Biomechanical analysis of trunk and lower limbs during stair activity in patients with scoliosis.

Staircases are a frequently encountered obstacle in daily life, requiring individuals to navigate ascending and descending movements that place additional demands on the trunk and lower limbs compared to walking on level surfaces. Therefore, it is crucial to examine the biomechanical characteristics of the trunk and lower limbs in individuals with scoliosis during stair activity. The aim of this study was to investigate the biomechanical differences in trunk and lower limbs during daily stair activities between patients with scoliosis and a healthy population. Additionally, the study aimed to explore the relationship between trunk abnormalities and lower limb biomechanics, providing a clinical and objective assessment basis for scoliosis. The Qualisys system, based in Gothenburg, Sweden, was employed for data collection in this study, with a sampling frequency of 150 Hz. It captured the kinematics of the trunk and lower limbs, as well as the kinetics of the lower limbs during stair ascent and descent for both the 28 individuals with scoliosis and the 28 control participants. The results indicate that scoliosis patients demonstrated significantly higher asymmetry compared to the control group in various measures during ascent and decent. These include different parts of kinematics and kinetics. Scoliosis patients demonstrate noticeable variations in their movement patterns compared to the healthy population when engaging in stair activities. Specifically, during stair ascent, scoliosis patients exhibit a seemingly more rigid movement pattern, whereas descent is characterized by an unstable pattern.

Transformable Quadruped Wheelchairs Capable of Autonomous Stair Ascent and Descent.

Despite advancements in creating barrier-free environments, many buildings still have stairs, making accessibility a significant concern for wheelchair users, the majority of whom check for accessibility information before venturing out. This paper focuses on developing a transformable quadruped wheelchair to address the mobility challenges posed by stairs and steps for wheelchair users. The wheelchair, inspired by the Unitree B2 quadruped robot, combines wheels for flat surfaces and robotic legs for navigating stairs and is equipped with advanced sensors and force detectors to interact with its surroundings effectively. This research utilized reinforcement learning, specifically curriculum learning, to teach the wheelchair stair-climbing skills, with progressively increasing complexity in a simulated environment crafted in the Unity game engine. The experiments demonstrated high success rates in both stair ascent and descent, showcasing the wheelchair's potential in overcoming mobility barriers. However, the current model faces limitations in tackling various stair types, like spiral staircases, and requires further enhancements in safety and stability, particularly in the descending phase. The project illustrates a significant step towards enhancing mobility for wheelchair users, aiming to broaden their access to diverse environments. Continued improvements and testing are essential to ensure the wheelchair's adaptability and safety across different terrains and situations, underlining the ongoing commitment to technological innovation in aiding individuals with mobility impairments.

Examining BMI-knee angle relationship in healthy young adults during stair ambulation using Kinovea® software.

OBJECTIVE: This study explored the correlation between body mass index (BMI) and knee angle during ascending and descending stairs in healthy young adults. The hypothesis was that higher BMI would be associated with altered knee angles during stair ambulation. PATIENTS AND METHODS: Participants' (n = 43) demographic characteristics, including age, height, weight, BMI, leg preference, and thigh lengths, were recorded. Gait parameters, such as cycle duration, stride phase, velocity, and knee angles, were analyzed using Kinovea® software. Inferential statistical tests, including ANOVA, t-tests, and correlation analysis, were performed to explore the relationships and differences between variables. RESULTS: No significant effect of BMI on knee angle was found [ascending stairs: F (2, 40) = 0.75, p = 0.47; descending stairs: F (2, 40) = 0.58, p = 0.56]. However, gait parameters differed significantly, with shorter cycle duration during ascending stairs (M = 4.52 s, SD = 0.76 s) compared to descending stairs (M = 4.72 s, SD = 0.81 s). The stride phase varied across BMI categories [F (2, 40) = 3.82, p < 0.05], with the ideal weight group (M = 47.12%, SD = 3.21%) exhibiting a distinct stride phase. Positive correlations were found between knee angle and thigh length difference during ascending (r = 0.42, p < 0.05) and descending stairs (r = 0.38, p < 0.05). CONCLUSIONS: This study demonstrated that BMI did not significantly affect knee angle during stair ambulation. However, gait parameters such as cycle duration, stride phase, and velocity differed between ascending and descending stairs. The positive correlation between knee angle and thigh length difference suggests that individuals with more significant thigh length differences may exhibit larger knee angles during stair climbing. The findings of this study have clinical implications for rehabilitation programs and the design of assistive devices. Understanding the relationship between BMI, thigh length difference, and knee angle during stair climbing can help clinicians better assess and manage gait abnormalities in individuals navigating stairs.

The effects of various stair-climbing exercises on functional mobility and trunk muscle activation in community-dwelling older adults: A pilot randomized controlled trial.

BACKGROUND: Stair-climbing (SC) is an essential daily life skill, and stair-climbing exercise (SCE) serves as a valuable method for promoting physical activity in older adults. This study aimed to compare the impact of SCEs with heel contact (HC) and heel off (HO) during SC on functional mobility and trunk muscle (TM) activation amplitudes in community-dwelling older adults. METHODS: In the pilot randomized controlled trial, participants were randomly allocated to either the HC group (n = 17; mean age 75.9 ± 6.3 years) or the HO group (n = 17; mean age 76.5 ± 4.6 years). The HC participants performed SCE with the heel of the ankle in contact with the ground, while the HO participants performed SCE with the heel of the ankle off the ground during SC. Both groups participated in progressive SCE for one hour per day, three days per week, over four consecutive weeks (totaling 12 sessions) at the community center. We measured timed stair-climbing (TSC), timed up and go (TUG), and electromyography (EMG) amplitudes of the TMs including rectus abdominis (RA), external oblique (EO), transverse abdominus and internal oblique abdominals (TrA-IO), and erector spinae (ES) during SC before and after the intervention. RESULTS: Both groups showed a significant improvement in TSC and TUG after the intervention (P < .01, respectively), with no significant difference between the groups. There was no significant difference in the EMG activity of the TMs between the groups after the intervention. The amplitude of TMs significantly decreased after the intervention in both groups (P < .01, respectively). CONCLUSION: Both SCE methods could improve balance and SC ability in older adults while reducing the recruitment of TMs during SC. Both SCE strategies are effective in improving functional mobility and promoting appropriate posture control during SC in older adults.

Nudging Interventions on Stair Use: A Scoping Review.

Stair use is a physical activity that can be incorporated into the daily lifestyle of a majority of the population, resulting in several health benefits. Nudges are increasingly used in public health interventions to encourage healthy behaviours such as physical activity in a cost-effective manner. This scoping review aimed to investigate the effect and the characteristics of nudges used on interventions to promote stair use. We reviewed the relevant literature published in PubMed, Cochrane Library, Mendeley and Google Scholar, from January 2009 to May 2022. Eligibility criteria included original studies of any type of design, written in English, targeting healthy adults, reporting nudging interventions, using elevator or escalator as comparators and defining a baseline for comparisons. Initially, 118 publications were identified, and after applying exclusion criteria, 27 articles were included in the analysis. Results showed that most of the nudging interventions had significant positive effect on stair use in several settings. The evidence from this review suggests that incorporating nudges into public health interventions can effectively promote physical activity through increased stair usage. Emphasizing prevention measures in public health interventions may contribute to better health outcomes.

Effect of age on ankle biomechanics and tibial compression during stair descent.

BACKGROUND: Stress fracture is a concern among older adults, as age-related decrements in ankle neuromuscular function may impair their ability to attenuate tibial compressive forces experienced during daily locomotor tasks, such as stair descent. Yet, it is unknown if older adults exhibit greater tibial compression than their younger counterparts when descending stairs. RESEARCH QUESTION: Do older adults exhibit differences in ankle biomechanics that alter their tibial compression during stair descent compared to young adults, and is there a relation between tibial compression and specific changes in ankle biomechanics? METHODS: Thirteen young (18-25 years) and 13 older (> 65 years) adults had ankle joint biomechanics and tibial compression quantified during a stair descent. Discrete ankle biomechanics (peak joint angle and moment, and joint stiffness) and tibial compression (maximum and impulse) measures were submitted to an independent t-test, while ankle joint angle and moment, and tibial compression waveforms were submitted to an independent statistical parametric mapping t-test to determine group differences. Pearson correlation coefficients (r) determined the relation between discrete ankle biomechanics and tibial compression measures for all participants, and each group. RESULTS: Older adults exhibited smaller maximum tibial compression (p = 0.004) from decreases in peak ankle joint angle and moment between 17 % and 34 % (p = 0.035), and 20-31 % of stance (p < 0.001) than young adults. Ankle biomechanics exhibited a negligible to weak correlation with tibial compression for all participants, with peak ankle joint moment and maximum tibial compression (r = -0.48 ±â€¯0.32) relation the strongest. Older adults typically exhibited a stronger relation between ankle biomechanics and tibial compression (e.g., r = -0.48 ±â€¯0.47 vs r = -0.27 ±â€¯0.52 between peak ankle joint moment and maximum tibial compression). SIGNIFICANCE: Older adults altered ankle biomechanics and decreased maximum tibial compression to safely execute the stair descent. Yet, specific alterations in ankle biomechanics could not be identified as a predictor of changes in tibial compression.

Effects of acute and chronic stair-climbing exercise on metabolic health: A systematic review.

Stair climbing exercise (SE) provides a feasible approach to elevate physical activity, but the effects on metabolic health are unclear. We systematically reviewed the currently available evidence on the effects of SE on fasting and postprandial glycaemia and lipidaemia. Studies were included if they investigated the effects of acute or chronic (at least 2 weeks) SE on fasting and/or postprandial glycaemic (insulin and glucose) and lipidaemic (triacylglycerols and non-esterified fatty acids) responses in healthy, prediabetic or type 2 diabetic adult populations. PubMed, Web of Science and Scopus were searched for eligible studies until July 2022. A total of 25 studies (14 acute and 11 chronic) were eligible for review. Acute bout(s) of SE can reduce postprandial glycaemia in individuals with prediabetes and type 2 diabetes (8 of 9 studies), but not in normoglycemic individuals. The effects of acute SE on postprandial lipidaemic responses and SE training on both fasting and postprandial glycaemia/lipidaemia were unclear. Acute SE may reduce postprandial glucose concentrations in people with impaired glycaemic control, but high-quality studies are needed. More studies are needed to determine the effect of chronic SE training on postprandial glucose and lipid responses, and the acute effects of SE on lipid responses.

The association between stair climbing and modifiable cardiovascular disease risk factors: the Suita Study.

BACKGROUND: Stair climbing is a readily available form of physical activity with potential cardiovascular benefits. This study aimed to investigate the association between stair climbing and numerous modifiable cardiovascular disease (CVD) risk factors. METHODS: In this cross-sectional study, we used data from 7282 Japanese people (30-84 years) residing in Suita City, Osaka. CVD risk factors and stair climbing frequency were assessed during the Suita Study health examination. Logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for CVD risk factors across stair climbing frequencies. RESULTS: After adjustment for age, sex, lifestyle, and medical conditions, stair climbing >60% of the time, compared to <20% of the time, was inversely associated with obesity, smoking, physical inactivity, and stress: ORs (95% CIs) = 0.63 (0.53, 0.75), 0.81 (0.69, 0.96), 0.48 (0.41, 0.55), and 0.67 (0.58, 0.78), respectively (p-trends < 0.05). CONCLUSION: Stair climbing was inversely associated with obesity, smoking, physical inactivity, and stress; suggesting a potential role for cardiovascular disease prevention.

Ankle inversion proprioception measured during stair descent can identify chronic ankle instability.

BACKGROUND: Individuals with chronic ankle instability (CAI) may experience recurrent ankle sprains and symptoms during daily activities such as stair descent, where the associated proprioceptive deficit is largely unevaluated. OBJECTIVES: To evaluate the reliability and validity of an ankle inversion discrimination apparatus for stair descent, and examine whether proprioceptive scores from this apparatus are associated with patient-reported symptoms. DESIGN: Cross-sectional study. METHOD: Sixty-six participants volunteered in this study. The ankle inversion discrimination apparatus was purpose-built to assess ankle proprioception across four positions of ankle inversion (10°, 12°, 14°, and 16°) during stair descent. The Area Under the Receiver Operating Curve (AUC) was employed as the ankle proprioceptive discrimination score. RESULTS: Test-retest reliability ICC (3,1) for the whole group was 0.825, with 0.747 for the non-CAI group (95%CI = 0.331-0.920) and 0.701 for CAI (95%CI = 0.242-0.904). The CAI group performed at a significantly lower level than non-CAI on the ankle inversion discrimination apparatus for stair descent assessment (0.769 ± 0.034 vs. 0.830 ± 0.035, F = 33.786, p < 0.001). CAIT scores were strongly and significantly correlated with scores from this apparatus (Spearman's rho = 0.730, p < 0.001). CONCLUSIONS: The ankle inversion discrimination apparatus for stair descent is reliable and valid for assessing task-specific ankle proprioceptive impairments in CAI. The strong and significant relationship found between ankle proprioception during stair descent and the severity of CAI suggests that rehabilitation programs focusing on deficits in ankle inversion proprioception during stair descent may improve self-reported instability in CAI.

Exercise snacks are a time-efficient alternative to moderate-intensity continuous training for improving cardiorespiratory fitness but not maximal fat oxidation in inactive adults: a randomized controlled trial.

The aims of this study were (1) to determine how stair-climbing-based exercise snacks (ES) compared to moderate-intensity continuous training (MICT) for improving cardiorespiratory fitness (CRF), and (2) to explore whether ES could improve maximal fat oxidation rate (MFO) in inactive adults. Healthy, young, inactive adults (n: 42, age: 21.6 ± 2.3 years, BMI: 22.5 ± 3.6 kg·m-2, peak oxygen uptake (VO2peak): 33.6 ± 6.3 mL·kg-1·min-1) were randomly assigned to ES, MICT, or Control. ES (n = 14) and MICT (n = 13) groups performed three sessions per week over 6 weeks, while the control group (n = 15) maintained their habitual lifestyle. ES involved 3 × 30 s "all-out" stair-climbing (6 flight, 126 steps, and 18.9 m total height) bouts separated by >1 h rest, and MICT involved 40 min × 60%-70% HRmax stationary cycling. A significant group × time interaction was found for relative VO2peak (p < 0.05) with ES significantly increasing by 7% compared to baseline (MD = 2.5 mL·kg-1·min-1 (95% CI = 1.2, 3.7), Cohen's d = 0.44), while MICT had no significant effects (MD = 1.0 mL·kg-1·min-1 (-1.1, 3.2), Cohen's d = 0.17), and Control experienced a significant decrease (MD = -1.7 mL·kg-1·min-1 (-2.9, -0.4), Cohen's d = 0.26). MFO was unchanged among the three groups (group × time interaction, p > 0.05 for all). Stair climbing-based ES are a time-efficient alternative to MICT for improving CRF among inactive adults, but the tested ES intervention appears to have limited potential to increase MFO.

Effect of single-radius design on in vivo kinematics during stair activities after total knee arthroplasty.

BACKGROUND: The single-radius design is one of the major total knee arthroplasty (TKA) designs and widely used all over the world. The objective of this study was to compare in vivo kinematics between the anteroposterior (AP) single-radius design with mediolateral (ML) single-radius (Non Restricted Geometry; NRG) and ML dual-radius (Triathlon) during stair activities. METHODS: A total of 21 knees in 18 patients (NRG group: 10 knees in 7 patients, Triathlon group: 11 knees in 11 patients) with a clinically successful posterior stabilized TKA were examined. Under fluoroscopic surveillance, each patient performed stair ascending and descending motions. In vivo kinematics were analyzed using 2D/3D registration technique. The knee flexion angle, rotation angle, varus-valgus angle, AP translation of the femorotibial contact point for both the medial and lateral sides of the knee, and post-cam engagement were evaluated. RESULTS: There were no significant differences between the two groups in rotation angle and AP translation at each flexion angle. Examining the varus-valgus angle, the NRG group showed varus position at an early flexion angle during both stair activities.Post-cam engagement was observed in both groups during both stair activities. The mean flexion angle of engagement in the NRG group, the post of which was located anterior to the Triathlon, was larger than that in the Triathlon group during both stair activities. CONCLUSION: Despite the same AP single-radius TKA, ML single-radius might affect varus motion at an early flexion angle.

Concurrent Validity and Reliability of Video-Based Approach to Assess Physical Function in Adults With Knee Osteoarthritis.

OBJECTIVES: The aim of this study was to determine the concurrent validity and reliability of the Osteoarthritis Research Society International recommended performance-based tests delivered by video-based in adults with knee osteoarthritis. METHODS: Thirty-two participants (aged 40-70 years; 15 men) undertook assessments of 4 performance-based tests via both video-based (real-time and recorded) and face-to-face approaches, on the same day. Outcome measures were performance-based test and the number of technical issues encountered. The performance-based tests included the 40-Meter Fast-Paced Walk Test (velocity, m/s), the 30-Second Chair Stand Test (number of repetitions), the Stair Climb Test (time, seconds), and the Timed "Up & Go" Test (time, seconds). The Bland-Altman limit of agreement measures, standard error of measurement (SEM), coefficient of variation (CV), minimal detectable changes, and bias (mean difference) were employed to analyze the concurrent validity between video-based and face-to-face approaches of the performance-based tests. Reliability was measured using intraclass correlation coefficients, CV, and SEM. RESULTS: A high degree of concurrent validity for the Timed "Up & Go" Test (bias = -0.22), the 30-Second Chair Stand Test (bias = -0.22), the Stair Climb Test (bias = -0.31), and the 40-Meter Fast-Paced Walk Test (bias = -0.06) was found. SEM and CV values were within the acceptable level for concurrent validity. There was a high degree of reliability demonstrated for all tests analyzed. Intraclass correlation coefficient measures ranged from 0.95 to 1.00 for intrarater reliability, and from 0.95 to 0.99 for interrater reliability. CONCLUSIONS: Video-based assessment of physical performance tests is a valid and reliable tool for measuring physical function among adults with knee osteoarthritis via Microsoft Teams (Microsoft Corp, Redmond, WA, USA). IMPACT: Video-based assessment is a promising public health tool to measure physical function in adults with knee osteoarthritis.

Relationship of device measured physical activity type and posture with cardiometabolic health markers: pooled dose-response associations from the Prospective Physical Activity, Sitting and Sleep Consortium.

AIMS/HYPOTHESIS: The aim of this study was to examine the dose-response associations of device-measured physical activity types and postures (sitting and standing time) with cardiometabolic health. METHODS: We conducted an individual participant harmonised meta-analysis of 12,095 adults (mean ± SD age 54.5±9.6 years; female participants 54.8%) from six cohorts with thigh-worn accelerometry data from the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. Associations of daily walking, stair climbing, running, standing and sitting time with a composite cardiometabolic health score (based on standardised z scores) and individual cardiometabolic markers (BMI, waist circumference, triglycerides, HDL-cholesterol, HbA1c and total cholesterol) were examined cross-sectionally using generalised linear modelling and cubic splines. RESULTS: We observed more favourable composite cardiometabolic health (i.e. z score <0) with approximately 64 min/day walking (z score [95% CI] -0.14 [-0.25, -0.02]) and 5 min/day stair climbing (-0.14 [-0.24, -0.03]). We observed an equivalent magnitude of association at 2.6 h/day standing. Any amount of running was associated with better composite cardiometabolic health. We did not observe an upper limit to the magnitude of the dose-response associations for any activity type or standing. There was an inverse dose-response association between sitting time and composite cardiometabolic health that became markedly less favourable when daily durations exceeded 12.1 h/day. Associations for sitting time were no longer significant after excluding participants with prevalent CVD or medication use. The dose-response pattern was generally consistent between activity and posture types and individual cardiometabolic health markers. CONCLUSIONS/INTERPRETATION: In this first activity type-specific analysis of device-based physical activity, ~64 min/day of walking and ~5.0 min/day of stair climbing were associated with a favourable cardiometabolic risk profile. The deleterious associations of sitting time were fully attenuated after exclusion of participants with prevalent CVD and medication use. Our findings on cardiometabolic health and durations of different activities of daily living and posture may guide future interventions involving lifestyle modification.

The Association of Stair Climbing Behaviors With Hazard of All-Cause Mortality in Adults With or At Risk of Knee Osteoarthritis.

OBJECTIVE: To investigate the association of stair climbing difficulty and stair climbing frequency with the risk of all-cause mortality over 13 years in adults with or at high risk for knee OA. METHODS: We used data from the Osteoarthritis Initiative (OAI), a prospective cohort study of community-dwelling adults with or at high risk for symptomatic knee OA. The exposures were stair climbing difficulty and frequency, assessed at baseline using self-report questionnaires. The outcome was all-cause mortality, assessed from baseline through 13 years of follow-up. Kaplan-Meier survival curves and Cox proportional hazards regression were used to investigate the association between stair climbing exposures and all-cause mortality. RESULTS: Three hundred seven (6.81%) and 310 (6.84%) participants in the difficulty and frequency samples, respectively, died during 13 years of follow-up. Those who were limited in any capacity in terms of their stair climbing ability had 54% to 84% greater hazard of all-cause mortality, and those who climbed at least 7 flights of stairs per week had 38% lower hazard of all-cause mortality. CONCLUSION: Adults with or at high risk for knee OA who report difficulty with climbing stairs or who infrequently use stairs are at greater hazard of all-cause mortality. Stair climbing difficulty and frequency are simple to collect and changes may occur early in OA progression, allowing for early intervention. Brief questions about stair climbing behaviors can serve as a functional vital sign within the clinician's toolbox.

Evaluating the impact of a short bout of stair-climbing on creative thinking in a between-subjects pretest posttest comparison study.

Recent studies have indicated potential links between short bouts of physical activity like stair-climbing and enhanced creative thinking. However, previous research featured limitations, such as using an uncommon 3 flights round-trip design and lacking baseline creative thinking evaluations. To rectify these limitations and build a more comprehensive understanding, the present study adopts a between-subjects pretest posttest comparison design to scrutinize the effects of ascending stair-climbing on both divergent and convergent thinking. 52 subjects underwent a pretest, followed by random assignment to one of four interventions: ascending stair-climbing for 2, 5, or 8 flights, or taking an elevator for 8 flights, before progressing to a posttest. The results revealed a notable improvement in convergent thinking, measured by the increased number of solved matchstick arithmetic problems (d = 1.165), for participants who climbed 2 flights of stairs compared to those who took the elevator. However, climbing 5 or 8 flights showed no such impact on convergent thinking, and stair-climbing, regardless of the number of flights, did not influence divergent thinking. These findings underscore the utility of brief stair-climbing as an accessible means to enhance convergent thinking in everyday settings, providing a nuanced insight into the relationship between physical activity and creative thinking processes.

Biomechanical effects of an articulating prosthetic toe joint during stair navigation for individuals with unilateral, below-knee limb loss.

Stair navigation is an essential and demanding form of locomotion. During stair ascent and descent, persons with lower limb loss exhibit gait characteristics which may increase their risk of falls and joint degeneration of the intact limb. To reduce deviations from typically-able-bodied gait and overloading of the intact limb for this population, one potential intervention involves modifying passive prosthetic feet by incorporating a flexible toe joint that simulates the biological metatarsophalangeal joint. In this study, we aimed to assess the user preferences and biomechanical effects of a flexible prosthetic toe joint during stair ascent and descent for persons with unilateral lower-limb loss. Nine participants with unilateral lower-limb loss were recruited (Male; Medicare Functional Classification Level: eight K4, one K3; age: 41 ± 11 years; mass: 95 ± 13 kg; height: 1.84 ± 0.05 m; mean ± SD). No significant changes in lower-limb joint mechanics were identified. Five of nine participants preferred the unmodified prosthesis with a standard carbon fiber keel for both stair ascent and descent. Varied user preferences and inconsistent changes in lower-limb joint parameters between participants highlight the importance of subject-specific analyses and individualized device prescription.

Daily stair climbing, disease susceptibility, and risk of atherosclerotic cardiovascular disease: A prospective cohort study.

BACKGROUND AND AIMS: The associations between intensity of stair climbing and atherosclerotic cardiovascular disease (ASCVD) and how these vary by underlying disease susceptibility are not fully understood. We aim to evaluate the intensity of stair climbing and risk of ASCVD types and whether these vary with the presence of ASCVD risk factors. METHODS: This prospective study used data of 458,860 adult participants from the UK Biobank. Information about stair climbing, sociodemographic, and lifestyle factors was collected at baseline and a resurvey 5 years after baseline. ASCVD was defined as coronary artery disease (CAD), ischemic stroke (IS), or acute complications. Associations between flights of stair climbing and ASCVD were examined as hazard ratios (HRs) from Cox proportional hazards models. The modification role of disease susceptibility on such associations was assessed by analyses stratified by levels of genetic risk score (GRS), 10-year risks of ASCVD, and self-reported family history of ASCVD. RESULTS: During a median of 12.5 years of follow-up, 39,043 ASCVD, 30,718 CAD, and 10,521 IS cases were recorded. Compared with the reference group (reported climbing stairs 0 times/day at baseline), the multivariable-adjusted HRs for ASCVD were 0.97 (95% CI, 0.93-1.01), 0.84 (0.82-0.87), 0.78 (0.75-0.81), 0.77 (0.73-0.80) and 0.81 (0.77-0.85) for stair climbing of 1-5, 6-10, 11-15, 16-20 and ≥21 times/day, respectively. Comparable results were obtained for CAD and IS. When stratified by different disease susceptibility based on the GRS for CAD/IS, 10-year risk, and family history of ASCVD, the protection association of stair climbing was attenuated by increasing levels of disease susceptibility. Furthermore, compared with people who reported no stair climbing (<5 times/d) at two examinations, those who climbed stairs at baseline and then stopped at resurvey experienced a 32% higher risk of ASCVD (HR 1.32, 95% CI:1.06-1.65). CONCLUSIONS: Climbing more than five flights of stairs (approx 50 steps) daily was associated with a lower risk of ASCVD types independent of disease susceptibility. Participants who stopped stair climbing between baseline and resurvey had a higher risk of ASCVD compared with those who never climbed stairs.

Stair climbing and the incidence of atherosclerotic cardiovascular disease: a population-based prospective cohort study.

BACKGROUND: Stair climbing is a readily available form of physical activity with potential cardioprotective merits. Herein, we investigated the association between stair climbing and atherosclerotic cardiovascular disease (ASCVD) incidence among Japanese people. METHODS: This prospective cohort study used data from 7,282 participants, aged 30-84 years, registered in the Suita Study and free from stroke and ischemic heart disease (IHD). Standard approaches were used to detect incident ASCVD events, including cerebral infarction and IHD, during follow-up. Stair climbing was assessed using a baseline questionnaire. We applied the Cox regression to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of incident ASCVD for climbing stairs in 20-39%, 40-59%, and ≥60% compared to <20% of the time. We adjusted the regression models for age, sex, body mass index, smoking, alcohol consumption, physical activity, hypertension, diabetes, atrial fibrillation, lipid profile, chronic kidney disease, and history of cardiac murmur or valvular diseases. RESULTS: A total of 536 new ASCVD events were detected within a median follow-up period of 16.6 years. In the age- and sex-adjusted model, stair climbing 20-39%, 40-59%, and ≥60% of the time was associated with lower ASCVD incidence: HRs (95% CIs) = 0.72 (0.56, 0.92), 0.86 (0.68, 1.08), and 0.78 (0.61, 0.99), respectively (p-trend = 0.020). The corresponding associations were attenuated after adjusting for lifestyle and clinical factors: HRs (95% CIs) = 0.74 (0.58, 0.95), 0.90 (0.71, 1.13), and 0.89 (0.69, 1.13), respectively (p-trend = 0.152). CONCLUSION: Frequent stair climbing was associated with lower ASCVD incidence; however, this association was partly explained by lifestyle and clinical factors of participants.

Risky behavior during stair descent for young adults: Differences in men versus women.

Injuries commonly occur on stairs, with high injury rates in young adults, especially young women. High injury rates could result from physiological and/or behavioral differences; this study focuses on behaviors. The purposes of this observational study were (1) to quantify young adult behaviors during stair descent and (2) to identify differences in stair descent behavior for young adult men versus women. Young adult pedestrians (N = 2,400, 1,470 men and 930 women) were videotaped during descent of two indoor campus staircases, a short staircase (2 steps) and a long staircase (17 steps). Behaviors during stair descent were coded by experimenters. Risky behaviors observed on the short staircase included: No one used the handrail, 16.1% used an electronic device, and 16.4% had in-person conversations. On the long staircase: 64.8% of pedestrians did not use the handrail, 11.9% used an electronic device, and 14.5% had in-person conversations. Risky behaviors observed more in women included: less likely to use the handrail (long staircase), more likely to carry an item in their hands (both staircases), more likely to engage in conversation (both staircases), and more likely to wear sandals or heels (both staircases) (p≤0.05). Protective behaviors observed more in women included: less likely to skip steps (both staircases), and more likely to look at treads during transition steps (long staircase) (p≤0.05). The number of co-occurring risky behaviors was higher in women: 1.9 vs 2.3, for men vs women, respectively (p<0.001). Five pedestrians lost balance but did not fall; four of these pedestrians lost balance on the top step and all five had their gaze diverted from the steps at the time balance was lost. The observed behaviors may be related to the high injury rate of stair-related falls in young adults, and young women specifically.