ECSS Paris 2023: CP-MH21
INTRODUCTION: Prolonged uninterrupted sitting has been associated with impaired vascular function, increased blood pressure, and cardiac autonomic dysfunction, highlighting the need to break up sitting time throughout the day, especially during work. Isometric wall squat exercise (IWSE) has proven effective in improving cardiovascular parameters in both normotensive and hypertensive individuals. However, whether this exercise is effective as a strategy to break up sitting time remains unknown. Thus, the aim of this study was to analyze the effects of breaking up sitting time with IWSE on vascular function, blood pressure, and cardiac autonomic modulation in sedentary adults. METHODS: This randomized controlled trial (#RBR-10k2wxrg) included 40 participants without known cardiovascular diseases (35±11 y.o. and 61% women) with high sedentary behavior (≥ 6 hours/day). Participants were randomly assigned to the IWSE group (2-minute breaks during occupational activities, incorporating IWSE while maintaining their knees at the angle determined by the incremental test every 60 minutes of sitting) or to the SHAM group (standing for 2 minutes every 60 minutes of sitting during occupational activities). Popliteal artery vascular function, ambulatory and clinic blood pressure, and cardiac autonomic modulation (assessed by heart rate variability) were evaluated at baseline and after 12 weeks. To compare the effects of the interventions (IWSE or SHAM) on cardiovascular parameters, Generalized Estimating Equations were used, followed by a post hoc pairwise comparison. An intention-to-treat analysis was conducted to estimate overall effects, including all randomized patients regardless of dropouts. The predicted mean matching method was used for this purpose. The significance level was set at P < 0.05 for all analysis. RESULTS: Per-protocol analysis showed that breaking up sitting time with IWSE increased the maximum diameter of the popliteal artery (IWSE: 5.2±0.2 vs. 5.7±0.3 mm; SHAM: 5.6±0.2 vs. 5.3±0.2 mm, P=0.011), while the intention-to-treat analysis indicated that the SHAM group reduced the baseline diameter of the popliteal artery (IWSE: 4.9±0.2 vs. 5.3±023 mm; SHAM: 5.3±0.2 vs. 5.1±0.2, P= 0.008). No effects of the interventions were observed on other vascular indicators, ambulatory and clinical blood pressure, or cardiac autonomic modulation (P>0.05 for all). CONCLUSION: Breaking up sitting time with IWSE during occupational activities did not improve blood pressure, cardiac autonomic modulation, or vascular function but altered vascular structure by increasing the arterial diameter of the popliteal artery in sedentary adults. This study was supported by CNPQ (#408860/2023-5) and FACEPE (#APQ-1142-4.09/21)
Read CV Breno FarahECSS Paris 2023: CP-MH21
INTRODUCTION: Lower-limb amputees need prosthesis walking to maintain their physical activity level and improve quality of life [1]. However, acquiring a prosthetic walking is difficult, potentially leading to reduced physical activity. Recently, the combination of virtual reality (VR) with prosthetic walking practice has been attracting attention as a tool to enhance its efficiency [2]. Despite this interest, few studies have investigated the effects of VR on static and dynamic balance abilities, which are important for prosthetic walking. This study aimed to confirm the acute effects of prosthetic walking practice combined with VR on balance ability in healthy adults wearing a simulated prosthesis as a preliminary study. METHODS: The participants were 14 healthy adults with no experience wearing a simulated prosthesis. The simulated prosthesis was a trans-femoral prosthesis with a 3R60 knee joint (OttoBock, Ltd, Japan). Participants were randomly divided into two groups: VR group, which practiced prosthetic walking with VR video showed a first-person perspective walking motion, and control group, which practiced without VR video. The prosthetic walking practice consisted of a 5-minute in-situ foot stamping in the parallel bars [3]. Dynamic balance ability was assessed using the Timed up and Go test (TUG test). Static standing balance was measured using the Zebris PDM-S system (Zebris Medical GmbH, Germany) for 30 seconds in the closed-eye, closed-leg standing posture. The measured parameters were center of pressure (COP) sway area, COP path length, and average COP sway speed. The improvement rate in balance ability before and after practice was calculated. Statistical analysis was performed using a t-test between groups for each improvement rate. The significance level was set at 5%. RESULTS: The improvement rates of the VR group (TUG test: 17.8 ± 4.8%, COP sway area: 32.2 ± 15.9%, COP path length: 23.8 ± 8.8%, COP sway speed: 23.6 ± 9.0%) were significantly higher than those in the control group (12.1 ± 2.6%, 1.9 ± 27.4%, 6.2 ± 15.4%, 6.2 ± 15.3%) (p<0.05, respectively). CONCLUSION: Performing in-situ foot stamping movements with VR video of walking motion gives the sensation as if the person is walking forward. This characteristic of VR effectively increased the load on the prosthetic side, and balance ability was significantly improved compared to the control group. The results of this study suggest that VR can be used in the rehabilitation of lower limb amputees, with the advantage of being safer and more flexible in terms of location. Further studies with lower-limb amputees and biomechanical studies focusing on walking should be conducted in the future to clarify the effects of VR in combination with prosthetic walking practice. References: 1. Tezuka Y et al. Bulletin of the Japanese Society of Prosthetics and Orthotics 35(4): 285-289, 2019. 2. Yildirim Şahan T et al. Games Health J 12(6): 459-467, 2023. 3. Fukui K et al. Symmetry 13(12): 2282, 2021.
Read CV Takumi NagaoECSS Paris 2023: CP-MH21
INTRODUCTION: Prescribed moderate-intensity aerobic exercise on health issues has been extensively investigated but additional exercise interventions may lead to behavioural compensation (e.g., reducing physical activity at other times). However, it is still unclear whether the timing of exercise can affect physical activity behaviours. This study was to examine the effect of exercise at different times of day on physical activity behaviours over a 72-hour period across exercise and non-exercise days. METHODS: 22 (20 females) young healthy physically inactive adults (age: 24 ± 5 yr; BMI: 21.8 ± 2.2 kg/m2) were recruited in a randomized crossover study with either 45-min brisk walking in the morning (8:00 ~ 11:00, Mwalk) or in the evening (18:00 ~ 21:00, Ewalk). Heart rate (HR) and rating of perceived exertion (RPE) were measured during exercise. Physical activity levels (i.e., step counts), physical activity intensity, and sedentary behaviours were recorded via a pedometer and an accelerometer over a 72 hours period (the exercise day for 24 hours, EX day; non-exercise day, 24 hours before and after EX day). The habitual physical activity levels were recorded over a period of 7 consecutive days. RESULTS: There were no differences in HR (120 ± 25 vs. 119 ± 23 bpm, p = 0.603) and RPE (11 ± 2 vs. 11 ± 2, p = 0.538) during exercise between Mwalk and Ewalk. Compared to habitual physical activity (5406 ± 1306 steps), both Mwalk (12797 ± 3226 steps) and Ewalk (13580 ± 3903 steps) increased physical activity levels on the EX day (p < 0.0001) and there was no difference between 2 trials (p = 0.437). Nonetheless, we did not observe any of behavioural compensation in physical activity levels, physical activity intensity, and sedentary behaviours, as no significant differences were found between Mwalk and Ewalk, regardless of whether it was an exercise day or a non-exercise day (all, p > 0.05). CONCLUSION: A 45-min of brisk walk prescribed either in the morning or evening can enhance physical activity levels in physically inactive adults. The timing of brisk walking does not appear to induce behavioural compensation (i.e., reduction of physical activity and/or changes in the pattern of physical activity intensity) across exercise and non-exercise days.
Read CV Chun-Yuan ChengECSS Paris 2023: CP-MH21