). Methods: A total of 121 healthy elders (mean age $68.00\pm 7.26$ ) were asked to complete the FTSST and submit the demographic information. By using a stationary push–pull dynamometer, the knee extensor strength of each participant was assessed. The multiple regression analysis was used to explore knee extensor strength prediction equation. Results: The findings demonstrated that the knee extensor strength equation was developed using variables obtained from gender, weight, and time to complete the FTSST. The equation was found to have a high correlation ($r=0.838$ ) and 70.1% estimation power. Its formula was as follows: Knee extensor $\mathrm{\text{strength}}=32.735+3.688$ (gender; $\mathrm{\text{female}}=0$ or $\mathrm{\text{male}}=1$ )$$ $+$ $$ 0.189 (weight)$$ −$$ 2.617 (time to complete the FTSST). However, there was an estimating error in this equation of 4.72$$ kg. Conclusion: The determining factors influencing knee extensor strength, which can be utilized to estimate the strength in elderly individuals, are demographic variables including gender, weight, and the time taken to complete the FTSST.