Spinal Cord-injured Individuals Research Articles

Intermittent colonic exoperistalsis for chronic constipation in spinal cord-injured individuals. A long-term structured patient feedback survey to evaluate home care use

Study designStructured patient feedback survey evaluating real-world home care use.ObjectivesTo assess the long-term effectiveness, tolerability, and satisfaction with the intermittent colonic exoperistalsis (ICE) treatment device MOWOOT in spinal cord-injured (SCI) individuals with chronic constipation.SettingFour specialized German hospitals.MethodsSCI individuals with chronic constipation were invited to use MOWOOT 10–20 min daily and answer a questionnaire about their bowel situation before treatment (feedback 1, F1) and after ≥10 months of use (feedback 2, F2). Collected variables were device use, bowel function effectiveness, chronic constipation symptoms, concomitant use of laxatives and evacuation aids, and satisfaction with bowel function and management, which were compared between time points. At F2, participants reported efficacy, tolerability/side effects, and ease of use.ResultsEleven participants used the device for a mean (SD) of 13.27 (4.03) months. From F1 to F2, mean time per evacuation decreased by 24.5 min (p = 0.0076) and the number of failed attempts to evacuate/week, by 1.05 (p = 0.0354) with a tendency toward increased bowel movements and softer stool consistency, and decreased incomplete bowel movements. Participants experienced decreased difficulty/strain (p = 0.0055), abdominal pain (p = 0.0230), bloating (p = 0.0010), abdominal cramps (p = 0.0019), and spasms (p = 0.0198), without significant changes in the use of laxatives and evacuation aids. Satisfaction with bowel function and management improved (p = 0.0095) and more participants reported being very satisfied/satisfied (p = 0.0300). Most reported tolerability, efficacy, and ease of use as very good/good.ConclusionLong-term in-home ICE treatment improved bowel function and chronic constipation symptoms in SCI individuals, providing clinical benefits to this population.Sponsorship (MOWOOT devices lending)4 M Medical GmbH, Norderstedt, Germany.

Differential Corticospinal Excitability and Cortical Functional Connectivity Modulation by Spinal Cord Transcutaneous Stimulation-based Motor Training versus Motor Training alone in Able-bodied and SCI participants: A Multiple Case Study.

Spinal cord transcutaneous stimulation (scTS) has shown its potential for boosting motor, sensory, and autonomic function recovery after a spinal cord injury. Despite the demonstrated benefits, little is known about the exact neuromodulatory mechanisms triggered by scTS and the cortex involvement in the beneficial effects observed. Here, we examine the effects of scTS-based motor training and motor training alone on sensorimotor cortical functional connectivity and corticospinal excitability in able-bodied and SCI participants.Clinical Relevance- The results show preliminary evidence of differential cortical involvement and modulation by scTS-based motor training in uninjured and spinal-cord injured individuals. A better understanding of scTS mechanisms of action could help optimize the intervention design and potentiate its benefits.

A novel reflex analysis of healthy and spinal cord-injured individuals

Abstract Spinal cord injury (SCI) has a drastic effect on the quality of life of those affected. There is thus a great need for new knowledge that may increase their quality of life. The goal of this research was to develop and set up a measurement system for exact measurements of times between events in a patellar reflex test and a transcutaneous spinal cord stimulation (tSCS) and compare the two in healthy and spinal cord-injured individuals. 21 individuals with a healthy nervous system and 2 spinal cord-injured individuals were subjected to the patellar reflex test and tSCS. The patellar reflex of one individual with a complete SCI at vertebras C6-C7 after an accident was delayed by 24% compared with the healthy subjects, while the reflex time of the other SCI individual, who had cancer in vertebra T3, was shortened by 23%. There was also a difference in the reflex between the patellar reflex test and the tSCS due to action potential conduction distance. In this study, a processing method was created for comparing muscle signals generated by patellar strikes or electrical stimulation to the posterior nerve roots. Data from the subjects with central nervous system lesions showed characteristic differences from reference data.

Brain activity and event-related potential analysis in healthy and spinal cord-injured individuals

Article Brain activity and event-related potential analysis in healthy and spinal cord-injured individuals was published on August 1, 2022 in the journal Current Directions in Biomedical Engineering (volume 8, issue 2).

EEG Monitoring Is Feasible and Reliable during Simultaneous Transcutaneous Electrical Spinal Cord Stimulation.

Transcutaneous electrical spinal cord stimulation (tSCS) is a non-invasive neuromodulatory technique that has in recent years been linked to improved volitional limb control in spinal-cord injured individuals. Although the technique is growing in popularity there is still uncertainty regarding the neural mechanisms underpinning sensory and motor recovery. Brain monitoring techniques such as electroencephalography (EEG) may provide further insights to the changes in coritcospinal excitability that have already been demonstrated using other techniques. It is unknown, however, whether intelligible EEG can be extracted while tSCS is being applied, owing to substantial high-amplitude artifacts associated with stimulation-based therapies. Here, for the first time, we characterise the artifacts that manifest in EEG when recorded simultaneously with tSCS. We recorded multi-channel EEG from 21 healthy volunteers as they took part in a resting state and movement task across two sessions: One with tSCS delivered to the cervical region of the neck, and one without tSCS. An offline analysis in the time and frequency domain showed that tSCS manifested as narrow, high-amplitude peaks with a spectral density contained at the stimulation frequency. We quantified the altered signals with descriptive statistics—kurtosis, root-mean-square, complexity, and zero crossings—and applied artifact-suppression techniques—superposition of moving averages, adaptive, median, and notch filtering—to explore whether the effects of tSCS could be suppressed. We found that the superposition of moving averages filter was the most successful technique at returning contaminated EEG to levels statistically similar to that of normal EEG. In the frequency domain, however, notch filtering was more effective at reducing the spectral power contribution of stimulation from frontal and central electrodes. An adaptive filter was more appropriate for channels closer to the stimulation site. Lastly, we found that tSCS posed no detriment the binary classification of upper-limb movements from sensorimotor rhythms, and that adaptive filtering resulted in poorer classification performance. Overall, we showed that, depending on the analysis, EEG monitoring during transcutaneous electrical spinal cord stimulation is feasible. This study supports future investigations using EEG to study the activity of the sensorimotor cortex during tSCS, and potentially paves the way to brain–computer interfaces operating in the presence of spinal stimulation.

Effects of NMES pulse width and intensity on muscle mechanical output and oxygen extraction in able-bodied and paraplegic individuals.

Neuromuscular Electrical Stimulation (NMES) is commonly used in neuromuscular rehabilitation protocols, and its parameters selection substantially affects the characteristics of muscle activation. Here, we investigated the effects of short pulse width (200µs) and higher intensity (short-high) NMES or long pulse width (1000µs) and lower intensity (long-low) NMES on muscle mechanical output and fractional oxygen extraction. Muscle contractions were elicited with 100Hz stimulation frequency, and the initial torque output was matched by adjusting stimulation intensity. Fourteen able-bodied and six spinal cord-injured (SCI) individuals participated in the study. The NMES protocol (75 isometric contractions, 1-s on-3-s off) targeting the knee extensors was performed with long-low or short-high NMES applied over the midline between anterior superior iliac spine and patella protrusion in two different days. Muscle work was estimated by torque-time integral, contractile properties by rate of torque development and half-relaxation time, and vastus lateralis fractional oxygen extraction was assessed by Near-Infrared Spectroscopy (NIRS). Torque-time integral elicited by the two NMES paradigms was similar throughout the stimulation protocol, with differences ranging between 1.4% (p = 0.877; able-bodied, mid-part of the protocol) and 9.9% (p = 0.147; SCI, mid-part of the protocol). Contractile properties were also comparable in the two NMES paradigms. However, long-low NMES resulted in higher fractional oxygen extraction in able-bodied (+ 36%; p = 0.006). Long-low and short-high NMES recruited quadriceps femoris motor units that demonstrated similar contractile and fatigability properties. However, long-low NMES conceivably resulted in the preferential recruitment of vastus lateralis muscle fibers as detected by NIRS.

Mechanomyography-based assessment during repetitive sit-to-stand and stand-to-sit in two incomplete spinal cord-injured individuals

Standing up and sitting down movements are important prerequisites to achieve functional independence in everyday life of spinal cord injury (SCI) patients. Thus, mechanomyography (MMG) was proposed as a safe monitoring tool to evaluate muscle function performance of these activities. Two incomplete SCI participants performed repetitive sit-to-stand (SitTS) and stand-to-sit (StandTS) until fatigued challenge. Three sets of these activities were completed with MMG sensors attached over the quadriceps muscles of both legs. A 5-min rest was allocated between each set, totalling 399 trials of SitTS and StandTS activities. There was a significant difference between MMG's mean root mean square maximum (RMSmax) in SitTS and StandTS activities (p = 0.014). The mean values of RMSmax and root mean square average (RMSave) on the right leg were detected to be significantly higher compared to those of the left leg during these activities (p < 0.05). In the frequency domain, MMG's mean power frequency (MPF) proved to be significantly higher at the beginning compared to the end of the three sets of both activities (p = 0.000). These muscle performances during both activities can be verified based on the analysis of MMG behaviour in time and frequency domains. Furthermore, this study indicated that MMG can be used as a monitoring tool to identify muscle fatigue throughout a prolonged event.

Effects of intensity-matched exercise at different intensities on inflammatory responses in able-bodied and spinal cord injured individuals

Objective: To compare the effects of intensity-matched acute exercise at different intensities on proinflammatory and anti-inflammatory cytokines between able-bodied (AB) and spinal cord injured (SCI) individuals. Design: Non-Randomized Controlled Trial. Setting: Community settings in São Paulo – Brazil. Participants: Eight AB and nine SCI paraplegic. Interventions: Participants underwent three exercise sessions at different relative intensities: at ventilatory threshold 1 intensity (VT1), 15% below VT1, and 15% above VT1. Similar energy expenditures were established from exercises with different intensities for each volunteer. The AB group was tested on a conventional treadmill, whereas the SCI group was tested on a treadmill adapted for wheelchair use. Blood samples were collected at baseline, immediately after, and 30 min after the exercise sessions. Outcome measures: Interleukin 1 receptor antagonist, interleukin 1 beta, interleukin 2, interleukin 4, interleukin 6, interleukin 10 and tumoral necrosis factor alpha were measured. Results: When groups were compared, interleukin – 2 was found higher, whereas interleukin – 4 and interleukin – 10 were found lower in the SCI group at all collection times in the three exercise intensities (all P < 0.05). Interleukin – 1 receptor antagonist was found higher immediately after exercise at VT1, 15% above VT1 and 30 min after 15% below VT1 in the AB group (all P < 0.05). In the AB group, an increase in interleukin – 6 immediately after the exercise at VT1 compared with baseline was found (P = 0.01). Conclusion: Individuals with SCI may have to perform physical exercise at a higher volume or energy expenditure than AB individuals to obtain similar anti-inflammatory benefits of acute exercise. Trial registration: Uniform Trial Number identifier: U1111-1232-8142.

ORTHOPEDIC RELATED COMORBIDITIES IN SPINAL CORD-INJURED INDIVIDUALS.

ABSTRACTObjective: This study aims to review, identify and study the determinations of the main orthopedic aspects in SCI patients.Methods: A total of 80 articles from PUBMED and three theses (MSc. /DSc.) were examined.Results: The results refer to the most essential joints. There is a chronic overload on the shoulder girdle due to the use of the upper limb as a supporting joint. The elbow presents osteoarthritis, subclinical, acute and chronic pain, mainly in quadriplegic patients. In the hand and wrist joints there are cases of paralysis, osteoporosis and osteoarthritis. Hips are the main weight-bearing joints while sitting which leads to a substantial degenerative process of this joint. Lastly, on the knee, feet and ankles, spasticity, contractures, osteoporosis and deformities can arise.Conclusion: Along with the increase in cases and research that analyze the alterations that spinal cord-injured individuals suffer, it is necessary to recognize the orthopedic changes to understand their limits and identify the relevance of the rehabilitation program to improve the muscle performance. Level of Evidence II, Prognostic Studies - Investigating the Effect of a Patient Characteristic on the Outcome of Disease.

Association of Ambulatory Ability on Complications and Medical Costs in Patients with Traumatic Spinal Cord Injury: A Decision-analytic Model.

Purpose The objective of this study was to determine the independent association of ambulatory ability with complications and medical costs in patients with spinal cord injury (SCI).MethodsPatients with SCI between T1-T12 enrolled in the National Spinal Cord Injury Database (NSCID) provided a minimum one-year follow-up. Covariate-adjusted annual rates of important medical complications (pressure sore, urinary tract infection, hospitalization) and associated medical costs were determined over five years post-injury. ResultsA total of 1,753 patients provided data at one-year follow-up and 1,340 patients provided five-year data. At one-year post-injury, 82% of patients were non-ambulatory and 18% were ambulatory. After adjusting for important covariates, ambulatory status was associated with a lower annual probability of urinary tract infection (43% vs. 68%), pressure sore (12% vs. 35%), and hospitalization (23% vs. 34%). Covariate-adjusted base-case medical costs due to urinary tract infection, pressure sore, and hospitalization were 34% lower in ambulatory vs. non-ambulatory patients ($31,358 vs. $47,266) over five years. Probabilistic sensitivity analyses confirmed the base-case results.ConclusionIn spinal cord-injured individuals, the ability to ambulate is independently associated with lower complication risks and associated medical costs over the five-year period following injury. Long-term clinical benefit and cost savings may be realized with assisted or unassisted ambulation in spinal cord-injured patients.

Embodying their own wheelchair modifies extrapersonal space perception in people with spinal cord injury.

Despite the many links between body representation, acting and perceiving the environment, no research has to date explored whether specific tool embodiment in conditions of sensorimotor deprivation influences extrapersonal space perception. We tested 20 spinal cord injured (SCI) individuals to investigate whether specific wheelchair embodiment interacts with extrapersonal space representation. As a measure of wheelchair embodiment, we used a Body View Enhancement Task in which participants (either sitting in their own wheelchair or in one which they had never used before) were asked to respond promptly to flashing lights presented on their above- and below-lesion body parts. Similar or slower reaction times (RT) to stimuli on the body and wheelchair indicate, respectively, the presence or absence of tool embodiment. The RTs showed that the participants embodied their own wheelchair but not the other one. Moreover, they coded their deprived lower limbs as external objects and, when not in their own wheelchair, also showed disownership of their intact upper limbs. To measure extrapersonal space perception, we used a novel, ad hoc designed paradigm in which the participants were asked to observe a 3D scenario by means of immersive virtual reality and estimate the distance of a flag positioned on a ramp. In healthy subjects, errors in estimation increased as the distance increased, suggesting that they mentally represent the physical distance. The same occurred with the SCI participants, but only when they were in their own wheelchair. The results demonstrate for the first time that tool embodiment modifies extrapersonal space estimations.

Effects of the Computer Desk Level on the Musculoskeletal Discomfort of Neck and Upper Extremities and EMG Activities in Patients with Spinal Cord Injuries.

Background Computers are used as a means of social communication, for work and other purposes. However, patients with spinal cord injuries may have a higher risk than normal individuals with musculoskeletal problems when using computers owing to their inability to control respective postures due to problems in motor and sensory functioning. Objectives This study is aimed at identifying the effect of computer desk heights on musculoskeletal discomforts of the neck and upper extremities and EMG activities in patients with spinal cord (C6) and upper thoracic spinal cord injuries. Methods Participants of the present study were the patients diagnosed with ASIA A or B. The patients were divided into two groups according to their spinal cord injuries: C6 group and T2-T6 group. The level of the desk was set at 5 cm below the elbow, at the elbow level, and 5 cm above the elbow level. Electromyography was used to measure the duration of typing task EMG(%RVC) of the cervical erector spinae, upper trapezius, anterior deltoid, and wrist extensor. Subjective musculoskeletal discomfort (Borg-RPE) was measured at the end of the experiment. Results The two groups showed differences in terms of RPE corresponding to each level of the computer desk (p < .05). Postanalysis revealed the C6 group had decreased RPE as the level of computer desk increased, whereas the subjects in the T2-T6 group had decreased RPE values in accordance with the decreasing level of computer desk (p < .05). In EMG, both groups had no significant differences (p > .05). However, in terms of the interaction between the muscles and the level of computer desk in both groups, the differences in the interactions of the upper trapezius and wrist extensor with each level of the desk were found (p < .05). Conclusion This study is meaningful in that it confirms computer work posture and preference of spinal cord-injured individuals.

Functional Selectivity of Lumbosacral Stimulation: Methodological Approach and Pilot Study to Assess Visceral Function in Pigs.

Nearly all spinal cord injured (SCI) individuals lose bladder control and are prone to kidney complications if intermittent catheterization is not applied. Electrical stimulation of the sacral anterior roots with an implantable neuroprosthesis is one means to restore continence and control micturition. However, only a small percentage of the SCI population benefits from this solution because of its drawbacks, e.g., section of sacral posterior roots with loss of spared sensitivity. There has been renewed interest in spinal cord stimulation in recent years, but most studies have focused on locomotion and only few have reported the impact on visceral functions. Moreover, even though the lumbosacral spinal cord is the location of many pre-cabled neural networks (involved in locomotion, bladder, and bowel management), the functional selectivity of spinal stimulations has never been investigated in detail. Here, we present: 1) a methodology designed to study lumbosacral epispinal-intradural stimulation selectivity; 2) preliminary results assessing the impact of epispinal stimulation on bladder and bowel functions in two domestic pigs; and 3) a comparison of these visceral responses with abdominal and lower limb activities. Our experiments resulted in selective bladder and rectal responses, i.e., without hind paw responses, thus reaffirming the rehabilitation potential of spinal cord stimulation.

Characteristics of cardiovascular responses to an orthostatic challenge in trained spinal cord-injured individuals

BackgroundWe investigated cardiovascular responses to an orthostatic challenge in trained spinal cord-injured (SCI) individuals compared to able-bodied (AB) individuals.MethodsA total of 23 subjects participated, divided into three groups: seven were trained as spinal cord-injured (Tr-SCI) individuals, seven were able-bodied individuals trained as runners (Tr-AB), and nine were untrained able-bodied individuals (UnTr-AB). We measured the cardiovascular autonomic responses in all three groups during each 5-min head-up tilt (HUT) of 0°, 40°, and 80°. Stroke volume (SV), heart rate (HR), and cardiac output (Qc) as cardiovascular responses were measured by impedance cardiography. Changes in deoxyhemoglobin (∆[HHb]) and total hemoglobin (∆[Hbtot]) concentrations of the right medial gastrocnemius muscle were measured using near-infrared spectroscopy (NIRS).ResultsAs the HUT increased from 0° to 80°, Tr-SCI group showed less change in SV at all HUT levels even if HR increased significantly. Mean arterial pressure (MAP) also did not significantly increase as tilting increased from 0° to 80°. Regarding peripheral vascular responses, the alterations of ∆[Hbtot] from 0° to 80° were less in Tr-SCI group compared to AB individuals.ConclusionThere is a specific mechanism whereby blood pressure is maintained during a HUT in Tr-SCI group with the elicitation of peripheral vasoconstriction and the atrophy of the vascular vessels in paraplegic lower limbs, which would be associated with less change in SV in response to an orthostatic challenge.

Neural Network-Based Muscle Torque Estimation Using Mechanomyography During Electrically-Evoked Knee Extension and Standing in Spinal Cord Injury.

This study sought to design and deploy a torque monitoring system using an artificial neural network (ANN) with mechanomyography (MMG) for situations where muscle torque cannot be independently quantified. The MMG signals from the quadriceps were used to derive knee torque during prolonged functional electrical stimulation (FES)-assisted isometric knee extensions and during standing in spinal cord injured (SCI) individuals. Three individuals with motor-complete SCI performed FES-evoked isometric quadriceps contractions on a Biodex dynamometer at 30° knee angle and at a fixed stimulation current, until the torque had declined to a minimum required for ANN model development. Two ANN models were developed based on different inputs; Root mean square (RMS) MMG and RMS-Zero crossing (ZC) which were derived from MMG. The performance of the ANN was evaluated by comparing model predicted torque against the actual torque derived from the dynamometer. MMG data from 5 other individuals with SCI who performed FES-evoked standing to fatigue-failure were used to validate the RMS and RMS-ZC ANN models. RMS and RMS-ZC of the MMG obtained from the FES standing experiments were then provided as inputs to the developed ANN models to calculate the predicted torque during the FES-evoked standing. The average correlation between the knee extension-predicted torque and the actual torque outputs were 0.87 ± 0.11 for RMS and 0.84 ± 0.13 for RMS-ZC. The average accuracy was 79 ± 14% for RMS and 86 ± 11% for RMS-ZC. The two models revealed significant trends in torque decrease, both suggesting a critical point around 50% torque drop where there were significant changes observed in RMS and RMS-ZC patterns. Based on these findings, both RMS and RMS-ZC ANN models performed similarly well in predicting FES-evoked knee extension torques in this population. However, interference was observed in the RMS-ZC values at a time around knee buckling. The developed ANN models could be used to estimate muscle torque in real-time, thereby providing safer automated FES control of standing in persons with motor-complete SCI.

Do spinal cord-injured individuals with stronger sense of coherence use different psychological defense styles?

Although the importance of sense of coherence (SOC) and psychological defense mechanisms (PDMs) in the process of coping has been demonstrated, it has not yet been clarified whether individuals with stronger SOC use specific PDMs. Demographic and injury-related variables including injury level, time since injury, American Spinal Cord Association (ASIA) Scale and Spinal cord independence measure-III were collected among individuals with spinal cord injury (SCI). SOC was assessed by the Short-form Sense of Coherence Scale. PDMs were identified using 40-version of the Defense Style Questionnaire. Neurotic defense style was the most commonly used style especially. The overall most commonly used PDM was ‘rationalization’, which was used by 95%. Individuals with stronger SOC used more mature style ( P = 0.001, r = 0.52), particularly ‘humor’ and ‘suppression’ mechanisms (Po0.0001 and 0.024, respectively). There was a negative correlation between stronger SOC and the use of immature defenses including passive aggression ( P = 0.001, r = −0.51), acting out ( P = 0.001, r = −0.48), isolation ( P = 0.009, r = −0.50), autistic fantasy ( P = 0.010, r = −0.30) and somatization (Po0.0001, r = −0.62). Married individuals had significantly stronger SOC ( P = 0.01). Age, gender, age at the time of injury incidence, time since injury, ASIA score and cause of injury were not determinants of SOC. In this study, PDMs, which are more probable to be used by individuals with stronger SOC, have been identified. Mature defenses including ‘humor’ and ‘suppression’ are used by stronger SOC more often, whereas immature mechanisms are less likely to be used.

Retained differentiation capacity of human skeletal muscle satellite cells from spinal cord-injured individuals.

Despite the well‐known role of satellite cells in skeletal muscle plasticity, the effect of spinal cord injury on their function in humans remains unknown. We determined whether spinal cord injury affects the intrinsic ability of satellite cells to differentiate and produce metabolically healthy myotubes. We obtained vastus lateralis biopsies from eight spinal cord‐injured and six able‐bodied individuals. Satellite cells were isolated, grown and differentiated in vitro. Gene expression was measured by quantitative PCR. Abundance of differentiation markers and regulatory proteins was determined by Western blotting. Protein synthesis and fatty acid oxidation were measured by radioactive tracer‐based assays. Activated satellite cells (myoblasts) and differentiated myotubes derived from skeletal muscle of able‐bodied and spinal cord‐injured individuals expressed similar (P > 0.05) mRNA levels of myogenic regulatory factors. Myogenic differentiation factor 1 expression was higher in myoblasts from spinal cord‐injured individuals. Desmin and myogenin protein content was increased upon differentiation in both groups, while myotubes from spinal cord‐injured individuals contained more type I and II myosin heavy chain. Phosphorylated and total protein levels of Akt‐mechanistic target of rapamycin and forkhead box protein O signalling axes and protein synthesis rate in myotubes were similar (P > 0.05) between groups. Additionally, fatty acid oxidation of myotubes from spinal cord‐injured individuals was unchanged (P > 0.05) compared to able‐bodied controls. Our results indicate that the intrinsic differentiation capacity of satellite cells and metabolic characteristics of myotubes are preserved following spinal cord injury. This may inform potential interventions targeting satellite cell activation to alleviate skeletal muscle atrophy.

An Examination of Affective Change in the Absence of Physical Sensation

Examination of affective responses to acute exercise has been plagued by the inability to find an appropriate control condition, as a true placebo has been elusive. This has resulted in various “control” conditions (e.g., quiet rest, reading, sitting in a chair on a treadmill, stretching). A potential option involves passive cycling. This would also provide a unique methodology for studying affective responses to activity in spinal cord injured (SCI) individuals. PURPOSE: To examine the psychological and physiological effects of Passive (PaC) versus Placebo cycling (PLC), both compared to Rest, in SCI individuals. METHODS: Heart rate (HR), Rating of Perceived Exertion (RPE), and affect (Calmness, Tension, Energy, Tiredness, State Anxiety) were recorded in 21 (11 male; 27 ± 6.52 yrs; M ± SD) participants before, during and after each Rest, PaC, and PLC 25-min bout. Each cycling session consisted of identically paced warm-ups (5-min @ 35 r·min-1), movement bout (15-min @ 60 r·min-1), and cool-down (5-min @ 35 r·min-1). RESULTS: PaC elicited psychological changes that varied significantly with respect to perceptions of Energy and Calmness, but not valenced (i.e., positive, negative) affect. Energy increased from Pre to Post-0 exercise (P= 0.024), then decreased Post-0 to Post-10 (P= 0.002). Enjoyment was greater following PaC relative to PLC (Mdiff= 8.29, P= 0.06) and Rest (Mdiff= 9.33, P=0.001). RPE was significantly higher during the PaC (M= 7.05±0.70) compared to both Rest (M= 6.11±0.08; P<0. 001) and PLC (M= 6.32±0.05; P< 0.001). There were no significant effects on physiological factors such as HR or Temperature across conditions. CONCLUSION: These results provide support for this methodological technique as a way of examining potential placebo effects of activity on affective outcomes. This also provides insights into how activity may influence affective responses in individuals with a SCI.

Motor recovery after activity-based training with spinal cord epidural stimulation in a chronic motor complete paraplegic

The prognosis for recovery of motor function in motor complete spinal cord injured (SCI) individuals is poor. Our research team has demonstrated that lumbosacral spinal cord epidural stimulation (scES) and activity-based training can progressively promote the recovery of volitional leg movements and standing in individuals with chronic clinically complete SCI. However, scES was required to perform these motor tasks. Herein, we show the progressive recovery of voluntary leg movement and standing without scES in an individual with chronic, motor complete SCI throughout 3.7 years of activity-based interventions utilizing scES configurations customized for the different motor tasks that were specifically trained (standing, stepping, volitional leg movement). In particular, this report details the ongoing neural adaptations that allowed a functional progression from no volitional muscle activation to a refined, task-specific activation pattern and movement generation during volitional attempts without scES. Similarly, we observed the re-emergence of muscle activation patterns sufficient for standing with independent knee and hip extension. These findings highlight the recovery potential of the human nervous system after chronic clinically motor complete SCI.

Experimental Protocol of a Three-minute, All-out Arm Crank Exercise Test in Spinal-cord Injured and Able-bodied Individuals.

Reliable exercise protocols are required to test changes in exercise performance in elite athletes. Performance improvements in these athletes may be small; therefore, sensitive tools are fundamental to exercise physiology. There are currently many exercise tests that allow for the examination of exercise capacity in able-bodied athletes, with protocols mainly for lower-body or whole-body exercise. There is a trend to test athletes in a sport-specific setting that closely resembles the actions that the participants are used to performing. Only a few protocols test short-term, high-intensity exercise capacity in participants with an impairment of the lower body. Most of these protocols are very sport-specific and are not applicable to a wide range of athletes. One well-known test protocol is the 30 s Wingate test, which is well-established in cycling and in arm crank exercise testing. This test analyzes high-intensity exercise performance over a 30 s time duration. In order to monitor exercise performance over a longer duration, a different method was modified for application to the upper body. The 3 min, all-out arm crank ergometer test allows athletes to be tested in a manner specific to 1,500 m wheelchair racing (in terms of exercise duration), as well as to upper body exercises such as rowing or hand-cycling. In order to increase the reliability with identical test conditions, it is crucial to precisely replicate settings such as the resistance (i.e., torque factor) and the position of the participants (i.e., the height of the crank, the distance between the crank and the participant, and the fixation of the participant). Another important issue concerns the beginning of the exercise test. Fixed revolutions per minute are required to standardize the test conditions for the start of the exercise test. This exercise protocol shows the importance of accurate operations to reproduce identical test conditions and settings.