Minjung Kim

Objective: To evaluate the feasibility, safety, and usability of a novel fully immersive virtual reality (VR) exergame, designed to incorporate cognitive-motor dual-task training for patients with Parkinson’s disease (PD).Methods: We developed a specialized fully immersive VR exergame program, featuring seven cognitive-motor dual-task games. Prior to the pilot study, we refined the system through two successive usability evaluations involving 17 and 15 rehabilitation experts, respectively, to optimize safety and interface design. Subsequently, four patients with idiopathic PD completed a 30-minute VR exergame session using the finalized system under therapist supervision. We assessed cybersickness using the Simulator Sickness Questionnaire (SSQ) and evaluated usability via the User Experience Questionnaire (UEQ) and a self-developed Custom Usability and Satisfaction Survey.Results: All participants completed the session without adverse events. Mean SSQ total scores decreased from 14.75±9.43 to 4.75±1.89 without statistical significance (p>0.05). UEQ demonstrated positive experiences, with Attractiveness (1.167), Efficiency (1.063), and Stimulation (1.500) exceeding benchmarks. Custom Usability and Satisfaction Survey scores for interest (6.00/7) and overall satisfaction (6.25/7) were high; however, physical comfort was rated relatively lower (4.25/7) due to the headset weight and safety harness.Conclusion: The developed fully immersive VR exergame system is feasible, safe, and engaging in patients with PD. Limitations include the small sample size and single-session design. Future research should focus on large-scale randomized controlled trials and hardware improvements to enhance physical comfort for long-term clinical application.

Background and Objectives: Sarcopenia is a major risk factor for falls in older adults. The 2023 Korean Working Group on Sarcopenia (KWGS) introduced revised definitions, including functional sarcopenia, which considers low strength and performance despite normal muscle mass. This study investigated the prevalence of sarcopenia, severe sarcopenia, and functional sarcopenia using the KWGS criteria and their association with fall risk by sex and fall frequency. Materials and Methods: A cross-sectional analysis was conducted using data from 2061 community-dwelling Korean adults aged 70–84 years who participated in the Korean Frailty and Aging cohort study. Sarcopenia was classified based on muscle mass, grip strength, and four physical performance tests. Fall experiences in the past year were categorized as ≥1, ≥2, and ≥4 falls. Logistic regression analyses were performed separately according to sex to evaluate the association between sarcopenia definition and fall risk. Results: The prevalence of sarcopenia and severe sarcopenia was 32.9% and 10.1% in men and 21.5% and 5.0% in women, respectively. Functional sarcopenia was more prevalent in women (10.5%) than in men (5.1%). In men, sarcopenia (defined using gait speed) was associated with fall risk across all thresholds (odds ratio [OR] = 2.28 for ≥1 fall; OR = 5.64 for ≥4 falls). In women, sarcopenia (defined using gait speed) was associated with ≥1 fall (OR = 1.72), while functional sarcopenia (defined using gait speed and timed up-and-go test) was associated with frequent falls (OR = 3.79–3.87). Conclusions: The 2023 KWGS guidelines revealed sex-specific differences in the prevalence of sarcopenia and highlighted gait speed as a key predictor of fall risk in men, whereas functional sarcopenia was more prevalent in women. Limitations include the cross-sectional design and use of self-reported fall data, which may be subject to recall bias.

Previous studies have reported that low levels of physical activity result in sarcopenic obesity (SO). However, the effects of specific intensities of physical activity on SO and the optimal amount of physical activity for lowering the prevalence of SO have not been well studied. This study aimed to identify the effects of physical activity levels and intensity on SO and the optimal amount of physical activity related to a lower prevalence of SO. This cross-sectional study used data from the nationwide Korean Frailty and Aging Cohort Study (KFACS), which included 2071 older adults (1030 men, 1041 women). SO was defined according to the criteria of the European Society for Clinical Nutrition Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO). Multivariate logistic regression analysis was performed to investigate the association between the physical activity level and SO. The high activity group had a significantly lower prevalence of SO than the non-high activity (low and moderate activity) group. On the other hand, moderate-intensity physical activity was associated with a lower prevalence of SO. A total physical activity energy expenditure of > 3032 kcal/week (433 kcal/day) for men and 2730 kcal/week (390 kcal/day) for women was associated with a reduced prevalence of SO. The high physical activity and total physical energy expenditure described above may be beneficial for reducing the prevalence of SO.

Age-related degenerative changes lead to a gradual decrease in bone mineral density (BMD) and muscle mass. We aimed to assess the effects of decreased BMD and lumbar denervation on lumbar spinal muscle morphometry and the relationship between BMD and lumbar spinal muscular morphometry, respectively. Eighty-one patients, aged 50–85 years, diagnosed with unilateral lumbosacral radiculopathy based on electrodiagnostic studies between January 2016 and April 2021 were enrolled. BMD T scores in the lumbar spine and hip were measured using dual-energy X-ray absorptiometry. The cross-sectional area (CSA) of the psoas, multifidus, and erector spinae located in the middle of the lumbar spine, between the L3 and L4 and between the L4 and L5 levels, respectively, was measured using axial MRI. Functional CSA (FCSA) was defined as the CSA of lean muscle mass. Pearson correlation analyses were performed to evaluate the association between BMD T scores and the CSA, FCSA, and the ratio of the FCSA to the CSA (functional ratio) for each side. The CSA of lumbar spinal muscles showed no significant correlation with lumbar BMD. The FCSA and functional ratio of lumbar spinal muscles were significantly correlated with lumbar BMD. There was no correlation between femur BMD and lumbar spinal muscle morphometry.