Automatic application of neural stimulation during wheelchair propulsion after SCI enhances recovery of upright sitting from destabilizing events.
ABSTRACT: BACKGROUND:The leading cause of injury for manual wheelchair users are tips and falls caused by unexpected destabilizing events encountered during everyday activities. The purpose of this study was to determine the feasibility of automatically restoring seated stability to manual wheelchair users with spinal cord injury (SCI) via a threshold-based system to activate the hip and trunk muscles with electrical stimulation during potentially destabilizing events. METHODS:We detected and classified potentially destabilizing sudden stops and turns with a wheelchair-mounted wireless inertial measurement unit (IMU), and then applied neural stimulation to activate the appropriate muscles to resist trunk movement and restore seated stability. After modeling and preliminary testing to determine the appropriate inertial signatures to discriminate between events and reliably trigger stimulation, the system was implemented and evaluated in real-time on manual wheelchair users with SCI. Three participants completed simulated collision events and four participants completed simulated rapid turns. Data were analyzed as a series of individual case studies with subjects acting as their own controls with and without the system active. RESULTS:The controller achieved 93% accuracy in detecting collisions and right turns, and 100% accuracy in left turn detection. Two of the three subjects who participated in collision testing with stimulation experienced significantly decreased maximum anterior-posterior trunk angles (p?
Project description:Minimizing the effort to propel a manual wheelchair is important to all users in order to optimize the efficiency of maneuvering throughout the day. Assessing the propulsion cost of wheelchairs as a mechanical system is a key aspect of understanding the influences of wheelchair design and configuration. The objective of this study was to model the relationships between inertial and energy-loss parameters to the mechanical propulsion cost across different wheelchair configurations during straight and curvilinear trajectories. Inertial parameters of an occupied wheelchair and energy loss parameters of drive wheels and casters were entered into regression models representing three different maneuvers. A wheelchair-propelling robot was used to measure propulsion cost. General linear models showed strong relationships (R2 > 0.84) between the system-level costs of propulsion and the selected predictor variables representing sources of energy loss and inertial influences. System energy loss parameters were significant predictors in all three maneuvers. Yaw inertia was also a significant predictor during zero-radius turns. The results indicate that simple energy loss measurements can predict system-level performance, and inertial influences are mostly overshadowed by the increased resistive losses caused by added mass, though weight distribution can mitigate some of this added cost.
Project description:<h4>Background</h4>Chronic or recurrent musculoskeletal pain in the cervical and shoulder region is a common secondary problem after spinal cord injury (SCI), reported by 30% to 70% of individuals.<h4>Objective</h4>The purpose of this study was to investigate the effect of electromyographic (EMG) biofeedback training, in addition to a standard exercise program, on reducing shoulder pain in manual wheelchair users with SCI.<h4>Methods</h4>Fifteen individuals with SCI, C6 or lower, who were manual wheelchair users with shoulder pain were randomly assigned to 1 of 2 interventions. The Exercise group (n = 7) received instruction on a standard home-based exercise program. The EMG Biofeedback plus Exercise group (n = 8) received identical exercise instruction plus EMG biofeedback training to improve muscle balance and muscle relaxation during wheelchair propulsion. Shoulder pain was assessed by the Wheelchair Users Shoulder Pain Index (WUSPI) at baseline, at posttest 10 weeks after the start of intervention, and at follow-up 16 weeks after posttest.<h4>Results</h4>The number of participants per group allowed only within-group comparisons; however, the findings indicated a beneficial effect from EMG biofeedback training. Shoulder pain, as measured by WUSPI, decreased 64% from baseline to posttest for the EMG Biofeedback plus Exercise group (P = .02). Shoulder pain for the Exercise group decreased a nonsignificant 27%. At follow-up, both groups showed continued improvement, yet the benefit of EMG biofeedback training was still discernible. The EMG Biofeedback plus Exercise group had an 82% reduction in shoulder pain from baseline to follow-up (P = .004), while the Exercise group showed a 63% reduction (P = .03) over the same time period.<h4>Conclusions</h4>This study provides preliminary evidence that EMG biofeedback has value when added to an exercise intervention to reduce shoulder pain in manual wheelchair users with SCI. These findings indicate that EMG biofeedback may be valuable in remediating musculoskeletal pain as a secondary condition in SCI. This preliminary conclusion will need to be studied and verified through future work.
Project description:Objective: To conduct a pilot study of an intervention to decrease fall incidence and concerns about falling among individuals living with Spinal Cord Injury who use manual wheelchairs full-time. Design: Pre/post. After a baseline assessment, a structured intervention was implemented. The assessment protocol was repeated 12 weeks after the baseline assessment. Setting: Research laboratory and community. Participants: 18 individuals living with SCI who use a manual wheelchair full-time with an average age of 35.78?±?13.89 years, lived with SCI for 17.06?±?14.6 years; 61.1% were female. Intervention: A 1:1, 45 minute, in-person intervention focused on factors associated with falls and concerns about falling: transfers skills and seated postural control. Outcome measures: Participants reported fall incidence and completed the Spinal Cord Injury Fall Concerns Scale, Community Participation Indicators and the World Health Organization Quality of Life - short version (WHOQOL-BREF). Transfer quality was assessed with the Transfer Assessment Instrument (TAI) and seated postural control with the Function In Seating Test (FIST). Results: Recruitment, assessment and delivery of the intervention were successfully completed. After exposure to the intervention, fall incidence significantly decreased, (P?=?0.047, dz ?=?0.507) and FIST scores improved (P?=?0.035, dz? =?0.54). Significant improvements were also found in the WHOQOL-BREF Physical (P?=?0.05, dz ?=?1.566) and Psychological (P?=?0.040, dz ?=?0.760) domains. Conclusion: The feasibility of the structured intervention was established and the intervention has the potential to reduce fall incidence and improve quality of life among individuals living with SCI who use a wheelchair. Appropriately powered randomized controlled trials of the program are warranted.
Project description:Electrical neuromodulation of spinal networks improves the control of movement of the paralyzed limbs after spinal cord injury (SCI). However, the potential of noninvasive spinal stimulation to facilitate postural trunk control during sitting in humans with SCI has not been investigated. We hypothesized that transcutaneous electrical stimulation of the lumbosacral enlargement can improve trunk posture. Eight participants with non-progressive SCI at C3-T9, American Spinal Injury Association Impairment Scale (AIS) A or C, performed different motor tasks during sitting. Electromyography of the trunk muscles, three-dimensional kinematics, and force plate data were acquired. Spinal stimulation improved trunk control during sitting in all tested individuals. Stimulation resulted in elevated activity of the erector spinae, rectus abdominis, and external obliques, contributing to improved trunk control, more natural anterior pelvic tilt and lordotic curve, and greater multi-directional seated stability. During spinal stimulation, the center of pressure (COP) displacements decreased to 1.36 ± 0.98 mm compared with 4.74 ± 5.41 mm without stimulation (p = 0.0156) in quiet sitting, and the limits of stable displacement increased by 46.92 ± 35.66% (p = 0.0156), 36.92 ± 30.48% (p = 0.0156), 54.67 ± 77.99% (p = 0.0234), and 22.70 ± 26.09% (p = 0.0391) in the forward, backward, right, and left directions, respectively. During self-initiated perturbations, the correlation between anteroposterior arm velocity and the COP displacement decreased from r = 0.5821 (p = 0.0007) without to r = 0.5115 (p = 0.0039) with stimulation, indicating improved trunk stability. These data demonstrate that the spinal networks can be modulated transcutaneously with tonic electrical spinal stimulation to physiological states sufficient to generate a more stable, erect sitting posture after chronic paralysis.
Project description:Seated postural control is essential for wheelchair users to maintain proper position while performing activities of daily living. Clinical tests are commonly used to measure seated postural control, yet they are subjective and lack sensitivity. Lab-based measures are highly sensitive but are limited in scope and restricted to research settings. Establishing a valid, reliable, and accessible measurement tool of seated postural control is necessary for remote, objective assessments. Therefore, the purpose of this study was to examine the validity, reliability, and sensitivity of smartphone-based postural control assessments in wheelchair users. Eleven participants (age: 35.4 ± 17.9) completed two experimental visits 1-week apart consisting of three clinical tests: Trunk Control Test (TCT), Function in Sitting Test (FIST), and Tee-shirt Test, as well as, standardized instrumented balance tasks that manipulated vision (eyes open and closed), and trunk movement (functional reach and stability boundary). During these tasks, participants held a smartphone instrumented with a research-grade accelerometer to their chest. Maximum and root mean square (RMS) acceleration in the medial-lateral (ML) and anterior-posterior (AP) axes were derived. Participants were grouped into non-impaired and impaired postural groups based on FIST scores. Spearman rank-order correlations were conducted between the two devices' outcome measurements and between these measures and those of the clinical tests. Receiver operating characteristic (ROC) curves and the area under the curves (AUC) were determined to distinguish participants with and without impaired postural control. The reliability of outcome variables was assessed using inter-class correlations. Strong correlations between outputs derived from the smartphone and research-grade accelerometer were seen across balance tasks (? = -0.75-1.00; <i>p</i> ? 0.01). Numerous significant moderate correlations between clinical test outcomes and smartphone and research-grade RMS ML accelerometry were seen (? = -0.62 to 0.83 (<i>p</i> ? 0.044)]. On both devices, the AUC for ROC plots were significant for RMS ML sway during the eyes open task and functional stability boundary (<i>p</i> < 0.05). Reliability of smartphone accelerometry was comparable to the research-grade accelerometer and clinical tests. This pilot study illustrated that smartphone-based accelerometry may be able to provide a valid and reliable assessment of seated postural control and have the ability to distinguish between those with and without impaired postural control.
Project description:Study design:Randomised, controlled, single-blind crossover design study. Objective:Effect of indoor wheelchair curling training on trunk control of a person with chronic spinal cord injury (SCI). Setting:SCI Centre of Balgrist University Hospital in Zurich, Switzerland. Methods:The trunk control of 13 subjects was assessed by the modified functional reach test (MFRT) and nonlinear dynamic systems analysis (NDSA) before and after eight indoor curling training sessions and compared to everyday life over 4 weeks. Results:The attendance rate was 95% during the training sessions. There were no adverse events. Neither the MRFT nor the NDSA showed any significant differences in the sitting stability. The subjects subjectively reported improved physical feeling, an increase in their trunk control and strength; 39% of the participants wanted to continue the training. Conclusions:With subjective improvements and no adverse events, indoor wheelchair curling training is a safe physical activity for people with SCI. Wheelchair curling offers a suitable alternative to sports already used in rehabilitation and in recreational activities of a person with SCI. In order to be able to draw more unambiguous conclusions from the training method for trunk control and to answer the question of the study unambiguously, the number of subjects would have to be greater and the test methods should provide more exact and specific measurements.
Project description:Manual wheelchair users are at great risk for the development of upper extremity injury and pain. Any loss of upper limb function due to pain adversely impacts the independence and mobility of manual wheelchair users. There is growing theoretical and empirical evidence that fluctuations in movement (i.e., motor variability) are related to musculoskeletal pain. This perspectives paper discusses a local review on several investigations examining the association between variability in wheelchair propulsion and shoulder pain in manual wheelchair users. The experimental data reviewed highlights that the variability of wheelchair propulsion is impacted by shoulder pain in manual wheelchair users. We maintain that inclusion of these metrics in future research on wheelchair propulsion and upper limb pain may yield novel data. Several promising avenues for future research based on this collective work are discussed.
Project description:To test the effectiveness of a high-dose home exercise/telerehabilitation program for manual wheelchair users who have a spinal cord injury (SCI) by determining whether the intervention would reduce pain and increase function, as we hypothesized.A pre-post trial with outcomes measured at 3 time points: baseline, postintervention (12wk), and follow-up (>24 wk).Subjects performed an exercise program at their homes using telerehabilitation for therapist monitoring of technique and exercise advancement. Baseline and postintervention data were collected at a motion analysis laboratory in a tertiary medical center.A convenience sample of manual wheelchair users (N=16, 3 women; average age, 41y; average time in a wheelchair, 16y) with shoulder pain (average pain duration, 9y) and mechanical impingement signs on physical examination.A 12-week home exercise program of rotator cuff and scapular stabilization exercises was given to each participant. The program included a high dose of 3 sets of 30 repetitions, 3 times weekly, and regular physical therapist supervision via videoconferencing.Primary outcomes of pain and function were measured with the Wheelchair User's Shoulder Pain Index (WUSPI), Disabilities of Arm, Shoulder, and Hand (DASH) Index, and Shoulder Rating Questionnaire (SRQ). Secondary outcomes of strength were measured with isometric strength tests of scapulothoracic and glenohumeral muscles, and a static fatigue test of the lower trapezius.Pain was reduced and function improved after the intervention. There was a significant main effect for pain and function between the 3 time points based on the Friedman signed-ranked test, WUSPI (?(2)2=5.10, P=.014), DASH Index (?(2)2=5.41, P=.012), and SRQ (?(2)2=23.71, P?.001). Wilcoxon signed-rank tests demonstrated that isometric strength measurements of the serratus anterior and scapular retractors increased after the exercise intervention ([t=2.42, P=.04] and [t=4.67, P=.003], respectively). Muscle impulse produced by the lower trapezius during a fatigue task also improved (t=2.2, P=.02). No differences were measured in isometric strength for the lower trapezius, glenohumeral rotators, and abductors between the baseline and 12-week time points.A high-dose scapular stabilizer and rotator cuff strengthening program using telerehabilitation for supervision holds promise for shoulder pain treatment in manual wheelchair users with SCI. Additional work is needed to determine the effectiveness compared with other interventions, as well as the potential for earlier intervention to prevent development of shoulder pain.
Project description:OBJECTIVE:To review the literature that has explored conservative treatments for the management of shoulder pain in manual wheelchair users. METHODS:Five databases were systematically searched in february 2020 for terms related to shoulder pain and manual wheelchair use. Articles were screened and included if they investigated the conservative treatment of shoulder pain in wheelchair users. Participants' physical characteristics, experimental design and primary and secondary outcome measures were extracted from studies. Studies were grouped according to treatment type to identify gaps in the literature and guide future research. RESULTS:The initial search identified 407 articles, of which 21 studies met the inclusion criteria. Exercise-based treatment interventions were most prevalent (n?=?12). A variety of exercise modalities were employed such as strengthening and stretching (n?=?7), ergometer training (n?=?3), Pilates classes (n?=?1) and functional electrical stimulation (n?=?1). Only three studies supplemented exercise with an additional treatment type. The Wheelchair Users Shoulder Pain Index was used by 18 studies as the primary measure of shoulder pain. Only seven of these included an objective measure of shoulder function. Participant characteristics varied among studies, and physical activity levels were frequently not reported. CONCLUSIONS:Despite the high prevalence of shoulder pain in manual wheelchair users, the number of studies to have explored conservative treatment types is low. Exercise is the most commonly used treatment, which is encouraging as physical inactivity can exacerbate other health conditions. Few studies have adopted interdisciplinary treatment strategies or included objective secondary measures to better understand the mechanisms of pain.
Project description:INTRODUCTION:Falls are a concern for wheelchair users with spinal cord injury (SCI). Falls can negatively impact the physical and psychological well-being of fallers. To date, the perspectives of wheelchair users with lived experiences of SCI on the contributors to falls has been understudied. Information about factors that influence fall risk would guide the development of effective fall prevention strategies. OBJECTIVES:To gain a comprehensive understanding of the factors that influenced the risk of falling as perceived by wheelchair users with SCI. DESIGN:A qualitative study using photo-elicitation interviews. SETTING:A Canadian SCI rehabilitation hospital and the participants' home/community environments. PARTICIPANTS:Twelve wheelchair users living in the community with chronic SCI. METHODS:Participants captured photographs of situations, places or things that they perceived increased and decreased their risk of falling. Semistructured photo-elicitation interviews were conducted to discuss the content of the photographs and explore perceptions of fall risk factors. A hybrid thematic analysis and the Biological, Behavioural, Social, Economic, and Environmental model were used as a framework to organise/synthesise the data. RESULTS:Overall, the findings indicated that the risk of falling was individualised, complex and dynamic to each person's life situation. Four main themes were revealed in our analysis: (1) Falls and fall risk caused by multiple interacting factors; (2) Dynamic nature of fall risk; (3) Single factors were targeted to reduce falls and fall-related injuries; and (4) Fall prevention experiences and priorities. CONCLUSIONS:Each wheelchair user encountered numerous fall risk factors in their everyday lives. Information from this study can be used to set priorities for fall prevention. Fall prevention initiatives should consider a wheelchair user's fall risks in a holistic manner, acknowledging that a person's current situation, as well as anticipating their fall risks and fall prevention needs, will change over time.