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Kinematic analysis of movements of rotation of the knee joint during a single-leg drop-landing by quaternions: gender differences

Grant number: 10/20538-7
Support type:Regular Research Grants
Duration: August 01, 2011 - July 31, 2013
Field of knowledge:Health Sciences - Physical Education
Principal Investigator:Paulo Roberto Pereira Santiago
Grantee:Paulo Roberto Pereira Santiago
Home Institution: Escola de Educação Física e Esporte de Ribeirão Preto (EEFERP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil


Euler and Cardan angles, rotation matrices (3x3), helical axis and quaternions are some mathematical representations that have been used to describe the rotational component of the joints during human movements. Although quaternions is the less employed in Biomechanics, this method presents advantages compared to other representations as Euler angles, where singularities (and, consequently, Gimbal Lock) may occur, and several different rotation sequences might be related to one single rotation. Thus, the main aim of the present project is to investigate the possible differences of the rotational movements of knee using the quaternions representation between males and females during the single-leg drop-landing. Twenty subjects (i.e. ten male and ten female) without injury and musculoskeletal pain in the lower limbs will perform five single-leg drop-landing from a 40-cm platform. A motion capture system from OptiTrackTM will be used to obtain three-dimensional coordinates of markers attached on anatomical points of interest. The local coordinate systems from thigh and leg will be defined by the three-dimensional coordinates of markers. Thus, the quaternions will be calculated and used to investigate the rotational movements of knee between males and females. The rotational angles of ankle measured by quaternions will be analyzed using median and confidence interval to verify possible differences between the groups. (AU)