Current Issue

Older adults who have experienced falls have decreased location and physical mobility due to the fear of falling and limited walking ability and depend on others for their daily life activities (Lee et al, 2009; Kyeoung MJ,2022). Gait assistive devices are designed to alleviate the impact of mobility limitations, enhance independence, and promote greater freedom and independent living. They are necessary for seniors and individuals with mobility impairments to facilitate a more active and independent lifestyle while reducing the burden of therapy and care (Arefin et al, 2020; Dong CP, 2021). In particular, introducing gait assistive devices early during the initial stage of walking training or when independent walking is difficult can increase the base of support (BOS) while standing, induce symmetrical weight load on the lower extremities, and improve gait stability.

The most commonly used gait assistive devices in everyday life include canes, crutches, and walkers. Among them, walkers have the advantage of providing stability by securing a wide BOS and minimizing skewed gait by allowing the use of the assistive device with both hands. However, using walkers with both hands limits the swinging of the arms when walking, preventing the natural gait pattern (Liu 2009), and excessive weight support of walkers can reduce the effect of limb muscle strengthening and cause secondary musculoskeletal damage to the wrists (Bradley and Hernandez, 2011). Visintin and Barbeau (1994) reported that the reduction in the arm-swinging motion while walking with gait-assistive devices is a factor that interferes with the normal gait pattern, and Bateni and Makio (2005) reported that the free movement of the upper extremities should be considered in training for the normal gait pattern when applying gait-assistive devices because the motion of lifting the walker and pushing it forward can potentially disturb the center of mass.

Mobility and maneuverability are necessary to avoid multiple obstacles while moving in a narrow, complex space. However, while conventional walkers provide high structural safety, they have limitations in terms of mobility and maneuverability. Sufficient space is needed to change the direction when walking with a walker, and the user must lift the body of the walker and slightly change the direction in several steps. Such a directional change is a challenging task for older adults with insufficient muscle strength of the lower limbs and reduced concentration and cognitive function, and falls may occur while changing directions.

Therefore, we developed a motion-tracking gait-assistive walker (MTGAW) that reduces the fall-inducing factors of gait-assistive devices identified in previous research and clinical practice, and clinical specialists, including physiotherapists and occupational therapists, evaluated the usability of the walker. Functional satisfaction and improvement areas were determined through the usability evaluation and interviews, which will be reflected in the promotion for of commercialization of the walker in future product development.

Gait-assistive devices are used to improve independent mobility and prevent falls in older adults and individuals with a disability (Arefin et al, 2020). These devices are selected according to the user's level of balancing ability and whether the assistive device can be grasped using one or both upper limbs (Bruun, 1986; Wu et al, 2010; Hassan et al, 2014; Wilson et al, 2019). Walkers have limited location mobility compared with crutches or canes; however, they provide optimal stability with a wide BOS and help minimize users’ anxiety (Oh et al, 2022). However, both upper limbs are required to operate a walker, and incorrect use (e.g., relying on the walker for excessive weight support by using the upper limbs that hold the walker) can interfere with weight transfer to the lower limbs (Melis et al, 1999; Edelstein 2019). Moreover, prolonged, incorrect walker use can result in the user having an inappropriate gait pattern (Bateni and Maki, 2005; Bradley and Hernandez, 2011).

Therefore, we developed an MTGAW that compensates for the shortcomings of conventional walkers. The MTGAW detects gait intention through the wire displacement sensor connected to the user's lower extremities to track and assist the user's walking and allows unrestricted motion of the upper extremities. Additionally, the walker is equipped with Mecanum wheels and has been designed to enable front-back and left-right movements and in-situ rotation motion tracking of the user. While the MTGAW has been developed to address the known shortcomings of walkers, it is necessary to examine the currently developed prototype's stability, safety, and effectiveness before making it available to older adults and individuals with a disability. Accordingly, this study also involved the evaluation of the developed prototype's usability by clinical experts, including physiotherapists and occupational therapists.

The usability evaluation showed that the MTGAW's detection technology for user motion intention allowed free movement of the hands while walking, thereby providing psychological stability and preventing falls. Another advantage of the walker reported was that the tracking function for the left-right directional change and in-situ rotation motions is essential for everyday life at home, which is not provided in existing gait-assistive devices or walking rehabilitation robots. As such, high satisfaction levels were reported in the four areas. Nevertheless, a few areas for improvement were identified, namely, improvements to reduce the discomfort caused by a slow speed, safety measures to prevent posterior falls, and a function to adjust the height and width of the walker according to the user's body. Speed adjustment should be possible since the current fixed slow speed can further increase fall risk, and improvements are needed to enable the adjustment of the height and width of the product to tailor it to the user's body to prevent tripping on the product when walking. In particular, using the harness used in the study by Visintin and Barbeau (1994) instead of a Velcro-type strap worn on the thighs to connect the body to the wire displacement sensor for motion tracking will be more effective for weight support and enhancing a psychological sense of safety.

In this study, a usability evaluation, including a satisfaction survey and an interview, was conducted by physiotherapists and occupational therapists to identify the areas of improvement for the MTGAW developed for walking assistance for older adults and individuals with a disability. The survey showed overall high satisfaction levels on 19 items across four areas, and several improvement points were suggested in the interviews. This study constitutes a significant contribution to the field of domestic rehabilitation robotics in Korea. It offers a promising avenue for addressing the shortcomings of existing walking assistive devices. While the MTGAW compensated for the shortcomings of conventional walkers, suggestions were received to ensure safety measures to prevent posterior falls, ameliorate the discomfort caused by the slow speed, and add the height and width adjustment function to customize the walker to the user's body. In the future, an improved MTGAW that reflects the clinician-recommended needs derived from this study should be developed, and for its commercialization, a follow-up study should be performed to analyze the walker’s clinical effectiveness in older adults and individuals with a disability who require walking assistance.