Oqus 300 cameras

A 3-dimentional approach will be used for data collection. However, only kinematic data in the sagittal plane will be used for analysis. According to Shum et al [12 (link)], motions out of the sagittal plane have insignificant amplitudes and cannot be used for analysis. A total of 6 Oqus 300 cameras (Qualisys AB) will be set up and angled in a manner to decrease hidden spots that might obscure data collection. In addition, the QTM software will be used to synchronize the 6 Oqus 300 cameras that record marker motion. The cameras identify infrared reflective markers which are attached to the participants and output 3-dimensional coordinates for each marker. Prior to testing, the motion system will be calibrated by recording an L-frame and dynamic movement of a T-wand for 60 seconds. After data collection, the markers will be labeled according to the anatomical landmark to which each marker is attached.

The hip range of motion, a kinematic variable of gait, will be obtained by the Qualisys Motion Capture System (Qualisys Medical AB, 411 13, Gothenburg, Sweden). This system records the spatio-temporal variables of gait, as well as the angular variations of the hip, knee and ankle joints. It is a photographic system based on a video that reconstructs movement in three dimensions (3D), composed of six Qualisys Oqus 300 cameras, connected in series and that emit and capture infrared light, which is reflected by spherical markers placed on specific anatomical structures.