Design of a non-contact measurement system for motion of ankle joint

Ankle joint mobility is extremely important for standing, walking and daily activities. The restriction of ankle movements (dorsal and plantar flexion) is seen in foot and ankle pathologies. Determining the ankle joint range of motion is critical in the diagnosis and treatment of these pathologies seen on the ankle. Several methods are used in to measure the range of ankle joint range of motion. Traditional methods are plastic goniometer and inclinometer that measuring in one plane. In the measurements made with these methods, contact with the foot of the patients creates the effect of contact's stimulation. This stimulus effect also leads to measurement errors. As an alternative to these methods, photogrammetric measurement or video analysis measurement methods can be used. These measurement methods are expensive and require high specialization. For these reasons, devices with reliable and economical measurements are needed. The aim of our study is to design the device that measures the ankle joint range of motion in a contactless way. Ankle joint range of motion of healthy university students were measured with the designed device, the plastic goniometer and photogrammetric measurement. The measurements of the ankle joint range of motion were statistically compared. There was no statistically significant difference between all three measurements.