Assistive robots and technologies can play a key role in supporting the independence and social participation of older people, helping them living healthy lives and reducing the burden on caregivers. To support the effective development of assistive robots and technologies, it is important to develop a “living laboratory” to verify and adapt technology in real-life living spaces. The purpose of this study is to validate assistive robots using a living laboratory that simulates typical indoor and outdoor real-life situations. The rationale is to enable evaluation of daily living activities of older people in a simulated living space. To minimize the risk of trauma after falls, a ceiling suspension system was installed in the living laboratory. Six different commercially available mobility and transfer support robots were introduced and tested. We demonstrated that effective scenarios could be implemented using these assistive robots within the living laboratory. We implemented a 3D markerless motion capturing system in the outdoor space and showed that outdoor activities, including walking up and down a ramp, could be verified with sufficient accuracy in three cases: (i) normal use without a robot, (ii) use of the ceiling suspension system, and (iii) use of a mobility support robot on three healthy subjects. These results suggest that the proposed living laboratory can support testing and verification of assistive robots in simulated living environments.

Background: In recent years, there has been an increasing demand for markerless motion capture systems, which are being widely used in biomechanical and clinical research. Furthermore, by using a markerless motion capture system in a laboratory environment that mimics living spaces, the data acquired on various activities of daily living, such as level walking, ramp walking, and stair ascent and descent, should more closely resemble that of real-life activities. However, the absolute reliability of gait parameters in this context is still unclear. Objective: The aim of this study was to evaluate the reliability of a markerless motion capture system in assessing the ascent and descent of ramps and stairs during walking in a simulated living space. Methods: A total of 21 healthy participants performed level walking, ramp and stair ascent and descent on two separate days, with at least a 24-hour interval between sessions. Joint angles were measured using 27 synchronized cameras with a markerless motion capture application, Theia3D (Theia Markerless Inc), and analyzed in Visual3d for all planes of motion at the hip-, knee-, and ankle-joints. The absolute reliability of day-to-day reproducibility was assessed using full-curve analysis (root mean square difference [RMSD]) and discrete point analysis of gait events using the standard error of measurement (SEM). SEM was calculated only for level walking and ramp ascent and descent, where gait events were correctly detected. Results: The SEM values for level walking and ramp ascent and descent were all below the 5-degree threshold. However, while RMSD values were generally below 5°, this threshold was exceeded for knee-joint flexion-extension angles during ramp ascent and stair ascent (5.07° and 5.64°, respectively). Conclusions: The markerless motion capture system in the living laboratory setting demonstrated a high degree of accuracy for various environments and gait types. The low SEM values obtained indicate good reliability for joint angle measurements across different days. The slightly higher RMSD values for knee-joint angles during ramp and stair ascent may reflect the system’s ability to capture the adaptations in joint kinematics in response to changes in gait conditions. These measurements in a living laboratory environment validated the absolute reliability of various gait parameters not only in level walking but also in ramp and stair ascent and descent. The findings suggest potential clinical applications and research opportunities, including the development of assistive devices and robots, using markerless motion capture in more natural living situations, rather than in controlled environments.

Preventing falls is important in the elderly. One reason for falling is tripping or stumbling; hence, it is important to improve the crossing motion. This study aimed to compare speed- and accuracy-oriented crossing training and establish a useful training method. To investigate the effects of crossing motion training, we conducted a randomized controlled trial. Twenty healthy elderly individuals (aged 71.7 ± 1.5 years) were randomly assigned to two groups: speed training and accuracy training groups. They practiced initiating their crossing motion faster or more accurately for 12 weeks. Using a three-dimensional motion analysis system, the data on the crossing motion was captured before and after the training period. We set four conditions (normal speed, fast, leaning stance, and leaning stance and fast) and two directions (anterior and lateral) to analyze the crossing motion. The crossing motion of the speed training group became significantly faster compared to baseline (p < 0.05); however, the accuracy of the crossing motion of the accuracy training group was not statistically significant. Speed training in this study had clear effects on crossing motion. It is surprising that crossing motion training from a normal upright stance can also improve swing speed from the leaning stance. We believe that this training is easy and useful in the elderly population.

[Purpose] Treadmill-based interventions are widely utilized in rehabilitation due to their advantages of providing controlled environments and enabling individualized training. However, the differences between overground and treadmill walking during the subacute rehabilitation phase remain incompletely understood. This study aimed to compare gait parameters between treadmill walking at varying speeds and overground walking in a subacute rehabilitation setting. [Participants and Methods] A total of 42 inpatients with cerebrovascular and orthopedic conditions were recruited from a convalescent rehabilitation ward. Gait parameters were measured using the Gait Real-time Analysis Interactive Lab (GRAIL) system during comfortable overground walking and treadmill walking at various speeds, including self-selected comfortable speeds and speeds matched to overground walking. Walking speed, stride length, cadence, and step width were calculated without markers and compared across conditions. [Results] The comfortable treadmill walking speed was significantly lower than the overground walking speed (mean [standard deviation]: 0.85 [0.23] m/s vs. 1.20 [0.20] m/s). Stride length was significantly shorter during treadmill walking at comfortable speeds compared to overground walking (0.86 [0.22] m vs. 1.21 [0.18] m), whereas step width was significantly wider (0.17 [0.04] m vs. 0.13 [0.03] m). [Conclusion] Maintaining cadence at reduced treadmill speeds promotes comfortable endurance training in subacute rehabilitation patients.

Fall incidents are increasing every year and prevention is necessary. Preventing falls can increase the quality of life of the elderly and decrease medical costs. Stumbling and tripping are the main causes of falls and falls in the lateral direction, causing the hip fracture. This study aimed to analyze the accuracy and speed of lateral obstacle crossing in the elderly, especially from leaning posture. Twenty healthy older adults (6 men and 14 women, aged 71.7 ± 1.5 years) and 20 healthy young adults (5 men and 15 women, aged 21.4 ± 1.2 years) participated in this study. We set four conditions (normal, fast, leaning, and leaning fast), and participants crossed the obstacle laterally ten times under each condition. The crossing motion was captured using a three-dimensional analysis system. The trajectory of the foot, landed position, step time, center of gravity of the body, and moment of the lower extremity during the swing phase were calculated and compared between older and younger adults. In the leaning condition, the step time and knee moment of the elderly were significantly longer and larger than those of young adults. From the results of the trajectory of the foot and landed position in the leaning condition, motion inconsistency of the foot was found in the elderly. We believe that it is difficult for the elderly to perform the intended crossing motion and swing quickly because of aging. This inconsistency in motion is a serious cause of falls in the elderly.

Background: Falls and fear of falling adversely affect the quality of life and independence of older adults. Although various robotic systems have been developed for fall prevention, their psychological effects, particularly on self-efficacy, remain underexplored. A ceiling-mounted fall impact mitigation robot offers continuous protection with almost no limitations on the range of movement; however, its impact on users' psychological state and functional performance is unclear. Objective: This study aimed to evaluate the effect of a fall impact mitigation robot on psychological reassurance and task performance during dynamic balance tasks in healthy young adults, with a focus on self-efficacy and functional reach capacity. Methods: Twenty-four healthy adults (age: mean 28.9, SD 7.9 years) were randomly assigned to experimental (n=12) or control (n=12) groups. All participants performed a baseline functional reach test, followed by a series of progressively challenging reach tasks (starting at 98% of maximum reach and increasing by 2% until failure). The experimental group performed tasks while wearing the fall impact mitigation robot; the control group performed without it. Self-efficacy ratings (–5 to +5 scale) were recorded before each trial. Center of pressure (COP) data were continuously collected. Statistical analyses included Mann-Whitney U tests for self-efficacy, Kaplan-Meier survival analysis for task performance, and t tests for functional reach test and COP changes. Results: During reach trials ≥102% of baseline, the experimental group (median 1.0, IQR 0.0 to 3.0) reported significantly higher self-efficacy ratings than did the control group (median 0.0, IQR –1.0 to 2.0; U=1292.5; P=.047). However, no significant differences were observed in changes in functional reach capacity (experimental: mean 104.2%, SD 3.8%; control: mean 103.6%, SD 2.5%; P=.62) or COP displacement (experimental: mean 108.9%, SD 10.4%; control: mean 114.1%, SD 9.8%; P=.23). Survival analysis revealed a nonsignificant trend toward greater task persistence in the experimental group (χ²1=0.36, P=.55). Conclusions: The fall impact mitigation robot significantly improved self-efficacy during challenging balance tasks, despite providing no active physical support. These findings underscore the role of psychological reassurance in modulating balance-related behavior and suggest that robotic safety systems may influence motor performance through psychological mechanisms. Integrating psychological support into robotic fall prevention strategies may enhance their effectiveness. Trial Registration: UMIN Clinical Trials Registry UMIN000049284; https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000056126