"Taking action" to reduce pain-Has interpretation of the motor adaptation to pain been too simplistic?

Movement adapts during acute pain. This is assumed to reduce nociceptive input, but the interpretation may not be straightforward. We investigated whether movement adaptation during pain reflects a purposeful search for a less painful solution. Three groups of participants performed two blocks (Baseline, Experimental) of wrist movements in the radial-ulnar direction. For the Control group (n = 10) both blocks were painfree. In two groups, painful electrical stimulation was applied at the elbow in Experimental conditions when the wrist crossed radial-ulnar neutral. Different stimulus intensities were given for specific wrist angles in a secondary direction (flexion-extension) as the wrist passed radial-ulnar neutral (Pain 5-1 group:painful stimulation at ~5 or ~1/10-n = 21; Pain 5-0 group:~5 or 0(no stimulation)/10-n = 6)). Participants were not informed about the less painful alternative and could use any strategy. We recorded the percentage of movements using the wrist flexion/extension alignment that evoked the lower intensity noxious stimulus, movement variability, and change in wrist/forearm alignment during pain. Participants adapted their strategy of wrist movement during pain provocation and reported less pain over time. Three adaptations of wrist movement were observed; (i) greater use of the wrist alignment with no/less noxious input (Pain 5-1, n = 8/21; Pain 5-0, n = 2/6); (ii) small (n = 9/21; n = 3/6) or (iii) large (n = 4/21; n = 1/6) change of wrist/forearm alignment to a region that was not allocated to provide an actual reduction in noxious stimulus. Pain reduction was achieved with "taking action" to relieve pain and did not depend on reduced noxious stimulus.

A randomised clinical trial comparing 35 Hz versus 50 Hz frequency stimulation effects on hand motor recovery in older adults after stroke.

More solid data are needed regarding the application of neuromuscular electrical stimulation (NMES) in the paretic hand following a stroke. A randomised clinical trial was conducted to compare the effects of two NMES protocols with different stimulation frequencies on upper limb motor impairment and function in older adults with spastic hemiparesis after stroke. Sixty nine outpatients were randomly assigned to the control group or the experimental groups (NMES with 50 Hz or 35 Hz). Outcome measures included motor impairment tests and functional assessment. They were collected at baseline, after 4 and 8 weeks of treatment, and after a follow-up period. NMES groups showed significant changes (p < 0.05) with different effect sizes in range of motion, grip and pinch strength, the Modified Ashworth Scale, and the muscle electrical activity in the extensors of the wrist. The 35 Hz NMES intervention showed a significant effect on Barthel Index. Additionally, there were no significant differences between the groups in the Box and Block Test. Both NMES protocols proved evidence of improvements in measurements related to hand motor recovery in older adults following a stroke, nevertheless, these findings showed that the specific stimulation frequency had different effects depending on the clinical measures under study.

Effects of interphase interval during neuromuscular electrical stimulation of the wrist extensors with maximally tolerated current intensity.

Short interphase intervals (IPIs) within biphasic symmetrical pulses enhance maximal electrically induced isometric contractions (EIC). However, IPI effects have not been previously studied in muscles stimulated at the highest tolerated current intensity. Our aim was to examine IPI effects on the strength of EIC, degree of discomfort, and sensory and motor thresholds on the wrist extensor muscles. Eighteen subjects (mean age 25.5, SD ± 3.97 years) participated in a repeated-measures trial. Five parameter settings were used to stimulate the wrist extensors: monophasic pulses with phase durations (PD) 200 µs, and biphasic pulses with PDs either 200 or 500 µs, applied with/without an IPI of 200 µs duration. Order of settings was randomized, and current was set at the maximum intensity tolerated by each subject. IPIs applied at the maximally tolerated current intensity did not increase the strength of the EICs and did not reduce the degree of discomfort or the sensory and motor thresholds. These findings were not dependent on the PDs. Insertion of an IPI within the biphasic current during stimulation of the wrist muscle yielded no advantage in term of contraction strength or degree of discomfort. These results contradict previous studies indicating stronger contractions when an IPI is inserted during stimulation at a predetermined submaximal current intensity. As some of the clinical applications of neuromuscular electrical stimulation utilize the highest intensity tolerated by the individual, these findings are clinically relevant. Additional studies involving other muscle groups, electrode size and locations, and phase parameters are warranted.

Design and Implementation of an Intelligent Analgesic Bracelet Based on Wrist-ankle Acupuncture.

A flexible, multifunctional, and intelligent analgesic bracelet was proposed in this article to alleviate symptoms of pain. Based on the theory of wrist-ankle acupuncture in traditional Chinese medicine, transcutaneous electrical nerve stimulation is the technical basis of the method. A set of targeted circuit system capable of generating adjustable electrical stimulation signals to simulate filamentary acupuncture was designed. The system architecture includes a wireless communication module, a signal control module, a stimulus signal generation module, and a wearable, flexible bracelet. In addition, a pain assessment interface with a visual analog scale was designed to assess pain levels. Two comparative experiments were designed, involving a custom pain assessment scale and hand-held dolorimeter that were performed before and after wearing the bracelet to verify the analgesic effect of the bracelet. The results showed that the wrist-worn analgesic bracelet is significantly effective in alleviating pain in various parts of the human body.

Utilizing High-Density Electroencephalography and Motion Capture Technology to Characterize Sensorimotor Integration While Performing Complex Actions.

Studies of sensorimotor integration often use sensory stimuli that require a simple motor response, such as a reach or a grasp. Recent advances in neural recording techniques, motion capture technologies, and time-synchronization methods enable studying sensorimotor integration using more complex sensory stimuli and performed actions. Here, we demonstrate that prehensile actions that require using complex sensory instructions for manipulating different objects can be characterized using high-density electroencephalography and motion capture systems. In 20 participants, we presented stimuli in different sensory modalities (visual, auditory) containing different contextual information about the object with which to interact. Neural signals recorded near motor cortex and posterior parietal cortex discharged based on both the instruction delivered and object manipulated. Additionally, kinematics of the wrist movements could be discriminated between participants. These findings demonstrate a proof-of-concept behavioral paradigm for studying sensorimotor integration of multidimensional sensory stimuli to perform complex movements. The designed framework will prove vital for studying neural control of movements in clinical populations in which sensorimotor integration is impaired due to information no longer being communicated correctly between brain regions (e.g. stroke). Such a framework is the first step towards developing a neural rehabilitative system for restoring function more effectively.

Validity and reliability of the Modified Sphygmomanometer Test with fixed stabilization for clinical measurement of muscle strength.

OBJECTIVE: To investigate the concurrent validity of the Modified Sphygmomanometer Test (MST) with fixed stabilization, compared to the portable dynamometer, and to verify its test-retest and inter-raterreliability. METHODS: Methodological study. The muscle strength of the following groups was measured: flexors and extensors of the wrist, of the hip, and of the knee and plantar flexors. The Tycos® aneroid sphygmomanometer and the Microfet 2® dynamometer were used. Stabilization was performed using the Mullingan® belt. Descriptive statistics were performed for characterization of the sample. To determine the validity of the MST with fixed stabilization, comparing it with the portable dynamometer, we investigated the correlation between the measurements obtained with the two instruments using the Pearson correlation coefficient. Intraclass Correlation Coefficient (ICC) was used to investigate inter-examiner and test-retest reliability (α = 0.05). RESULTS: 59 individuals were included (1176 evaluations). A statistically significant correlation of moderate to high magnitude (0.58 ≤ r ≤ 0.81) was observed for concurrent validity of the MST with fixed stabilization versus the portable dynamometer for all muscle groups. Regarding inter-rater reliability, it was observed statistically significant ICC considered excellent to good (0.72 ≤ r ≤ 0.94) for all muscle groups. Regarding test-retest reliability, first evaluator presented good to excellent ICC (0.64 ≤ r ≤ 0.94), while second evaluator presented good to excellent ICC (0.74 ≤ r ≤ 0.96) for all muscle groups. CONCLUSION: The MST with fixed stabilization is valid and reliable for clinical measurement of muscle strength and can overcome previous limitations reported in the literature.

Haptic Stimulation for Improving Training of a Motor Imagery BCI Developed for a Hand-Exoskeleton in Rehabilitation.

The use of robotic devices to provide active motor support and sensory feedback of ongoing motor intention, by means of a Brain Computer Interface (BCI), has received growing support by recent literature, with particular focus on neurorehabilitation therapies. At the same time, performance in the use of the BCI has become a more critical factor, since it directly influences congruency and consistency of the provided sensory feedback. As motor imagery is the mental simulation of a given movement without depending on residual function, training of patients in the use of motor imagery BCI can be extended beyond each rehabilitation session, and practiced by using simpler devices than rehabilitation robots available in the hospital. In this work, we investigated the use of haptic stimulation provided by vibrating electromagnetic motors to enhance BCI system training. The BCI is based on motor imagery of hand grasping and designed to operate a hand exoskeleton. We investigated whether haptic stimulation at fingerpads proves to be more effective than stimulation at wrist, already experimented in literature, due to the higher density of mechano-receptors. Our results did not show significant differences between the two body locations in BCI performance, yet a wider and more stable event-relateddesynchronization appeared for the finger-located stimulation. Future investigations will put in relation training with haptic feedback at fingerpads with BCI performance using the handexoskeleton, in grasping tasks that naturally involve haptic feedback at fingerpads.

Developing a Quasi-Static Controller for a Paralyzed Human Arm: A Simulation Study.

Individuals with paralyzed limbs due to spinal cord injuries lack the ability to perform the reaching motions necessary to every day life. Functional electrical stimulation (FES) is a promising technology for restoring reaching movements to these individuals by reanimating their paralyzed muscles. We have proposed using a quasi-static model-based control strategy to achieve reaching controlled by FES. This method uses a series of static positions to connect the starting wrist position to the goal. As a first step to implementing this controller, we have completed a simulated study using a MATLAB based dynamic model of the arm in order to determine the suitable parameters for the quasi-static controller. The selected distance between static positions in the path was 6 cm, and the amount of time between switching target positions was 1.3 s. The final controller can complete reaches of over 30 cm with a median accuracy of 6.8 cm.

Elicited Finger and Wrist Extension Through Transcutaneous Radial Nerve Stimulation.

Individuals with neurological disorders, such as stroke or spinal cord injury, often have weakness and/or spasticity in their hand and wrist muscles, which can lead to impaired ability to extend their fingers and wrists. Functional electrical stimulation can help to restore these motor functions. However, the conventional stimulation method can lead to fast muscle fatigue and limited movements due to a non-physiological recruitment of motor units and a limited recruitment of deep muscles. In this paper, we investigated the feasibility of eliciting various hand opening and wrist extension movement patterns through a transcutaneous electrical stimulation array, which targeted the proximal segment of the radial nerve bundle proximal to the elbow. The wrist and finger joint kinematics were used to classify the different movement patterns through a cluster analysis, and electromyogram signals from the wrist and finger extensors were recorded to investigate the muscle activation patterns. The results showed that the finger and wrist motions can be elicited both independently and in a coordinated manner, by changing the stimulation intensity and stimulation location. H-reflex activity was also observed, which demonstrated the potential of recruiting motor units in a physiological order. Our approach could be further developed into a rehabilitative/assistive tool for individuals with impaired hand opening and/or wrist extension.

An Acute Randomized Controlled Trial of Noninvasive Peripheral Nerve Stimulation in Essential Tremor.

OBJECTIVE: To evaluate the safety and effectiveness of a wrist-worn peripheral nerve stimulation device in patients with essential tremor (ET) in a single in-office session. METHODS: This was a randomized controlled study of 77 ET patients who received either treatment stimulation (N = 40) or sham stimulation (N = 37) on the wrist of the hand with more severe tremor. Tremor was evaluated before and immediately after the end of a single 40-minute stimulation session. The primary endpoint compared spiral drawing in the stimulated hand using the Tremor Research Group Essential Tremor Rating Assessment Scale (TETRAS) Archimedes spiral scores in treatment and sham groups. Additional endpoints included TETRAS upper limb tremor scores, subject-rated tasks from the Bain and Findley activities of daily living (ADL) scale before and after stimulation as well as clinical global impression-improvement (CGI-I) rating after stimulation. RESULTS: Subjects who received peripheral nerve stimulation did not show significantly larger improvement in the Archimedes spiral task compared to sham but did show significantly greater improvement in upper limb TETRAS tremor scores (p = 0.017) compared to sham. Subject-rated improvements in ADLs were significantly greater with treatment (49% reduction) than with sham (27% reduction; p = 0.001). A greater percentage of ET patients (88%) reported improvement in the stimulation group as compared to the sham group (62%) according to CGI-I ratings (p = 0.019). No significant adverse events were reported; 3% of subjects experienced mild adverse events. CONCLUSIONS: Peripheral nerve stimulation in ET may provide a safe, well-tolerated, and effective treatment for transient relief of hand tremor symptoms.

Prospects of Synchronous fMRI-EEG Recording as the Basis for Neurofeedback (Exemplified on Patient with Stroke Sequelae).

Synchronous fMRI-EEG mapping of cerebral activity in stroke patients made it possible to implement neurofeedback, a novel and promising therapeutic technology. This method integrates a real-time monitoring of cerebral activity by EEG and fMRI signals and training of the patients to control this activity simultaneously or alternatively via neurofeedback. The targets of such cerebral stimulation are cortical regions controlling arbitrary movements (Brodmann area 4), whereas its aim is optimization of activity in these regions in order to achieve better rehabilitation of stroke patients. The paper discusses the methodical details, advantages, and promise of bimodal neurofeedback treatment.

Dynamics of fMRI and EEG Parameters in a Stroke Patient Assessed during a Neurofeedback Course Focused on Brodmann Area 4 (M1).

A course of interactive stimulation of primary motor cortex (Brodmann area 4) in the brain of a stroke patient resulted in recovery of locomotion volume in the paretic extremities and in improvement of general health accompanied with diverse changes in cerebral activity. During the training course, the magnitude of response in the visual fields of Brodmann areas 17 and 18 decreased; in parallel, the motor areas were supplemented with other ones such as area 24 (the ventral surface of anterior cingulate gyrus responsible for self-regulation of human brain activity and implicated into synthesis of tactile and special information) in company with Brodmann areas 40, 41, 43, 44, and 45. EEG data showed that neurofeedback sessions persistently increased the θ rhythm power in Brodmann areas 7, 39, 40, and 47, while the corresponding powers progressively decreased during a real motion. Both real motion and its virtual sibling constructed by interactive stimulation via neurofeedback were characterized with decreasing powers of the EEG ß rhythm in Brodmann areas 6 and 8. The neurofeedback course decreased the coherence between the left Brodmann area 6 and some other ones examined in α and θ ranges. In the context of real motions, the coherence assessed in the EEG ß range generally increased. Overall, the EEG and fMRI parameters attest to growing similarity between the moieties of functional communications effected in real and imaginary movements during neurofeedback course. The data open the vista for interactive stimulation to rehabilitate stroke patients; they highlight the important role of Brodmann areas in rearrangement of the brain in such patients; finally, the present results revealed the "common nervous pathway" that can be used to restore the capability for imaginary and real movements by a neurofeedback course after stroke.

A Wearable Multifunctional Pulse Monitor Using Thermosensation-Based Flexible Sensors.

OBJECTIVE: This study proposes a novel wearable pulse monitoring system, which can realize the synchronous measurements of pulse wave, skin, temperature, and pulse wave velocity (PWV). METHODS: A flexible sensor based on thermosensation is used to detect pressure and temperature stimuli simultaneously. A total of two sensors are integrated to detect pulse transit along two specific points of the artery, e.g., Cun and Chi at a wrist, the data of which are subsequently used to figure out the PWV by using a tailor-designed algorithm conducted in a microprocessor. Calibration experiments and application cases are conducted to validate the effectiveness of the monitor. RESULTS: The developed monitor detects the physiological signals of pulse wave, PWV, and skin temperature simultaneously. In addition, the monitor can measure the pulse changes before and after exercises and track skin temperature variations when warming and cooling. Moreover, the monitor can be also used to detect the local PWV at the wrist. CONCLUSION: The synchronous measurements of pulse wave, skin temperature, and PWV using a wearable monitor are feasible. SIGNIFICANCE: The monitor is small, simple-structured, with multifunction, and thus provides a promising auxiliary approach for traditional Chinese medicine pulse diagnosis.

The modulation of force steadiness by electrical nerve stimulation applied to the wrist extensors differs for young and older adults.

PURPOSE: We compared the modulation of force steadiness by different types of electrical nerve stimulation in young (n = 13, 25 ± 4 years) and older (n = 12, 78 ± 5 years) adults. METHODS: The protocol involved four types of isometric contractions with the wrist-extensor muscles at 10% of the maximal force. Three of the contractions involved electrical nerve stimulation that comprised two forms of neuromuscular electrical stimulation (NMES) to evoke muscle contractions and a voluntary contraction with superimposed transcutaneous electrical nerve stimulation (TENS) at an intensity less than motor threshold. RESULTS: The coefficient of variation (CV) for force during voluntary wrist extension was less (P = 0.03) for young (1.82 ± 0.43%) than older adults (2.80 ± 1.08%). The CV for force did not differ between age groups during the three types of electrical nerve stimulation but was reduced relative to the value observed during voluntary wrist extension for older adults. In contrast, the CV for force increased during the voluntary contraction with superimposed TENS for young adults but not for older adults. Moreover, there were significant negative correlations in older adults between the CV for force during the voluntary contraction and its decrease with electrical nerve stimulation. CONCLUSION: Differences in the CV for force between the evoked and voluntary contractions for the two age groups suggest that the variance in common synaptic input to motor neurons during steady voluntary contractions with the wrist extensors is greater for older adults than young adults.

A Timeline of Motor Preparatory State Prior to Response Initiation: Evidence from Startle.

Response preparation in simple reaction time (RT) tasks has been modeled as an increase in neural activation to a sub-threshold level, which is maintained until the go-signal. However, the amount of time required for response preparation following a warning signal (WS) is currently unclear, as experiments typically employ long foreperiods to ensure maximal preparation. The purpose of the present experiments was to examine the time course of motor preparation in a simple RT task when given a limited amount of time to engage in preparatory processing. In Experiment 1, participants completed wrist extension movements in a simple RT paradigm with a short (500 ms) fixed foreperiod, and a long (8.5-10.5 s) inter-trial interval. To probe response preparation, a startling acoustic stimulus (SAS), which involuntarily triggers the release of sufficiently prepared responses, was randomly presented during the foreperiod at one of six equally spaced time points between 0 and 500 ms prior to the go-signal. Results showed that the long inter-trial interval was not always effective at preventing participants from engaging in preparatory processing between trials; thus, in Experiment 2 participants performed wrist flexion or extension movements in an instructed delay paradigm, where the required movement was cued by the WS. Results showed that the proportion of startle trials where the intended response was elicited by the SAS at short latency significantly increased until 100 ms prior to the go-signal, indicating response preparation can take up to 300-400 ms following the WS in a simple RT task with a short fixed foreperiod.

Ultrasonographic and clinical evaluation of additional contribution of kinesiotaping to tendon and nerve gliding exercises in the treatment of carpal tunnel syndrome

Background and aim: This study aims to ultrasonographically and clinically evaluate the additive contribution of kinesiotaping to tendon and nerve gliding exercises in the treatment of mild or moderate carpal tunnel syndrome (CTS). Materials and methods: Thirty-eight wrists of patients (n = 21) with CTS were randomized into two groups as the intervention group (n = 19) and the control group (n = 19). Tendon and nerve gliding exercises were given to both groups. In the intervention group, additional kinesiotaping was performed three times with 5-day intervals. Functional assessments were performed with the Boston Carpal Tunnel Syndrome Questionnaire and the Moberg pick-up test. Hand grip and pinch strength were evaluated. Cross-section area (CSA) of the median nerve was measured by ultrasonography. All assessments were performed at baseline and at 3 and 6 weeks after treatment. Results: In the intervention group, there was a significant improvement in all clinical assessments and in the CSA of the median nerve at the level of proximal carpal bones. In the control group, a significant improvement was detected in all clinical parameters except grip strength and ultrasonographic measurements. There was no significant difference in the clinical and ultrasonographic findings between the groups at 6 weeks. Conclusion: Kinesiotaping may provide a positive contribution to ultrasonographic and clinical outcomes in the treatment of mild or moderate CTS in the short term.

The effects of strengthening exercises for wrist flexors and extensors on muscle strength and counter-stroke performance in amateur table tennis players.

This study aims to evaluate the effects of strengthening exercises on wrist flexor and extensor strength, hand grip strength, and counter-stroke performance. Thirty amateur table tennis players were recruited and randomly allocated into two groups: the control and the training group (n = 15/group). Pre- and post-data were collected. The training group performed home exercises for six weeks using a bucket filled with water, while the controls were asked to keep their lifestyle as usual. The general characteristics were no significant differences. The training group showed significantly higher levels of wrist flexor and extensor strength than the control group (p < 0.05). However, the difference in hand grip strength was not statistically significant. Both groups showed significant improvement in counter-stroke performance (p < 0.05), however, there was no difference between the groups. In conclusion, specific strengthening exercises increase wrist flexor and extensor strength, but they have no effect on either hand grip strength or counter-stroke performance.

Wrist-ankle acupuncture (WAA) for primary dysmenorrhea (PD) of young females: study protocol for a randomized controlled trial.

BACKGROUND: Primary dysmenorrhea (PD) is one of the most common health complaints all over the world, specifically among young females. Acupuncture has been employed to relieve the pain-based symptoms and to avoid the side effects of conventional medication, and wrist-ankle acupuncture (WAA) has confirmed analgesic efficacy for various types of pain. The aim of this study is to evaluate the immediate analgesia effect of WAA on PD of young females. METHODS/DESIGN: This study will carry out a randomized parallel controlled single-blind trial to observe the immediate analgesia effect of WAA in PD of young females. Sixty participants who meet inclusion criteria will be recruited from September 2016 to September 2017 in Changhai hospital of China. They are randomly assigned to WAA therapy or sham acupuncture groups (30 patients for each group), and then receive real or sham acupuncture treatment, respectively. In this trial, the primary outcome measure is simple form of McGill pain questionnaire (SF-MPQ), while expectation and treatment credibility scale (ETCS), safety assessment, the COX menstrual symptom scale (CMSS), questionnaire about the feeling of being punctured are included in the secondary outcomes. DISCUSSION: This trial will be the first study protocol designed to evaluate the immediate analgesia effect of WAA in PD of young females. The strengths in methodology, including rigorous randomized, sham-controlled, participants-blinded and assessors-blinded, will guarantee the quality of this study. WAA doesn't require any needling sensation, so non-penetrating sham acupuncture can serve as an effective placebo intervention in this trial. TRIALS REGISTRATION: Chinese Clinical Trial Registry (identifier: ChiCTR-IOR-16008546 ; registration date: 27 May 2016).

Randomized, sham-controlled trial based on transcranial direct current stimulation and wrist robot-assisted integrated treatment on subacute stroke patients: Intermediate results.

The main goal of this study is to analyse the effects of combined transcranial direct current stimulation (tDCS) and wrist robot-assisted therapy in subacute stroke patients. Twenty-four patients were included in this study and randomly assigned to the experimental (EG) or control group (CG). All participants performed wrist robot-assisted training a) in conjunction with tDCS (real stimulation for patients in EG) or b) without tDCS (sham stimulation for patients in CG). Clinical scales and kinematic parameters recorded by the robot were used for the assessment. Clinical outcome measures show a significant decrease in motor impairment after the treatment in both groups. Kinematic data show several significant improvements after the integrated therapy in both groups. However, no significant differences in both clinical outcome measures and kinematic parameters was found between two groups. The potential advantages of combined tDCS and wrist robot-assisted therapy in subacute stroke patients are still unclear.

Real-time changes in corticospinal excitability related to motor imagery of a force control task.

OBJECTIVE: To investigate real-time excitability changes in corticospinal pathways related to motor imagery in a changing force control task, using transcranial magnetic stimulation (TMS). METHODS: Ten healthy volunteers learnt to control the contractile force of isometric right wrist dorsiflexion in order to track an on-screen sine wave form. Participants performed the trained task 40 times with actual muscle contraction in order to construct the motor image. They were then instructed to execute the task without actual muscle contraction, but by imagining contraction of the right wrist in dorsiflexion. Motor evoked potentials (MEPs), induced by TMS in the right extensor carpi radialis muscle (ECR) and flexor carpi radialis muscle (FCR), were measured during motor imagery. MEPs were induced at five time points: prior to imagery, during the gradual generation of the imaged wrist dorsiflexion (Increasing phase), the peak value of the sine wave, during the gradual reduction (Decreasing phase), and after completion of the task. The MEP ratio, as the ratio of imaged MEPs to resting-state, was compared between pre- and post-training at each time point. RESULTS: In the ECR muscle, the MEP ratio significantly increased during the Increasing phase and at the peak force of dorsiflexion imagery after training. Moreover, the MEP ratio was significantly greater in the Increasing phase than in the Decreasing phase. In the FCR, there were no significant consistent changes. CONCLUSION: Corticospinal excitability during motor imagery in an isometric contraction task was modulated in relation to the phase of force control after image construction.