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Background Achilles tendinopathy (AT) may affect ground reaction force (GRF) and muscle synergy (MS) during walking due to pain, biological integrity changes in the tendon and neuroplastic adaptations. The objective of this study was to compare GRF asymmetries and MS attributes between symptomatic and asymptomatic lower limbs (LL) during walking at natural and fast speeds in adults with unilateral AT. Methods A convenience sample consisting of twenty-eight participants walked on an instrumented treadmill at natural (1.3 m/s) and fast (1.6 m/s) speeds. Peak GRF were measured in mediolateral, anteroposterior and vertical directions. Individualized electromyography (EMG) activation profiles were time- and amplitude-normalized for three consecutive gait cycles and MS were extracted using non-negative matrix factorization algorithms. MS were characterized by the number, composition (i.e., weighting of each muscle) and temporal profiles (i.e., duration and amplitude) of the MS extracted during walking. Paired Student’s t-tests assessed peak GRF and MS muscle weighting differences between sides whereas Pearson correlation coefficients characterized the similarities of the individualized EMG and MS activation temporal profiles within sides. Results AT had limited effects on peak GRF asymmetries and the number, composition and temporal profiles of MS between symptomatic and asymptomatic LL while walking on a level treadmill at natural and fast speeds. In most participants, four MS with a specific set of predominantly activated muscles were extracted across natural (71 and 61%) and fast (54 and 50%) walking speeds for the symptomatic and asymptomatic side respectively. Individualized EMG activation profiles were relatively similar between sides (r = 0.970 to 0.999). As for MS attributes, relatively similar temporal activation profiles (r = 0.988 to 0.998) and muscle weightings (p Conclusion Faster walking speed increased peak GRF values but had limited effects on GRF symmetries and MS attribute differences between the LL. Corticospinal neuroplastic adaptations associated with chronic unilateral AT may explain the preserved quasi-symmetric LL motor control strategy observed during natural and fast walking among adults with chronic unilateral AT.

The effects of walking speeds on lower-extremity muscle synergies (MSs) were investigated among 20 adults who walked 20 m at SLOW (0.6 ± 0.2 m/s), natural (NAT; 1.4 ± 0.1 m/s), and FAST (1.9 ± 0.1 m/s) speeds. Surface electromyography of eight lower-extremity muscles was recorded before extracting MSs using a nonnegative matrix factorization algorithm. Increasing walking speed tended to merge MSs associated with weight acceptance and limb deceleration, whereas reducing walking speed does not change the number and composition of MSs. Varying gait speed, particularly decreasing speed, may represent a gait training strategy needing additional attention given its effects on MSs.

This is a retrospective longitudinal study.The Standing and Walking Assessment Tool (SWAT) combines stages of standing and walking recovery (SWAT stages) with established measures (Berg Balance Scale (BBS), 10-m walk test (10MWT), 6-min walk test (6MWT), and modified Timed Up-and-Go (mTUG)). We evaluated the SWAT's validity (known-groups and convergent) and responsiveness among inpatients with sub-acute, traumatic spinal cord injury (SCI).Ten Canadian rehabilitation hospitals.Upon admission, SWAT stage and core measures (BBS, 10MWT, 6MWT, and mTUG), International Standards for Neurological Classification of SCI sensory and motor scores, and Spinal Cord Independence Measure III (SCIM) were collected from 618 adults with SCI. Known-groups validity was evaluated by comparing SWAT stage distributions across American Spinal Injury Association Impairment Scale (AIS) classification. Convergent validity was evaluated by correlating SWAT stages with scores on other measures using Spearman's rho. The SWAT (stage and core measures) was re-administered at discharge. To evaluate responsiveness, SWAT stages at admission and discharge were compared. The standardized response mean (SRM) was used to evaluate the responsiveness of core SWAT measures.The SWAT stage distribution of participants with AIS D injuries differed from those of participants with AIS A-C injuries (p ≤ 0.002). SWAT stages correlated strongly with BBS and motor scores (ρ = 0.778-0.836), and moderately with SCIM, mTUG, 10MWT, 6MWT, and sensory scores (ρ = 0.409-0.692). Discharge SWAT stage was greater than the admission stage (p 0.0001). The BBS was the most responsive core SWAT measure (SRM = 1.26).The SWAT is a valid and responsive approach to the measurement of standing and walking ability during sub-acute SCI.

Summary Background The effects of lower limb (L/L) control options, developed for overground walking with a wearable robotic exoskeleton (WRE), on the neuromotor control of L/L muscles [i.e., muscle synergies (MSs)] during walking remain uncertain. Objective To gain initial insights regarding the effects of different control options on the number of MSs at the L/L and on their muscle weighting within each MS when walking with a WRE. Methods Twenty able-bodied adults walked overground without and with the WRE set at two control options with a predetermined foot pathway imposed by the WRE, and at three other control options with free L/L kinematics in the sagittal plane. Surface electromyography of eight right L/L muscles was recorded. MSs were extracted using a non-negative matrix factorisation algorithm. Cosine similarity and correlation coefficients characterised similarities between the MSs characteristics. Results Freely moving the L/L in the sagittal plane (i.e., non-trajectory controlled options) during WRE walking best duplicated typical MSs extracted when walking without WRE. Conversely, WRE walking while fully controlling the L/L trajectory presented the lowest correlations to all MSs extracted when walking without WRE, especially during early swing and L/L deceleration. Conclusion Neuromotor control of L/L muscles is affected by the selected control option during WRE walking, particularly when a predetermined foot pathway is imposed. Significance This exploratory study represents the first step in informing the decision-making process regarding the use of different L/L control options when using WRE and calls for further research among adults with sensorimotor impairments.

OBJECTIVE The 6-Min Manual Wheelchair Propulsion Test is proposed to easily and rapidly assess aerobic fitness among long-term (≥3 mos) manual wheelchair users with spinal cord injury. However, aerobic responses to this test have not been established. This study aimed (1) to characterize aerobic responses during the 6-Min Manual Wheelchair Propulsion Test, (2) to establish parallel reliability between the 6-Min Manual Wheelchair Propulsion Test and the Maximal Arm Crank Ergometer Test, and (3) to quantify the strength of association between the total distance traveled during the 6-Min Manual Wheelchair Propulsion Test and peak oxygen consumption. DESIGN Twenty manual wheelchair users with a spinal cord injury completed both tests. Aerobic parameters were measured before, during, and after the tests. Main outcome measures were peak oxygen consumption and total distance traveled. RESULTS Progressive cardiorespiratory responses, consistent with guidelines for exercise testing, were observed during both tests. Similar peak oxygen consumption values were obtained during both tests (6-Min Manual Wheelchair Propulsion Test: 20.2 ± 4.9 ml/kg·min; Maximal Arm Crank Ergometer Test: 20.4 ± 5.0 ml/kg·min), were highly correlated (r = 0.92, P < 0.001), and had a good agreement (mean absolute difference = 0.21, 95% confidence interval = -0.70 to 1.11, P = 0.639). The peak oxygen consumption and total distance traveled (mean = 636.6 ± 56.9 m) during the 6-Min Manual Wheelchair Propulsion Test were highly correlated (r = 0.74, P < 0.001). CONCLUSIONS The 6-Min Manual Wheelchair Propulsion Test induces progressive aerobic responses consistent with guidelines for exercise testing and can be used to efficiently estimate aerobic fitness in manual wheelchair users with a spinal cord injury. TO CLAIM CME CREDITS Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Explain how to administer the Six-Minute Manual Wheelchair Propulsion Test in long-term manual wheelchair users with a spinal cord injury; (2) Contrast how the workload is developed between the Six-Minute Manual Wheelchair Propulsion Test and the Maximal Arm Crank Ergometry Test and recognize how these differences may affect physiological responses; and (3) Explain why caution is advised regarding the use of the Six-Minute Manual Wheelchair Propulsion Test if aiming to estimate aerobic fitness. LEVEL Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Background Many manual wheelchair users with a spinal cord injury are at risk of developing secondary upper extremity musculoskeletal impairments. The use of a mobility assistance dog may represent a way to mitigate this risk. This study aims to compare upper extremity muscular effort in this population when propelling a manual wheelchair on tiled and carpeted surfaces with and without the assistance of a dog. Method Thirteen adults with a spinal cord injury propelled their manual wheelchairs at a self-selected natural speed over a 10-meter distance on tiled abrasive and carpeted floors with and without their mobility assistance dog. Surface electromyography of the pectoralis major, anterior deltoid, biceps, and triceps was recorded and normalized against its maximal value extracted from maximal voluntary contractions. Time needed to perform each task was also computed. Findings The forward pull provided by the dog significantly and meaningfully reduced the muscular effort when propelling on the tiled floor and, even more so, on carpeted surfaces for the pectoralis major (−27.0% and −59.2%), the anterior deltoid (−54.8% and −92.4%), the biceps (−53.9% and −57.6%), and the triceps (−45.7% and −67.3%). The time needed to travel the 10-meter distance was also significantly and meaningfully reduced on the tiled and carpeted surfaces (−21.9% and −30.3%, respectively). Interpretation The provision of a mobility assistance dog represents a viable rehabilitation alternative to minimizing upper extremity muscular effort while also optimizing speed during propulsion in manual wheelchair users with a spinal cord injury.

Many individuals with spinal cord injury (SCI) rely on wheelchairs as their primary mode of locomotion leading to reduced weight-bearing on the lower extremities, which contributes to severe bone loss and increased risk of fragility fractures. Engaging in a walking program may reverse this vicious cycle, as this promotes lower extremity weight-bearing and mobility, which may reduce bone loss and fragility fracture risk. However, fragility fracture risk associated with the use of wearable robotic exoskeletons (WREs) in individuals with SCI needs consideration. A 35-year-old man with chronic complete sensorimotor SCI (neurological level = T6) and low initial bone mineral density enrolled in a 6- to 8-week WRE-assisted walking program after successfully completing an initial clinical screening process and two familiarization sessions with the WRE. However, after the first training session with the WRE, he developed bilateral localized ankle edema. Training was suspended, and a CT-scan revealed bilateral calcaneal fractures, which healed with conservative treatment over a 12-week period. Opportunities for improving clinical screening and WRE design are explored. The relevance of developing clinical practice guidelines for safe initiation and progression of intensity during WRE-assisted walking programs is highlighted. This case of bilateral calcaneal fractures illustrates that aiming for "zero risk" during WRE-assisted walking programs may not be realistic. Although WREs are a relatively new technology, current evidence confirms their potential to greatly improve health and quality of life in individuals with chronic SCI. Hence, ensuring their safe use remains a key priority.

Background Lumbar stabilization exercise programs (LSEPs) act positively on clinical outcome measures in patients with low back pain (LBP), but the underlying mechanisms are not well understood. Among the various neuromuscular mechanisms, a good candidate is better activation of the abdominal wall, as measured with rehabilitative ultrasound imaging (RUSI). Objectives To determine whether RUSI measures are (1) sensitive to LBP status and treatment (LSEP) and (2) correlate with clinical outcomes following the LSEP. Design An exploratory one-arm clinical trial with healthy participants as a control group. Setting LSEP was delivered in a clinical setting; outcomes were measured in a laboratory setting. Participants Thirty-one patients with nonacute LBP and 30 healthy controls. Methods Outcome measures were performed before and after an 8-week LSEP in patients with LBP, and with the same time interval for control participants to compare with patients at baseline. Main outcome measurements Pain, disability, as well as static (at rest) and dynamic (percent thickness change) RUSI measures for abdominal muscles (transversus abdominis, internal oblique [IO], and external oblique [EO]). Results Patients did not produce systematic changes in RUSI measures relative to controls, even if patients had significant improvement in pain and disability. However, the correlational analyses between the absolute change (pre- to post-LSEP) (1) of EO and IO thickness (in mm) at rest (bilaterally), and (2) in pain following the LSEP were significant and consistent (range: .36-.45) in patients. Conclusions Although positive clinical improvements were observed following LSEP, there were minimal systematic changes in RUSI measures, likely because patients were not different from controls at baseline. Correlational analyses, however, indicated that greater reductions in pain were associated with reduced thickness of the EO and IO following the LSEP, suggesting the presence of some heterogeneity (or clinical subgroups) among the patients. Level of evidence II.

Wheelchair basketball is one of the most popular Paralympic sports. Dribbling a ball while propelling is a key feature of wheelchair basketball. Very few studies have investigated the biomechanical impact of dribbling. This study aims to analyze the impact of dribbling on the amplitude and symmetry of spatiotemporal and kinetic parameters of wheelchair propulsion.Ten experienced wheelchair basketball athletes (31.5 ± 10.6 years old; 7 men, 3 women) with various classifications performed eight 9-m sprints along a straight line on a basketball court: four sprints using classic synchronous propulsion, and four sprints while dribbling a ball down the court.Dribbling decreased velocity, mean propulsive moments and the force rate of rise, as well as increased push time, force rate of rise asymmetry and angular impulse asymmetry. All kinetic variables were asymmetric and higher on the dominant limb.The combination of reduced velocity and propulsive moments when dribbling indicates that wheelchair basketball athletes may deliberately preserve a safety margin of acceleration to adapt to uncontrolled ball rebounds. Dribbling was not associated with any factors associated with an increased risk of musculoskeletal disorders.

Background Many wheelchair users adopt a sedentary lifestyle, which results in progressive physical deconditioning with increased risk of musculoskeletal, cardiovascular and endocrine/metabolic morbidity and mortality. Engaging in a walking program with an overground robotic exoskeleton may be an effective strategy for mitigating these potential negative health consequences and optimizing fitness in this population. However, additional research is warranted to inform the development of adapted physical activity programs incorporating this technology. Objectives To determine cardiorespiratory demands during sitting, standing and overground walking with a robotic exoskeleton and to verify whether such overground walking results in at least moderate-intensity physical exercise. Methods We enrolled 13 long-term wheelchair users with complete motor spinal cord injury in a walking program with an overground robotic exoskeleton. Cardiorespiratory measures and rate of perceived exertion (RPE) were recorded by using a portable gas analyzer system during sitting, standing and four 10 m walking tasks with the robotic exoskeleton. Each participant also performed an arm crank ergometer test to determine maximal cardiorespiratory ability (i.e., peak heart rate and O 2 uptake [HR peak , VO 2peak ]). Results Cardiorespiratory measures increased by a range of 9%–35% from sitting to standing and further increased by 22%–52% from standing to walking with the robotic exoskeleton. During walking, median oxygen cost (O 2Walking ), relative HR (%HR peak ), relative O 2 consumption (%VO 2peak ) and respiratory exchange ratio (RER) reached 0.29 mL/kg/m, 82.9%, 41.8% and 0.9, respectively, whereas median RPE reached 3.2/10. O 2Walking was moderately influenced by total number of sessions and steps taken with the robotic exoskeleton since the start of the walking program. Conclusion Overground walking with the robotic exoskeleton over a short distance allowed wheelchair users to achieve a moderate-intensity level of exercise. Hence, an overground locomotor training program with a robotic exoskeleton may have cardiorespiratory health benefits in the population studied.

The main objectives of this study were to quantify clients' satisfaction and perception upon completion of a locomotor training program with an overground robotic exoskeleton.A group of 14 wheelchair users with a spinal cord injury, who finished a 6-8-week locomotor training program with the robotic exoskeleton (18 training sessions), were invited to complete a web-based electronic questionnaire. This questionnaire encompassed 41 statements organized around seven key domains: overall satisfaction related to the training program, satisfaction related to the overground robotic exoskeleton, satisfaction related to the program attributes, perceived learnability, perceived health benefits and risks and perceived motivation to engage in physical activity. Each statement was rated using a visual analogue scale ranging from "0 = totally disagree" to "100 = completely agree".Overall, respondents unanimously considered themselves satisfied with the locomotor training program with the robotic exoskeleton (95.7 ± 0.7%) and provided positive feedback about the robotic exoskeleton itself (82.3 ± 6.9%), the attributes of the locomotor training program (84.5 ± 6.9%) and their ability to learn to perform sit-stand transfers and walk with the robotic exoskeleton (79.6 ± 17%). Respondents perceived some health benefits (67.9 ± 16.7%) and have reported no fear of developing secondary complications or of potential risk for themselves linked to the use of the robotic exoskeleton (16.7 ± 8.2%). At the end of the program, respondents felt motivated to engage in a regular physical activity program (91.3 ± 0.1%).This study provides new insights on satisfaction and perceptions of wheelchair users while also confirming the relevance to continue to improve such technologies, and informing the development of future clinical trials. Implications for Rehabilitation All long-term manual wheelchair users with a spinal cord injury who participated in the study are unanimously satisfied upon completion of a 6-8-week locomotor training program with the robotic exoskeleton and would recommend the program to their peers. All long-term manual wheelchair users with a spinal cord injury who participated in the study offered positive feedback about the robotic exoskeleton itself and feel it is easy to learn to perform sit-stand transfers and walk with the robotic exoskeleton. All long-term manual wheelchair users with a spinal cord injury who participated in the study predominantly perceived improvements in their overall health status, upper limb strength and endurance as well as in their sleep and psychological well-being upon completion of a 6-8-week locomotor training program with the robotic exoskeleton. All long-term manual wheelchair users with a spinal cord injury who participated in the study unanimously felt motivated to engage in a regular physical activity program adapted to their condition and most of them do plan to continue to participate in moderate-to-strenuous physical exercise. Additional research on clients' perspectives, especially satisfaction with the overground exoskeleton and locomotor training program attributes, is needed.

PURPOSE To assess the effects of a mobility service dog (MSD) on pain, fatigue, wheelchair-related functional tasks, participation and satisfaction among manual wheelchair users over a nine-month period. METHOD A longitudinal study with repeated assessment times before and three, six and nine months after intervention was achieved. Intervention consisted in partnering each participant with a MSD. The setting is a well-established provincial service dog training school and participants homes. A convenience sample of 24 long-term manual wheelchair users with a spinal cord injury was involved. Outcome measures were: Wheelchair User's Shoulder Pain Index (WUSPI), Rate of Perceived Exertion (RPE), vitality scale from the SF-36, grip strength, Wheelchair Skills Test (WST), Canadian Occupational Performance Measure (COPM), Reintegration to Normal Living Index (RNLI), Life Space Assessment, Psychosocial Impact of Assistive Devices Scale (PIADS) and Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0). RESULTS Shoulder and wrist pain as well as fatigue decreased significantly over time with the use of a MSD as evidenced by scores from WUSPI, RPE and SF-36 (feeling less worn out). Manual wheelchair propulsion skills (steep slopes, soft surfaces and thresholds) improved significantly over time as confirmed by the WST. Participation increased significantly over time as revealed by the COPM (for five occupations) and the RNLI (for five items). Satisfaction with the MSD was high over time (QUEST: nine items) and with a high positive psychosocial impact (PIADS: 10 items). CONCLUSION MSD represents a valuable mobility assistive technology option for manual wheelchair users. IMPLICATIONS FOR REHABILITATION For manual wheelchair users partenered with mobility service dog • Shoulder pain and fatigue significantly decreased and continued to decrease between the third and sixth month and the ninth month. • Performance with propelling the wheelchair up steep slopes increased from 41 to 88% and on soft surfaces increased from 53 to 100% after 3 months, respectively. • Occupational performance satisfaction was significantly increased for mobility in relation with the transfers, navigating in a natural environment and picking up objects. • High satisfaction towards psychosocial competency, psychosocial adequacy and self-esteem were reported at months three, six and nine.

Thoracic spinal cord injury (SCI) can have significant negative consequences, which can affect the ability to maintain unsupported sitting. The objectives of this study were to compare postural control of individuals with high- and low-thoracic SCI to able-bodied people and evaluate the effects of upper-limb support on postural control during quiet sitting. Twenty-five individuals were recruited into: (a) high-thoracic SCI; (b) low-thoracic SCI; and (c) able-body subgroups. Participants were seated and asked to maintain a steady balance in the following postures: (1) both hands resting on thighs; (2) both arms crossed over the chest; and (3) both arms extended. Center of pressure (COP) fluctuations were evaluated to compare postural performance between groups and different postures. Results showed that individuals with high- and low-thoracic SCI swayed more compared to the able-bodied group regardless of upper-limb support. No differences between the two SCI groups were observed, but the neurological level of injury was correlated to postural performance implying that those with higher injuries swayed more and faster. Unsupported sitting was more unstable in comparison to supported sitting posture, especially in the anterior-posterior direction. The velocity of postural sway was not different between groups, but the results suggest that postural regulation had unique effect during different postures in different groups. These results imply reduced postural stability after thoracic SCI. Overall, the way individuals with high-thoracic SCI achieved stability was different from that of individuals with low-thoracic SCI, suggesting different postural regulation strategies.

Spinal cord injury (SCI) can result in paralysis of trunk muscles, which can affect sitting balance. The objective of this study was to analyze trunk muscle coordination of individuals with thoracic SCI and compare it to able-body individuals. A total of 27 individuals were recruited and subdivided into: (a) high thoracic SCI; (b) low thoracic SCI; and (c) able-body groups. Participants were seated and asked to lean their trunk in eight directions while trunk muscle activity was recorded. Muscle coordination was assessed using the non-negative matrix factorization (NMF) method to extract muscle modules, which are the synergistic trunk muscle activations, and their directional activation patterns. Our results showed that individuals with SCI used less muscle modules, more co-contractions, and less directional tuning, compared to able-bodied people. These results suggest impaired and simplified muscle coordination due to the loss of supraspinal input after SCI. Observed variability in muscle coordination within SCI groups also suggests that other mechanisms such as spasticity and muscle stretch reflexes or individual factors such as experience and training contributed to the postural muscle synergies. Overall, muscle coordination deficits revealed impaired neuromuscular strategies which provide implications for rehabilitation of trunk muscles during sitting balance after SCI.

Cardiorespiratory fitness training is commonly provided to manual wheelchair users (MWUs) in rehabilitation and physical activity programs, emphasizing the need for a reliable task-specific incremental wheelchair propulsion test.Quantifying test-retest reliability and minimal detectable change (MDC) of key cardiorespiratory fitness measures following performance of a newly developed continuous treadmill-based wheelchair propulsion test (WPTTwenty-five MWUs completed the WPTExcellent test-retest reliability was reached for almost all outcome measures (ICC=0.91-0.76), except for RERThe WPT

Background Cardiorespiratory fitness assessment and training among manual wheelchair (MW) users are predominantly done with an arm-crank ergometer. However, arm-crank ergometer biomechanics differ substantially from MW propulsion biomechanics. This study aimed to quantify cardiorespiratory responses resulting from speed and slope increments during MW propulsion on a motorized treadmill and to calculate a predictive equation based on speed and slope for estimating peak oxygen uptake (VO 2peak ) in MW users. Methods In total, 17 long-term MW users completed 12 MW propulsion periods (PP), each lasting 2 min, on a motorized treadmill, in a random order. Each PP was separated by a 2-min rest. PPs were characterized by a combination of 3 speeds (0.6, 0.8 and 1.0 m/s) and 4 slopes (0°, 2.7°, 3.6° and 4.8°). Six key cardiorespiratory outcome measures (VO 2 , heart rate, respiratory rate, minute ventilation and tidal volume) were recorded by using a gas-exchange analysis system. Rate of perceived exertion (RPE) was measured by using the modified 10-point Borg scale after each PP. Results For the 14 participants who completed the test, cardiorespiratory responses increased in response to speed and/or slope increments, except those recorded between the 3.6 o and 4.8 o slope, for which most outcome measures were comparable. The RPE was positively associated with cardiorespiratory response ( r s ≥ 0.85). A VO 2 predictive equation ( R 2 = 99.7%) based on speed and slope for each PP was computed. This equation informed the development of a future testing protocol to linearly increase VO 2 via 1-min stages during treadmill MW propulsion. Conclusions Increasing speed and slope while propelling a MW on a motorized treadmill increases cardiorespiratory response along with RPE. RPE can be used to easily and accurately monitor cardiorespiratory responses during MW exercise. The VO 2 can be predicted to some extent by speed and slope during MW propulsion. A testing protocol is proposed to assess cardiorespiratory fitness during motorized MW propulsion.

Introduction Current tertiary Spinal Cord Injury (SCI) rehabilitation funding and rehabilitation length of stay (R-LOS) in most North American jurisdictions are linked to an individual’s impairment. Our objectives were to: 1) describe the impact of relevant demographic, impairment and medical complexity variables at rehabilitation admission on R-LOS among adult Canadians with traumatic SCI; and 2) identify factors which extend R-LOS. Methods Data from 1,376 adults with traumatic SCI were obtained via chart abstraction and administrative data linkage from 15 Rick Hansen SCI Registry sites (2004–2014). Variables included age, sex, neurological impairment (level, severity), rehabilitation onset days, R-LOS, Glasgow Coma Score (GCS) at admission, prior ventilation or endotracheal tube (Vent/ETT), or indwelling bladder catheter at acute discharge, pain interference score, intensive care unit (ICU) length of stay (LOS), and lower extremity motor scores (LEMS) at rehabilitation admission. Variables related to R-LOS in bivariate analysis were included in multivariate analysis to determine their impact on R-LOS. Results Prior Vent/ETT tube, indwelling bladder catheter, GCS, LEMS, and neurological impairment were related to R-LOS in bivariate analysis. Multivariate linear regression analyses identified five variables as significant predictors: age, Vent/ETT for >24 hours in acute care, indwelling bladder catheter at acute discharge, LEMS, and NLI/AIS subgroup at rehabilitation admission explained 32% of the variation in R-LOS (p

The objectives of the present study were to test the feasibility of measuring humeral head displacements using quantitative ultrasound imaging during the performance of two different dynamic glenohumeral neuromuscular control exercises and to investigate the influence of these exercises on the acromiohumeral distance (AHD) and anterior-posterior distance (APD). Ten individuals who have no history of shoulder injury at the non-dominant shoulder completed three repetitions of an active humeral head lowering exercise and three repetitions of a posteriorisation exercise in a random order in a seated position. The AHD and the APD of the humeral head relative to the glenoid cavity were measured continuously using an ultrasound imaging system during each exercise. Variations in AHD and APD, defined as the difference between the distance obtained before the exercise and the maximal distance reached during the exercise, were compared for each exercises. The active humeral head lowering exercise significantly increased the AHD by 0.94 ± 0.28 mm (relative: + 11.4%), but had no significant effect on the APD. The active humeral head posteriorisation exercise significantly increased the AHD by 0.65 ± 0.41 mm (relative: + 6.3%) and the APD by 1.51 ± 0.51 mm (relative: + 13.8%). The use of quantitative ultrasound imaging allows physiotherapists to quantify inferior and posterior humeral head displacements during dynamic glenohumeral neuromuscular control exercises. These measures, confirming favourable inferior and posterior humeral head displacements at the shoulder, may become useful when studying the effectiveness of rehabilitation programs incorporating dynamic glenohumeral neuromuscular control exercises.

Tendon integrity can be described using a wide range of biomarkers via specialized analysis software for images recorded by musculoskeletal ultrasonography. This study proposes a minimal biomarker data set to characterize Achilles tendon ultrasound images and to differentiate between symptomatic and asymptomatic Achilles tendon images. Forty-one individuals with unilateral Achilles tendinopathy and 35 healthy controls had their Achilles tendon images recorded bilaterally by ultrasonography in the longitudinal and transverse planes. A set of 22 biomarkers, organized around three dimensions (geometric, composition and texture), were computed in each plane. A symmetry index, reflecting relative side differences, was compared between groups and analyzed through principal component analysis to isolate biomarkers that best explained data variance. A specific minimal data set was identified by linear regression in the longitudinal (mean thickness, echogenicity, variance and homogeneity at 90°) and transverse (mean thickness, echogenicity and mean homogeneity) planes to characterize and differentiate Achilles tendon integrity.

Objective Neuromobilization exercises are increasingly advocated in the conservative management of individuals with carpal tunnel syndrome (CTS), as they may mitigate CTS-related signs and symptoms via potential peripheral (ie, musculoskeletal) and central (ie, neurophysiological) adaptations. However, the mechanisms underlying these adaptations have not been studied extensively. Hence, this exploratory and mechanistic study aims to evaluate the potential peripheral and central adaptations that may result in individuals with CTS who have completed a neuromobilization program. Methods Fourteen individuals with CTS were evaluated before and 1 week after the completion of a 4-week neuromobilization program that incorporated median nerve sliding exercises. Pain and upper limb functional abilities were assessed using standardized questionnaires. The biological integrity and mechanical properties of the median nerve and the corticospinal excitability were quantified using musculoskeletal ultrasound imaging and transcranial magnetic stimulation, respectively. Results Upon completion of the program, participants reported both large and moderate improvements in pain (P ≤ .03) and upper limb functional abilities (P = .02), respectively. The biological integrity and mechanical properties of the median nerve remained unchanged (P ≥ .22), whereas a small significant increase in corticospinal excitability (P = .04) was observed. Conclusion The proposed neuromobilization program appears promising to improve pain and upper limb functional abilities in individuals with CTS. These improvements may be preferentially mediated via central, rather than peripheral, adaptations. Future studies, especially with a larger sample size, longer intervention duration, and additional measurement times, are needed to strengthen current evidence.

Biomechanical evidence is needed to determine to what extent the use of a mobility assistance dog (ADMob) may minimize mechanical loads and muscular demands at the upper limbs among manual wheelchair users. This study quantified and compared upper limb efforts when propelling up a ramp with and without an ADMob among manual wheelchair users. Ten manual wheelchair users with a spinal cord injury who own an ADMob ascended a ramp with and without their ADMob. The movements of the wheelchair and upper limbs were captured and the forces applied at the pushrims were recorded to compute shoulder mechanical loading. Muscular demand of the pectoralis major, anterior deltoid, biceps, and the triceps was normalized against the maximum electromyographic values. The traction provided by the ADMob significantly reduced the total force applied at the pushrim and its tangential component while the mechanical effectiveness remained similar. The traction provided by the ADMob also resulted in a significant reduction in shoulder flexion, internal rotation, and adduction moments. The muscular demands of the anterior deltoid, pectoralis major, biceps, and triceps were significantly reduced by the traction provided by the ADMob. The use of ADMob represents a promising mobility assistive technology alternative to minimize upper limb mechanical loads and muscular demands and optimize performance during wheelchair ramp ascent.

This study aims to quantify the force applied during posterior-to-anterior lumbar vertebrae mobilizations of different grades (I to IV) and compare that force between experienced physiotherapists and final year physiotherapy students. Four experienced physiotherapists and four final year physiotherapy students participated in this study along with five healthy asymptomatic individuals. A manual therapy table positioned over three force plates allowed for measurements of the force oscillation frequency and intensity applied during grade I, II, III and IV posterior-to-anterior (PA) mobilizations at two lumbar vertebral levels (L2 and L4). Mixed model ANOVAs were used to compare the force applied between the experienced physiotherapists and students, and between the various grades. The results showed that the mean oscillation frequency was similar between the groups for all grades. Grade I and grade IV PA mobilizations showed similar mean oscillation frequency as did grade II and III PA mobilizations. The minimum and maximum force applied was higher for the physiotherapists than for the students for all mobilization grades (p values

The prognosis for patients with a complete traumatic spinal cord injury (SCI) is generally poor. It is unclear whether some subgroups of patients with a complete traumatic SCI could benefit from early surgical decompression of the spinal cord. The objectives of this study were: (1) to compare the effect of early and late surgical decompression on neurological recovery in complete traumatic SCI and (2) to assess whether the impact of surgical timing is different in patients with cervical or thoracolumbar SCI. A prospective cohort study was followed in a single Level 1 Trauma Center specializing in SCI care. All consecutive patients who sustained a traumatic SCI and were referred between 2010 and 2013 were screened for eligibility. Neurological status was assessed systematically using the American Spinal Injury Association impairment scale (AIS) at arrival to the trauma center and at rehabilitation discharge. Patients operated within 24 h of the trauma were compared with patients operated later than 24 h after the trauma. Potential confounders such as age, Injury Severity Score (ISS), smoking history, body mass index (BMI), Glasgow Coma Scale (GCS) score, and duration of follow-up were recorded. Fifty-three patients with complete SCI were included in the study: 33 thoracolumbar and 20 cervical SCIs. The 38 patients operated24 h were generally younger than the 15 patients operated ≥ 24 h (p = 0.049). Overall, 28% (15/53) of complete SCI had improvement in AIS: 34% (13/38) who were operated24 h and 13% (2/15) who were operated ≥ 24 h (p = 0.182). Sixty-four percent (9/14) of cervical complete SCI operated24 h had improvement in AIS as opposed to none in the subgroup of six complete cervical SCI operated ≥ 24 h (p = 0.008). Surgical decompression within 24 h in complete SCI may optimize neurological recovery, especially in patients with cervical SCI.

Study design Case series. Background Changes in the number of muscle synergies (MSs) and in the weighting of muscles composing each MS are typically altered following an incomplete spinal cord injury (iSCI). Wearable robotic exoskeletons (WRE) represent a promising rehabilitation option, though the effects of various WRE control modes on MSs still remain unknown. Objective This case series characterizes how WRE control modes affect the number of MSs and the weighting of muscles composing each MS in individuals with iSCI. Setting Pathokinesioly laboratory of a rehabilitation research center. Methods Three participants with a chronic iSCI walked at a self-selected comfortable speed without and with a WRE set in two trajectory-controlled (Total Assistance, TOT; Assistance-as-Needed, ADAPT) and three non-trajectory controlled modes (High Assistance, HASSIST; High Resistance, HRESIST; NEUTRAL). Surface EMG of eight lower extremity (L/E) muscles was recorded and used to extract MSs using a nonnegative matrix factorization algorithm. Cosine similarity and weighting relative differences characterized similarities in MSs between individuals with iSCI and able-bodied controls. Results The mode providing movement assistance within a self-selected L/E trajectory (HASSIST) best replicated MSs in able-bodied controls during overground walking. MSs extracted with the trajectory-controlled modes differed to the greatest extent from able-bodied group MSs. Conclusions Most WRE control modes did not replicate the motor control required for typical L/E muscle coordination during stereotypical overground walking. These results highlight the need to gain a better understanding of the effects of various control modes on L/E motor control for rehabilitation professionals to incorporate research evidence when selecting WRE control mode(s) during WRE locomotor interventions.

Teaching manual wheelchair users to perform wheelies using various rolling resistances is expected to facilitate learning of this advanced wheelchair skill. However, limited scientific evidence is available to support this approach. This study aimed to measure and compare postural stability and control requirements when maintaining a stationary wheelie on different rolling resistances. Eighteen manual wheelchair users with a spinal cord injury performed in a random order and maintained four 30-second wheelies on four rolling resistances: natural hard floor (NAT), 5-cm thick soft foam (LOW), 5-cm thick memory foam (MOD), and rear wheels blocked by wooden blocks (HIGH). All wheelies were performed over a large instrumented force plate to continuously record the center of pressure (CoP). To quantify postural stability, resultant and directional time- and frequency-domain CoP measures were computed and compared across all four rolling resistances. All resultant time-domain measures confirmed increased postural stability from NAT to LOW and from MOD to HIGH rolling resistances. Most time-domain measures confirmed a shift in postural control from an anticipatory to a predominantly compensatory strategy, accompanied by increased reliance on proprioceptive feedback, especially from NAT to LOW and from MOD to HIGH rolling resistances. Postural stability gradually increased with various rolling resistances while maintaining a stationary wheelie, whereas the postural control strategy shifted from an anticipatory to a reactive strategy. Blocking the rear wheels is recommended when first teaching this advanced wheelchair skill. Rapid progression on foam and natural surfaces is advocated to refine learning and enhance proper postural control strategies.

This study determined test–retest reliability and minimum detectable change in longitudinal median nerve excursion during upper limb neurodynamic tests (ULNTs). Seven participants with unilateral or bilateral carpal tunnel syndrome and 11 healthy participants were randomly tested with two ULNTs ( i.e ., tensioner and slider). Each ULNT was performed three times each at 45° and 90° of shoulder abduction on two separate visits. Video sequences of median nerve excursion, recorded by a physical therapist using ultrasound imaging, were quantified using computer software. The generalizability theory, encompassing a G-Study and a D-study, measured the dependability coefficient (Φ) along with standard error of measurement (SEM) accuracy and allowed various testing protocols to be proposed. The highest reliability (Φ = 0.84) and lowest minimal measurement error (SEM = 0.58 mm) of the longitudinal median nerve excursion were reached during the ULNT-slider performed with 45° of shoulder abduction and when measures obtained from three different image sequences recorded during a single visit were averaged. It is recommended that longitudinal median nerve excursion measures computed from three separate image sequences recorded during a single visit be averaged in clinical practice. Ideally, adding a second visit (six image sequences) is also suggested in research protocols.

Gait initiation and termination are potentially challenging tasks for balance due to the transition from a quasi-static bipedal phase to a dynamic single-support phase. The purpose of this study was to compare the bipedal and single-support phases of gait initiation and termination in individuals with incomplete spinal cord injury (ISCI). Twelve individuals with ISCI were evaluated on the dynamic and postural components of balance using the stabilizing and destabilizing forces during gait initiation, termination and natural gait. Phase comparisons were made using non parametric tests. Visual inspection of the force profile of the factors explaining the forces was also conducted. Gait termination challenged more the postural control during the single-support phase than the bipedal phase for the dynamic component of the stabilizing/destabilizing forces model (p=.002). For gait initiation, the most challenging phase varied with the components analyzed (single-support phase for the dynamic component, bipedal phase for the postural component) (p⩽.008). The single support phase is more challenged during gait termination (both components) (p⩽.015) while the bipedal phase is more challenged during gait initiation (dynamic components) (p=.012). The stabilizing force and the speed of the center of mass on the one hand, and destabilizing force and the distance between the center of pressure and the base of support on the other hand, had a similar profile. The single-support phase of gait termination was the most challenging among all phases evaluated, being as challenging as the single-support phase of level natural gait. This phase should be targeted in rehabilitation in order to improve balance and decrease the risk of falling in this population.

BACKGROUND The function of specific abdominal muscles can be assessed using both electromyography (EMG) and ultrasound imaging (USI) thickness measures. However, the relationship between these two measurements is not conclusive during sitting isometric trunk efforts. OBJECTIVE This study was conducted to assess the relationship between USI thickness and EMG amplitude measures of the right external oblique (EO) muscle during isometric efforts in the sitting position. METHOD Eighteen subjects performed ramp isometric efforts progressing from 0 to 50% of their maximal voluntary contraction (MVC) in three trunk directions on a dynamometer: (1) forward flexion; (2) right lateral flexion; and (3) left axial rotation. USI and surface EMG amplitude measures of the EO muscle were recorded concomitantly and both normalized against rest values and maximal EMG, respectively. RESULTS EO muscle was significantly more activated (p < 0.001) during forward flexion (42% on average) and axial rotation (35%) than during lateral flexion (24%). Non-significant (r=0.01; P=0.979) to highly significant (r=0.98; P < 0.0001) and negative and positive Pearson correlations were observed between EMG and EO thickness measures for both flexion and rotation directions. CONCLUSION The negative correlations between EMG and USI measures as well as the great variability of these correlations across individuals suggest that USI is not a valid measures of EO muscle activity. USI thickness measures should be interpreted with great caution in research and clinical settings.

Wheelchair mobility is a prerequisite to being able to carry out important activities and to participate in social life. Level of satisfaction with the wheelchair and overall quality of life were found to be positively associated. The aim of this study was to determine the level of satisfaction of French manual wheelchair (MW) users and caregivers with MW characteristics. A total of 132 users and 76 caregivers completed a questionnaire about their level of satisfaction with their MW characteristics. Satisfaction scores were independent of age, sex, reason for MW use, and time of use. As a whole, MW users are satisfied. However, a few parameters such as MW weight and difficulties propelling outdoors demonstrate a low level of satisfaction among users. MW weight, brakes, and height of pushing handles are the less satisfying elements among caregivers. In conclusion, the majority of French MW users are satisfied, but some characteristics, such as weight, must be optimized. Considering caregiver needs is paramount when aiming to improve MW parameters such as brakes or pushing handles. Improvement in some wheelchair parameters seems to be important in achieving improved level of satisfaction and increased participation and active lifestyle among MW users and caregivers.

Eighteen manual wheelchair users (MWUs) with spinal cord injury participated in a training session on a new manual wheelchair simulator with haptic biofeedback (HB). The training aimed to modify participants' mechanical effective force (MEF) along the push phase to achieve a target MEF pattern slightly more effective than their pre-training pattern. More HB was provided if the participants' achieved MEF pattern deviated from the target. Otherwise, less HB was provided. The deviation between the participants' achieved MEF and the target, as well as the mean achieved MEF, were computed before, during and after the training session. During the training, participants generally exceeded the target pattern at the beginning of the push cycle and achieved it towards the end. On average, participants also increased their mean MEF by up to 15.7% on the right side and 12.4% on the left side between the pre-training and training periods. Finally, eight participants could modify their MEF pattern towards the target in post-training. The simulator tested in this study represents a valuable tool for developing new wheelchair propulsion training programs. Haptic biofeedback also provides interesting potential for training MWUs to improve propulsion effectiveness.

Background For individuals who sustain a complete motor spinal cord injury (SCI) and rely on a wheelchair as their primary mode of locomotion, overground robotic exoskeletons represent a promising solution to stand and walk again. Although overground robotic exoskeletons have gained tremendous attention over the past decade and are now being transferred from laboratories to clinical settings, their effects remain unclear given the paucity of scientific evidence and the absence of large-scale clinical trials. This study aims to examine the feasibility of a locomotor training program with an overground robotic exoskeleton in terms of recruitment, attendance, and drop-out rates as well as walking performance, learnability, and safety. Methods Individuals with a SCI were invited to participate in a 6 to 8-week locomotor training program with a robotic exoskeleton encompassing 18 sessions. Selected participants underwent a comprehensive screening process and completed two familiarization sessions with the robotic exoskeleton. The outcome measures were the rate of recruitment of potential participants, the rate of attendance at training sessions, the rate of drop-outs, the ability to walk with the exoskeleton, and its progression over the program as well as the adverse events. Results Out of 49 individuals who expressed their interest in participating in the study, only 14 initiated the program (recruitment rate = 28.6%). Of these, 13 individuals completed the program (drop-out rate = 7.1%) and attended 17.6 ± 1.1 sessions (attendance rate = 97.9%). Their greatest standing time, walking time, and number of steps taken during a session were 64.5 ± 10.2 min, 47.2 ± 11.3 min, and 1843 ± 577 steps, respectively. During the training program, these last three parameters increased by 45.3%, 102.1%, and 248.7%, respectively. At the end of the program, when walking with the exoskeleton, most participants required one therapist (85.7%), needed stand-by or contact-guard assistance (57.1%), used forearm crutches (71.4%), and reached a walking speed of 0.25 ± 0.05 m/s. Five participants reported training-related pain or stiffness in the upper extremities during the program. One participant sustained bilateral calcaneal fractures and stopped the program. Conclusions This study confirms that larger clinical trials investigating the effects of a locomotor training program with an overground robotic exoskeleton are feasible and relatively safe in individuals with complete motor SCI. Moreover, to optimize the recruitment rate and safety in future trials, this study now highlights the need of developing pre-training rehabilitation programs to increase passive lower extremity range of motion and standing tolerance. This study also calls for the development of clinical practice guidelines targeting fragility fracture risk assessment linked to the use of overground robotic exoskeletons.

Background Manual wheelchair (MWC) propulsion is increasingly assessed on a motorized treadmill (TM), which is often considered more ecologically valid than stationary rollers. However, no clear consensus on the similarities between overground (OG) and TM propulsion has yet been reached. Furthermore, no study has investigated the participants’ perceptions of propelling a MWC on a TM compared to OG. Research question The present study aims to assess the perception of speed when propelling on a TM vs OG, and to relate this perception to measured spatiotemporal variables, kinetics and work. Methods In this repeated-measures study, the propulsion’s spatiotemporal variables, kinetics, and work of nineteen experienced wheelchair users with a spinal cord injury were compared between three conditions: 1) OG at a self-selected speed, 2) on a TM at a self-selected speed perceived as being similar to the OG speed (TMperceived), and 3) on a TM at the same speed as OG (TMmatched). Each variable was compared between conditions using an analysis of variance for repeated measures. Results All participants selected a lower speed for TMperceived than OG, with a difference of −0.6 m/s (−44%). This adaptation may be due to a combination of two factors: 1) the absence of speed information, and 2) the feeling of urgency to grab the wheels during the recovery phase. The power output, work per cycle, and work per minute were also much lower on TMperceived than OG. However, in contrast to other work on MWC propulsion on a TM, the kinetic variables assessed were all similar between the OG and TMmatched conditions. Significance Training on a TM should be performed at a speed that matches the OG speed and not at a self-selected speed on the TM, which would reduce the power output and work and therefore reduce the efficiency of the training.

Lumbar stabilization programs reduce pain and disability, but the mechanisms of action underlying this treatment are unknown. Trunk postural control during unstable sitting represents a surrogate measure of motor control mechanisms involved to maintain the dynamic stability of the spine. This exploratory study aimed to determine the reliability of trunk postural control measures over an 8-week interval, their sensitivity to low back pain status and treatment and their relationship with clinical outcomes. Trunk postural control measures were determined in patients with low back pain before and after an 8-week lumbar stabilization exercise program. Healthy controls were assessed over the same interval, but without any treatment, to determine the reliability of the measures and act as a control group at baseline. The kinematics of a wobble chair during unstable sitting was summarized using different linear and nonlinear measures quantifying the quantity and quality of movement, respectively. The reliability of the measures was moderate to excellent. The results showed significant reduction in pain and disability following the intervention. While no impairment at baseline scores was found, some linear and nonlinear measures changed over the intervention period among the patient group. However, for nonlinear measures only, significant correlations were detected with the change scores of pain and disability. The change of measures over the intervention period was likely due to learning rather than the intervention as similar alteration was detected in the healthy subjects. The results suggest that only the quality (not the quantity) of movement may have relationship with pain and disability.

International audience; It is still unknown to what extent overground walking with a WRE is equivalent to natural overground walking without a WRE. Hence, the interpretability of the 10-m (10MWT) and six-minute (6MWT) walk tests during overground walking with a WRE against reference values collected during natural overground walking without a WRE is challenging. This study aimed to 1) compare walking performance across three different overground walking conditions: natural walking without a WRE, walking with a WRE providing minimal assistance (active walking), and walking with a WRE proving complete assistance (passive walking) and 2) assess the association and the agreement between the 10MWT and the 6MWT during passive and active walking with a WRE. Seventeen healthy individuals who underwent basic locomotor training with a WRE performed the 10MWT (preferred and maximal speeds) and the 6MWT under the three conditions. For the 10MWT, the speed progressively and significantly decreased from natural walking without a WRE (preferred: 1.40±0.18m/s; maximal: 2.16±0.19m/s), to active walking with a WRE (preferred: 0.48±0.10m/s; maximal: 0.61±0.14m/s), and to passive walking with a WRE (preferred: 0.38±0.09m/s; maximal: 0.42±0.10m/s). For the 6MWT, total distances decreased from walking without a WRE (609±53.9m), to active walking with a WRE (196.6±42.6m), and to passive walking with a WRE (144.3±33.3m). The 10MWT and 6MWT provide distinct information and can't be used interchangeably to document speed only during active walking with the WRE. Speed and distance drastically decrease during active and, even more so, passive walking with the WRE in comparison to walking without a WRE. Selection of walking tests should depend on the level of assistance provided by the WRE.

No comprehensive biomechanical study has documented upper extremity (U/E) kinematics and kinetics during the performance of wheelchair wheelies among manual wheelchair users (MWUs). The aim of this study was to describe movement strategies (kinematics), mechanical loads (kinetics), and power at the nondominant U/E joints during a wheelie among MWUs with spinal cord injury (SCI). During a laboratory assessment, 16 MWUs with SCI completed four wheelie trials on a rigid surface. Each participant’s wheelchair was equipped with instrumented wheels to record handrim kinetics, while U/E and wheelchair kinematics were recorded with a 3D motion analysis system. The greatest mean and peak total net joint moments were generated by the shoulder flexors (mean = 7.2 ± 3.5 N·m; peak = 20.7 ± 12.9 N·m) and internal rotators (mean = 3.8 ± 2.2 N·m; peak = 11.4 ± 10.9 N·m) as well as by the elbow flexors (mean = 5.5 ± 2.5 N·m; peak = 14.1 ± 7.6 N·m) during the performance of wheelies. Shoulder flexor and internal rotator efforts predominantly generate the effort needed to lift the front wheels of the wheelchair, whereas the elbow flexor muscles control these shoulder efforts to reach a state of balance. In combination with a task-specific training program that remains essential to properly learn how to control wheelies among MWUs with SCI, rehabilitation professionals should also propose a shoulder flexor, internal rotator, and elbow flexor strengthening program.

Muscle vibrations can induce motor responses and illusions of complex movements. However, inducing gait-like cyclical movements and illusions requires the application of multiple fast alternating vibrations to lower-limb muscles. The objectives were (1) to test the feasibility of delivering complex vibrations in a time-organized manner and (2) to illustrate the possibility of inducing alternate gait-in-place-like movements using these vibrations. Patterns of vibration, produced by 12 vibrators applied bilaterally on the flexor and extensor muscle groups of the lower limbs, were based on normal gait kinemat- ics. We tested 1 s and 2 s cycle patterns of vibration. Vibrator responses were assessed using auto- and crosscorrelations and frequency analyses based on accelerometry measurements, and compared between patterns. High auto- (>0.8) and crosscorre- lation (>0.6) coefficients demonstrated a good response by the vibrators to the control signal. Vibrations induced cyclical, low-amplitude stepping-in-place movements that mimicked alternate walking movements with both legs, with 1 s and 2 s cycle durations, in one nondisabled participant and one partici- pant with American Spinal Injury Association Impairment Scale B spinal cord injury standing, relaxed, with body-weight support. Electromechanical vibrators can deliver complex cyclical vibrations and trigger gait-like lower-limb movements. These results warrant the application of these vibration patterns on individuals with sensorimotor impairments to test their potential in gait rehabilitation.

INTRODUCTION The majority of people who sustain a spinal cord injury (SCI) will not regain the necessary sensorimotor capabilities to walk independently or efficiently and must consequently learn to get around in a manual wheelchair (MWC). During the rehabilitation process, they will be encouraged to learn basic and advanced MWC skills so they can optimize their level of independence during MWC propulsion and MWC-related functional activities performed in their natural environment. For example, they will often have to negotiate slopes of different lengths and angles. For MWC users (MWUs), slopes are not just an environmental or architectural challenge to overcome, but they also represent a way to access many public and private spaces or buildings, which facilitates their social integration and participation [1]. According to various recommendations and standards in Canada and the United States [2-4], access ramps can have different slopes, ranging from 1 unit of height to 12, 16, or 20 units of length for ramps less than 9 m long in new buildings or 8 or 10 units of length for ramps less than 3 m long or for vertical rises less than 15 cm in existing buildings or confined spaces. Under no circumstance are slopes steeper than 1:8 permitted by these recommendations and standards. However, in reality, slopes are sometimes steeper because of space limitations (e.g., private residential property) or the inherent inability to modify the natural environment. Consequently, it is relevant to gain additional insight on the specificities of these different slopes during MWC propulsion. To date, only a few studies have investigated upper-limb (UL) efforts during uphill propulsion among MWUs. In a study done with 20 MWUs with various diagnoses, Sanford et al. reported that, for a 9 m-long adjustable slope, 85 percent of the participants could climb a slope of 1:12, 80 percent successfully negotiated a 1:10 slope, and only 75 percent managed to ascend a 1:8 slope while propelling their own MWC at a self-selected natural speed [5]. Moreover, other studies confirmed that a substantial number of MWUs are unable to climb steeper slopes: Templer et al. reported that only 80 percent of MWUs could manage a slope gradient of 1:10 [6], Sweeney et al. mentioned that 88 percent of their participants were able to climb 1:12 to 1:7 slopes [7], and Steinfield et al. documented that approximately 50 percent of MWUs tested could propel the full length of a 1:12 ramp measuring approximately 40 m in length [8]. To date, no study has investigated whether these success rates measured during uphill propulsion in a simulated natural environment are comparable with those reached during treadmill propulsion among MWUs. In addition to the UL efforts routinely generated by MWUs during propulsion and other functional activities (e.g., transfers, pressure-relief lifts, loading the MWC in a car), propelling uphill puts additional demand on the MWU's ULs, which further increases the risk of second ary musculoskeletal impairments, especially at the wrists and shoulders [9-10]. In fact, Arabi et al. calculated among nondisabled subjects that 46 percent of the maximal isometric propulsive force generated is necessary to move an MWC up a slope of 1:20 and 61 percent for a slope of 1:10 when propelling on a dynamometer [11]. Richter et al. found that among a large group of MWUs with SCI, propelling at a self-selected velocity on a motorized treadmill, the speed was about 1.5 and 2.7 times slower when pushing up 3[degrees] and 6[degrees] slopes, respectively, in comparison with the level surface (0[degrees] slope) [12]. Additionally, Richter et al. also documented that the peak total force ([F.sub.TOT]) was about 1.7 and 2.2 times slower when pushing up 3[degrees] and 6[degrees] slopes, respectively, in comparison with the level surface (0[degrees] slope) despite the reduced treadmill speed [12]. More recently, Yang et al. found that among a group of MWUs with SCI, propelling at a steady speed of 0. …

Background Lumbar stabilization exercise programs (LSEP) produce positive effects on clinical outcomes, but the underlying mechanisms remain relatively unexplored. Psychological and neuromuscular mechanisms can be involved, such as a better activation of the lumbar multifidus, which represents one possibility. Objectives To determine the following: (1) the effect of an LSEP on lumbar multifidus muscle thickness and activation, as measured with rehabilitative ultrasound imaging (RUSI), in patients with low back pain (LBP); (2) the correlation between RUSI measures and any change in clinical outcomes following the LSEP; and (3) the reliability of RUSI measures in control subjects over 8 weeks. Design One-arm clinical trial with healthy subjects as a control group; reliability study. Setting LSEP delivered in a clinical setting; outcomes measured in a laboratory setting. Participants A total of 34 patients with nonacute LBP and 28 healthy control subjects. Methods Outcomes were measured before and after an 8-week LSEP in patients with LBP, and at the same time interval (without treatment, to assess reliability) in control subjects. Main Outcome Measurements Pain numeric rating scale, Oswestry Disability Index (function), as well as RUSI measures for the lumbar multifidus (LM) muscles at 3 vertebral levels (L5-S1, L4-5, and L3-4) during rest (static) and dynamic contractions (percent thickness change). Results Patients did not show systematic changes in RUSI measures relative to controls, even though RUSI impairments were observed at baseline (dynamic measure at L5-S1) and even though patients had significant improvements in pain and disability. Correlational analyses with these clinical outcomes suggested that patients had reduced muscle thickness at baseline that was associated with a greater reduction in disability following LSEP; however, LM activation measured at baseline showed the opposite. Static RUSI measures showed excellent reliability at the L4-5 and L3-4 levels, whereas dynamic measures were not reliable. Conclusions Patients showed less muscle activation than controls at baseline (L5-S1 level), but the LSEP did not normalize this impairment. The links between RUSI measures and the change in clinical outcomes during LSEP should be further explored. This clinical trial has been recorded in the International Standard Registered Clinical/soCial sTudy Number (ISRCTN) registry (ID: ISRCTN94152969). Level of Evidence II

1 b abstract The purpose of this study was to investigate the effects of imposing different degrees of forward trunk flexion during sitting pivot transfers on electromyographic activity at the leading and trailing upper limb muscles and on dynamic stability requirements. Thirty-two individuals with a spinal cord injury per- formed three types of sitting pivot transfers: natural technique, exaggerated forward trunk flexion and upright trunk position. Ground reaction forces, trunk kinematics, and bilateral electromyographic activity of eight upper limb muscles were recorded. Electromyographic data were analyzed using the area under the curve of the muscular utilization ratio. Dynamic stability requirements of sitting pivot transfers were assess using a dynamic equilibrium model. Compared to the natural strategy, significantly greater muscle activities were found for the forward trunk flexion condition at the anterior deltoid and both heads of the pectorialis major, whereas the upright trunk strategy yielded greater muscle activity at the latissimus dorsii and the triceps. The forward flexed condition was found to be more dynamically stable, with a lower stabilizing force, increased area of base of support and greater distance traveled. Thus, transferring with a more forward trunk inclination, even though it increases work of few muscles, may be a beneficial trade-off because increased dynamic stability of this technique and versatility in terms of potential dis- tance of the transfer.

High upper extremity (U/E) demands are required when manual wheelchair users (MWUs) with spinal cord injury (SCI) ascend curbs; this may contribute to the risk of developing U/E musculoskeletal impairments. The aim of this study was to compare movement strategies (kinematics), mechanical loads (kinetics) and muscular demand (EMG) at the non-dominant U/E among 15 MWUs with SCI when ascending curbs of 4 cm (3 trials), 8 cm (3 trials) and 12 cm high (3 trials) from a starting line set 3 m before the curb. Biomechanical data was collected during three trials for each height. The curb ascent task was divided into three adjustment phases: caster pop, rear-wheel ascent and post-ascent. The greatest effort was generated by the shoulder flexors and internal rotators as well as the elbow flexors. A significant difference (p < 0.0167) between the curb heights was found for most outcome measures studied: movement excursion, net joint moments and muscular utilization ratio (MUR) of the main muscles increased with the higher curb heights, mainly around the shoulder joint. These results provide insight that aside from adhering to a highly structured training method for wheelchair curb ascent, rehabilitation professionals need to propose task-specific strength training programs based on the demands documented in this study and continue to advocate for physically accessible environments.

Objective: To compare the mechanical and muscular efforts generated in the non-dominant upper limb (U/L) when ascending a ramp with and without the use of a mobility assistance dog (ADMob) in a manual wheelchair user with a spinal cord injury. Method: The participant ascended a ramp at natural speed using his personal wheelchair with (three trials) and without (three trials) his ADMob. Movement parameters of the wheelchair, head, trunk, and non-dominant U/L (i.e. hand, forearm, and arm segments) were recorded with a motion analysis system. The orthogonal force components applied on the hand rims by the U/Ls were computed with instrumented wheels. Muscular activity data of the clavicular fibers of the pectoralis major, the anterior fibers of the deltoid, the long head of the biceps brachii, and the long head of the triceps brachii were collected at the non-dominant U/L. Results: During uphill propulsion with the ADMob, the total and tangential forces applied at the non-dominant handrim, along with the rate of rise of force, were reduced while mechanical efficiency was improved compared to uphill propulsion without the ADMob. Similarly, the resultant net joint movements (wrist, elbow, and shoulder) and the relative muscular demands (biceps, triceps, anterior deltoid, pectoralis major) decreased during uphill propulsion with an ADMob versus without an ADMob. Conclusion: Propelling uphill with the assistance of an ADMob reduces U/L efforts and improves efficiency compared to propelling uphill without its assistance in a manual wheelchair user with a spinal cord injury.

This study aims to verify whether individuals with physical impairments and ambulatory disabilities perform functional mobility tests faster using an assistance dog for mobility (AD(Mob)). Thirty-four individuals with various physical impairments and functional disabilities performed at least one of the four functional mobility tests within their natural environment during an in-home assessment. Participants randomly performed the 10-meter walk test, the timed up-and-go (TUG) test, and the stair ascent and descent tests with and without an AD(Mob) during an in-home assessment. The main outcome measure was the time needed to complete all tests with and without an AD(Mob). When using an AD(Mob), many participants (or = 70.4%) were faster when performing the 10-meter walk test (15.7 +/- 8.5s vs. 19.1 +/- 11.2s), TUG test (23.6 +/- 14.2s vs. 27.3 +/- 16.5s), and stair ascent test (18.6 +/- 13.5s vs. 22.4 +/- 17.5s) compared to doing the tests without an AD(Mob). As for the stair descent test, the use of the AD(Mob) had no significant effect on performance (20.7 +/- 15.9s vs. 24.0 +/- 17.1s). When using an AD(Mob), the majority of individuals with physical impairments and functional disabilities significantly improved their performance (i.e., reduced their time) during the 10-meter walk test, the TUG test and the stair ascent test.

Propelling a manual wheelchair (MWC) is a strenuous task that causes upper limb musculoskeletal disorders (MSD) in a large proportion of MWC users. Although most studies on MWC propulsion biomechanics assume that MWC propulsion is a relatively symmetric task, recent literature suggests that this is the case only when the assessed outcome measures are averaged over long periods of time, and not over short periods (i.e., instantaneously). No method is currently available to assess instantaneous symmetry. In this work, we present the Instantaneous Symmetry Index (ISI), a new method that quantifies how a variable has been instantaneously asymmetric during a selected time period. Thirteen experienced MWC users propelled on different cross slopes of 0%, 2%, 4%, 6% and 8%. As the cross slope is increased, the upper hand produced less propulsive moments and the lower hand produced more propulsive movements. This has been reflected in the ISI, which increased from 0.20 (0% slope) to 0.84 (8% slope) with a Spearman׳s coefficient of 0.90. The ISI has great potential to evaluate the ability of a user to propel symmetrically and synchronously, and will be a relevant measure to include in future studies on the impact of MWC propulsion asymmetry on MSD risk.

Objectives (1) To evaluate the reliability of ultrasonographic measures of the acromiohumeral distance (AHD) in shoulder positions linked to wheelchair propulsion in manual wheelchair users (MWUs) with spinal cord injury (SCI) and able-bodied individuals; (2) to compare ultrasonographic measures of AHD, supraspinatus tendon thickness, and occupation ratio between MWUs with SCI with and without shoulder pain (rotator cuff [RC] tendinopathy); and (3) to compare these ultrasonographic measures between MWUs with SCI and able-bodied individuals. Design Cross-sectional study. Setting Rehabilitation centers. Participants Three groups of participants (N=95; aged between 18 and 60y) were recruited within a convenience sample: objective 1: 16 MWUs with SCI (mean age, 43±9y; height, 172±13 cm, weight, 84±10 kg) and 16 able-bodied individuals (mean age, 28±9y; height, 176±11 cm, weight, 72±12 kg); objectives 2 and 3: 37 MWUs with SCI (17 with [mean age, 47±11y; height, 172±14 cm, weight, 68±11 kg] and 20 without [mean age, 45±10y; height, 172±15 cm, weight, 84±30 kg] RC tendinopathy) and 26 able-bodied individuals (mean age, 31±5y; height, 175±12 cm; weight, 89±14 kg). Interventions Not applicable. Main Outcome Measures AHD, supraspinatus tendon thickness, and occupation ratio of the supraspinatus tendon measured using ultrasound imaging systems. Results (1) Excellent intra- and interrater reliability of AHD was obtained in each arm position (intraclass correlation coefficient>.85); (2) MWUs without shoulder pain have thicker tendon than do MWUs with RC tendinopathy; and (3) a significant Group × Position interaction was found for AHD measures when comparing MWUs with SCI with able-bodied individuals (greater AHD at the end of the push phase for MWUs with SCI). A thicker tendon and a higher occupation ratio were also found in MWUs with SCI than in able-bodied individuals. Conclusions Ultrasonography is a reliable technology to evaluate AHD in MWUs in shoulder positions linked to wheelchair propulsion. Supraspinatus tendon thickness and occupation ratio of AHD adequately discriminate between MWUs with SCI and able-bodied individuals. This shows that these ultrasonographic measures can be used in future studies of populations with SCI to better understand the changes at the shoulder joint in MWUs.

The commercially available SmartWheelTM is largely used in research and increasingly used in clinical practice to measure the forces and moments applied on the wheelchair pushrims by the user. However, in some situations (i.e. cambered wheels or increased pushrim weight), the recorded kinetics may include dynamic offsets that affect the accuracy of the measurements. In this work, an automatic method to identify and cancel these offsets is proposed and tested. First, the method was tested on an experimental bench with different cambers and pushrim weights. Then, the method was generalized to wheelchair propulsion. Nine experienced wheelchair users propelled their own wheelchairs instrumented with two SmartWheels with anti-slip pushrim covers. The dynamic offsets were correctly identified using the propulsion acquisition, without needing a separate baseline acquisition. A kinetic analysis was performed with and without dynamic offset cancellation using the proposed method. The most altered kinetic variables during propulsion were the vertical and total forces, with errors of up to 9N (p

The aim of this study was to compare cardiorespiratory demand during manual wheelchair (MWC) propulsion among MWC users with a spinal cord injury (SCI) in a natural environment with and without the use of a trained mobility assistance dog (MAD).In this quasi-experimental repeated-measures analysis of difference, 13 experienced MWC users with an SCI propelled themselves with and without their trained MAD at a self-selected natural speed along a standardized 630-m course in a natural environment. Participants were equipped with a portable gas analyzer to measure their oxygen consumption, ventilation, tidal volume, respiratory quotient, respiratory rate, and heart rate before, during, and after completing the course. Participants also rated their perceived exertion on a modified Borg scale following each trial.All cardiorespiratory outcome measures decreased significantly with the use of a MAD (P ≤ 0.013; mean difference, -9% to -38%). Furthermore, most participants completed the course significantly faster (P ≤ 0.001; mean difference, -34%), while reporting considerably lower perceived exertion rates (P = 0.007; mean difference, -65%).A trained MAD decreases cardiorespiratory demand and rate of perceived exertion during MWC propulsion on a 630-m course among experienced MWC users with SCI. Trained MADs represent a valuable mobility assistive technology option for MWC users.

Seated postural stability has not been studied extensively in individuals with spinal cord injury (SCI). The main purpose of this study was to compare the effects of upper limb (U/L) positions and U/L weight support roles on quasi-static postural stability between individuals with SCI and healthy controls. Fourteen individuals with SCI and 14 healthy controls sat on an instrumented seat with their feet resting on force plates and randomly maintained five short-sitting positions for 60s with or without hand support. Center-of-pressure (COP) measures based on displacement and frequency series were computed. Individuals with SCI exhibited greater mean COP displacement and velocity measures compared to healthy controls, as well as lower COP frequency measures, irrespective of the U/L positions and weight support roles, confirming reduced stability and a difference in preferential postural regulation strategies. The use of U/L support is a compensatory strategy that influences seated stability in individuals with SCI.

Dynamic stability requirements have never been quantified when long-term manual wheelchair users transfer themselves in a seated position from an initial surface to a target surface, a functional task commonly referred to as sitting pivot transfers (SPTs). Ten individuals with spinal cord injury (SCI), who rely on a manual wheelchair for mobility, underwent a comprehensive biomechanical SPT assessment. SPTs performed toward a target seat of same height (even) and a seat 10cm higher than the initial seat (uneven), repeated three times for each task, were assessed. A dynamic equilibrium model, continuously measuring the theoretical forces required to move the center of pressure to the limit of the base of support (destabilizing force) and to neutralize the kinetic energy and stop the displacement of the center of mass at the limit of the base of support (stabilizing force) at each instance during the performance of SPTs, was used to identify the phases of greatest instability during the SPT tasks. The greatest levels of instability were reached around the time the buttocks lost contact with the initial seat and around the time the buttocks landed on the target seat (pre- and post-lift transition phases). These transition periods, characterized by the lowest destabilizing force (424.7-487.1N) and the greatest stabilizing force (24.2-33.2N), confirmed the greatest level of instability. The height of the target seat had no significant effect (p=0.278-0.739) on dynamic postural stability requirements during the SPTs. During SPTs towards even and uneven target seats, the greatest postural instability occurs during the transition phases in individuals with complete motor thoracic SCI.

In this study we investigated the reliability of ultrasound in measuring median nerve characteristics including cross-sectional area (CSA), flattening ratio (FR), swelling ratio (SR), and mean grayscale. Generalizability theory was used to assess inter- and intrarater reliability using the dependability coefficient (phi), normalized standard error of measurement, and normalized minimum detectable change (MDC(NORM)) for multiple study design protocols. Interrater reliability was generally moderate. Intrarater reliability was mostly good (phi > 0.876) when using a single image, captured on one occasion, and being read once. Intrarater MDC(NORM) ranged from 3.8% to 6.2% for all CSA measures and SR. Using multiple images and/or readings at multiple occasions did not appreciably improve reliability measures. Ultrasound is a reliable tool for measuring median nerve characteristics. We recommend that a single evaluator capture all images for protocols aimed at quantifying median nerve ultrasound measures. We believe an appropriately designed protocol can utilize ultrasound to accurately assess changes in median nerve characteristics after activity.

Ultrasound is a proven method for examining soft tissue structures, including tendons, and recently quantitative ultrasound has become more prevalent in research settings. However, limited reliability data have been published for these new quantitative ultrasound measures. The main objective of this study was to quantify the reliability and measurement error of multiple quantitative ultrasound imaging protocols for the biceps and supraspinatus tendons.Two examiners captured ultrasound images of the non-dominant long head of the biceps tendon and supraspinatus tendon from 15 able-bodied participants and five manual wheelchair users. Each examiner captured two images per subject under two different preparations, which included subject positioning and reference marker placement. Image processing (reading) was performed twice to compute nine quantitative ultrasound measures of grayscale tendon appearance using first-order statistics and texture analysis. Generalizability theory was applied to compute interrater and intrarater reliability using the coefficient of dependability (Phi) for multiple study design protocols.Interrater reliability was generally low (0.26Phi0.82), and it is recommended that a single evaluator capture all images for quantitative ultrasound protocols. Most of the quantitative ultrasound measures (n = 14 of 18) exhibited at least moderate (Phi0.50) intrarater reliability for a single image captured under one preparation and read once.By following a protocol designed to minimize measurement error, one can increase the reliability of quantitative ultrasound measures. An appropriately designed protocol will allow quantitative ultrasound to be used as an outcome measure to identify structural changes within tendons.