Posture influences on vestibulospinal tract excitability.

The human vestibulospinal tract has important roles in postural control, but it has been unknown whether vestibulospinal tract excitability is influenced by the body's postures. We investigated whether postures influence the vestibulospinal tract excitability by a neurophysiological method, i.e., applying galvanic vestibular stimulation (GVS) 100 ms before tibial nerve stimulation evoking the soleus H-reflex. GVS is a percutaneous stimulation, and it has not been clarified how the cutaneous input from GVS influences the facilitation effect of cathodal GVS on the soleus H-reflex amplitude. In Experiment 1, we evaluated the effects of GVS on the soleus H-reflex amplitude of subjects in the prone, supine, and sitting positions in random order to clarify the differences in the GVS effects among these postures. In Experiment 2, to determine whether the effects of GVS in the supine and sitting positions are due solely to cutaneous input from GVS, we provided GVS and cutaneous stimulations as conditioning stimuli and compared the effects in both postures. Interaction effects between postures and stimulus conditions were observed in both experiments. The facilitation rate of the maximum H-reflex amplitude by GVS in the sitting position was significantly higher than those in the prone and supine positions (Experiment 1). The facilitation rate of GVS was significantly larger than the cutaneous stimulation only in the sitting position (Experiment 2). These results indicate that vestibulospinal tract excitability may be higher in the sitting position than in either lying position (prone and supine), due mainly to the increased need for postural control.

Modulation of the rate of force development in hip abductor muscles by neuromuscular electrical stimulation during gait.

Purpose/aim of the study: An increase of hip abductor muscle strength contributes to the increase in gait speed. It is known that the rate of force development (RFD), an indicator of muscle strength, is increased by the combined use of low-intensity neuromuscular electrical stimulation (NMES) to the glutaeus medius (GM) and low-load resistance training (RT). However, it is unclear whether low-intensity neuromuscular electrical stimulation of the glutaeus medius during walking also increases the rate of force development. The aim of this study was to clarify whether NMES to the GM during gait modulates the RFD of the hip abductor muscles in healthy adults.Materials and methods: Twenty-two healthy adults randomly received both gait with sub-motor threshold NMES and gait with sham NMES conditions. The RFD was assessed at pre- and post-intervention. A two-way repeated measures analysis of variance was used to analyse the effects of time and intervention.Results: Gait with sub-motor threshold NMES condition significantly increased the RFD in shorter time interval (0-50 and 0-100 ms) compared to gait with sham NMES condition.Conclusions: These findings suggest that the adding low-intensity NMES of the GM to gait is effective in increasing the RFD of the hip abductor muscles.

Comparison of the Effect of Sensory-Level and Conventional Motor-Level Neuromuscular Electrical Stimulations on Quadriceps Strength After Total Knee Arthroplasty: A Prospective Randomized Single-Blind Trial.

OBJECTIVE: To compare sensory-level neuromuscular electrical stimulation (NMES) and conventional motor-level NMES in patients after total knee arthroplasty. DESIGN: Prospective randomized single-blind trial. SETTING: Hospital total arthroplasty center: inpatients. PARTICIPANTS: Patients with osteoarthritis (N=66; mean age, 73.5±6.3y; 85% women) were randomized to receive either sensory-level NMES applied to the quadriceps (the sensory-level NMES group), motor-level NMES (the motor-level NMES group), or no stimulation (the control group) in addition to a standard rehabilitation program. INTERVENTIONS: Each type of NMES was applied in 45-minute sessions, 5d/wk, for 2 weeks. MAIN OUTCOME MEASURES: Data for the quadriceps maximum voluntary isometric contraction, the leg skeletal muscle mass determined using multiple-frequency bioelectrical impedance analysis, the timed Up and Go test, the 2-minute walk test, the visual analog scale, and the range of motion of the knee were measured preoperatively and at 2 and 4 weeks after total knee arthroplasty. RESULTS: The motor-level NMES (P=.001) and sensory-level NMES (P=.028) groups achieved better maximum voluntary isometric contraction results than did the control group. The motor-level NMES (P=.003) and sensory-level NMES (P=.046) groups achieved better 2-minute walk test results than did the control group. Some patients in the motor-level NMES group dropped out of the experiment because of discomfort. CONCLUSIONS: Motor-level NMES significantly improved muscle strength and functional performance more than did the standard program alone. Motor-level NMES was uncomfortable for some patients. Sensory-level NMES was comfortable and improved muscle strength and functional performance more than did the standard program alone.

Anorexia assessment using the Simplified Nutritional Appetite Questionnaire and its association with activities of daily living in patients with stroke.

OBJECTIVE: This study aimed to validate the assessment of anorexia in patients with acute stroke using the Simplified Nutritional Appetite Questionnaire. METHODS: This cross-sectional observational study assessed appetite using the Simplified Nutritional Appetite Questionnaire in patients with acute stroke at discharge from an acute care hospital. Additionally, the relationship between the Simplified Nutritional Appetite Questionnaire and Mini Nutritional Assessment, Mini Nutritional Assessment - Short Form scores, skeletal muscle mass, muscle strength, and activities of daily living measured using the Functional Independence Measures for the motor domain was investigated. A multiple regression analysis was conducted with the Functional Independence Measure for the motor domain as the dependent variable and the Simplified Nutritional Appetite Questionnaire and other confounding factors as explanatory variables to evaluate the association between the Simplified Nutritional Appetite Questionnaire and functional outcomes. RESULTS: Among the 234 patients with stroke analyzed in this study, the median Simplified Nutritional Appetite Questionnaire score was 15 (IQR = 13-16) points. The Simplified Nutritional Appetite Questionnaire score significantly correlated with weight change, Functional Independence Measure for the motor domain, nutritional assessment index, and energy and protein intake. However, no significant differences in body mass index, muscle mass, or muscle strength were observed. In the multiple regression analysis adjusted for confounders, the Simplified Nutritional Appetite Questionnaire score (ß = 0.106; P = 0.007) was independently associated with the Functional Independence Measure for the motor domain (adjusted R2 = 0.662). CONCLUSIONS: This study's results found a significant correlation between Simplified Nutritional Appetite Questionnaire scores and nutritional status as well as an independent association with functional outcomes in patients with stroke. These findings suggest that the Simplified Nutritional Appetite Questionnaire can be a valuable tool for evaluating anorexia in this patient population.

High intensity-transcutaneous electrical nerve stimulation does not inhibit temporal summation of the nociceptive flexion reflex.

Pain facilitation contributes to chronic pain conditions. Transcutaneous electrical nerve stimulation (TENS) is used to alleviate pain. The effects of conventional TENS on chronic pain have been limited, and its effects on pain facilitation are controversial. Because the analgesic effects of TENS depend on the setting parameters (e.g., pulse intensities or treatment time), the optimal TENS settings to maximize analgesic effects under various pain conditions have been investigated. High-intensity TENS (HI-TENS), which involves tolerable-level pulse intensities for a short duration, is another conventional TENS method that used to alleviate pain. However, the effects of HI-TENS on pain facilitation remain unclear. The temporal summation of pain is widely used to evaluate pain facilitation, and the temporal summation-nociceptive flexion reflex (TS-NFR) is a neuropsychological parameter that can be used to evaluate pain facilitation. We aimed to investigate the effects of HI-TENS on the TS-NFR in healthy participants. Participants were randomly allocated into HI-TENS (n = 15) and control groups (n = 16). HI-TENS was administered at the left lateral lower leg for 1 min. The TS-NFR elicited by three noxious stimuluses at the left sural nerve was obtained from electromyography of the left biceps femoris. The nociceptive flexion reflex (NFR) was obtained by a single noxious stimulus. We measured the thresholds of the NFR and the TS-NFR at baseline and post-intervention. The application of HI-TENS significantly increased the NFR threshold (p = 0.013) but not the TS-NFR threshold (p > 0.05). These results suggest that HI-TENS does not inhibit pain facilitation.

Effects of postural-control training with different sensory reweightings in a patient with body lateropulsion: a single-subject design study.

INTRODUCTION: Body lateropulsion (BL) is an active lateral tilt of the body during standing or walking that is thought to be affected by a lesion of the vestibulospinal tract (VST) and the subjective visual vertical (SVV) tilt. Interventions for BL have not been established. OBJECTIVE: We examined the effects of postural-control training with different sensory reweighting on standing postural control in a patient with BL. METHODS: The patient had BL to the left when standing or walking due to a left-side medullary and cerebellar infarct. This study was a single-subject A-B design with follow-up: Phase A was postural-control training with visual feedback; phase B provided reweighting plantar somatosensory information. Postural control, VST excitability, and SVV were measured. RESULTS: At baseline and phase A, the patient could not stand with eyes-closed on a rubber mat, but became able to stand in phase B. The mediolateral center of pressure (COP) position did not change significantly, but the COP velocity decreased significantly during phase B and the follow-up on the firm surface. VST excitability was lower on the BL versus the non-BL side, and the SVV deviated to the right throughout the study. CONCLUSION: Postural-control training with reweighting somatosensory information might improve postural control in a patient with BL.

Effects of dual task balance training on dual task performance in elderly people: a randomized controlled trial.

OBJECTIVE: To investigate the effects of dual task balance training in the elderly on standing postural control while performing a cognitive task. DESIGN: A randomized two-group parallel controlled trial. PARTICIPANTS: Forty-three subjects (all >65 years old) were enrolled in the study and were assigned randomly to either an experimental group (n = 21) or a control group (n = 22). INTERVENTIONS: Subjects in the experimental group were given strength and balance training while performing cognitive tasks simultaneously. Subjects in the control group were given strength and balance training only. The training was administered twice a week for three months. MEASUREMENTS: The Chair Stand Test, Functional Reach Test, Timed Up and Go Test and Trail Making Test were measured. The sway length of the centre of gravity was measured during standing while performing the Stroop task. The rate of Stroop task was also measured. All measurements were collected at baseline and after the training period. RESULTS: There were no significant differences in Functional Reach Test, Timed Up and Go Test and sway length at baseline and after training between the two groups. However, the rate of Stroop task (P < 0.05) was significantly higher after training in the experimental group than in the control group. CONCLUSIONS: These results suggest that dual task balance training in elderly people improves their dual task performance during standing postural control.

Effects of peripheral sensory nerve stimulation plus task-oriented training on upper extremity function in patients with subacute stroke: a pilot randomized crossover trial.

OBJECTIVE: To investigate the feasibility of peripheral sensory nerve stimulation combined with task-oriented training in patients with stroke during inpatient rehabilitation. DESIGN: A pilot randomized crossover trial. SETTING: Two rehabilitation hospitals. SUBJECTS: Twenty-two patients with subacute stroke. INTERVENTIONS: Participants were randomly assigned to two groups and underwent two weeks of training in addition to conventional inpatient rehabilitation. The immediate group underwent peripheral sensory nerve stimulation combined with task-oriented training in the first week, followed by another week with task-oriented training alone. The delayed group underwent the same training in reverse order. MAIN MEASURES: Outcome measures were the level of fatigue and Wolf Motor Function Test. Patients were assessed at baseline, one and two weeks. RESULTS: All participants completed the study with no adverse events. There was no significant difference in level of fatigue between each treatment. From baseline to one week, the immediate group showed larger improvements than the delayed groups in the Wolf Motor Function Test (decrease in mean time (± SD) from 41.9 ± 16.2 seconds to 30.6 ± 11.4 seconds versus from 46.8 ± 19.4 seconds to 42.9 ± 14.7 seconds, respectively) but the difference did not reach significance after Bonferroni correction (P = 0.041). Within-group comparison showed significant improvements in the Wolf Motor Function Test mean time after the peripheral sensory nerve stimulation combined with task-oriented training periods in each group (P < 0.01). CONCLUSION: Peripheral sensory nerve stimulation is feasible in clinical settings and may enhance the effects of task-oriented training in patients with subacute stroke.

Effect of intensive rehabilitation on physical function and arterial function in community-dwelling chronic stroke survivors.

BACKGROUND: Atherothrombosis due to arteriosclerosis is a risk factor for recurrence of stroke. Although exercise therapy is essential to prevent progression of arteriosclerosis and to improve endothelial function, little is known about the effect of rehabilitation in chronic stroke survivors. OBJECTIVE: The purpose of this study was to investigate the effect of intensive rehabilitation on physical and arterial function among community-dwelling stroke survivors. METHODS: Forty-four community-dwelling stroke survivors participated in the study. The experimental group (n = 22) received primarily intensive strengthening exercise and the control group (n = 22) received standard physical therapy consisting mainly of stretching and gait training. Both groups underwent the rehabilitation program for 12 weeks. Physical function was evaluated using 10-m gait velocity, the 30-s chair stand test, Timed Up and Go test, and grip strength. Arterial function of the affected and unaffected sides was evaluated using the cardio-ankle vascular index (CAVI) as an index of arterial stiffness and the ankle-brachial pressure index (ABI) as an index of arterial occlusion. RESULTS: After the 12-week rehabilitation period, improvement in physical function did not differ between the 2 groups; whereas with regard to arterial function, a significant improvement in the CAVI for the affected side was observed in the experimental group (P < .001). Also, the ABI for the unaffected side in the experimental group was significantly improved after intervention (P < .001). No significant differences were found for the unaffected-side CAVI and affected-side ABI between the 2 groups. CONCLUSIONS: These findings suggested that intensive rehabilitation for stroke patients during the chronic stage preserved physical function and improved arterial function.

Cachexia criteria in chronic illness associated with acute weight loss in patients with stroke.

OBJECTIVES: Weight loss after a stroke is associated with poor outcomes. However, the causes of weight loss in the acute phase of a stroke are not fully understood. The purpose of this study was to investigate the relationship between acute weight changes and cachexia criteria in patients with an acute stroke. METHODS: In this prospective-cohort study, we assessed patients' body weight change during hospitalization, and investigated the five cachexia criteria (muscle strength, fatigue, anorexia, skeletal muscle mass, and abnormal biochemistry) at time of discharge in patients with an acute stroke. A patient was defined as being cachectic if ≥3 cachexia criteria were met. A multivariate analysis was performed to investigate the relationship between weight changes and cachexia criteria. RESULTS: A total of 155 patients with an acute stroke were enrolled in this study, and 30 patients (19%) were found to have weight loss (≥5% weight loss). A univariate regression analysis found that the cachexia criteria were significantly associated with weight changes (ß = -0.338; P < 0.001). The multivariate analyses after adjusting for energy intake, age, sex, body mass index at time of admission, National Institutes of Health stroke scale score, inflammatory disease, length of hospital stay, length of bed rest, and swallowing function showed that the cachexia criteria were significantly associated with weight changes (ß = -0.154; P = 0.043). CONCLUSIONS: The cachexia criteria were independently associated with acute weight loss in patients with a stroke.

Effect of galvanic vestibular stimulation on axial symptoms in Parkinson's disease.

Postural imbalance, abnormal axial posture, and axial rigidity are the characteristic features of Parkinson's disease (PD), and they are referred to as axial symptoms. The symptoms are difficult to manage since they are often resistant to both L-DOPA and deep brain stimulation. Hence, other treatments that can improve Parkinsonian axial symptoms without adverse effects are required. Vestibular dysfunction occurs in PD since neuropathological changes and reflex abnormalities are involved in the vestibular nucleus complex. Galvanic vestibular stimulation (GVS), which activates the vestibular system, is a noninvasive method. This review aimed to assess the clinical effect of GVS on axial symptoms in PD. To date, studies on the effects of GVS on postural instability, anterior bending posture, lateral bending posture, and trunk rigidity and akinesia in PD had yielded interesting data, and none of the patients presented with severe adverse events, and the others had mild reactions. GVS indicated a possible novel therapy. However, most included a small number of patients, and the sample sizes were not similar in some studies that included controls. In addition, there was only one randomized controlled clinical trial, and it did not perform an objective evaluation of axial symptoms. In this type of research, vestibular contributions to balance should be distinguished from others such as proprioceptive inputs or nonmotor symptoms of PD.

The effect of gait training with low-intensity neuromuscular electrical stimulation of hip abductor muscles in two patients following surgery for hip fracture: Two case reports.

BACKGROUND: The rate of force development (RFD) is an indicator of muscle strength. A previous study reported that the RFD of hip abductor muscles was increased by neuromuscular electrical stimulation (NMES) to gluteus medius (GM) during gait in healthy adults. However, the effects for patients following femoral head replacement for hip fracture are unclear. PURPOSE: The aim of this case report was to investigate the effects of gait training with sub-motor threshold NMES on RFD of hip abductor muscles in two patients following femoral head replacement for hip fracture compared to gait training without NMES. CASE DESCRIPTION: Two elderly patients following femoral head replacement for hip fracture received both interventions of gait training with sub-motor threshold NMES to GM and without NMES. Intervention phases involved 14 sessions each, for 28 sessions total. OUTCOMES: The RFD of hip abductor muscles, maximum walking speed, six-minute walk distance (6MWD), Berg Balance Scale, one-leg standing time (OLST), functional independence measure, and Numeric Pain Rating Scale (NPRS) were used as outcome measures. In both patients, RFD, 6MWD, OLST, and NPRS were improved by gait training with NMES compared to without NMES. CONCLUSION: Our results suggest the potential of NMES as a treatment methodology for these two patients undergoing femoral head replacement for hip fracture.

Footsteps and walking trajectories during the Timed Up and Go test in young, older, and Parkinson's disease subjects.

BACKGROUND: Footsteps and walking trajectories during the Timed Up and Go test (TUG), and their relationships with spatiotemporal gait parameters during turning in people with Parkinson's disease (PD) and older people have not been clarified. RESEARCH QUESTION: We investigated the footsteps, walking trajectories, and spatiotemporal parameters during the TUG in PD, healthy older (HO), and healthy young (HY) subjects and the associations between the parameters of footsteps or walking trajectories and the spatiotemporal parameters during turning. METHODS: Twenty-six PD, 20 HO, and 20 HY subjects participated. They performed the TUG at self-selected speed and underwent evaluations of spatiotemporal parameters in the forward, turning, and return phases and parameters of footsteps and walking trajectories by a system using laser range sensors to measure the two-dimensional distance data of the legs. Foot placement for each foot was measured as the estimated position when the leg speed of movement reached the minimum between foot-contact and foot-off. We calculated the minimum distance from a TUG marker to footsteps and the maximum anterior distance from the start to the footsteps. Step length was calculated using a method for non-linear walking. RESULTS: The PD subjects showed significantly smaller step lengths in all phases. The minimum distance from the marker to the footsteps in PD subjects was significantly smaller than in HO subjects and was significantly positively correlated only with the turning-phase step length. The maximum anterior distance from the start to footsteps in HO subjects was significantly larger than in PD and HY subjects and was not correlated with any spatiotemporal parameters. SIGNIFICANCE: This study demonstrated that people with PD turn close to the TUG marker, and this turning strategy may be associated with the decreased step length when turning. These findings could help in providing instructions which prevent the exaggeration of step-length reduction when turning.

Reliability and laterality of the soleus H-reflex following galvanic vestibular stimulation in healthy individuals.

The vestibulospinal tract (VST) plays an important role in the control of the ipsilateral antigravity muscles, and the balance of left and right VST excitability is important in human postural control. A method for measuring VST excitability is the application of galvanic vestibular stimulation (GVS) before tibial nerve stimulation that evokes the soleus H-reflex; the change rate of the H-reflex amplitude is then evaluated. Assessments of VST excitability and the left and right balance could be useful when determining the pathology for interventions in postural control impairments. However, the reliability and laterality of this assessment have not been clarified, nor has its relationship to postural control. We investigated the reliability, laterality and standing postural control in relation to the degree of facilitation of the H-reflex following GVS in 15 healthy adults. The assessments were performed in two sessions, one each for the left- and right-sides, in random order. The inter-session reliability of the short-interval assessments of an increase in the H-reflex following GVS on both sides were sufficient. The degree of H-reflex facilitation by GVS showed no significant difference between the left- and right-sides in any session. There was a moderate positive correlation between the mediolateral position of the center of pressure in the eyes-closed standing on foam condition and the left/right ratio of the degree of increased H-reflex in the first-session. We concluded that this method for evaluating the increase in the soleus H-reflex following GVS has high inter-session reliability in the short-interval that did not differ between sides.

Effectiveness of Long-Term Physiotherapy in Parkinson's Disease: A Systematic Review and Meta-Analysis.

BACKGROUND: Long-term physiotherapy is acknowledged to be crucial to manage motor symptoms for Parkinson's disease (PD) patients, but its effectiveness is not well understood. OBJECTIVE: This systematic review and meta-analysis aimed to assess the evidence regarding the effectiveness of long-term physiotherapy to improve motor symptoms and reduce antiparkinsonian medication dose in PD patients. METHODS: Pubmed, Cochrane, PEDro, and CINAHL were searched for randomized controlled trials before August 31, 2020 that investigated the effectiveness of physiotherapy for 6 months or longer on motor symptoms and levodopa-equivalent dose (LED) in PD patients with Hoehn and Yahr stage 1- 3. We performed random effects meta-analyses for long-term physiotherapy versus no/control intervention and estimated standard mean differences with 95% confidence intervals (CIs). Levels of evidence were rated by the Grading of Recommendation Assessment, Development and Evaluation approach. RESULTS: From 2,940 studies, 10 studies involving 663 PD patients were assessed. Long-term physiotherapy had favorable effects on motor symptoms in off medication state [- 0.65, 95% CI - 1.04 to - 0.26, p = 0.001] and LED [- 0.49, 95% CI - 0.89to - 0.09, p = 0.02]. Subgroup analyses demonstrated favorable effects on motor symptoms in off medication state by aerobic exercise [- 0.42, 95% CI - 0.64 to - 0.20, p < 0.001] and LED by multidisciplinary rehabilitation of primarily physiotherapy [- 1.00, 95% CI - 1.44 to - 0.56, p < 0.001]. Quality of evidence for aerobic exercise and multidisciplinary rehabilitation were low and very low. CONCLUSION: This review provided evidence that long-term physiotherapy has beneficial impact on motor symptoms and antiparkinsonian medication dose in PD patients and could motivate implementation of long-term physiotherapy.

Role of somatosensory and/or vestibular sensory information in subjective postural vertical in healthy adults.

The body's subjective postural vertical (SPV) has been thought to be affected by somatosensory information. How the SPV is perceived based on what types of somatosensory information has not been determined experimentally by manipulating somatosensory conditions. We investigated the effects of disturbing the somatosensory information from a seat pad and/or vestibular sensory information on the SPV in 15 healthy adults. Their SPV values were measured under four conditions (control, somatosensory, vestibular, and somatosensory + vestibular) in random order. The average and absolute SPV values were measured. In the somatosensory condition, a foam rubber pad was placed on the seating surface and the subject's SPV was measured. In the vestibular condition, the SPV was measured during galvanic vestibular stimulation (GVS). The somatosensory + vestibular condition was used to measure the SPV during combined somatosensory and vestibular stimulation. The mean SPV value was significantly increased in the somatosensory + vestibular condition compared to the other three conditions. The absolute value of SPV was significantly increased in the somatosensory and somatosensory + vestibular conditions compared to the control and vestibular conditions. There was no significant difference in the average or absolute SPV values in the vestibular condition compared to the other conditions. There was no significant difference between SPV errors when somatosensory information was disturbed or when somatosensory + vestibular information was disturbed. When the somatosensory information from the seat was disturbed, the SPV error increased, and it also shifted under the influence of the vestibular sensory information modulation. These results indicate that somatosensory information from the seat plays an important role in SPV in healthy adults.

Contralateral segmental transcutaneous electrical nerve stimulation inhibits nociceptive flexion reflex in healthy participants.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is a non-invasive treatment to relieve pain. Contralateral TENS (i.e. TENS administered to the contralateral side of a painful body part) is beneficial when TENS cannot be directly applied to pain site, such as in cases of trauma. Although TENS produces segmental analgesia in an ipsilateral limb, it has been unclear whether TENS produces higher analgesic effects in the contralateral segmental area. The aim of the present study was to investigate the analgesic effects of TENS in contralateral segmental or extra-segmental areas on physiological and subjective pain outcomes, using a nociceptive flexion reflex (NFR) method. METHODS: We randomly allocated 60 healthy participants to three groups: contralateral segmental TENS (CS-TENS); contralateral extra-segmental TENS (CE-TENS); and contralateral placebo TENS (CP-TENS). CS-TENS was applied to right superficial sural nerve and CE-TENS was applied to the right superficial femoral nerve, each for 30 minutes. The magnitude of the NFR elicited by electrical stimulation of the left sural nerve was measured at baseline and at three subsequent 10-minute intervals. Subjective pain intensity was measured simultaneously with a visual analogue scale (VAS). RESULTS: At 30 min, the NFR magnitude of CS-TENS group was significantly lower than that of the CP-TENS group (p = 0.021). There were no significant differences in VAS scores among the groups at any time point. CONCLUSIONS: Our findings suggest that CS-TENS inhibited NFR. Although there was no significant between-group difference in subjective pain intensity, factors such as a placebo effect probably impacted it. SIGNIFICANCE: Our findings provide support for the contralateral approach at stimulation sites when TENS cannot be directly administered to a pain site (e.g. due to disease or trauma).

Relationship between the rate of force development in knee extensor muscles and gait speed in patients with chronic stroke: A cross-sectional study.

BACKGROUND: The relationship between peak torque of the knee extensor muscles and gait speed was previously investigated in patients with chronic stroke, but whether the rate of force development (RFD), another indicator of muscle strength, affected gait speed remained unknown. OBJECTIVE: To clarify the relationships between the RFD of the knee extensor muscles over multiple time intervals and gait speed in patients with chronic stroke. METHODS: Twenty chronic stroke patients participated in this study. The RFD of affected and unaffected knee extensor muscles was measured. Time intervals of the RFD were set to 0-50 ms, 0-100 ms (100RFD), 0-200 ms (200RFD), and 0-300 ms (300RFD). Gait speed was assessed at comfortable and maximum pace. Pearson correlation coefficient (r) was used to analyze the relationships between RFD and gait speeds. RESULTS: The RFD of affected knee extensor muscles over all intervals was moderately correlated with both comfortable and maximum gait speeds, whereas only limited combinations (100, 200 and 300RFD with maximum gait speed) were correlated on the unaffected side. CONCLUSIONS: The present results suggest that various factors related to the RFD of affected knee extensor muscles, such as neural drive and muscle size, affect gait speed.

Transcranial Direct Current Stimulation Combined with Action Observation and Electromyographic Biofeedback Training in a Patient with Writer's Cramp.

We present a 47-year-old right-handed woman with a 15-year history of writer's cramp who was provided with six sessions of cathodal transcranial direct current stimulation (tDCS) combined with observation of writing actions performed by a healthy subject and electromyographic (EMG) biofeedback training to decrease EMG activities in her right forehand muscles while writing for 30 min for 4 weeks. She showed improvement in dystonic posture and writing speed after the intervention. The writing movement and writing speed scores on a writer's cramp rating scale decreased, along with writing time. Our findings demonstrated that cathodal tDCS combined with action observation and EMG biofeedback training might improve dystonic writing movements in a patient with writer's cramp.

Can Postural Instability Respond to Galvanic Vestibular Stimulation in Patients with Parkinson's Disease?

OBJECTIVE: Galvanic vestibular stimulation (GVS) activates the vestibular afferents, and these changes in vestibular input exert a strong influence on the subject's posture or standing balance. In patients with Parkinson's disease (PD), vestibular dysfunction might contribute to postural instability and gait disorders. METHODS: Current intensity was increased to 0.7 mA, and the current was applied to the patients for 20 minutes. To perform a sham stimulation, the current intensity was increased as described and then decreased to 0 mA over the course of 10 seconds. The patient's status was recorded continuously for 20 minutes with the patient in the supine position. RESULTS: Three out of 5 patients diagnosed with PD with postural instability and/or abnormal axial posture showed a reduction in postural instability after GVS. The score for item 12 of the revised Unified Parkinson's Disease Rating Scale part 3 was decreased in these patients. CONCLUSIONS: The mechanism of postural instability is complex and not completely understood. In 2 out of the 5 patients, postural instability was not changed in response to GVS. Nonetheless, the GVS-induced change in postural instability for 3 patients in our study suggests that GVS might be a therapeutic option for postural instability.