3D photogrammetric images to evaluate foot morphology and ankle kinematics during gait of Middle Eastern adults

3D photogrammetric images to evaluate foot morphology and ankle kinematics during gait of Middle Eastern adults

To prevent high fall rates, foot injury and ankle sprain during daily activities and sport, footwear should be designed based on foot shape and ankle kinematics. The purpose of this thesis is to develop an accurate3D photogrammetric images captured by smartphone cameras technique that is non-invasive, low-cost and high-quality to analyse the morphology of the foot surface, investigate the foot shape characteristics of both genders, and evaluate the medial longitudinal arch (MLA) in static and dynamic conditions. Furthermore, the validation and investigation of ankle kinematics during gait according to gender is undertaken, as is an assessment of ankle kinematics in normal and unsteady gait. The photogrammetry technique utilises images of objects captured by multiple cameras from differing viewpoints to produce a digital 3D model of objects. In photogrammetry, camera calibration is an important step to improve the accuracy of measured imaged coordinates (x, y). This system calibration process involves individual calibrations of 7-Galaxy smartphones and the internal accuracy is 0.36 pixels. In this study, 33 healthy voluntary participants (18 males and 15 females, aged between 25and 47years), all of whom were Middle Eastern postgraduate students at the University of Southern Queensland (USQ) were recruited. In clinical settings, a number of landmarks were mounted on foot skin to measure the angles and the distances between anatomical bone locations. The results indicated that there were significant differences in some morphological characteristics of the feet of each gender. For example, the mean value of the foot length of males (26.01cm) was larger than females (22.39cm), and the mean values of arch length, ankle height and Chippaux-Smirak ratio for males was higher than for females. An accurate geometrical 3D close-range photogrammetry (CRP) method was used to evaluate the MLA in static (50% weight-bearing (WB), 10% WB, 90% WB standing and sitting non-WB) and dynamic motion during gait. MLA angle differences between males and females in static and dynamic conditions were also measured. In the static condition, the observation of the MLA angle was lower at about (137°)when sitting, indicating that the MLA was higher in non-WB. In the dynamic condition during walking, the higher mean value was found in the mid-stance phase (150.57°) when the foot tended to flatten.

The results of ankle kinematics during walking refer to significant differences between females and males for the transverse plane of range of motion of the ankle (F=12.21, Sig=0.013) however no significant differences of coronal and sagittal planes were found between genders. The CRP technique was also used to measure ankle kinematics during normal gait and three unsteady gait trials ((1) eyes closed,(2) on single beam, and (3) dragging ankle weights) in four phases of stance. We found that the eyes closed gait had higher ankle kinematic values than other gait conditions in the heel strike phase(3.38°, 11.72° and 8.48°) of the coronal, sagittal and transverse planes, respectively. Overall, the study was appropriate because it used a novel precise 3D images technique to evaluate foot morphology and ankle kinematics during gait.