Walking assessment in the phase space by using ultra-miniaturized Inertial Measurement Units

Physical therapy helps patients to restore the use of the musculoskeletal and the nervous systems through the use of specifics techniques and exercises. The introduction of measurement systems for patient assessment may allow detection of initial stage of diseases, an objective severity assessment, and efficient delivery of drugs and therapies. In rehabilitation centers, sometimes there are specific devices and methodologies available for the locomotion assessment. However, the measurements are usually carried out in a short time slot and this could lead to an overestimation of the walking abilities. The authors propose a system, named WB-4R, which can provide a fast and objective walking assessment using a set of Inertial Measurement Units (IMUs). The WB-4R can be used for the gait analysis in rehabilitation centers or at home because it is compact and relatively maintenance-free. In this paper, it will be shown that our system is able to reconstruct the joint angles of lower limbs and build a foot phase space diagram during straight line walking. Furthermore, we compared the results with an optical system used in the clinical practice.