Modular control of gait after incomplete spinal cord injury: differences between sides.

STUDY DESIGN: This is an analytical descriptive study. OBJECTIVES: The main goal of this study was to compare the modular organization of bilateral lower limb control in incomplete spinal cord injury (iSCI) patients during overground walking, using muscle synergies analysis. The secondary goal was to determine whether the similarity between the patients and control group correlate with clinical indicators of walking performance. SETTING: This study was conducted in National Hospital for Spinal Cord Injury (Toledo, Spain). METHODS: Eight iSCI patients and eight healthy subjects completed 10 walking trials at matched speed. For each trial, three-dimensional motion analysis and surface electromyography (sEMG) analysis of seven leg muscles from both limbs were performed. Muscle synergies were extracted from sEMG signals using a non-negative matrix factorization algorithm. The optimal number of synergies has been defined as the minimum number needed to obtain variability accounted for (VAF) ⩾90%. RESULTS: When compared with healthy references, iSCI patients showed fewer muscle synergies in the most affected side and, in both sides, significant differences in the composition of synergy 2. The degree of similarity of these variables with the healthy reference, together with the composition of synergy 3 of the most affected side, presented significant correlations (P<0.05) with walking performance. CONCLUSION: The analysis of muscle synergies shows potential to detect differences between the two sides in patients with iSCI. Specifically, the VAF may constitute a new neurophysiological metric to assess and monitor patients' condition throughout the gait recovery process.

Shoulder kinetics and ultrasonography changes after performing a high-intensity task in spinal cord injury subjects and healthy controls.

This corrects the article DOI: 10.1038/sc.2015.140.

Diagnostic reference levels and complexity indices in interventional radiology: a national programme.

OBJECTIVES: To propose national diagnostic reference levels (DRLs) for interventional radiology and to evaluate the impact of the procedural complexity on patient doses. METHODS: Eight interventional radiology units from Spanish hospitals were involved in this project. The participants agreed to undergo common quality control procedures for X-ray systems. Kerma area product (KAP) was collected from a sample of 1,649 procedures. A consensus document established the criteria to evaluate the complexity of seven types of procedures. DRLs were set as the 3rd quartile of KAP values. RESULTS: The KAP (3rd quartile) in Gy cm2 for the procedures included in the survey were: lower extremity arteriography (n = 784) 78; renal arteriography (n = 37) 107; transjugular hepatic biopsies (THB) (n = 30) 45; biliary drainage (BD) (n = 314) 30; uterine fibroid embolization (UFE) (n = 56) 214; colon endoprostheses (CE) (n = 31) 169; hepatic chemoembolization (HC) (n = 269) 303; femoropopliteal revascularization (FR) (n = 62) 119; and iliac stent (n = 66) 170. The complexity involved the increases in the following KAP factors from simple to complex procedures: THB x4; BD x13; UFE x3; CE x3; HC x5; FR x5 and IS x4. CONCLUSIONS: The evaluation of the procedure complexity in patient doses will allow the proper use of DRLs for the optimization of interventional radiology. KEY POINTS: • National DRLs for interventional procedures have been proposed given level of complexity • For clinical audits, the level of complexity should be taken into account. • An evaluation of the complexity levels of the procedure should be made.

Shoulder kinetics and ultrasonography changes after performing a high-intensity task in spinal cord injury subjects and healthy controls.

STUDY DESIGN: This is a prospective and comparative study between two groups. OBJECTIVES: The objective of this study was to compare the changes in shoulder joint forces and their moments, as well as any possible ultrasound changes, when subjects with spinal cord injury (SCI) and healthy controls (CG) undertake a high-intensity manual wheelchair propulsion test. SETTING: This study was conducted in an inpatient SCI rehabilitation center. METHODS: A group of 22 subjects with SCI at level T2 or below who use a manual wheelchair (MWU), categorized as AIS grade A or B, were compared with a CG of 12 healthy subjects. Subjects in each group performed a high-intensity wheelchair propulsion test. The variables analyzed were shoulder joint forces and the moments at the beginning and at the end of the test. Ultrasound variables before and after the propulsion test were also analyzed. Correlations were also drawn between the ultrasonography and demographic variables. RESULTS: In both groups, peak shoulder forces and moments increased after the test in almost all directions. No differences in the ultrasound parameters were found. A greater long-axis biceps tendon thickness (LBTT) was associated with more shoulder pain according to WUSPI or VAS (r=0.428, P<0.05 and r=0.452, P<0.05, respectively). CONCLUSIONS: Shoulder joint forces and moments increase after an intense propulsion task. In subjects with SCI, these increases center on forces with less chance of producing subacromial damage. No changes are produced in ultrasonography variables, whereas a poorer clinical and functional evaluation of the shoulder of the MWUs appears to be related to a thicker long-axis biceps tendon.

The Impact of Robotic Therapy on the Self-Perception of Upper Limb Function in Cervical Spinal Cord Injury: A Pilot Randomized Controlled Trial.

BACKGROUND: The aim of the present study was to evaluate the impact of robotic therapy in patients with cervical spinal cord injury (SCI), measured on the basis of the patients' self-perception of limited upper limb function and level of independence in activities of daily living. METHODS: Twenty-six patients with cervical SCI completed the treatment after being randomly assigned to the intervention or control group. The training consisted of 40 experimental sessions 1 h in duration, ideally occurring 5 days/week for 8 weeks. In addition to the conventional daily therapy (30 min), the control group received another 30 min of conventional therapy, whereas the intervention group received 30 min of robotic therapy. Patients were evaluated by means of the Capabilities of Upper Extremity Questionnaire (CUE) and Spinal Cord Independence Measure (SCIM) clinical scales. RESULTS: The improvement in the feeding item of SCIM was significantly higher in the intervention group than in the control group after the treatment (2.00 (0.91) vs. 1.18 (0.89), p = 0.03). The correlation between the CUE and SCIM scales was higher at the ending than at baseline for both groups. CONCLUSIONS: Although both groups improved, the clinical relevance related to the changes observed for both assessments was slightly higher in the intervention group than in the control group.

Effects of whole-body vibration on blood flow and neuromuscular activity in spinal cord injury.

STUDY DESIGN: Crossover trial. OBJECTIVES: To investigate the effects of whole-body vibration (WBV) on muscular activity and blood flow velocity after different vibration treatments in patients with spinal cord injury (SCI). SETTING: Research Center on Physical Disability (Spain). METHODS: Eight individuals with SCI received six 3-min WBV treatments depending on a combination of frequency (10, 20 or 30 Hz) and protocol (constant, that is, three consecutive minutes of WBV, or fragmented, that is, three sets of 1 min of WBV with 1 min of rest between the sets). Femoral artery blood flow velocity was registered at minutes 1, 2 and 3 of WBV, and at minutes 1 and 2 after the end of the stimulus. Electromyography activity (EMG) of vastus lateralis (VL) and vastus medialis (VM) was registered at baseline and during WBV. RESULTS: Peak blood velocity (PBV) increased after 1, 2 and 3 min of WBV. The 10 Hz frequency did not alter blood flow, whereas the 20 Hz frequency increased PBV after 2 and 3 min of WBV, and the 30 Hz frequency increased PBV after 1, 2 and 3 min of WBV and during the first minute after the end of the stimulus. No protocol effect was observed for blood parameters. EMG activity of VL and VM increased independently of the applied frequency or protocol. CONCLUSION: WBV is an effective method to increase leg blood flow and to activate muscle mass in SCI patients, and could be considered to be incorporated in their rehabilitation programs.

Shoulder joint kinetics during wheelchair propulsion on a treadmill at two different speeds in spinal cord injury patients.

STUDY DESIGN: Prospective study using biomechanics patient data. OBJECTIVES: To analyze shoulder joint kinetics while propelling a wheelchair placed on a treadmill and compare shoulder joint net forces and moments when changing the speed of wheelchair propulsion on the treadmill. SETTING: National Hospital for Spinal Cord Injury, Toledo, Spain. METHODS: Sixteen subjects with thoracic spinal cord injury participated. A kinematic analysis system consisting of four camcorders (Kinescan-IBV) and a kinetic device that registered the contact force of the hand on the pushrim (SMART(Wheel)) were used. The wheelchair was propelled at 3 and 4 km h(-1) without any ramp. An inverse dynamic model allowed shoulder joint net forces and moments to be calculated from the contact force of the hand on the pushrim and kinematic data. RESULTS: Increasing propulsion speed increased most of the temporal parameters of propulsion and pushrim kinetics and shoulder joint net forces and moments. Compared with other studies that used an ergometer or dynamometer at the same speed, the magnitude of the shoulder joint net forces and moments elicited by wheelchair propulsion on the treadmill were lower than obtained by wheelchair propulsion on other devices. CONCLUSION: Lower magnitude of shoulder joint forces and moments found on the treadmill may be due to the lower friction compared with the other devices reviewed. Shoulder joint forces and moments depended strongly on the propulsion speed, increasing in magnitude when speed increased from 3 to 4 km h(-1).

[Robot therapy with the H2 exoskeleton for gait rehabilitation in patients with incomplete spinal cord injry. A clinical experience]. / Terapia robótica con el exoesqueleto H2 en la rehabilitación de la marcha en pacientes con lesión medular incompleta. Una experiencia clínica.

BACKGROUND AND OBJECTIVE: Robotic exoskeletons have emerged as a promising tool in gait rehabilitation in patients with a spinal cord injury. The aim of this study was to assess the clinical applicability of a new robotic exoskeleton model (Exo H2) in the rehabilitation of people with incomplete spinal cord injury. MATERIAL AND METHODS: Exo H2 exoskeleton training was performed for 15 sessions in patients with incomplete subacute spinal cord injury. We analysed the appearance of undesirable events and the patient's perception of pain, fatigue and comfort. In addition, a pilot test was carried out on the possible effectiveness of the device by analysing gait characteristics before and after treatment measured by the 10mWT, the 6mWT, the TUG, the WISCI-II, and the impact on the SCIM III scale. RESULTS: Of a group of 8 patients recruited, we were able to analyse data from 4. No undesirable effects were reported. The VAS value was 2.28±1.55 for pain, 3.75±1.55 for fatigue and 4.17±1.68 for comfort. All values improved on the WISCI-I and the TUG and almost all in the 10MWT and in the 6MWT. CONCLUSIONS: The performance of the Exo H2 exoskeleton was robust during a clinical protocol for gait rehabilitation. The treatment was safe, without undesirable effects and with good patient tolerance. These results might justify the performance of clinical trials with an adequate sample size.

Simultaneous estimation of human and exoskeleton motion: A simplified protocol.

Adequate benchmarking procedures in the area of wearable robots is gaining importance in order to compare different devices on a quantitative basis, improve them and support the standardization and regulation procedures. Performance assessment usually focuses on the execution of locomotion tasks, and is mostly based on kinematic-related measures. Typical drawbacks of marker-based motion capture systems, gold standard for measure of human limb motion, become challenging when measuring limb kinematics, due to the concomitant presence of the robot. This work answers the question of how to reliably assess the subject's body motion by placing markers over the exoskeleton. Focusing on the ankle joint, the proposed methodology showed that it is possible to reconstruct the trajectory of the subject's joint by placing markers on the exoskeleton, although foot flexibility during walking can impact the reconstruction accuracy. More experiments are needed to confirm this hypothesis, and more subjects and walking conditions are needed to better characterize the errors of the proposed methodology, although our results are promising, indicating small errors.

Effectiveness of the Virtual Reality System Toyra on Upper Limb Function in People with Tetraplegia: A Pilot Randomized Clinical Trial.

The aim of this study was to investigate the effects of a virtual reality program combined with conventional therapy in upper limb function in people with tetraplegia and to provide data about patients' satisfaction with the virtual reality system. Thirty-one people with subacute complete cervical tetraplegia participated in the study. Experimental group received 15 sessions with Toyra(®) virtual reality system for 5 weeks, 30 minutes/day, 3 days/week in addition to conventional therapy, while control group only received conventional therapy. All patients were assessed at baseline, after intervention, and at three-month follow-up with a battery of clinical, functional, and satisfaction scales. Control group showed significant improvements in the manual muscle test (p = 0,043, partial η (2) = 0,22) in the follow-up evaluation. Both groups demonstrated clinical, but nonsignificant, changes to their arm function in 4 of the 5 scales used. All patients showed a high level of satisfaction with the virtual reality system. This study showed that virtual reality added to conventional therapy produces similar results in upper limb function compared to only conventional therapy. Moreover, the gaming aspects incorporated in conventional rehabilitation appear to produce high motivation during execution of the assigned tasks. This trial is registered with EudraCT number 2015-002157-35.

A novel FES control paradigm based on muscle synergies for postural rehabilitation therapy with hybrid exoskeletons.

Hybrid exoskeletons combine robotic orthoses and motor neuroprosthetic devices to compensate for motor disabilities and assist rehabilitation. The basic idea is to take benefits from the strength of each technology, primarily the power of robotic actuators and the clinical advantages of using patient's muscles, while compensating for the respective weaknesses: weight and autonomy for the former, fatigue and stability for the latter. While a wide repertory of solutions have been proposed in literature for the control of robotic orthoses and simple motor neuroprosthesis, the same problem on a complex hybrid architecture, involving a wide number of muscles distributed on multiple articulations, still waits for a practical solution. In this article we present a general algorithm for the control of the neuroprosthesis in the execution of functional coordinated movements. The method extracts muscle synergies as a mean to diagnose residual neuromotor capabilities, and adapts the rehabilitation exercise to patient requirements in a dynamic way. Fatigue effects and unexpected perturbations are compensated by monitoring functional state variables estimated from sensors in the robot. The proposed concept is applied to a case-study scenario, in which a postural balance rehabilitation therapy is presented.

Comparative biomechanical gait analysis of patients with central cord syndrome walking with one crutch and two crutches.

BACKGROUND: Ambulatory people with central cord syndrome often require assistive devices. The selection of a suitable assistive device should be based on an objective assessment. Our objective in this study was to determine whether there was any difference in using two crutches over one crutch, considering that these patients have bilateral upper-limb involvement. METHODS: Kinematic gait analysis was conducted in 12 patients with central cord syndrome of more than one year of evolution and functional capacity for walking with one crutch or without crutches. Patients were asked to walk with one crutch and with two crutches at a freely chosen walking speed through a 10-m walkway. Three-dimensional kinematic equipment based on active markers was used to analyze temporospatial and articular parameters (maximum, minimum, and range of motion, ROM, throughout the cycle) FINDINGS: During two-crutch versus one-crutch walking, speed was lower (P=0041), stride time and step time were longer (P=0.004 and P=0.005) and there were fewer strides/minute and steps/minute (P=0.005 and P=0.006). The duration of the single support stance was longer during two-crutch walking (P=0.008). With respect to the articular parameters, both ankle ROMs (dorsi-plantar flexion P=0.003 and pronation-supination P=0.004) were greater with one-crutch walking than with two-crutch walking. INTERPRETATION: In patients with central cord syndrome capable of walking with one crutch or without crutches, walking with two crutches decreases speed, increases stride time and step time and improves stability by increasing single support, and diminishes ankle plantar flexion during swing phase.

Comparative study of pressure distribution at the user-cushion interface with different cushions in a population with spinal cord injury.

BACKGROUND: Few studies have offered comparative information on the mechanical characteristics of different wheelchair seat cushions. The objective of the present study was to compare the benefits of the wheelchair seat cushions most frequently used in a population of patients with spinal cord injury in terms of pressure distribution and contact surface at the user-cushion interface. METHODS: Each one of 48 patients with spinal cord injury was seated in his or her own wheelchair on the four models of cushions analyzed (low-profile air, high-profile air, dual-compartment air, and gel and firm foam), which were presented in randomized order. The pressure distribution readings and support surface area of the user-cushion interface were obtained with a matrix of piezocapacitive sensors. FINDINGS: The dual-compartment air cushion yielded lower readings for all pressure parameters analyzed (P(max), P(mean), P(sd), and P(isch)) than the other three cushion models (P<0.05). The best surface parameter results (S(tot), S>60 and %S>60) also were obtained with the dual-compartment air cushion (P<0.05). INTERPRETATION: In the sample analyzed, the dual-compartment air cushion was the cushion with the best pressure distribution and largest contact surface of the user-cushion interface compared to the other three cushions studied.