Abstract—An integrated wireless system of lower limb angle measurement and Functional Electrical Stimulation (FES) control was developed in our previous study for application to motor rehabilitation. In the motor rehabilitation, it is also considered that voluntary effort to move their limbs is effective. In this paper, gait movements of a hemiplegic subject were measured with and without voluntary effort of ankle dorsiflexion during FES assisted foot drop correction as a preliminary test for gait rehabilitation with FES. Some characteristics of hemiplegic gait and differences in joint angles between the paralyzed and the non-paralyzed sides were found in the measurement. The foot and the shank inclination angles at the toe off timing showed small change with the voluntary effort of dorsiflexion during FES control. In addition, variations of the inclination angles of some segments of the paralyzed side were larger than those with only FES at the toe off timing, maximum angle point and the foot contact timing in the case of the voluntary effort. These results suggested that voluntary effort could change movement in FES control. However, these changes with voluntary effort were not seen with larger stimulation intensity. Therefore, it was considered that the movement changes with voluntary effort were small because the subject could not produce further voluntary muscle force in excess of the muscle force production by FES. It would be necessary to determine appropriate intensity of electrical stimulation for rehabilitation use.

Index Terms—Functional electrical stimulation, FES, rehabilitation, voluntary effort, foot drop, angle, inertial sensor.

T. Watanabe and S. Endo are with Grad. School of Biomed. Eng., Tohoku University, Sendai, Miyagi, Japan (email: nabet@ bme.tohoku.ac.jp).
K. Murakami, Y. Kumagai, and N. Kuge are with Kurokawa Hospital, Kurokawa, Miyagi, Japan.

 

Cite:Takashi Watanabe, Shun Endo, Katsunori Murakami, Yoshimi Kumagai, and Naomi Kuge, "A Measurement of Lower Limb Angles Using Wireless Inertial Sensors during FES Assisted Foot Drop Correction with and without Voluntary Effort," International Journal of Bioscience, Biochemistry and Bioinformatics vol. 3, no. 3, pp. 216-220, 2013.