Abstract
Accelerometer based gait analysis (AGA) is a potential alternative to the more commonly used skin marker based optical motion analysis system(OMAS). The use of gyroscopes in conjunction with accelerometers (i.e. inertial sensors), enables the assessment of position and angular movements of body segments and provides ambulatory kinematic characterisation of gait.
We investigated commonly used gait parameters and also a novel parameter, Pelvic obliquity (PO) and whether they can be used as a parameter of physical function and correlate with classic clinical outcome scores
Gait was studied in healthy subjects (n=20), in patients with end stage hip OA (n=20) and in patients with end stage knee OA (n=20). Subjects walked 20 metres in an indoor environment along a straight flat corridor at their own preferred speed. A 3D inertial sensor was positioned centrally between the posterior superior iliac spines (PSIS) overlying S1.
Comparing gait parameters of end stage hip OA patients with an age and gender matched healthy control group, significantly lower walking speed, longer step duration and shorter step length was observed. After correcting for walking speed between groups, significantly less average range of motion of PO (RoMpo) was observed for patients with end stage hip OA compared to healthy subjects and patients with end stage knee OA.
IGA allows objective assessment of physical function for everyday clinical practice and allows assessment of functional parameters beyond time only. IGA measures another dimension of physical function and could be used supplementary to monitor recovery of OA patients after TJR.
