Abstract: Objective this study analyzes the characteristics of support and balance control during backward slip induced by sit-to-stand movement and the related factors. Methods ten subjects are tested for their slips on sliding platforms to measure their joint torque, proprioception and reaction time. Results 1) The successful balance recovery is characterized by a significantly raised ground reaction force (GRF), action time and COP displacement in X and Y direction. 2) The IEMG change of tibialis anterior (TA), erector spinae (ES) and deltoideus (DE) increased significantly during backward slip. 3) Ankle's force and proprioception is highly related to the adjustment time during backward slip. Conclusion When encountered with sudden backward slip during sit-to-stand, it is the trend of human body people to always take backward recovery step against backward slip. Larger support base and more time can be acquired to adjust balance by greater stride of recovery step. Meanwhile, powerful arm swing is also important to balance control.

Key words: sit-to-stand, slip, balance control, sEMG, proprioception