*Article* **A Symmetry Evaluation Method, Using Elevation Angle, for Lower Limb Movement Patterns during Sitting-to-Standing †**

**Kensuke Nakamura and Norihiko Saga \***

**\*** Correspondence: saga@kwansei.ac.jp

† This paper is an extended version of the proceedings of the IMEKO XXIII World Congress held in Yokohama, Japan, 30 August–3 September 2021. *Measurement: Sensors* **2021**, *18*, 100195. https://doi.org/10.1016/j.measen.2021.100195.

**Abstract:** In this paper, we propose a method that uses the femoral and tibial elevation angles to quantitatively evaluate the symmetry of lower limb movement during the transition from a sitting position to a standing position. In kinematic analysis of the transition from sitting to standing, the angles of the three joints of the lower limb are often measured. However, due to the large number of variables, it is difficult to evaluate the symmetry of the lower limb movement by comparing data from the six joints of the left and right lower limbs. In this study, therefore, we measured the femoral and tibial elevation angles of healthy participants and rehabilitation patients and visually and numerically evaluated the symmetry and asymmetry of the movement of the left and right lower limbs. We were able to identify the kinematically major lower limbs in the transition from sitting to standing and quantify the symmetry of the movement patterns of the left and right lower limbs. Furthermore, we examined the possibility that the method could be effectively used in the rehabilitation field to evaluate the motor co-ordination that constitutes the lower limb movement pattern in the transition from the sitting to standing position, such as the gait plane rule.

**Keywords:** symmetry; sit-to-stand; elevation angle; coordination
