Repetitive Passive Movements Research Articles

Generalization of visuomotor adaptation associated with use-dependent learning across different movement workspaces and limb postures

Use-dependent learning has been investigated to some extent, although how motor patterns obtained through use-dependent learning are generalized across different movement conditions remains to be further understood. Here, we investigate the generalizability of use-dependent learning by determining how visuomotor adaptation associated with use-dependent learning was generalized across different workspaces and limb postures. In our experiments, participants first adapted to a visuomotor rotation while reaching from a given starting position toward a training target in a given limb posture. They concurrently experienced repetitive passive movements from varying starting positions (Exp. 1) or in varying limb postures (Exp. 2). Following that, they adapted to the same rotation while reaching from the original start circle to a transfer target. Regardless of the workspaces or limb postures experienced, passive training facilitated visuomotor adaptation in the transfer session, indicating that visuomotor adaptation can generalize across different movement conditions. However, the extent of generalization decreased as the experienced workspaces or limb postures deviated from the original condition experienced. Our findings indicate that use-dependent learning results in motor instances that are workspace and limb-posture specific, although they are still useful for enhancing the generalization of motor learning across varying conditions.

Normalization factor for the assessment of elbow spasticity with passive stretch measurement: maximum torque VS. body weight.

Spasticity of the elbow was generally assessed by repeated passive stretch movement, including the modified Ashworth Scale (MAS) from physiotherapist, and biomechanics analysis of the movement. The MAS-based method depends on the subjective evaluations and the performance of biomechanics analysis assessment is affected by the individual difference. Therefore, the normalization to reduce the individual difference for the assessment of spasticity is very important. In this study, the elbow spasticity was assessed with MAS by one skillful physiotherapist and biomechanics measurements during repetitive passive isokinetic movements at velocity of 60 degree$/$second. 20 post-stroke patients with elbow spasticity caused by hemorrhagic cerebral damage were divided into three groups according to the MAS grades (MAS $=1, 1+$, 2). The torque and position were recorded when the patients extension their elbows passively. The mean stiffness and the mean torque features of the passive isokinetic were calculated. Two normalization factors for biomechanics analysis assessment were investigated: body weight normalization factor and maximum isometrics volunteer contraction normalization factor. Spearman correlation analysis was used to investigate the relationship between the features and spasticity grades. The results showed that the correlation between MAS and two biomechanics features (mean stiffness, mean torque) were significant improved. For mean stiffness feature, the correlation coefficients were $-0.313, -0.563$ and -0.603 individually for non-normalization, body weight normalization and maximum isometrics volunteer contraction normalization. For mean torque feature, the correlation coefficients were $-0.260, -0.523$ and -0.691, respectively. These results suggest that the normalization methods would be helpful for the assessment of spasticity in biomechanics and will be a necessary way of spasticity estimation in clinical methods.

Enhancing Generalization of Visuomotor Adaptation by Inducing Use-dependent Learning

Learning a motor task in one condition typically generalizes to another, although it is unclear why it generalizes substantially in certain situations, but only partially in other situations (e.g., across movement directions and motor effectors). Here, we demonstrate that generalization of motor learning across directions and effectors can be enhanced substantially by inducing use-dependent learning, that is, by having subjects experience motor actions associated with a desired trajectory repeatedly during reaching movements. In Experiments 1 and 2, healthy human adults adapted to a visuomotor rotation while concurrently experiencing repetitive passive movements guided by a robot. This manipulation increased the extent of generalization across movement directions (Expt. 1) and across the arms (Expt. 2) by up to 50% and 42%, respectively, indicating crucial contribution of use-dependent learning to motor generalization. In Experiment 3, we applied repetitive transcranial magnetic stimulation (rTMS) to the left primary motor cortex (M1) of the human subjects prior to passive training with the right arm to increase cortical excitability. This intervention resulted in increased motor-evoked potentials (MEPs) and decreased short-interval intracortical inhibition (SICI) in the rTMS group, but not in the sham group. These changes observed in the rTMS group were accompanied by enhanced generalization of visuomotor adaptation across the arms, which was not the case in the sham group. Collectively, these findings confirm the involvement of M1 in use-dependent learning, and suggest that use-dependent learning can contribute not only to motor learning, but also to motor generalization.

Rehabilitation Robots: Concepts and Applications in Stroke Rehabilitation

Robotics is a tool to assist human in different applications from industry to medicine. There are many reasons that human tends to use these machines. They are very reliable in repetitive, high precision, preprogrammed and high risk jobs in which human is not too good enough. In medicine, robotic applications are evolving so fast that in near future nobody can imagine a surgery without a robot involved. In Rehabilitation we have the same scenario; there are commercialized robots to assist disable people to eat and perform daily activities. There are also clinical rehabilitation robots which can train handicaps. They can help subjects as a passive tool that improves low level impairments such as rigidity. On the other hand robots can train brain as an active tool to have a better movement again. We will see how robots can help therapist to apply repetitive passive movements in quadriplegic subject (i.e. in Brunnstrom stages 1 to 3). On the other hand they can teach subjects how to complete a task in an active manner (i.e. in stages 5 and 6) which can facilitate neuroplasticity. There are different robots designed for different organs; for example rehabilitation of upper extremities (e.g. Gloreha) or lower extremities (e.g. Lokomat). There are also exoskeleton robots to help subjects to grip objects and perform ADLs easily (e.g. Bioservo) or help paraplegic patient to walk again (e.g. Rewalk). In this talk, we will also discuss about how robots are helping rehab specialist to improve standard protocols. For example we will show how action observation therapy, bimanual therapy, assistive active therapy, proprioceptive facilitation and passive mobilization therapy are realized using an upper extremity rehabilitation robot. Robotics is the future of technology and rehabilitation needs this technology. Be part of this technology!

Sensorimotor modulation by botulinum toxin A in post-stroke arm spasticity: Passive hand movement

IntroductionIn post-stroke spasticity, functional imaging may uncover modulation in the central sensorimotor networks associated with botulinum toxin type A (BoNT) therapy. Investigations were performed to localize brain activation changes in stroke patients treated with BoNT for upper limb spasticity using functional magnetic resonance imaging (fMRI). MethodsSeven ischemic stroke patients (4 females; mean age 58.86) with severe hand paralysis and notable spasticity were studied. Spasticity was scored according to the modified Ashworth scale (MAS). fMRI examination was performed 3 times: before (W0) and 4 (W4) and 11weeks (W11) after BoNT. The whole-brain fMRI data were acquired during paced repetitive passive movements of the plegic hand (flexion/extension at the wrist) alternating with rest. Voxel-by-voxel statistical analysis using the General Linear Model (GLM) implemented in FSL (v6.00)/FEAT yielded group session-wise statistical maps and paired between-session contrasts, thresholded at the corrected cluster-wise significance level of p<0.05. ResultsAs expected, BoNT transiently lowered MAS scores at W4. Across all the sessions, fMRI activation of the ipsilesional sensorimotor cortex (M1, S1, and SMA) dominated. At W4, additional clusters transiently emerged bilaterally in the cerebellum, in the contralesional sensorimotor cortex, and in the contralesional occipital cortex. Paired contrasts demonstrated significant differences W4>W0 (bilateral cerebellum and contralesional occipital cortex) and W4>W11 (ipsilesional cerebellum and SMA). The remaining paired contrast (W0>W11) showed activation decreases mainly in the ipsilesional sensorimotor cortex (M1, S1, and SMA). ConclusionsThe present study confirms the feasibility of using passive hand movements to map the cerebral sensorimotor networks in patients with post-stroke arm spasticity and demonstrates that BoNT-induced spasticity relief is associated with changes in task-induced central sensorimotor activation, likely mediated by an altered afferent drive from the spasticity-affected muscles.

To see bruxism: a functional MRI study.

Since the pathophysiology of bruxism is not clearly understood, there exists no possible treatment. The aim of this study is to investigate the cerebral activation differences between healthy subjects and patients with bruxism on behalf of possible aetiological factors. 12 healthy subjects and 12 patients with bruxism, a total of 24 right-handed female subjects (aged 20-27 years) were examined using functional MRI during tooth-clenching and resting tasks. Imaging was performed with 3.0-T MRI scanner with a 32-channel head coil. Differences in regional brain activity between patients with bruxism and healthy subjects (control group) were observed with BrainVoyager QX 2.8 (Brain Innovation, Maastricht, Netherlands) statistical data analysis program. Activation maps were created using the general linear model: single study and multistudy multisubject for statistical group analysis. This protocol was approved by the ethics committee of medical faculty of Kirikkale University, Turkey (02/04), based on the guidelines set forth in the Declaration of Helsinki. The group analysis revealed a statistically significant increase in blood oxygenation level-dependent signal of three clusters in the control group (p<0.005), which may indicate brain regions related with somatognosis, repetitive passive motion, proprioception and tactile perception. These areas coincide with Brodmann areas 7, 31, 39 and 40. It is conceivable that there are differences between healthy subjects and patients with bruxism. Our findings indicate that there was a decrease of cortical activation pattern in patients with bruxism in clenching tasks. This indicates decreased blood flow and activation in regional neuronal activity. Bruxism, as an oral motor disorder concerns dentistry, neurology and psychiatry. These results might improve the understanding and physiological handling of sleep bruxism.

Brain Activation Evoked by Sensory Stimulation in Patients with Spinal Cord Injury : Functional Magnetic Resonance Imaging Correlations with Clinical Features.

ObjectiveThe purpose of this study is to determine whether the changes of contralateral sensorimotor cortical activation on functional magnetic resonance imaging (fMRI) can predict the neurological outcome among spinal cord injury (SCI) patients when the great toes are stimulated without notice.MethodsThis study enrolled a total of 49 patients with SCI and investigated each patient's preoperative fMRI, postoperative fMRI, American Spinal Injury Association (ASIA) score, and neuropathic pain occurrence. Patients were classified into 3 groups according to the change of blood oxygenation level dependent (BOLD) response on perioperative fMRI during proprioceptive stimulation with repetitive passive toe movements : 1) patients with a response of contralateral sensorimotor cortical activation in fMRI were categorized; 2) patients with a response in other regions; and 3) patients with no response. Correlation between the result of fMRI and each parameter was analyzed.ResultsIn fMRI data, ASIA score was likely to show greater improvement in patients in group A compared to those belonging to group B or C (p<0.001). No statistical significance was observed between the result of fMRI and neuropathic pain (p=0.709). However, increase in neuropathic pain in response to the signal change of the ipsilateral frontal lobe on fMRI was statistically significant (p=0.030).ConclusionWhen there was change of BOLD response at the contralateral sensorimotor cortex on perioperative fMRI after surgery, relief of neurological symptoms was highly likely for traumatic SCI patients. In addition, development of neuropathic pain was likely to occur when there was change of BOLD response at ipsilateral frontal lobe.

Rapid repetitive passive movement promotes knee proprioception in the elderly

AbstractJoint proprioception plays an important role in the generation of coordinated movements, maintenance of normal body posture, body conditioning, motor learning, and relearning. Previous studies have demonstrated that proprioceptive function of the elderly can be enhanced via specific exercises; however, not all of the elderly can actively and safely participate in physical activities. The purpose of this study was to evaluate the effects of rapid repetitive passive movement in an average velocity of 90°/s on knee proprioception in the elderly. A repeated-measure design was employed. Two age groups (12 young/12 elderly) were intervened with repetitive passive movements of 60 repetitions to the knee joint via two machines (isokinetic dynamometer/self-designed machine) in separate days. Changes in proprioception were evaluated via joint active repositioning and kinesthesia, both before and after the intervention. The results revealed that all subjects demonstrated good test–retest reliabilities on proprioceptive measurements. For the active repositioning and kinesthesia, significant statistical main effects were found for group and time, but not for machine. No statistical interactions were revealed. Despite of age-related proprioceptive declines, elderly subjects could benefit from rapid repetitive passive movements. This indicates that repetitive passive movement may be an alternative to physical activity for those who are home-bound, in a sedentary lifestyle, or with other health conditions that may limit their abilities to actively maintain or strengthen joint proprioception.

The Effect of Repetitive Passive and Active Movements on Proprioception Ability in Forearm Supination

[Purpose] This study was conducted in order to investigate the effect of repetitive passive movement and repetitive active movement on proprioception in forearm supination. [Subjects] This study had a cross-sectional design. Twenty-three right-handed healthy subjects were recruited. All subjects randomly received both repetitive passive movement and repetitive active movement (repetitive passive/active movement at 120°/s with 60 repetitions over a 0–80° range). Active and passive joint repositioning of all subjects was measured using the error score for position sense, both before and after repositioning intervention. [Results] In the repetitive passive movement test, there was a statistically significant decrease in the pre- versus post-repositioning error scores in the active and passive angle examinations. In the repetitive active movement test, there was a statistically significant increase in pre- versus post-repositioning error scores in the active and passive angle examinations. In the comparison of position sense, there was a statistically significant decrease in both active and passive angle repositioning error scores in repetitive passive movement versus repetitive active movement. [Conclusion] Repetitive passive movement improved the proprioception results for forearm supination, compared to repetitive active movement. Results of this study indicate that repetitive passive movement can be recommended to clinicians for rehabilitation therapy as it provides greater proprioception benefits.

Managing spastic hypertonia in children with cerebral palsy via repetitive passive knee movements

Most children with cerebral palsy have increased muscle tension in the lower extremities, which inevitably leads to abnormal gait characteristics. Proper management of excessive muscle tension is therefore of great importance. The aim of this study was to explore the effects of continuous passive motion on children with cerebral palsy, regarding their lower extremity spastic hypertonia and ambulatory function. A repeated measures design. Sixteen children with cerebral palsy. Intervention was applied to the subject's knees with a continuous passive motion device (at velocities of 15 and 0º/s) for 20 min. Effects were evaluated via variables measuring range-of-motion, muscle tone, and ambulatory function before, immediately after, and 30 min after intervention. For the 15º/s intervention, significant differences were found in time, intervention, and interaction among variables, including active range-of-motion of the knee (increased), relaxation index (increased), Modified Ashworth Scale (decreased), Timed Up-and-Go (decreased), and 6-Minute Walk test (increased). No difference was found in passive range of motion measurements. For the 0º/s control condition, none of the dependent variables demonstrated statistically significant differences. Repetitive passive movement can reduce lower extremity spastic hypertonia in children with cerebral palsy, and improve ambulatory function in terms of walking speed.

Effects of active fatiguing movement versus passive repetitive movement on knee proprioception

Background Proprioception can be affected by many factors such as age, gender, injury, disease, exercise, and fatigue. To date, the mechanisms or pathways by which fatigue influences proprioception have not been elucidated. Generally, it is accepted that local muscular effects occurred during fatigue state may negatively affect proprioception. Research has indicated that metabolic acidosis resulting from active muscle activities, along with tissue stretching and joint laxity resulting from repetitive joint movements, are likely related to proprioceptive deterioration. So far, little direct evidence or research supports these statements. The purpose of this study was to examine the effects of fatigue exercises (repetitive active movement) and repetitive passive movements on knee proprioception. Methods A quasi-experimental design with repeated measure on proprioception following two forms of knee joint movement (repetitive active/passive movement in 120°/s with 60 repetitions over a 10°–100° range) was conducted. Fifteen healthy volunteers underwent two forms of movement intervention in two consecutive days in a counter-balanced manner. Knee joint repositioning errors were measured before and after the movement intervention. Findings Study results showed a statistically significant increase in absolute repositioning error following repetitive active movement, but a decrease following repetitive passive movement intervention. Interpretation This study concluded that a repetitive passive movement protocol was capable of improving knee joint position sense. Meanwhile, the negative effect from the muscle receptors following the repetitive active movement overwhelmed the positive effect from the repetitive passive movement intervention. It supports the clinical utilization of repetitive passive movement to promote proprioception. This utilization can be implemented for proprioceptive training in sports activities, plus injury prevention and rehabilitation.

Use-Dependent Up- and Down-Regulation of Sensorimotor Brain Circuits in Stroke Patients

Objective. To examine whether cerebral activity during passive movements decreases with time after stroke, and if reduced activity in the representation for the upper extremity can be reversed with training. Methods. Brain activity was measured by functional magnetic resonance imaging (fMRI) during passive wrist flexion-extension in 7 patients at varying time points after stroke, in a cross-sectional design. Upper limb function was also measured in all patients. Five of the patients took part in a training program and were measured again, behaviorally and with fMRI posttraining. Healthy control individuals of comparable age were also studied. Results. In patients, reduced activity over time after stroke was found for the group in the supplementary motor area (SMA), contralateral primary motor cortex, and prefrontal and parietal association areas along with ipsilateral cerebellum. Activity in most of these areas was also reduced in the patient group as compared to the control group. After a half-hour of daily training for 4 weeks with repetitive passive and active arm movements, cerebral activation increased in the pre-SMA and SMA, ipsilateral primary sensory cortex and intraparietal sulcus, and contralateral cerebellum in parallel with functional improvements of the upper limb. Areas common to both analyses included the SMA, pre-SMA, primary sensory cortex, intraparietal sulcus, and cerebellum. Conclusions. Our findings suggest that a down-regulation of sensorimotor activity occurs progressively over time as a result of inactivity and that training may reverse the reduced brain activity.

Biomechanical Analysis of Different Operative Techniques for Complete Acromioclavicular Joint Disruptions

The goal of this study was to evaluate three different operative techniques for acromioclavicular joint fixation: trans-articular K-wire fixation; ligament reconstruction along with a synthetic augmentation device (LARS®); and coracoclavicular Bosworth screw. Mechanical properties were tested in a cadaver study in order to determine the primary mechanical stability during repetitive passive motion. Eighteen fresh cadavers were used to test a cyclic load (50 000 cycles). Secondary joint dislocation and the rate of implant loosening were monitored by standard AP stress X-ray. Metal markers in the coracoid, the acromion, and the lateral clavicle were used to measure the acromioclavicular distance increase (Δ-AC) and the coracoclavicular distance increase (Δ-CC). The range of motion was set on 30-90° of abduction for the first 25 000 cycles and then was raised to 60-120°. The least amount of vertical dislocation was seen in the K-wire and the LARS® group (mean Δ-CC 0.3 mm; range: 0-1.3 mm and 1.5 mm; range 0-6.7 mm, respectively). The Bosworth group showed significantly higher dislocation rates (4.2 mm; range 2.3-7.1 mm; p = 0.005). This was true especially when the abduction range was extended to a maximum of 120°. The rate of implant loosening in the K-wire group was higher than that in the other two groups. This study shows that the LARS® procedure and the K-wires technique give equal results concerning stability after repetitive passive motion, but with a high rate of implant loosening in the K-wire group. According to our findings, abduction should be limited to 90° after implanting a Bosworth screw in order to prevent loosening or failure of the hardware.

Neural substrate for the effects of passive training on sensorimotor cortical representation: a study with functional magnetic resonance imaging in healthy subjects.

Repetitive passive movements are part of most rehabilitation procedures, especially in patients with stroke and motor deficit. However, little is known about the consequences of repeated proprioceptive stimulations on the intracerebral sensorimotor network in humans. Twelve healthy subjects were enrolled, and all underwent two functional magnetic resonance imaging (fMRI) sessions separated by a 1-month interval. Passive daily movement training was performed in six subjects during the time between the two fMRI sessions. The other six subjects had no training and were considered as the control group. The task used during fMRI was calibrated repetitive passive flexion-extension of the wrist similar to those performed during training. The control task was rest. The data were analyzed with SPM96 software. Images were realigned, smoothed, and put into Talairach's neuroanatomical space. The time effect from the repetition of the task was assessed in the control group by comparing activation versus rest in the second session with activation versus rest in the first session. This time effect then was used as null hypothesis to assess the training effect alone in our trained group. Passive movements compared with rest showed activation of most of the cortical areas involved in motor control (i.e., contralateral primary sensorimotor cortex, supplementary motor area [SMA], cingulum, Brodmann area 40, ipsilateral cerebellum). Time effect comparison showed a decreased activity of the primary sensorimotor cortex and SMA and an increased activity of ipsilateral cerebellar hemisphere, compatible with a habituation effect. Training brought about an increased activity of contralateral primary sensorimotor cortex and SMA. A redistribution of SMA activity was observed. The authors demonstrated that passive training with repeated proprioceptive stimulation induces a reorganization of sensorimotor representation in healthy subjects. These changes take place in cortical areas involved in motor preparation and motor execution and represent the neural basis of proprioceptive training, which might benefit patients undergoing rehabilitative procedures.

Spasticity in spinal cord injury: Self- and clinically rated intrinsic fluctuations and intervention-induced changes

Objectives: (1) To determine patterns of intrinsic fluctuations in spasticity, using repeated self-ratings, in subjects with spinal cord injury (SCI); and (2) To determine the relation between self-ratings of spasticity using a visual analogue scale (VAS) and clinical ratings of spasticity using the Modified Ashworth Scale (MAS) before and after spasticity-reducing treatment.Design: Part 1: observational, prospective cross-sectional study; part II: experimental, prospective longitudinal study.Setting: Outpatient clinic of the Karolinska Hospital, Stockholm, Sweden.Patients: Forty-five persons with SCI (39 men, 6 women); mean age at injury, 26yrs; mean time since injury, l Iyrs.Intervention: Repetitive passive movements of standardized range of motion in three different body positions, performed by two motorized tables.Main Outcome Measures: VAS ratings of spasticity, every other hour when awake, and of movement-provoked spasticity, rated before and after each treatment session, and MAS ratings of movement-provoked spasticity, before and after each treatment session.Results: The spasticity of cervical SCI subjects fluctuated significantly (p < .05) during the day, unlike the spasticity of thoracic SCI subjects. Immediately after intervention with passive movements, spasticity ratings in thoracic motor complete SCI patients decreased by 11 to 14mm (90%, p < .001) as self-rated on VAS and by 1 to 2 grades (50%, p < .001) as measured with MAS. A 3096 (p <.018) decrease in VAS values of intrinsic pattern of spasticity was maintained over time when treatment was given regularly and was maintained for at least 1 week after discontinuation of treatment. VAS ratings correlated significantly with MAS ratings (r = .44 to 62,p < .001).Conclusion: Repetitive passive movement intervention decreased spasticity when performed regularly, as assessed by VAS and MAS ratings. VAS and MAS ratings were significantly correlated. It is recommended that SCI patients repeatedly rate their spasticity to establish a baseline before and to tract changes after intervention aimed at reducing spasticity. The time of day when spasticity is measured seems more important in cervically injured individuals, because of their more pronounced intrinsic fluctuations.

Effect of passive motions on the initiation of fast knee extension in patients with paraparesis.

Using reaction time paradigm, the effect of repetitive passive motion (RPM) on the initiation of fast knee extension was analyzed in seven normal subjects and 10 patients with paraparesis. Before and after 5 min RPM of the responding lower extremity, i.e., alternate flexion and extension of the knee and the hip with frequency of 0.5 Hz, the following five variables were examined: premotor time (PMT), latency from sound stimulus to initiation of EMG activities of the rectus femoris; tension lag time (TLT), period between onset of EMG activities and rise of tension; contraction time (FTmax); maximum tension (Tmax); and rate of tension development (RTD, Fmax/FTmax). In the normal group, PMT decreased significantly after RPM, whereas the other four variables did not show any change due to RPM. In the patient group, shortening of both PMT and FTmax after RPM was significant and Fmax tended to be small. These results suggested that RPM of an extremity induces behavioral alertness when the afferent pathway from moving parts to the higher center is not interrupted and also that RPM modulates abnormal pattern of motor neuron activities at the spinal level.