A kinesiological study of turnaround motion

Abstract

[Purpose] The purpose of this study is to investigate the kinematic and kinetic characteristics ofturnaround motion. [Methods] The ten healthy young males performed a turnaround motion to 180°targets (at Comfortable and Max speed conditions) while standing on a horizontal plane facing. Theturnaround motion was recorded by using the motion analysis system, force plates and surfaceelectromyography (EMG). EMG data were collected from twelve muscles (including the left andright muscles of the external oblique, erector spinae, tensor fasciae latae (TFL), gluteus maximus(GM), biceps femoris (BF), and soleus). [Results] The center of gravity and center of pressuredisplacement were inconsistent in all the participants. There was a nonlinear relationship betweenthe craniocervical and thoracolumbar angle coordination, while the thoracolumbar and pelvic anglecoordination had a linear relationship at both speed conditions. There was an evident increasing in EMG amplitude only in the TFL of the turnaround side, and BF of the non-turnaround side at bothspeed conditions. There was no evident increasing in the GM activity amplitude. [Conclusions] Thepresent results demonstrated that the whole-body movement performed on horizontal movement wascontrolled by the muscle torque dominance, but a possible involvement of moment of the coupleforce was also suggested.