Effect of Spatially Distributed Sequential Stimulation on Fatigue in Functional Electrical Stimulation Rowing.

OBJECTIVE: A critical limitation in clinical applications using functional electrical stimulation (FES) for rehabilitation exercises is the rapid onset of muscle fatigue. Spatially distributed sequential stimulation (SDSS) has been demonstrated to reduce muscle fatigue during FES compared to conventional single electrode stimulation (SES) in single joint movements. Here we investigated the fatigue reducing ability of SDSS in a clinical application, i.e., FES-rowing, in able-bodied (AB) participants. METHODS: FES was delivered to the quadriceps and hamstring of 15 AB participants (five female, ten male) for fatiguing FES-rowing trials using SES and SDSS, participants rowed with voluntary arm effort while endeavoring to keep their legs relaxed. Fatigue was characterized by the time elapsed until a percent decrease occurred in power output (TTF), as well as the trial length indicating the time elapsed until the complete stop of rowing. RESULT: Trial length was significantly longer in SDSS rowing than in SES (t-test, , d=0.71 ), with an average SDSS:SES trial length ratio of 1.31 ± 0.47. TTF SDSS was significantly longer than TTF SES with a median TTF SDSS :TTF SES ratio of 1.34 ranging from 1.03 to 5.41 (Wilcoxon Ranked Sum, , r=0.62 ). No rower experienced a decrease in TTF with SDSS. CONCLUSION: SDSS reduced fatigue during FES-rowing when compared to SES in AB individuals, resulting in a lengthened FES-rowing period by approximately 30%. Application of SDSS would increase the effectiveness of FES-rowing as rehabilitative exercise for individuals with paralyses.

Development of a Coaching System for Functional Electrical Stimulation Rowing: A Feasibility Study in Able-Bodied Individuals.

BACKGROUND: Functional electrical stimulation (FES) during rowing has substantial effects on cardiovascular health in individuals with spinal cord injuries. Currently, manual stimulation control where stimulation is operated by rowers is mostly utilized. However, it takes time to obtain the skill to initiate FES at the optimal timing. The purpose of this study was to develop a coaching system that helps rowers to initiate FES at the optimal timing. METHODS: The optimal range for FES application was identified based on the electromyography of the left quadriceps in 10 able-bodied individuals (AB). Then, the effects of the coaching system on the timing of button-pressing, power, and work were investigated in 7 AB. RESULTS: Vastus lateralis (VL) activation began consistently before the seat reached the anterior-most position. Therefore, seat position at the onset of VL was used as the variable to control the switch timing in the coaching system. The results revealed significantly higher power and work outputs in the coaching than the no-coaching condition (median power coaching: 19.10 W, power no-coaching: 16.48 W, p = 0.031; median work coaching: 109.74 J, work no-coaching: 65.25 J, p = 0.047). CONCLUSIONS: The coaching system can provide the optimal timing for FES, resulting in improved performance.

The measurement properties of the Lean-and-Release test in people with incomplete spinal cord injury or disease.

OBJECTIVE: To evaluate test-retest reliability, agreement, and convergent validity of the Lean-and-Release test for the assessment of reactive stepping among individuals with incomplete spinal cord injury or disease (iSCI/D). DESIGN: Multi-center cross-sectional multiple test design. SETTING: SCI/D rehabilitation hospital and biomechanics laboratory. PARTICIPANTS: Individuals with motor incomplete SCI/D (iSCI/D). INTERVENTIONS: None. OUTCOME MEASURES: Twenty-six participants attended two sessions to complete the Lean-and-Release test and a battery of clinical tests. Behavioral (i.e. one-step, multi-step, loss of balance) and temporal (i.e. timing of foot off, foot contact, swing of reactive step) parameters were measured. Test-retest reliability was determined with intraclass correlation coefficients, and agreement was evaluated with Bland-Altman plots. Convergent validity was assessed through correlations with clinical tests. RESULTS: The behavioral responses were reliable for the Lean-and-Release test (ICC = 0.76), but foot contact was the only reliable temporal parameter using data from a single site (ICC = 0.79). All variables showed agreement according to the Bland-Altman plots. The behavioral responses correlated with scores of lower extremity strength (0.54, P<0.01) and balance confidence (0.55, P < 0.01). Swing time of reactive stepping correlated with step time (0.73, P < 0.01) and cadence (-0.73 P < 0.01) of over ground walking. CONCLUSIONS: The behavioral response of the Lean-and-Release test is a reliable and valid measure for people with iSCI/D. Our findings support the use of the behavioral responses to evaluate reactive stepping for research and clinical purposes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02960178.

Views of individuals with spinal cord injury on the use of wearable cameras to monitor upper limb function in the home and community.

OBJECTIVE: Hand function impairment after cervical spinal cord injury (SCI) can significantly reduce independence. Unlike current hand function assessments, wearable camera systems could potentially measure functional hand usage at home, and thus benefit the development of neurorehabilitation strategies. The objective of this study was to understand the views of individuals with SCI on the use of wearable cameras to track neurorehabilitation progress and outcomes in the community. DESIGN: Questionnaires. SETTING: Home simulation laboratory. PARTICIPANTS: Fifteen individuals with cervical SCI. OUTCOME MEASURES: After using wearable cameras in the simulated home environment, participants completed custom questionnaires, comprising open-ended and structured questions. RESULTS: Participants showed relatively low concerns related to data confidentiality when first-person videos are used by clinicians (1.93 ± 1.28 on a 5-point Likert scale) or researchers (2.00 ± 1.31). Storing only automatically extracted metrics reduced privacy concerns. Though participants reported moderate privacy concerns (2.53 ± 1.51) about wearing a camera in daily life due to certain sensitive situations (e.g. washrooms), they felt that information about their hand usage at home is useful for researchers (4.73 ± 0.59), clinicians (4.47 ± 0.83), and themselves (4.40 ± 0.83). Participants found the system moderately comfortable (3.27 ± 1.44), but expressed low desire to use it frequently (2.87 ± 1.36). CONCLUSION: Despite some privacy and comfort concerns, participants believed that the information obtained would be useful. With appropriate strategies to minimize the data stored and recording duration, wearable cameras can be a well-accepted tool to track function in the home and community after SCI.