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: Methods for evaluating the strength of the knee extensor muscles play a vital role in determining the functionality of the lower limbs and monitoring any alterations that occur over time in older individuals. This study assessed the validity of the Modified Squat Test (MST) in predicting knee extensor muscle strength in older adults. Methods: This study included a total of 110 older adults. We collected demographic information such as sex, age, body weight, height, and thigh circumference. Muscle strength was assessed by measuring the maximum voluntary isometric contraction of the knee extensors, and by performing the MST (5 and 10 repetitions) and single-leg standing balance test. Stepwise multiple linear regression analysis was used to investigate multiple factors impacting the prediction of knee extensor strength. Results: Factors such as age, sex, thigh circumference, performance on the single-leg standing eye-open (SSEO) task, and the time required to complete the 10 MST repetitions together explained 77.8% of the variation in knee extensor muscle strength among older adults. We further developed a predictive equation to calculate strength as follows: strength = 36.78 − 0.24 (age) + 6.16 (sex) + 0.19 (thigh circumference) + 0.05 (SSEO) − 0.54 (time required to complete 10 MST repetitions) ± 5.51 kg. Conclusion The 10-repetition MST is an invaluable instrument for establishing an equation to accurately predict lower limb muscle strength.

Objective: To formulate an equation estimating months to independent walking in moderate to late preterm infants based on neonatal characteristics and gross motor development from 7 months to independent walking. Methods: Sixty infants born between 32 to 36 weeks were assessed using Alberta Infant Motor Scale (AIMS) for gross motor development. Neonatal characteristics were recorded at 7 months, and caregiver-reported independent walking onset. Pearson correlation analyzed age, AIMS scores, and neonatal factors. Multiple regression developed the prediction equation. Results: The equation for independent walking onset, which included gestational age (GA) at birth, total AIMS score at 10 months of age (10th AIMS), and birth head circumference (BHC), exhibited a strong correlation (r=0.707) and had a predictive power of 50.0%. The equation is as follows: age onset of independent walking (months)=33.157, -0.296 (GA), -0.132 (10th AIMS), -0.196 (BHC), with an estimation error of 0.631 months. Conclusion Neonatal characteristics, such as GA, 10th AIMS, and BHC, are key determinants in estimating the onset of independent walking in moderate to late preterm infants.