Shoe-Type Walking Assist Device with Controllable Subtalar Joint Alignment at Heel Contact.

In this study, we propose a shoe-type walking assist device that can control the inversion/eversion angle of the subtalar joint during heel contact, with the aim of improving the long-term quality of life of both elderly people and young healthy people. The proposed device enables the heel mechanism to rotate dynamically in the frontal plane to lead the subtalar joint alignment to the neutral position when the heel contacts the ground. The effectiveness of the proposed mechanism was demonstrated by comparing the amount of lateral thrust (lateral sway) during stepping movements with and without the mechanism assist in 5 healthy male subjects wearing the device.

Ankle foot orthosis that prevents slippage for tibial rotation in knee osteoarthritis patients.

Knee osteoarthritis (OA) is a disease caused by age-related muscle weakness, obesity, or sports injury that leads to gait disability due to pain during walking. Knee OA is characterized by abnormal knee joint alignment and rotational dyskinesia, which are believed to worsen the symptoms. We previously developed an ankle orthosis that mechanically induces the rotation of the lower limb in conjunction with that of the ankle joint. This orthosis can effectively correct the alignment of the knee joint. However, slippage between the orthosis and leg can occur during walking, decreasing the corrective force. In this study, we clarify the effect of slippage between the orthosis and body on the correction force of the orthosis, and develop a lower leg tracking mechanism to suppress slippage and minimize reduction of force. The effectiveness of the proposed mechanism was evaluated by three-dimensional motion analysis of gait. Analysis results confirmed that the proposed mechanism was effective in suppressing slippage and improving correction force, demonstrating the effectiveness of the mechanism for knee OA.

Mechanical Orthosis with Rotation Induction to Lower Leg for Patients with Knee Osteoarthritis.

Knee osteoarthritis (Knee-OA) is a disease caused by age-related muscle weakness, obesity, or sports injury, and it has been estimated to occur in approximately half of all people by the age of 85. One of the characteristics of knee-OA is rotation dyskinesia of the knee joint due to the degeneration of the system around the knee. This rotation movement, a key element of walking, is crucial for impact absorption, balanced walking, and stabilization of the knee joint. In the present study, we focused on the rotation of the lower leg relative to the movement of the ankle joint during the walking stance phase, and we developed a mechanical orthosis that induces rotation of the lower leg in conjunction with the movement of the ankle joint mechanically. The mechanical induction of rotation movement uses the movement difference due to the angle change of the inside and outside bars in conjunction with the ankle angle. We verified the effectiveness of the developed orthosis by measuring the amount of rotation and by administering the Womac test in 5 subjects with knee osteoarthritis. The results confirmed the effectiveness of our orthosis.

An assistance device to help people with trunk impairment maintain posture.

People with trunk impairment cannot lean forward because of the dysfunction of the trunk resulting from events such as cervical cord injury (CCI). It is therefore difficult for such people to work at a table because they may easily fall from their wheelchair, and it is also hard for them to return to their original position. This limits the activities of daily living (ADLs) of people with trunk impairment. These problems can be solved to some extent with equipment such as a wheelchair belt or a spinal orthosis that can help the person to maintain his or her posture. However, people cannot move freely with this equipment. Furthermore, if this equipment is used for a long time, there is a risk of physical pain and skin issues. In this study, we developed a device that assists the trunk of people with trunk impairment when they lean forward. This device supports people with trunk impairment so that they may take their meals at the table and prevents them from falling over their wheelchair without hindering their daily performance when they are sitting normally. The effectiveness of our proposed device was verified by experiments involving having a meal, operating a wheelchair, and colliding with a curb. Our device can help people with trunk impairment by improving their ADLs and quality of life (QOL).