Fall injuries often occur on extension ladders. The extendable fly section of an extension ladder is typically closer to the user than the base section, though this design is minimally justified. This study investigates the effects of reversing the fly on foot placement, frictional requirements, adverse stepping events (repositioning the foot or kicking the rung), and user preferences. Participant foot placement was farther posterior (rung contacted nearer to toes) in the traditional ladder compared to the reversed fly condition during descent, with farther anterior foot placements during ascent. The reversed configuration had similar friction requirements during early/mid stance and significantly lower frictional requirements during late stance. Increased friction requirements during late stance were associated with farther anterior foot placement and further plantar flexed foot orientation. The reversed fly had 5 adverse stepping events versus 22 that occurred in the traditional configuration. Users typically preferred the reversed fly. These results suggest that a reversed extension ladder configuration offers potential benefits in reducing fall-related injuries that should motivate future research and development work.

Excessive muscle co-contraction is one of the factors related to the progression of knee osteoarthritis (OA). A previous study demonstrated that pain, joint instability, lateral thrust, weight, and lower extremity alignment were listed as factors affecting excessive co-contraction in knee OA. However, this study aimed to assess the association between fear-avoidance beliefs and muscle co-contraction during gait and stair climbing in people with knee OA. Twenty-four participants with knee OA participated in this cross-sectional study. Co-contraction ratios (CCRs) were used to calculate muscle co-contraction during walking and stair climbing, using surface electromyography. Fear-avoidance beliefs were assessed by the Tampa Scale for Kinesiophobia-11 (TSK-11) for kinesiophobia and the Pain Catastrophizing Scale (PCS) for pain catastrophizing. Secondary parameters that may influence co-contraction, such as degree of pain, lateral thrust, weight, and lower extremity alignment, were measured. The relationships between the CCR during each movement, TSK-11, and PSC were evaluated using Spearman\'s rank correlation coefficient and partial correlation analysis, adjusted by weight and lower extremity alignment. Partial correlation analysis showed a significant correlation only between medial muscles CCR and TSK-11 during stair descent (r = 0.54, p < 0.05). Our study revealed that kinesiophobia could be associated with co-contraction during stair descent in people with knee OA.

OBJECTIVE: This study aimed to examine whether indirectly deterring elevator use through time-targeted Point-of-Decision Prompts (PODPs) efficiently increased stair usage in a university setting.
METHODS: A quasi-experimental design (pre-post design) was employed over 2 weeks in September 2023. Baseline observations were conducted for 1 week prior to signage placement at two locations. The intervention in this study lasted for 1 week, immediately following baseline observations. Three hundred and thirty-one and 384 participants were observed during the baseline and intervention periods, respectively. Logistic regression analysis was used to examine the increase in the act of ascending the stairs.
RESULTS: Our intervention, which focused on time-related messages, effectively increased stair usage among university students (coefficient = 0.435, p-value < 0.01). Furthermore, females (coefficient = -0.820, p-value < 0.05) and individuals aged ≥ 30 years (coefficient = 1.048, p-value < 0.01) were notably more likely to be influenced by our intervention than males and individuals aged < 30 years.
CONCLUSIONS: Indirectly discouraging elevator use through time-targeted PODPs may amplify the effects of the previously employed time-related messages. Our findings suggested that a deterrence nudge should primarily be directed towards promoting stair usage among females or individuals aged ≥ 30 years.

BACKGROUND: Individuals who are living with obesity often adopt alternative lower limb walking mechanics compared to persons with a healthy weight. Stair negotiation is a common activity of daily living that, when used consistently with diet and other physical activity, can help promote the reversal of health-related risk factors associated with people who are obese. The purpose of this study was to determine how stair negotiation affects normalized and non-normalized peak knee extension and abduction moments in young adults who live with obesity (BMI between 30 and 40 kg/m2) compared to adults with a healthy weight (BMI between 18.5 and 25 kg/m2).
METHODS: Fifteen young adults living with obesity and fifteen with a healthy weight performed stair ascent and descent walking trials on a 3-step instrumented staircase at a self-selected walking speed. A one-way ANCOVA (covariate: gait speed) was used to compare knee moment variables between groups.
RESULTS: No significant differences were found between groups in peak knee joint moments normalized to body mass. The individuals living with obesity demonstrated significantly larger non-normalized peak knee extension moments during stair ascent and descent but no differences in the non-normalized peak knee abduction moments for stair ascent or descent.
CONCLUSIONS: Results of this study indicate differences in non-normalized peak knee extension moments between BMI groups. The young age of the obese group may have contributed to minimal differences overall. Future research should determine how these findings differ in an older obese population and how using a handrail would affect these results.

CONCLUSIONS: The activity of daily living (ADL) related to stair climbing is one of the most compromised ADLs among the elders. It requires good muscle strength, balance, and range of motion (ROM) in the lower limb. We aimed to investigate the effects of Yoga complemented with physiotherapy (Intervention group) compared to only physiotherapy (control group) on lower limb muscle strength, balance, and ROMs among elders with ADL limitation in stair climbing. Sixty-five community-dwelling elders with compromised stair climbing were enrolled. Elders who consented to yoga along with physiotherapy were enrolled in the intervention arm. Data were collected and analyzed following 12 weeks of intervention. Endline assessment showed that the intervention group had more improvement in all test scores and ROMs as compared to the control group, although there were improvements in both arms as compared to baseline. Considering the beneficial effects of both interventions, yoga can be added to gain additional advantages.Trial Registration:Indian Clinical Trials Registry number CTRI/2021/08/035825.

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.

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.

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.

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.
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.

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).
CONCLUSIONS: 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.