The Effectiveness of Functional Electrical Stimulation (FES) in On-Off Mode for Enhancing the Cycling Performance of Team Phoenix at 2016 Cybathlon

Abstract

In this study we designed a Functional Electrical Stimulation (FES) trike for a female subject with spinal cord injury to exercise her lower limbs and improve her lower limb muscle condition for attending the 2016 Cybathlon FES bike competition. Our FES pilot was the only female participant, in the FES cycling competition and she rode for Team Phoenix from the Chinese University of Hong Kong. Due to the weakness of muscles in the lower limb of the subject, and due to scoliosis over her thoracolumbar aéra, the mechanical structure of the trike had to be tailor-made to ensure she sat on the bike in a safe and secure position. A six-phase angle-driven stimulation pattern was developed to stimulate quadriceps and hamstrings without gluteus muscles for contraction through four surface electrodes, thereby creating a cycling movement. To improve the cycling endurance and reduce the muscle fatigue, an on-off mode was developed for controlling the stimulation time that allowed the subject to cycle for 20s, then pause while the trike advanced without stimulation for 5s, followed by a subsequent 20 sec stimulation, to continue cycling. The pilot participated in the training procedure including training exercise at home, trike fitting in the trike by modifying the mechanical structure, and conducting the cycling exercise for six months. We observed significant improvements in the pilot’s lower limb condition. The on-off mode enabled our pilot to extend her cycling endurance effectively, from 1 min to 2.5 mins and the distance from 62m to 100m. Over the eight minutes time limit, our team successfully finished 100 m in the Cybathlon FES.

Contributions of the Cybathlon championship to the literature on functional electrical stimulation cycling among individuals with spinal cord injury: A bibliometric review

“…The increase in publications in 2017 ( Fig. 3 ) was because of the studies published from the Cybathlon participating teams ( n = 13) in that year, 6 , 8 , 18 , 22 , 23 , 33 , 34 , 35 , 36 , 37 , 39 , 40 , 41 as shown in the findings from the present study ( Table 1 ). Because the Cybathlon championship encouraged the exchange of information among people with disabilities, the general public, researchers, and developers of equipment, 43 the blending of technology and clinical neurorehabilitation science gained vast attention and thus contributed to the increase in the number of studies.…”

“…With the exception of work by Guimarães et al, 33 the authors were unable to determine whether “subjects asked to participate in the study were representative of the entire population from which they were recruited” (Criterion 11) and “those subjects who were prepared to participate were representative of the entire population from which they were recruited” (Criterion 12). The authors of the studies were unable to determine whether “losses of patients to follow up taken into account” (Criterion 26), with the exception of Guimarães et al, 33 Leung et al, 35 and Tong et al, 36 where the criterion was not applicable.…”

“…1 ), and only 27.5% of the Cybathlon studies were included in the study quality assessment. 6 , 8 , 22 , 23 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 The low number of the Cybathlon studies included in the assessment of study quality was because duplicate titles were removed from the search of the 5 databases. Based on D&B criteria checklist 31 ( Supplementary Table 1 ), only open access, full-length articles and conference proceedings were appropriate for the quality assessment.…”

Reporting for Duty: The duty cycle in Functional Electrical Stimulation research. Part I: Critical commentaries of the literature

“…In addition, Leung, et al compared two forms of stimulation with one being more intermittent than the other in their study from the Chinese University of Hong Kong. 23 Therefore, the duty cycle can be changed to increase intensity of exercise in FES research projects or competitive events such as a cycling race preparation. The duty cycle may also be harnessed to increase therapy efficacy over time.…”

Development of a battery-free ultrasonically powered functional electrical stimulator for movement restoration after paralyzing spinal cord injury

“…Repetitive use of FES can also promote motor learning and recovery of function by regaining previously learned motor skills which have been lost due to the local damage of neural circuits [26]. Besides, FES can keep SCI patients physically active [13], and thus improve cardiorespiratory fitness [32], enhance exercise performance [38] and increase muscle strength [19]. Hence, FES is widely used in SCI rehabilitation due to its functional and therapeutic benefits.…”