AFOs and equipment
ankle joints, damper joints, AFOs, metatarsophalangeal joints, AFO
The two types of AFOs shown in Fig. AFOs used in this study. A schematic design of the AFO with oil damper unit. The oil damper unit consists of a hydraulic cylinder(1), a ring portion metal plate (2), and a metal plate (3). An adjustment screw (4) controls the flow rate of the oil by varying the orifice diameter; the smaller the orifice diameter, the lower the flow rate, allowing for greater resistance to plantarflexion of the ankle joint at heel strike. A spring (5) assists with dorsiflexion. The rod cap (6) is used to set the initial angle of the ankle jointThe initial ankle joints of both AFOs were set to a neutral position. All AFOs in two groups were customized by three orthotists in the prosthetic and orthotic department of the facility. Eight oil damper joints were prepared (4 right and 4 left) for the AFO-OD group. The AFOs were fitted well to ensure suitability.Gait was measured by a three-dimensional (3D) motion capture system with 6 motion capture cameras (Qualisys AB, Sweden) and 2 force plates (Bertec Corp, USA), which were placed diagonally adjacent to each other in the middle of the eight-meter walkway. Thirty-seven infrared reflective markers were positioned at specified landmarks of participants according to Plug-In-Gait Marker Placement. Markers were set on the lower limbs (both metatarsophalangeal joints, heels, ankles, shanks, knees, thighs, and hips) and the upper limbs (both wrists, elbows, and shoulders). Markers were also placed on the thorax (the spinous processes of the 7th cervical vertebra, the 7th thoracic vertebrae, the xiphoid process of the sternum, and the jugular notch where the clavicles meet the sternum) and on the pelvis (both anterior superior iliac spines and the posterior superior iliac spines). The trajectories of markers and the ground reaction force data were sampled at the frequency of 200 Hz and 1000 Hz, respectively.