Deciphering Functional Connectivity Differences Between Motor Imagery and Execution of Target-Oriented Grasping.

This study aimed to delineate overlapping and distinctive functional connectivity in visual motor imagery, kinesthetic motor imagery, and motor execution of target-oriented grasping action of the right hand. Functional magnetic resonance imaging data were obtained from 18 right-handed healthy individuals during each condition. Seed-based connectivity and multi-voxel pattern analyses were employed after selecting seed regions with the left primary motor cortex and supplementary motor area. There was equivalent seed-based connectivity during the three conditions in the bilateral frontoparietal and temporal areas. When the seed region was the left primary motor cortex, increased connectivity was observed in the left cuneus and superior frontal area during visual and kinesthetic motor imageries, respectively, compared with that during motor execution. Multi-voxel pattern analyses revealed that each condition was differentiated by spatially distributed connectivity patterns of the left primary motor cortex within the right cerebellum VI, cerebellum crus II, and left lingual area. When the seed region was the left supplementary motor area, the connectivity patterns within the right putamen, thalamus, cerebellar areas IV-V, and left superior parietal lobule were significantly classified above chance level across the three conditions. The present findings improve our understanding of the spatial representation of functional connectivity and its specific patterns among motor imagery and motor execution. The strength and fine-grained connectivity patterns of the brain areas can discriminate between motor imagery and motor execution.

Vision-aided brain-machine interface training system for robotic arm control and clinical application on two patients with cervical spinal cord injury.

BACKGROUND: While spontaneous robotic arm control using motor imagery has been reported, most previous successful cases have used invasive approaches with advantages in spatial resolution. However, still many researchers continue to investigate methods for robotic arm control with noninvasive neural signal. Most of noninvasive control of robotic arm utilizes P300, steady state visually evoked potential, N2pc, and mental tasks differentiation. Even though these approaches demonstrated successful accuracy, they are limited in time efficiency and user intuition, and mostly require visual stimulation. Ultimately, velocity vector construction using electroencephalography activated by motion-related motor imagery can be considered as a substitution. In this study, a vision-aided brain-machine interface training system for robotic arm control is proposed and developed. METHODS: The proposed system uses a Microsoft Kinect to detect and estimates the 3D positions of the possible target objects. The predicted velocity vector for robot arm input is compensated using the artificial potential to follow an intended one among the possible targets. Two participants with cervical spinal cord injury trained with the system to explore its possible effects. RESULTS: In a situation with four possible targets, the proposed system significantly improved the distance error to the intended target compared to the unintended ones (p < 0.0001). Functional magnetic resonance imaging after five sessions of observation-based training with the developed system showed brain activation patterns with tendency of focusing to ipsilateral primary motor and sensory cortex, posterior parietal cortex, and contralateral cerebellum. However, shared control with blending parameter α less than 1 was not successful and success rate for touching an instructed target was less than the chance level (= 50%). CONCLUSIONS: The pilot clinical study utilizing the training system suggested potential beneficial effects in characterizing the brain activation patterns.

Inertial Measurement Unit Based Upper Extremity Motion Characterization for Action Research Arm Test and Activities of Daily Living.

In practical rehabilitation robot development, it is imperative to pre-specify the critical workspace to prevent redundant structure. This study aimed to characterize the upper extremity motion during essential activities in daily living. An IMU-based wearable motion capture system was used to access arm movements. Ten healthy subjects performed the Action Research Arm Test (ARAT) and six pre-selected essential daily activities. The Euler angles of the major joints, and acceleration from wrist and hand sensors were acquired and analyzed. The size of the workspace for the ARAT was 0.53 (left-right) × 0.92 (front-back) × 0.89 (up-down) m for the dominant hand. For the daily activities, the workspace size was 0.71 × 0.70 × 0.86 m for the dominant hand, significantly larger than the non-dominant hand (p ≤ 0.011). The average range of motion (RoM) during ARAT was 109.15 ± 18.82° for elbow flexion/extension, 105.23 ± 5.38° for forearm supination/pronation, 91.99 ± 0.98° for shoulder internal/external rotation, and 82.90 ± 22.52° for wrist dorsiflexion/volarflexion, whereas the corresponding range for daily activities were 120.61 ± 23.64°, 128.09 ± 22.04°, 111.56 ± 31.88°, and 113.70 ± 18.26°. The shoulder joint was more abducted and extended during pinching compared to grasping posture (p < 0.001). Reaching from a grasping posture required approximately 70° elbow extension and 36° forearm supination from the initial position. The study results provide an important database for the workspace and RoM for essential arm movements.

Recovery of Proprioception in the Upper Extremity by Robotic Mirror Therapy: a Clinical Pilot Study for Proof of Concept.

A novel robotic mirror therapy system was recently developed to provide proprioceptive stimulus to the hemiplegic arm during a mirror therapy. Validation of the robotic mirror therapy system was performed to confirm its synchronicity prior to the clinical study. The mean error angle range between the intact arm and the robot was 1.97 to 4.59 degrees. A 56-year-old male who had right middle cerebral artery infarction 11 months ago received the robotic mirror therapy for ten 30-minute sessions during 2 weeks. Clinical evaluation and functional magnetic resonance imaging (fMRI) studies were performed before and after the intervention. At the follow-up evaluation, the thumb finding test score improved from 2 to 1 for eye level and from 3 to 1 for overhead level. The Albert's test score on the left side improved from 6 to 11. Improvements were sustained at 2-month follow-up. The fMRI during the passive motion revealed a considerable increase in brain activity at the lower part of the right superior parietal lobule, suggesting the possibility of proprioception enhancement. The robotic mirror therapy system may serve as a useful treatment method for patients with supratentorial stroke to facilitate recovery of proprioceptive deficit and hemineglect.

Swallowing Function and Kinematics in Stroke Patients with Tracheostomies.

The purpose of this study was to compare the swallowing function and kinematics in stroke patients with and without tracheostomies. In this retrospective matched case-control study, we compared stroke patients with (TRACH group, n = 24) and without (NO-TRACH group, n = 24) tracheostomies. Patients were matched for age, sex, and stroke-type. Swallowing function was evaluated using the videofluoroscopic dysphagia scale (VDS) and functional oral intake scale (FOIS) obtained from videofluoroscopic swallow study (VFSS) images. Swallowing kinematics were evaluated using a two-dimensional kinematic analysis of the VFSS images. Mean duration of tracheostomy was 132.38 ± 150.46 days in the TRACH group. There was no significant difference in the total VDS score between the TRACH (35.17 ± 15.30) and NO-TRACH groups (29.25 ± 16.66, p = 0.247). FOIS was significantly lower in the TRACH group (2.33 ± 1.40) than in the NO-TRACH group (4.33 ± 1.79, p = 0.001). The TRACH group had a significantly lower maximum vertical displacement (15.23 ± 7.39 mm, p = 0.011) and velocity (54.99 ± 29.59 mm/s, p = 0.011), and two-dimensional velocity (61.07 ± 24.89 mm/s, p = 0.013) of the larynx than the NO-TRACH group (20.18 ± 5.70 mm, 82.23 ± 37.30 mm/s, and 84.40 ± 36.05 mm/s, respectively). Maximum horizontal velocity of the hyoid bone in the TRACH group (36.77 ± 16.97 mm/s) was also significantly lower than that in the NO-TRACH group (47.49 ± 15.73 mm/s, p = 0.032). This study demonstrated that stroke patients with tracheostomies had inferior swallowing function and kinematics than those without tracheostomies. A prospective longitudinal study is needed to elucidate the effect of a tracheostomy on swallowing recovery in stroke patients.

Smartwatch-based functional assessment for upper extremity impairment after musculoskeletal injuries: A pilot study.

Introduction: Wearable sensors are increasingly applied to rehabilitation for arm movement analysis. However, simple and clinically relevant applications are scarce. Objectives: To investigate the feasibility of single smart watch-based parameters for functional assessment in upper limb rehabilitation for musculoskeletal injuries using a commercial smart watch. Method: Ten patients with unilateral shoulder pain and range-of-motion limitations were enrolled. They wore Galaxy Watch® and performed three sets of upper extremity tasks consisting of gross activities-of-daily-living tasks, Wolf Motor Function Test (WMFT), and Upper Extremity Functional Index (UEFI), and the acceleration and angular velocities were acquired. The motion segment size (MSS), representing motion smoothness from a clinical perspective, and various sensor-based parameters were extracted. The correlation between the parameters and clinical outcome measures were analyzed. The percent relative range (PRR) of the significant parameters was also calculated. Results: For overhead and behind body activity task set, mean MSS for elbow flexion/extension axis significantly correlated with WMFT score (R = 0.784, p = .012). For planar tasks, mean MSS for the forearm supination/pronation (R = 0.815, p = .007) and shoulder rotation (R = 0.870, p = .002) axes significantly correlated with WMFT score. For forearm and fine movement task set, mean MSS of the elbow flexion/extension angle showed significant correlation with WMFT (R = 0.880, p < .001) and UEFI (R = 0.718, p = .019). The total performance time (R = -0.741, p = .014) also showed significant correlation with WMFT score. The PRR for mean MSS in forearm supination (71.5%, planar tasks) and mean MSS in x-direction (49.8%, forearm and fine motor movements) were similar to the PRR of WMFT (58.5%), suggesting sufficient variation range across different degree of impairments. Conclusion: The commercial smart watch-based parameters showed consistent potential for use in clinical functional assessments.

Factors associated with sedentary behavior among community-dwelling breast cancer survivors aged 50 years or older.

Although increased sedentary behavior is associated with poor health outcomes among breast cancer survivors, the factors associated with high sedentary time in community-dwelling breast cancer survivors are unknown. This study aimed to identify factors associated with sedentary behavior in Korean community-dwelling breast cancer survivors aged ≥ 50 years. We included 205 breast cancer survivors from the Korea National Health and Nutrition Examination Survey. Total daily sedentary time was evaluated using questions from the Korean version of the Global Physical Activity Questionnaire. We used complex-sample multivariable-adjusted logistic regression analyses to analyze the associations between sociodemographic factors, medical factors, and health-related quality of life and high sedentary time (≥ 420 min/day). Among the Korean community-dwelling breast cancer survivors, 48.2% had a high daily sedentary time. Insufficient aerobic exercise (OR 2.29; 95% CI 1.12-4.69), diabetes (OR 3.37; 95% CI 1.22-9.33), and unemployed status (OR 2.29; 95% CI 1.05-5.02) were independently associated with high sedentary time after the adjustment for multiple sociodemographic and medical confounders. Participants with a low sedentary time (< 420 min/day) showed a significantly higher mean European Quality of Life 5-Dimensions (EQ-5D) index than those with a high sedentary time after adjusting for multiple confounders (0.89 ± 0.03 vs. 0.82 ± 0.04; P = 0.001). Among the EQ-5D dimensions, problems in mobility (OR 3.37; 95% CI 1.42-7.98) and pain/discomfort (OR 2.64; 95% CI 1.24-5.63) dimensions showed positive associations with high sedentary time. Middle- or older-aged breast cancer survivors with insufficient aerobic exercise, diabetes, unemployed status, and impaired quality of life are more likely to have a high sedentary time. Reducing sedentary behavior in this population requires a tailored approach that considers diverse sociodemographic, medical, and quality-of-life factors.

Differential association between physical activity behaviours and dynapenia by comorbid diseases in community-dwelling Korean older adults.

BACKGROUND: Physical activity (PA) behaviours and comorbid diseases are associated with muscle strength. However, the association between dynapenia and detailed PA behaviours, including participation in aerobic and resistance exercises and sedentary behaviour (SB), in relation to comorbid diseases has not yet been investigated. Using nationwide data, this study aimed to evaluate the independent association of dynapenia with detailed PA behaviour (participation in aerobic and resistance exercises and SB), and assess the differential associations of detailed PA behaviour with dynapenia according to comorbid diseases with prevalent sarcopenia. METHODS: A total of 7,558 community-dwelling older adults aged ≥ 65 years who were included in the Korea National Health and Nutrition Examination Survey from 2014 to 2019 were included in the present study. Cross-sectional associations between PA behaviours (participation in aerobic exercise, participation in resistance exercise, and SB) and dynapenia were analysed using complex-sample multivariable-adjusted logistic regression models according to the type of comorbid disease (cardiovascular disease [CVD], diabetes mellitus [DM], and chronic lung disease [CLD]). RESULTS: Sufficient aerobic exercise, sufficient resistance exercise, and low sedentary time of < 420 min/day showed independent negative associations with dynapenia (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.60-0.83; OR, 0.54; 95% CI, 0.42-0.69; and OR, 0.84; 95% CI, 0.72-0.97, respectively). Among the participants with CVD or CLD, the associations of sufficient resistance exercise (OR, 0.46; 95% CI, 0.26-0.82 and OR, 0.51; 95% CI, 0.35-0.75 for CVD and CLD, respectively) and low sedentary time (OR, 0.66; 95% CI, 0.45-0.98 and OR, 0.71; 95% CI, 0.55-0.93 for CVD and CLD, respectively) with dynapenia were significant, whereas the association of sufficient aerobic exercise with dynapenia was insignificant. Meanwhile, in participants with DM, sufficient aerobic exercise (OR, 0.70; 95% CI, 0.52-0.94) and sufficient resistance exercise (OR, 0.45; 95% CI, 0.29-0.70) were independently associated with dynapenia, whereas no association between SB and dynapenia was found. CONCLUSION: We observed an independent inverse association between PA behaviours and dynapenia. Disease-specific associations between each PA behaviour (sufficient aerobic exercise, sufficient resistance exercise, and low sedentary time) and dynapenia differed in the older adults. Therefore, these differences should be acknowledged during interventions for this population.

Insole Pressure Sensors to Assess Post-Stroke Gait.

OBJECTIVE: To confirm that the simplified insole does not affect the gait speed and to identify objective sensor-based gait parameters that correlate strongly with existing clinical gait assessment scales. METHODS: Ten participants with gait impairment due to hemiplegic stroke were enrolled in this study. Pairs of insoles with four pressure sensors on each side were manufactured and placed in each shoe. Data were extracted during the 10-Meter Walk Test. Several sensor-derived parameters (for example stance time, heel_on-to-toe_peak time, and toe_peak pressure) were calculated and correlated with gait speed and lower extremity Fugl-Meyer (F-M) score. RESULTS: The insole pressure sensor did not affect gait, as indicated by a strong correlation (ρ=0.988) and high agreement (ICC=0.924) between the gait speeds with and without the insole. The parameters that correlated most strongly with highest ß coefficients against the clinical measures were stance time of the non-hemiplegic leg (ß=-0.87 with F-M and ß=-0.95 with gait speed) and heel_on-to-toe_peak time of the non-hemiplegic leg (ß=-0.86 with F-M and -0.94 with gait speed). CONCLUSION: Stance time of the non-hemiparetic leg correlates most strongly with clinical measures and can be assessed using a non-obtrusive insole pressure sensor that does not affect gait function. These results suggest that an insole pressure sensor, which is applicable in a home environment, may be useful as a clinical endpoint in post-stroke gait therapy trials.

Kinematic effects of hyolaryngeal electrical stimulation therapy on hyoid excursion and laryngeal elevation.

The purpose of this study was to assess the effect of repeated sessions of electrical stimulation therapy (EST) on the neck muscles with respect to the stimulation site by using quantitative kinematic analysis of videofluoroscopic swallowing studies (VFSS) in dysphagia patients with acquired brain injury. We analyzed 50 patients in a tertiary hospital who were randomly assigned into two different treatment groups. One group received EST on the suprahyoid muscle only (SM), and the other group received stimulation with one pair of electrodes on the suprahyoid muscle and the other pair on the infrahyoid muscle (SI). All patients received 10-15 sessions of EST over 2-3 weeks. The VFSS was carried out before and after the treatment. Temporal and spatial parameters of the hyoid excursion and laryngeal elevation during swallowing were analyzed by two-dimensional motion analysis. The SM group (n = 25) revealed a significant increase in maximal anterior hyoid excursion distance (mean ± SEM = 1.56 ± 0.52 mm, p = 0.008) and velocity (8.76 ± 3.42 mm/s, p = 0.017), but there was no significant increase laryngeal elevation. The SI group (n = 25), however, showed a significant increase in maximal superior excursion distance (2.09 ± 0.78 mm, p = 0.013) and maximal absolute excursion distance (2.20 ± 0.82 mm, p = 0.013) of laryngeal elevation, but no significant increase in hyoid excursion. There were no significant differences between the two groups with respect to changes in maximal anterior hyoid excursion distance (p = 0.130) and velocity (p = 0.254), and maximal distance of superior laryngeal elevation (p = 0.525). EST on the suprahyoid muscle induced an increase in anterior hyoid excursion, and infrahyoid stimulation caused an increase in superior laryngeal elevation. Hyolaryngeal structural movements were increased in different aspects according to the stimulation sites. Targeted electrical stimulation based on pathophysiology is necessary.

Differences in Associated Factors of Sedentary Behavior by Diabetes Mellitus Status: A Nationwide Cross-Sectional Study.

This study aimed to identify the lifestyle and comorbidity factors associated with sedentary behavior by diabetes mellitus (DM) status. A total of 17,832 participants aged ≥50 years from the Korea National Health and Nutrition Examination Survey were included. Factors associated with long sedentary time (LST, ≥420 min/day) in individuals with and without DM (non-DM) were assessed. Among individuals with DM, LST was independently associated with excessive alcohol drinking (OR, 1.34; 95% CI, 1.02-1.74) and cardiovascular disease (OR, 1.47; 95% CI, 1.16-1.85). In individuals without DM, cancer (OR, 1.24; 95% CI, 1.06-1.44) and past smoking (OR, 1.16; 95% CI, 1.01-1.35) were independently associated with LST. Obesity (DM: OR, 1.28; 95% CI, 1.05-1.54; non-DM: OR, 1.24; 95% CI, 1.11-1.37), insufficient aerobic exercise (DM: OR, 1.55; 95% CI, 1.30-1.84; non-DM: OR, 1.50; 95% CI, 1.37-1.63), current smoking (DM: OR, 1.51; 95% CI, 1.11-2.05; non-DM: OR, 1.23; 95% CI, 1.05-1.45), and arthritis (DM: OR, 1.28; 95% CI, 1.04-1.56; non-DM: OR, 1.15; 95% CI, 1.04-1.27) were consistently associated with LST regardless of DM status. To reduce sedentary behavior time, it is important to consider an individual's diabetes status and adopt a personalized approach.

Evaluation of Motion Segment Size as a New Sensor-based Functional Outcome Measure in Stroke Rehabilitation.

OBJECTIVE: To evaluate a novel parameter, motion segment size (MSS), in stroke patients with upper limb impairment and validate its clinical applicability by correlating results with a standard clinical task-based functional evaluation tool. METHODS: In this cross-sectional study, patients with hemiplegia and healthy controls equipped with multiple inertial measurement unit (IMU) sensors performed Action Research Arm Test (ARAT) and activities of daily living (ADL) tasks. Acceleration of the wrist and Euler angles of each upper limb segment were measured. The average and maximum MSS, accumulated motion, total performance time, and average motion speed (AMS) were extracted for analysis. RESULTS: Data from nine patients and 10 controls showed that the average MSS of forearm supination/pronation and elbow flexion/extension during full ARAT tasks showed a significant difference between patients and controls and a significant correlation with ARAT scores. CONCLUSIONS: We suggest that MSS may provide clinically relevant information regarding upper limb functional status in stroke patients.

Functional improvement by body-powered 3D-printed prosthesis in patients with finger amputation: Two case reports.

RATIONALE: The most common upper limb amputations are finger amputations, resulting in functional limitations that lead to problems with activities of daily living or job loss. For many years, prosthetic options for finger amputations have been limited to passive prostheses. In many countries including South Korea, body-powered finger prostheses have rarely been prescribed due to high cost, lack of experience of physicians and prosthetists, low interest and no coverage by insurance benefits. We report 2 cases of work-related finger amputations in patients who received body-powered 3D-printed finger prostheses. PATIENT CONCERNS AND DIAGNOSIS: Patient 1 was a 25-year-old woman with second and third finger amputations at the proximal interphalangeal level. Patient 2 was a 26-year-old man who sustained a second finger amputation at proximal interphalangeal level. INTERVENTIONS: We created body-powered 3D-printed finger prostheses that mimicked distal interphalangeal joint motion through patient-driven metacarpophalangeal joint motion using a string connected to a wrist strap and a linkage system. The source code "Knick Finger" was downloaded from e-NABLE. OUTCOMES: After 1 month of prosthesis training, both patients were satisfied with the prostheses and showed improved performance in patient-derived goals of cooking (patient 1) and typing on a computer (patient 2). LESSONS: Over the past decade, significant advances have been made in 3D-printed prosthetics owing to their light weight, low cost, on-site fabrication, and easy customization. Although there are still several limitations in the general application of 3D-printed finger prostheses, our study suggests that for patients with finger amputations, body-powered 3D-printed finger prostheses have high potential as an additional prosthetic option to the existing passive cosmetic prostheses.

Exploring user perspectives on a robotic arm with brain-machine interface: A qualitative focus group study.

Brain-machine Interface (BMI) is a system that translates neuronal data into an output variable to control external devices such as a robotic arm. A robotic arm can be used as an assistive living device for individuals with tetraplegia. To reflect users' needs in the development process of the BMI robotic arm, our team followed an interactive approach to system development, human-centered design, and Human Activity Assistive Technology model. This study aims to explore the perspectives of people with tetraplegia about activities they want to participate in, their opinions, and the usability of the BMI robotic arm. Eight people with tetraplegia participated in a focus group interview in a semistructured interview format. A general inductive analysis method was used to analyze the qualitative data. The 3 overarching themes that emerged from this analysis were: 1) activities, 2) acceptance, and 3) usability. Activities that the users wanted to do using the robotic arm were categorized into the following 5 activity domains: activities of daily living (ADL), instrumental ADL, health management, education, and leisure. Participants provided their opinions on the needs and acceptance of the BMI technology. Participants answered usability and expected standards of the BMI robotic arm within 7 categories such as accuracy, setup, cost, etc. Participants with tetraplegia have a strong interest in the robotic arm and BMI technology to restore their mobility and independence. Creating BMI features appropriate to users' needs, such as safety and high accuracy, will be the key to acceptance. These findings from the perspectives of potential users should be taken into account when developing the BMI robotic arm.

Early Quantitative Partial Weight-Bearing Exercise After Periarticular Fractures of the Tibia Using a Lower-Body Positive-Pressure Treadmill: A Case Series.

The partial weight-bearing protocol after lower limb fracture is an important issue in postoperative rehabilitation. Because it is difficult to quantify the actual weight load and provide a constant weight, the protocol is unestablished. By training with a lower-body positive-pressure treadmill and using an in-shoe pressure-measuring device, partial weight-bearing exercise can be performed with quantified loads. This case series illustrates the applicability of an early quantitative partial weight-bearing rehabilitation program using lower-body positive-pressure treadmill with an in-shoe pressure-measuring device after periarticular tibial fractures, which provides a quantitatively predetermined constant load.

Temporal characteristics of laryngeal penetration and aspiration in stroke patients.

BACKGROUND: Despite the importance of understanding penetration-aspiration (PA) in patients with stroke, the pathophysiology of PA remains unclear. OBJECTIVES: This study aimed to investigate the temporal characteristics of PA in post-stroke patients in terms of the timing of the PA event and hyolaryngeal incoordination. METHODS: Fifty-eight swallows (38 stroke patients), showing PA when swallowing a thin liquid, were included. The timing of PA was classified kinematically as before or during the swallow. The movement sequence of vertical laryngeal elevation, horizontal hyoid excursion, and epiglottic rotation were compared with healthy controls. Spatiotemporal measurements, videofluoroscopic dysphagia scale parameters were compared between subgroups. RESULTS: Thirteen swallows (22.4%) were classified as PA before the swallow and 45 were classified as PA during the swallow (77.6%). Among the PA during the swallow, 26 (57.8%) swallows exhibited abnormal sequences of hyolaryngeal movements and 19 (42.2%) swallows showed normal sequences of hyolaryngeal movements compared with healthy controls. The onset time of horizontal hyoid excursion (P = 0.028), the time to maximal horizontal hyoid excursion (P = 0.010), and maximal epiglottic rotation (P = 0.030) were significantly more delayed in the PA during the swallow group than in the PA before the swallow group. In the swallows with abnormal sequential movements, the onset of horizontal hyoid excursion occurred significantly later than the onset of epiglottic rotation (P < 0.001). Pyriform sinus residue was observed significantly more often in the swallows with abnormal sequences (P = 0.030) than in the swallows with normal sequences. CONCLUSIONS: The timing of PA can be classified as before and during the swallow with significantly different temporal characteristics. The horizontal movement of hyoid is the most important factor associated with the pathophysiology of PA in stroke patients.

Differential kinematic features of the hyoid bone during swallowing in patients with Parkinson's disease.

This study aimed to investigate spatiotemporal characteristics of the hyoid bone during swallowing in patients with Parkinson's disease (PD) and dysphagia. Spatiotemporal data of the hyoid bone was obtained from videofluoroscopic images of 69 subjects (23 patients with PD, 23 age- and sex-matched healthy elderly controls, and 23 healthy young controls). Normalized profiles of displacement/velocity were analyzed during different periods (percentile) of swallowing using functional regression analysis, and the maximal values were compared between the groups. Maximal horizontal displacement and velocity were significantly decreased during the initial backward (P = 0.006 and P < 0.001, respectively) and forward (P = 0.008 and P < 0.001, respectively) motions in PD patients compared to elderly controls. Maximal vertical velocity was significantly lower in PD patients than in elderly controls (P = 0.001). No significant difference was observed in maximal displacement and velocity in both horizontal and vertical planes between the healthy elderly and young controls, although horizontal displacement was significantly decreased during the forward motion (51st-57th percentiles) in the elderly controls. In conclusion, reduced horizontal displacement and velocity of the hyoid bone during the forward motion would be due to combined effects of disease and aging, whereas those over the initial backward motion may be considered specific to patients with PD.

Target-oriented motor imagery for grasping action: different characteristics of brain activation between kinesthetic and visual imagery.

Motor imagery (MI) for target-oriented movements, which is a basis for functional activities of daily living, can be more appropriate than non-target-oriented MI as tasks to promote motor recovery or brain-computer interface (BCI) applications. This study aimed to explore different characteristics of brain activation among target-oriented kinesthetic imagery (KI) and visual imagery (VI) in the first-person (VI-1) and third-person (VI-3) perspectives. Eighteen healthy volunteers were evaluated for MI ability, trained for the three types of target-oriented MIs, and scanned using 3 T functional magnetic resonance imaging (fMRI) under MI and perceptual control conditions, presented in a block design. Post-experimental questionnaires were administered after fMRI. Common brain regions activated during the three types of MI were the left premotor area and inferior parietal lobule, irrespective of the MI modalities or perspectives. Contrast analyses showed significantly increased brain activation only in the contrast of KI versus VI-1 and KI versus VI-3 for considerably extensive brain regions, including the supplementary motor area and insula. Neural activity in the orbitofrontal cortex and cerebellum during VI-1 and KI was significantly correlated with MI ability measured by mental chronometry and a self-reported questionnaire, respectively. These results can provide a basis in developing MI-based protocols for neurorehabilitation to improve motor recovery and BCI training in severely paralyzed individuals.

Effect of reclining angle on lumbar lordosis at driving posture: A radiological evaluation.

BACKGROUND: Optimal seatback angles for automobile drivers' seats have been investigated based on comfort and back muscle activities; however, radiology supported evidences are scarce. OBJECTIVE: The aim of this study was to evaluate optimal range of the seatback reclining regarding torso angles for an automobile driver's seat to preserve lumbar lordosis. METHODS: Thirty-one healthy volunteers were recruited among five body type categories. Lateral lumbar spine X-rays were obtained for the neutral sitting posture without seatback (reference), and with reclining angles of 23∘ to 33∘ by 2∘ intervals. The Cobb angles for the L1-L4, L4-S1, and L1-S1 segments were measured. RESULTS: The Cobb angle for L4-S1 was nearest to the reference (18.74 ± 1.57∘, mean ± standard error mean) at reclining angles of 29∘ and 31∘ (14.51 ± 1.41∘ and 14.47 ± 1.43∘, respectively). The Cobb angle at L4-S1 between reclining angles of 27∘(12.02 ± 1.31∘) and 29∘ (14.51 ± 1.41∘) were significantly different (p< 0.001). Tall men showed relatively preserved lordosis angles at all reclining angles. Fat men and short women demonstrated prominent loss of lordosis with excessively kyphotic L1-L4 segment. CONCLUSIONS: Reclining angles of 29∘ to 31∘ revealed to be optimal for preserving lordosis at the L4-S1 segment. Individualized healthcare-related guideline for driver's seat adjustment setting is necessary.

Biomechanical Reactions of Exoskeleton Neurorehabilitation Robots in Spastic Elbows and Wrists.

Spasticity is an important factor in designing wearable and lightweight exoskeleton neurorehabilitation robots. The proposed study evaluates biomechanical reactions of an exoskeleton robot to spasticity and establishes relevant guidelines for robot design. A two-axis exoskeleton robot is used to evaluate a group of 20 patients post-stroke with spastic elbow and/or wrist joints. All subjects are given isokinetic movements at various angular velocities within the capable range of motion for both joints. The resistance torque and corresponding angular position at each joint are recorded continuously. Maximal resistance torques caused by low (modified Ashworth scale (MAS) 0, 1), intermediate (MAS 1+), and high (MAS 2 and 3) grade spasticity were 3.68 ± 2.42, 5.94 ± 2.55, and 8.25 ± 3.35 Nm for the elbow flexor ( , between each grades) and 4.23 ± 1.75, 5.68 ± 1.96, and 5.44 ± 2.02 Nm for the wrist flexor ( , for low versus intermediate, low versus high grade spasticity). The angular velocity did not significantly influence maximal resistance torque in either joint. The catch occurred more quickly at higher velocities for low and intermediate elbow flexor spasticity ( ). Spasticity caused considerable resistance to the robots during mechanically actuated movements. The resistance range according to the degree of spasticity should be considered when designing practical neurorehabilitation robots.