Motor networks in children with autism spectrum disorder: a systematic review on EEG studies.

Motor disturbance and altered motor networks are commonly reported in individuals with autism spectrum disorder (ASD). It has been suggested that electroencephalogram (EEG) can be used to provide exquisite temporal resolution for understanding motor control processes in ASD. However, the variability of study design and EEG approaches can impact our interpretation. Here, we conducted a systematic review on recent 11 EEG studies that involve motor observation and/or execution tasks and evaluated how these findings help us understand motor difficulties in ASD. Three behavior paradigms with different EEG analytic methods were demonstrated. The main findings were quite mixed: children with ASD did not always show disrupted neuronal activity during motor observation. Additionally, they might have intact ability for movement execution but have more difficulties in neuronal modulation during movement preparation. We would like to promote discussions on how methodological selections of behavioral tasks and data analytic approaches impact our interpretation of motor deficits in ASD. Future EEG research addressing the inconsistency across methodological approaches is necessary to help us understand neurophysiological mechanism of motor abnormalities in ASD.

Encouraging performance monitoring promotes proactive control in children.

Monitoring progression towards one's goals is essential for efficient cognitive control. Immature performance monitoring may contribute to suboptimal cognitive control engagement in childhood, potentially explaining why children engage control reactively even when proactive control would be more effective. This study investigated whether encouraging children to actively monitor their performance results in more mature control engagement. Electroencephalography data were collected while children and adults performed a flanker task in three conditions in which they were provided no feedback, standard feedback, or were asked to estimate their own feedback. Both age groups accurately estimated their own feedback. Critically, feedback estimation promoted online performance monitoring and proactive engagement of attention and inhibition during the flanker period in children. These findings indicate that proactive control engagement in childhood can be effectively supported by encouraging performance monitoring.

Cognitive Characteristics Associated With Device Adoption, Skill Retention, and Early Withdrawal From a Study of an Advanced Upper Limb Prosthesis.

OBJECTIVE: The aim of the study was to examine the role of cognition in device adoption, skill retention, and withdrawal from a study of an advanced upper limb prosthesis (the DEKA Arm). DESIGN: T tests and Wilcoxon rank-sum tests were used to compare test performance among study completers and noncompleters. Multivariable regression analyses were used to predict study withdrawal and DEKA Arm skill retention. RESULTS: Compared with self-withdrawn participants, those who were withdrawn by study staff performed significantly worse on tests indexing processing speed, set-shifting, and memory encoding. The DEKA Arm configuration (transradial, transhumeral, shoulder-based on amputation level) was a stronger predictor of skill retention than neuropsychological test performance. CONCLUSIONS: Frontally-mediated cognitive skills may influence the successful adoption of the DEKA Arm. The DEKA Arm configurations at higher amputation levels (e.g., shoulder) appear to be more strongly associated with prosthetic skill retention than users' cognitive status. This may be due to noncognitive user demands (e.g., device weight) statistically masking the discrete influence of cognitive status on skill retention at higher configuration levels. Neuropsychological assessment warrants consideration as a valuable tool in rehabilitation settings to assist in functional device candidacy evaluations.

EMG Pattern Recognition Control of the DEKA Arm: Impact on User Ratings of Satisfaction and Usability.

The DEKA Arm has multiple degrees of freedom which historically have been operated primarily by inertial measurement units (IMUs). However, the IMUs are not appropriate for all potential users; new control methods are needed. The purposes of this study were: 1) to describe usability and satisfaction of two controls methods-IMU and myoelectric pattern recognition (EMG-PR) controls-and 2) to compare ratings by control and amputation level. A total of 36 subjects with transradial (TR) or transhumeral (TH) amputation participated in the study. The subjects included 11 EMG-PR users (82% TR) and 25 IMU users (68% TR). The study consisted of in-laboratory training (Part A) and home use (Part B). The subjects were administered the Trinity Amputation and Prosthesis Experience satisfaction scale and other usability and satisfaction measures. Wilcoxon rank-sum tests compared the differences by control type. The differences were compared for those who did and did not want a DEKA Arm. The preferences for features of the DEKA Arm were compared by control type. The comparisons revealed poorer ratings of skill, comfort, and weight among EMG-PR users. The TR amputees using IMUs rated usability more favorably. TH amputees rated usability similarly. The TR amputees using EMG-PR were less satisfied with weight, pinch grip, and wrist display, whereas the TH amputees were less satisfied with the full system, wires/cables, and battery. Usability and satisfaction declined after Part B for EMG-PR users. Overall, we found that the IMU users rated the DEKA Arm and the controls more favorably than the EMG-PR users. The findings indicate that the EMG-PR system we tested was less well accepted than the IMUs for control of the DEKA Arm.

EMG pattern recognition compared to foot control of the DEKA Arm.

INTRODUCTION: EMG pattern recognition control (EMG-PR) is a promising option for control of upper limb prostheses with multiple degrees of freedom (DOF). The purposes of this study were to 1) evaluate outcomes of EMG-PR and inertial measurement units (IMU) control of the DEKA Arm as compared to personal prosthesis; and 2) compare outcomes of EMG-PR to IMU control of DEKA Arm. METHODS: This was a quasi-experimental, multi-site study with repeated measures that compared non-randomized groups using two types of controls: EMG-PR and IMUs. Subjects (N = 36) were transradial (TR) and transhumeral (TH) amputees. Outcomes were collected at Baseline (using personal prosthesis), and after in-laboratory training (Part A), and home use (Part B). Data was compared to personal prosthesis, stratified by amputation level and control type. Outcomes were also compared by control type. RESULTS: The EMG-PR group had greater prosthesis use after Part A, but worse dexterity, lower satisfaction, and slower activity performance compared to Baseline; the IMU group had slower activity performance. After Part B, the EMG-PR group had less perceived activity difficulty; the IMU group had improved activity performance, improved disability and activity difficulty, but slower performance. No differences were observed for TH group by control type in Part A or B. The TR group using EMG-PR had worse dexterity (Parts A & B), and activity performance (Part A) as compared to IMU users. DISCUSSION/CONCLUSION: Findings suggest that for the TR group that IMUs are a more effective control method for the DEKA Arm as compared to the EMG-PR prototypes employed in this study. Further research is needed to refine the EMG-PR systems for multi-DOF devices. Future studies should include a larger sample of TH amputees. TRIAL REGISTRATION: ClinicalTrials.gov NCT01551420.

User experience of controlling the DEKA Arm with EMG pattern recognition.

INTRODUCTION: A commercially available EMG Pattern Recognition (EMG-PR) control system was adapted to interface with the multi-degree of freedom (DOF) DEKA Arm. PURPOSE: To describe users' experience of controlling the DEKA Arm using EMG-PR. METHODS: Sample: Twelve persons with upper limb amputation participated, 10 with transradial (TR), 2 with transhumeral (TH) level amputation. Ten were male, and 11 were users of a prosthesis at baselines. Design: This was a two-part study consisting of in-laboratory prosthetic training (Part A) and up to 12 weeks of home use of the prosthesis (Part B). Data collection: Qualitative data were collected through open-ended survey questions and semi-structured interviews. Data Analysis: The study used a qualitative case series design with a constant comparative approach to identify common categories of experience. Coding categories were iteratively refined until saturation of categories was achieved. The data were organized in a primary category, major categories of experience, factors impacting experience, and broader contextual factors. RESULTS: Users had mixed perspectives on the desirability of the EMG-PR control system in combination with the DEKA Arm. Major aspects of user experience related to the system complexity, process of calibrating, and functional benefits. Factors influencing user experience included training and acclimation, fatigue, prosthesis design, technical issues and control changes. Broader contextual factors, both personal and environmental, also impacted users' experience. DISCUSSION/CONCLUSION: This study provided an in-depth description of user experience operating the DEKA Arm using EMG-PR control. The majority of participants expressed a preference for the controls of their personal prosthesis and controls rather than the iteration of EMG-PR controlled DEKA Arm used in this study. Most were positive about the future potential of EMG-PR as a control method. An understanding of patient experience will assist clinicians and patients choosing prosthetic options.

Function, quality of life, and community integration of DEKA Arm users after discharge from prosthetic training: Impact of home use experience.

BACKGROUND:: Research on adaptation to advanced upper limb prostheses is needed. OBJECTIVES:: To (1) examine change in function, quality of life and community integration after prosthetic training, (2) determine whether change in outcomes varied by prosthesis complexity, and (3) compare patterns of change at 1 month for those who withdrew from the study and those who did not. STUDY DESIGN:: Quasi-experimental time series. METHODS:: Data were analyzed for 22 participants (18 completers). Performance and self-report outcome measures were collected after in-laboratory training (Part A) and every 4 weeks of home use (Part B). Outcomes from End of A to End of B were compared statistically. Outcomes across assessments and by configuration level were compared graphically. Changes in scores were compared graphically for completers and non-completers. RESULTS:: Quality of life scores did not change between End of A and End of B, whereas scores improved for one activity measure, two measures of self-reported function, and three dexterity measures ( p < 0.05). Outcomes of community integration, self-reported function, four dexterity measures, and one activity measure varied by prosthesis level. For participants who withdrew early, dexterity and activity scores worsened, perceived disability increased, and prosthesis satisfaction decreased after 4 weeks of home use. CONCLUSION:: Study completers adapted to the DEKA Arm. CLINICAL RELEVANCE: Findings suggest that for the majority of upper limb amputees discharged from prosthetic rehabilitation, function continues to improve with home use. However, a minority experience a decline in function, greater perceived disability, and greater dissatisfaction after 4 weeks, suggesting a need for continued therapy after intensive prosthetic training ends.

How do the outcomes of the DEKA Arm compare to conventional prostheses?

OBJECTIVES: Objectives were to 1) compare self-reported function, dexterity, activity performance, quality of life and community integration of the DEKA Arm to conventional prostheses; and 2) examine differences in outcomes by conventional prosthesis type, terminal device type and by DEKA Arm configuration level. METHODS: This was a two-part study; Part A consisted of in-laboratory training. Part B consisted of home use. Study participants were 23 prosthesis users (mean age = 45 ± 16; 87% male) who completed Part A, and 15 (mean age = 45 ± 18; 87% male) who completed Parts A and B. Outcomes including self-report and performance measures, were collected at Baseline using participants' personal prostheses and at the End of Parts A and B. Scores were compared using paired t-tests. Wilcoxon signed-rank tests were used to compare outcomes for the full sample, and for the sample stratified by device and terminal device type. Analysis of outcomes by configuration level was performed graphically. RESULTS: At the End of Part A activity performance using the DEKA Arm and conventional prosthesis was equivalent, but slower with the DEKA Arm. After Part B, performance using the DEKA Arm surpassed conventional prosthesis scores, and speed of activity completion was equivalent. Participants reported using the DEKA Arm to perform more activities, had less perceived disability, and less difficulty in activities at the End of A and B as compared to Baseline. No differences were observed in dexterity, prosthetic skill, spontaneity, pain, community integration or quality of life. Comparisons stratified by device type revealed similar patterns. Graphic comparisons revealed variations by configuration level. CONCLUSION: Participants using the DEKA Arm had less perceived disability and more engagement of the prosthesis in everyday tasks, although activity performance was slower. After home use experience, activity performance was improved and activity speed equivalent to using conventional prostheses.

Does the DEKA Arm substitute for or supplement conventional prostheses.

BACKGROUND: Research on home use of advanced upper limb prostheses is needed. OBJECTIVES: To describe and compare DEKA Arm usage patterns during the last 4 weeks of a home trial for participants with a personal prosthesis and those without. To compare usage patterns during home trial to those of the personal prosthesis prior to home trial. To evaluate user activity preferences for the DEKA Arm and personal prosthesis after a trial of home use. STUDY DESIGN: Quasi-experimental, time-series design. METHODS: Data from 17 participants were analyzed. At baseline, prosthesis users reported days and hours they wore and used personal device(s). Home trial diaries documented days and hours of wear and use for the DEKA Arm and personal device(s), if applicable. Questionnaires asked prosthesis users to list activities they could do with the DEKA Arm but not with their current prosthesis and vice versa and activities they preferred doing with either devices. RESULTS: The DEKA Arm was worn 81% and used 73% of functioning days, averaging 4.2 h worn and 2.4 h used on days worn. During home trial, prosthesis users used personal devices and any prosthesis for fewer hours/day than at baseline. CONCLUSION: The DEKA supplemented but did not substitute for the personal prosthesis. Clinical relevance Findings strongly suggest that given the limitations of the DEKA Arm and conventional prosthesis, persons with upper limb amputation would be best served and would be able to perform the widest range of activities if they had several types of devices.

The DEKA hand: A multifunction prosthetic terminal device-patterns of grip usage at home.

BACKGROUND: Research is needed to understand how upper limb prosthesis users take advantage of multiple grip options. OBJECTIVES: To quantify usage of DEKA hand grip patterns during home use and compare patterns of usage at home to test sessions. STUDY DESIGN: Observational study design. METHODS: Data were collected from 21 subjects. Engineering data on grip were downloaded at various intervals. Proportion of time in each grip was calculated for the first 4 weeks of home use, later months, and test sessions (testing use) and compared statistically across intervals. Exploratory analyses compared grip proportion by DEKA Arm level and prior prosthesis use. RESULTS: Three most commonly used grips during home use were power, pinch open, and lateral pinch. There were no significant differences between grip use during the first month and later months. Power grip was used 55% of the time at home and 23% of the time in testing use. Pinch closed, lateral, and chuck grip were used less at home than in tests. Comparisons were by configuration level and prosthetic use and no significant differences were found. CONCLUSION: Patterns of DEKA hand grip usage differed between home and test environments, suggesting that users relied on fewer grip patterns at home. Clinical relevance These findings have implications for prosthetic training with multi-articulating terminal devices.

Brief activity performance measure for upper limb amputees: BAM-ULA.

BACKGROUND: Measures of activity performance for adults with upper limb amputation are needed. The purposes of this study were to evaluate the measurement properties of a new measure of activity performance for adults with upper limb amputation, which we call the Brief Activity Measure for Upper Limb Amputees (BAM-ULA) and to compare BAM-ULA scores for users of different types of prostheses. METHODS: In all, 35 persons with upper limb amputation were administered the BAM-ULA, twice within 1 week. Internal consistency and test-retest reliability were evaluated. Construct validity was examined by comparing scores by amputation level. Concurrent validity was evaluated by examining correlations with other measures. Exploratory analyses using linear regression compared sub-group scores for users of myoelectric and body-powered devices, and for users of single-degree-of-freedom and multi-articulating devices, controlling for amputation level. RESULTS: The scale alpha was 0.83; intraclass correlation coefficient was 0.91. Item scores differed by amputation level and device type. Persons with transradial amputation completed more items than those with amputations at the transhumeral or shoulder level ( p < 0.05). Users of myoelectric devices completed more items than users of body-powered devices ( p < 0.05). The BAM-ULA strongly correlated with the Activities Measure for Upper Limb Amputees; R = 0.86) and three modified Jebsen-Taylor Hand Function Tests ( R = 0.62-0.68) and moderately correlated with one Jebsen-Taylor Hand Function Test ( R = 0.46) as well as with the Wong-Baker FACES Pain Rating Scale. No differences in scores were found by degree of freedom of the terminal device after controlling for amputation level. CONCLUSION: Analyses support reliability, construct validity, and concurrent validity of the Brief Activity Measure for Upper Limb Amputees. This new briefer measure is easier to score than the Activities Measure for Upper Limb Amputees. Clinical relevance This article reported on the development and evaluation of a brief 10-item measure of activity performance for persons with upper limb impairment, the BAM-ULA. The BAM-ULA takes 10 min to administer and has a simple scoring method, which may facilitate its adoption by clinicians in the field.

Perceptions of satisfaction, usability and desirability of the DEKA Arm before and after a trial of home use.

OBJECTIVES: To: 1) describe perceptions of satisfaction with and usability of the DEKA Arm and preferences for the DEKA Arm or personal prosthesis; 2) compare perceptions of satisfaction and usability by DEKA Arm configuration level; and 3) evaluate satisfaction and usability for study completers and non-completers; and for those who did and did not want to receive a DEKA Arm. METHODS: The study had 2 phases: in-laboratory (Part A) and home trial (Part B). 32 participants with amputation, (50% transradial, 38% transhumeral and 13% shoulder) completed Part A and 18 completed Part B 16 (89%) of whom were prosthesis users at baseline. Measures of satisfaction, usability and user preferences were administered. Responses were compared for completers of Part A only and completers of Parts A and B. Preferences for the DEKA Arm over personal prosthesis and proportion of participants who wanted to receive a DEKA Arm were evaluated. Relationships between satisfaction, usability and desire to receive a DEKA Arm were examined. RESULTS: At end of Part A, 22 (69%) of the 32 participants who completed in-laboratory training wanted to receive a DEKA Arm and 5 (16%) might want one. At end of Part B, 14 (88%) of 16 prosthesis users who completed the home trial preferred the overall function of the DEKA Arm, 13 (81%) preferred DEKA hand function and 14 (88%) preferred DEKA wrist function to their own prosthesis. In contrast, 14 (88%) preferred the weight and 13 (81%) preferred the look of their own prosthesis. Most aspects of the DEKA Arm were rated "easy" to use. No items were rated as "difficult". Users were satisfied with most aspects of the DEKA Arm, except for the weight, shoulder appearance and harnessing. There were few differences in perceived usability or satisfaction by configuration level. Findings about desire to receive a DEKA Arm pertain only to study completers. Non-completers viewed the DEKA Arm less favorably than completers. Satisfaction was strongly related to participants' expressed desire to receive a DEKA Arm in the future. SIGNIFICANCE: To maximize likelihood of adoption of the DEKA Arm, findings suggest that both an in-laboratory and a home use trial may be useful prior to finalizing a recommendation for prescription.

Timed activity performance in persons with upper limb amputation: A preliminary study.

STUDY DESIGN: 55 subjects with upper limb amputation were administered the T-MAP twice within one week. PURPOSE: To develop a timed measure of activity performance for persons with upper limb amputation (T-MAP); examine the measure's internal consistency, test-retest reliability and validity; and compare scores by prosthesis use. INTRODUCTION: Measures of activity performance for persons with upper limb amputation are needed The time required to perform daily activities is a meaningful metric that implication for participation in life roles. METHODS: Internal consistency and test-retest reliability were evaluated. Construct validity was examined by comparing scores by amputation level. Exploratory analyses compared sub-group scores, and examined correlations with other measures. RESULTS: Scale alpha was 0.77, ICC was 0.93. Timed scores differed by amputation level. Subjects using a prosthesis took longer to perform all tasks. T-MAP was not correlated with other measures of dexterity or activity, but was correlated with pain for non-prosthesis users. DISCUSSION: The timed scale had adequate internal consistency and excellent test-retest reliability. CONCLUSIONS: Analyses support reliability and construct validity of the T-MAP. LEVEL OF EVIDENCE: 2c "outcomes" research.

Appropriateness of advanced upper limb prosthesis prescription for a patient with cognitive impairment: a case report.

PURPOSE: To describe a participant with scapulo-thoracic amputation and cognitive impairment trained to use the DEKA Arm and discuss factors relevant to the determination that he was not an appropriate candidate for independent home use of the device. METHOD: The participant underwent 40 h of in-laboratory training with the DEKA Arm Advanced Upper Limb Prosthesis. Pre-training neuropsychological measures of cognition were collected. Qualitative and quantitative data related to functional performance, quality of life and pain were collected after 10 h of training, and at the conclusion of training. Using a constant comparative approach, data were binned into major themes; elements within each theme were identified. RESULTS: Six themes were relevant to the determination that the participant was inappropriate for home use of the DEKA Arm: physical and mental health; learning, memory and cognition; adult role function; functional performance; user safety and judgement and capacity for independent device use. Issues contraindicating unsupervised device use included: uncontrolled health symptoms, poor knowledge application, safety concerns, absenteeism and performance degradation under stress. CONCLUSION: The findings have implications for training with and prescription of the DEKA Arm and other complex upper limb prostheses. Further research is needed to develop a model to guide prescription of technologically complex upper limb prostheses. Implications for Rehabilitation Advanced upper limb prostheses, like the DEKA Arm, promise greater functionality, but also may be cognitively demanding, raising questions of when, and if, prescription is appropriate for patients with cognitive impairment. At this time, no formal criteria exist to guide prescription of advanced upper limb prostheses. Each clinical team applies their own informal standards in decision-making. In this case report, we described six factors that were considered in determining whether or not a research participant, with scapulo-thoracic amputation and cognitive impairment was appropriate for home use of a complex upper limb prosthesis. The findings have implications for training with and prescription of the DEKA Arm, and highlights the need for further research to develop prescription guidelines for advanced assistive devices.

The neural dynamics of somatosensory processing and adaptation across childhood: a high-density electrical mapping study.

Young children are often hyperreactive to somatosensory inputs hardly noticed by adults, as exemplified by irritation to seams or labels in clothing. The neurodevelopmental mechanisms underlying changes in sensory reactivity are not well understood. Based on the idea that neurodevelopmental changes in somatosensory processing and/or changes in sensory adaptation might underlie developmental differences in somatosensory reactivity, high-density electroencephalography was used to examine how the nervous system responds and adapts to repeated vibrotactile stimulation over childhood. Participants aged 6-18 yr old were presented with 50-ms vibrotactile stimuli to the right wrist over the median nerve at 5 blocked interstimulus intervals (ranging from ∼7 to ∼1 stimulus per second). Somatosensory evoked potentials (SEPs) revealed three major phases of activation within the first 200 ms, with scalp topographies suggestive of neural generators in contralateral somatosensory cortex. Although overall SEPs were highly similar for younger, middle, and older age groups (6.1-9.8, 10.0-12.9, and 13.0-17.8 yr old), there were significant age-related amplitude differences in initial and later phases of the SEP. In contrast, robust adaptation effects for fast vs. slow presentation rates were observed that did not differ as a function of age. A greater amplitude response in the later portion of the SEP was observed for the youngest group and may be related to developmental changes in responsivity to somatosensory stimuli. These data suggest the protracted development of the somatosensory system over childhood, whereas adaptation, as assayed in this study, is largely in place by ∼7 yr of age.