Using Swing Resistance and Assistance to Improve Gait Symmetry in Individuals Post-Stroke

A major characteristic of hemiplegic gait observed in individuals post-stroke is spatial and temporal asymmetry, which may increase energy expenditure and the risk of falls. The purpose of this study was to examine the effects of swing resistance/assistance applied to the affected leg on gait symmetry in individuals post-stroke. We recruited 10 subjects with chronic stroke who demonstrated a shorter step length with their affected leg in comparison to the non-affected leg during walking. They participated in two test sessions for swing resistance and swing assistance, respectively. During the adaptation period, subjects counteracted the step length deviation caused by the applied swing resistance force, resulting in an aftereffect consisting of improved step length symmetry during the post-adaptation period. In contrast, subjects did not counteract step length deviation caused by swing assistance during adaptation period and produced no aftereffect during the post-adaptation period. Locomotor training with swing resistance applied to the affected leg may improve step length symmetry through error-based learning. Swing assistance reduces errors in step length during stepping; however, it is unclear whether this approach would improve step length symmetry. Results from this study may be used to develop training paradigms for improving gait symmetry of stroke survivors

Robotic Resistance/Assistance Training Improves Locomotor Function in Individuals Poststroke: A Randomized Controlled Study

Objective To determine whether providing a controlled resistance versus assistance to the paretic leg at the ankle during treadmill training will improve walking function in individuals poststroke. Design Repeated assessment of the same patients with parallel design and randomized controlled study between 2 groups. Setting Research units of rehabilitation hospitals. Participants Patients (N=30) with chronic stroke. Intervention Subjects were stratified based on self-selected walking speed and were randomly assigned to the resistance or assistance training group. For the resistance group, a controlled resistance load was applied to the paretic leg at the ankle to resist leg swing during treadmill walking. For the assistance group, a load that assists swing was applied. Main Outcome Measures Primary outcome measures were walking speed and 6-minute walking distance. Secondary measures included clinical assessments of balance, muscle tone, and quality of life. Outcome measures were evaluated before and after 6 weeks of training and at 8 weeks\u27 follow-up, and compared within group and between the 2 groups. Results After 6 weeks of robotic training, walking speed significantly increased for both groups, with no significant differences in walking speed gains observed between the 2 groups. In addition, 6-minute walking distance and balance significantly improved for the assistance group but not for the resistance group. Conclusions Applying a controlled resistance or an assistance load to the paretic leg during treadmill training may induce improvements in walking speed in individuals poststroke. Resistance training was not superior to assistance training in improving locomotor function in individuals poststroke

A Novel Cable-Driven Robotic Training Improves Locomotor Function in Individuals Post-Stroke

A novel cable-driven robotic gait training system has been tested to improve the locomotor function in individuals post stroke. Seven subjects with chronic stroke were recruited to participate in this 6 weeks robot-assisted treadmill training paradigm. A controlled assistance force was applied to the paretic leg at the ankle through a cable-driven robotic system. The force was applied from late stance to mid-swing during treadmill training. Body weight support was provided as necessary to prevent knee buckling or toe drag. Subjects were trained 3 times a week for 6 weeks. Overground gait speed, 6 minute walking distance, and balance were evaluated at pre, post 6 weeks robotic training, and at 8 weeks follow up. Significant improvements in gait speed and 6 minute walking distance were obtained following robotic treadmill training through a cable-driven robotic system. Results from this study indicate that it is feasible to improve the locomotor function in individuals post stroke through a flexible cable-driven robot

Locomotor Adaptation to Resistance During Treadmill Training Transfers to Overground Walking in Human SCI

Treadmill training has been used as a promising technique to improve overground walking in patients with spinal cord injury (SCI). Previous findings showed that a gait pattern may adapt to a force perturbation during treadmill training and show aftereffects following removal of the force perturbation. We hypothesized that aftereffects would transfer to overground walking to a greater extent when the force perturbation was resisting rather than assisting leg swing during treadmill training. Ten subjects with incomplete SCI were recruited into this study for two treadmill training sessions: one using swing resistance and the other using swing assistance during treadmill stepping. A controlled resistance/assistance was provided to the subjects’ right knee using a customized cable-driven robot. The subjects’ spatial and temporal parameters were recorded during the training. The same parameters during overground walking were also recorded before and after the training session using an instrumented walkway. Results indicated that stride length during treadmill stepping increased following the release of resistance load and the aftereffect transferred to overground walking. In contrast, stride length during treadmill stepping decreased following the release of assistance load, but the aftereffect did not transfer to overground walking. Providing swing resistance during treadmill training could enhance the active involvement of the subjects in the gait motor task, thereby aiding in the transfer to overground walking. Such a paradigm may be useful as an adjunct approach to improve the locomotor function in patients with incomplete SCI

Robotic Resistance Treadmill Training Improves Locomotor Function in Human Spinal Cord Injury: A Pilot Study

Objective To determine whether cable-driven robotic resistance treadmill training can improve locomotor function in humans with incomplete spinal cord injury (SCI). Design Repeated assessment of the same patients with crossover design. Setting Research units of rehabilitation hospitals in Chicago. Participants Patients with chronic incomplete SCI (N=10) were recruited to participate in this study. Interventions Subjects were randomly assigned to 1 of 2 groups. One group received 4 weeks of assistance training followed by 4 weeks of resistance training, while the other group received 4 weeks of resistance training followed by 4 weeks of assistance training. Locomotor training was provided by using a cable-driven robotic locomotor training system, which is highly backdrivable and compliant, allowing patients the freedom to voluntarily move their legs in a natural gait pattern during body weight supported treadmill training (BWSTT), while providing controlled assistance/resistance forces to the leg during the swing phase of gait. Main Outcome Measures Primary outcome measures were evaluated for each participant before training and after 4 and 8 weeks of training. Primary measures were self-selected and fast overground walking velocity and 6-minute walking distance. Secondary measures included clinical assessments of balance, muscle tone, and strength. Results A significant improvement in walking speed and balance in humans with SCI was observed after robotic treadmill training using the cable-driven robotic locomotor trainer. There was no significant difference in walking functional gains after resistance versus assistance training, although resistance training was more effective for higher functioning patients. Conclusions Cable-driven robotic resistance training may be used as an adjunct to BWSTT for improving overground walking function in humans with incomplete SCI, particularly for those patients with relatively high function

Repeat Exposure to Leg Swing Perturbations During Treadmill Training Induces Long-Term Retention of Increased Step Length in Human SCI: A Pilot Randomized Controlled Study

Objective: To determine whether repeat exposure to force perturbations during treadmill training can induce long-term retention of improved step length and overall improvements in locomotor function in persons with spinal cord injury. Design: Fourteen patients with spinal cord injury were recruited and randomly assigned to swing resistance or swing assistance training groups. A controlled swing resistance or assistance force, for resistance or assistance training groups, respectively, was applied to both legs through a cable-driven robotic system during treadmill training. Each participant trained 3 times per week for 6 weeks. Step length, walking speed, 6-minute walking distance, and other clinical assessments were evaluated before and after 6 weeks of training and 8 weeks after the end of training. Results: A significant increase in step length was observed after 6 weeks of resistance training (P = 0.04). Step length tended to increase after assistance treadmill training, but the change was not significant (P = 0.18). The changes in step length and functional gains had no significant difference between 2 groups. Conclusions: Repeat exposure to swing resistance during treadmill training may induce a prolonged retention of increased step length, although it remains unclear whether swing resistance versus assistance is more effective in inducing increased step length

Antrodia camphorata

Antrodia camphorata (A. camphorata) is a fungus generally used in Chinese folk medicine for treatment of viral hepatitis and cancer. Our previous study found A. camphorata has neuroprotective properties and could reduce stroke injury in cerebral ischemia animal models. In this study, we sought to investigate the molecular mechanisms of neuroprotective effects of A. camphorata in middle cerebral artery occlusion (MCAO) rats. A selective occlusion of the middle cerebral artery (MCA) with whole blood clots was used to induce ischemic stroke in rats and they were orally treated with A. camphorata (0.25 and 0.75 g/kg/day) alone or combined with aspirin (5 mg/kg/day). To provide insight into the functions of A. camphorata mediated neuroprotection, the expression of Bax, inducible nitric oxide synthase (iNOS), haem oxygenase-1 (HO-1), and activated caspase-3 was determined by Western blot assay. Treatment of aspirin alone significantly reduced the expressions of HO-1 (P<0.001), iNOS (P<0.001), and Bax (P<0.01) in ischemic regions. The reduction of these expressions was more potentiated when rats treated by aspirin combined with A. camphorata (0.75 g/kg/day). Combination treatment also reduced apoptosis as measured by a significant reduction in active caspase-3 expression in the ischemic brain compared to MCAO group (P<0.01). Moreover, treatment of A. camphorata significantly (P<0.05) reduced fenton reaction-induced hydroxyl radical (OH•) formation at a dose of 40 mg/mL. Taken together, A. camphorata has shown neuroprotective effects in embolic rats, and the molecular mechanisms may correlate with the downregulation of Bax, iNOS, HO-1, and activated caspase-3 and the inhibition of OH• signals

Case report: Presentations and cytokine profiles of inflammatory non-pulmonary COVID-19 and related diseases in children

The coronavirus disease 2019 (COVID-19) pandemic has evolved to dynamic waves of different SARS-CoV-2 variants. Initially, children diagnosed with COVID-19 presented pulmonary involvement characterized by mild diseases. In the later waves of the COVID-19 pandemic, life-threatening non-pulmonary inflammatory diseases such as (1) aseptic meningoencephalitis (ME), (2) acute necrotizing encephalopathies (ANE), and (3) multisystem inflammatory syndrome in children (MIS-C) have been reported, affecting the pediatric population. To alert timely identification and prevention of the life-threatening non-pulmonary COVID-19, we present the cases of ME, ANE, and MIS-C in terms of clinical manifestation, cytokine profile, and follow-up consequences. Based on the immunopathogenesis and risk factors associated with non-pulmonary COVID-19, we delineate strategies for an early diagnosis and treatment to reduce morbidity and mortality in children