Dexterity Measures Research Articles

Relationship Between Hand Grip Strength, Cognition, And Hand Dexterity In Older Adults: A Pilot Study

Background and Objective: In older adults most important two factor is cognition and hand motorfunctions, most noticeable in requiring much skill in fine motor activities. The normal process of aginginvolves declines in cognitive and sensorimotor functions that affect performance of activities of dailyliving. Dexterity measures help to detects early decline of hand function and it is necessary to quantifymanual dexterity of older adults not only design for work but also for the product and system daily activitiesby older adults. Force control is necessary for grip because most daily object required acquired force formovement not maximum force. While using large grip forces can lead to changes in the aging neuromotorsystem other than impaired tactile afferent functioning. Some older adults may produce less stable isometricforces with hand and arm muscles because of peripheral reorganization of their muscles. There is greaterconnection between hand grip strength and cognition, the deterioration of cognitive function is a high risk ofAD. Therefore, handgrip strength considers as an early marker of cognitive decline and incident dementia.Objective is to find relationship between hand grip strength, cognition, and hand dexterity in older adults.Methodology: 16 subjects were recruited on the basis of selection criteria. Subjects evaluated cognition,grip strength, and hand dexterity using outcome measures are MoCA, hand held dynamometer, and 9-holepeg test respectively.Results: Karl Pearson correlation were used for the statistical analysis. The result showed that moderatecorrelation between cognition and grip strength for right and left side with p value 0.031 and r value 0.540,and p = 0.40 and r = 0.517 respectively and weak correlation between cognition and hand dexterity for bothright and left with p value 0.162 and r = -.367 and p = .180, r= -.353 respectively.Conclusion: the study shows moderate association between cognition and grip strength and weak correlationbetween cognition and hand dexterity for both right and left side.

Manual dexterity in late childhood is associated with maturation of the corticospinal tract

PurposeDespite the important role of manual dexterity in child development, the neurobiological mechanisms associated with manual dexterity in childhood remain unclear. We leveraged fixel-based analysis (FBA) to examine the longitudinal association between manual dexterity and the development of white matter structural properties in the corticospinal tract (CST). MethodsHigh angular diffusion weighted imaging (HARDI) data were acquired for 44 right-handed typically developing children (22 female) aged 9-13 across two timepoints (timepoint 1: mean age 10.5 years ± 0.5 years, timepoint 2: 11.8 ± 0.5 years). Manual dexterity was assessed using the Grooved Pegboard Test, a widely used measure of manual dexterity. FBA-derived measures of fiber density and morphology were generated for the CST at each timepoint. Connectivity-based fixel enhancement and mixed linear modelling were used to examine the longitudinal association between manual dexterity and white matter structural properties of the CST. ResultsLongitudinal mixed effects models showed that greater manual dexterity of the dominant hand was associated with increased fiber cross-section in the contralateral CST. Analyses further demonstrated that the rate of improvement in manual dexterity was associated with the rate of increase in fiber cross-section in the contralateral CST between the two timepoints. ConclusionOur longitudinal data suggest that the development of manual dexterity in late childhood is associated with maturation of the CST. These findings significantly enhance our understanding of the neurobiological systems that subserve fine motor development and provide an important step toward mapping normative trajectories of fine motor function against microstructural and morphological development in childhood.

The Correlation Between Reach and Grasp Kinematic Measures and Clinical Measures of Manual Dexterity in Patients With Parkinson Disease

Background and Objectives: To investigate the correlation between reach and grasp kinematic measures and clinical measures of gross and fine manual dexterity in patients with idiopathic Parkinson Disease (PD). Methods: Sixty patients (44 men, 16 women) with idiopathic PD (Mean±SD of age: 59.85±11.89 years) were recruited in this non-experimental cross-sectional study using a non-probability sampling method. Their gross and fine manual dexterity were assessed using the Box and Block Test (BBT) and Nine Hole Peg Test (NHPT), respectively. Also, reach and grasp kinematic measures (including normalized movement time, peak velocity, Maximum Grip Aperture [MGA], and percentage of movement time in which MGA occurred [PMGA]) were measured in the more affected hand. Results: The results showed a significant and moderate correlation between reach kinematic measures (i.e. normalized movement time and peak velocity) and both gross and fine manual dexterity assessed by BBT (P=0.000) and NHPT (P=0.000), respectively. However, there was not a significant correlation between grasp kinematic measures (i.e. MGA and PMGA) and gross manual dexterity measured by BBT (P>0.05) as well as fine manual dexterity assessed by NHPT (P>0.05). Conclusion: This study showed no to moderate correlation between reach and grasp kinematic measures and clinical measures of gross and fine manual dexterity in patients with PD, supporting the significance of multi-level evaluation using both clinical and kinematic measures in the evaluation of upper limb function in patients with PD.

Dexterity, activity performance, disability, quality of life, and independence in upper limb Veteran prosthesis users: a normative study

Purpose To present population data on standardized measures of dexterity, activity performance, disability, health-related quality of life (HRQoL) and community integration for persons with upper limb amputation (ULA), compare outcomes to normative values, and examine differences by prosthesis type and laterality (unilateral vs. bilateral amputation). Materials and methods Multi-site, cross-sectional design, with in-person evaluations, functional performance, and self-report measures. Descriptive and comparative analyses were performed by amputation level and prosthesis type, data were compared for unilateral and bilateral amputation. Results One hundred and twenty-seven individuals participated; mean age 57 years, 59% percent body-powered prostheses users. All measures of dexterity differed (p < 0.05) by amputation level and by laterality. All measures of activity differed by amputation level with the best scores in transradial (TR) amputation groups. Comparisons of body-powered users with TR amputation found that dexterity was better for those with bilateral compared to unilateral amputation. Conclusions Dexterity is markedly impaired in persons with ULA. Individuals with more proximal ULA levels are most impacted. HRQoL and community participation are less impacted and more equivalent to unimpaired persons. Further research is needed to examine differences by terminal device type and determine how best to match persons with ULA to the optimal prosthesis type and componentry, based on individual characteristics. Implications for Rehabilitation This study provides population-based, comparative data on dexterity, activity performance, disability, quality of life, and independence in upper limb prosthesis users. The study provides preliminary analyses comparing the effectiveness of body-powered devices, myoelectric devices with single degree of freedom and multi-degree of freedom terminal devices. The data presented in this study can be used to benchmark outcomes in patients who are upper limb prosthesis users. The data will also be useful to inform comparative evaluations of existing and emerging prosthetic technology.

Cognitive impairment in the HTLV-1 infection: a comparative study associated with functional performance.

Human T cell leukemia virus type-I (HTLV-1) infection courses with a myelopathy, the tropical spastic paraparesis (HAM/TSP). In a case-control study, we compared the neuropsychological profile and functional characteristics in two case HTLV-1-infected groups (asymptomatic and with HAM/TSP) with a control group negative for HTLV-1. Subjects were paired for age, sex, and educational features. The case group differed from control group in neuropsychological measures such as in episodic memory recall, executive functions, and fine motor dexterity measure. Individuals with HAM/TSP have more depressive symptoms and worst performance in activities of daily living (ADL) presenting a less functionality. In multivariate models, the fine motor performance, the executive functioning, the recognition memory, and the depressive symptoms explained part of the variance in functionality. Those findings may contribute to understand of everyday life impairments and limitations of HTLV-1-infected population and to organize the rehabilitation. Once more, based in neuropsychological and functional data, we can reaffirm that HTLV-1 is never a benign condition, but sometimes it is only in a stage coursing with less symptoms.

A Collaborative and Cognitive-based Intervention for Young People with Cerebral Palsy.

Evidence-based approaches to improve function in individuals with cerebral palsy are needed. To investigate the effectiveness of the Cognitive Orientation to daily Occupational Performance approach™ (CO-OP) to improve performance on self-chosen, functional goals as compared to traditional occupational therapy for cerebral palsy. Crossover design with 12 participants, aged 6-15 years, randomly assigned to CO-OP and traditional intervention groups, followed by crossover and a 3-month follow-up. The participants identified three occupation-based goals for CO-OP and each group received ten 45-minutes intervention twice weekly in clinical context. Occupational performance, manual dexterity and Gross Motor Function Measures were analysed using generalized estimating equations. There were clinical and statistically significant improvements in functional goals following CO-OP and not traditional therapy. There were gains in dexterity but not in gross motor skills. CO-OP was effective to improve functional performance in young people with cerebral palsy and should be more utilized.

Use of the Box and Block Test for the evaluation of manual dexterity in individuals with central nervous system disorders: A systematic review

Introduction: Therapies designed to improve the functional capacity of the upper limb have become a vast field of research. Current clinical methods for upper extremity evaluations address function, motor control, sensory deficiency, dexterity, muscle tone and range of motion. The quality and performance in relation to activities related to the work of daily living and recreational activities are largely determined by hand functions and manual dexterity. Abnormal dexterity and the loss of motor coordination are among the main adverse conditions stemming from neurological disorders. Objective: The aim of the present study was to perform a systematic review of the literature on the use of the Box and Block Test (BBT) for the evaluation of manual dexterity in patients with central nervous system disorders. Methods: Searches were performed the Medline, PEDro, Lilacs, Scielo and PubMed databases. The articles retrieved during the initial search were analyzed independently by two blinded reviewers based on the following inclusion criteria: (1) controlled clinical trial; (2) population with neurological disorders; (3) evaluation involving the BBT; (4) outcome: evaluation of manual dexterity; (5) year of publication: 2005 and 2016. Preselected articles were evaluated for methodological quality using the Physiotherapy Evidence Database (PEDro) scale (minimum score for inclusion: 5 points). Results: The search resulted in the retrieval of 51 articles, 42 of which did not meet the inclusion criteria. Nine articles addressed the use of the BBT as one of the methods for the evaluation of manual dexterity in patients with central nervous system disorders, were considered methodologically adequate and were included in the present systematic review. Conclusion: The studies analyzed suggest that the BBT is a fast, easy, safe measure of manual dexterity with good applicability for adults and children with neurofunctional diseases.

Different laterality indexes are poorly correlated with one another but consistently show the tendency of males and females to be more left- and right-lateralized, respectively.

The most common way to assess handedness is based on the preferred hand for writing, leading to a binary (left or right) trait. Handedness can also be assessed as a continuous trait with laterality indexes, but these are not time- and cost-effective, and are not routinely collected. Rarely, different handedness measures are collected for the same individuals. Here, we assessed the relationship of preferred hand for writing with four laterality indexes, reported in previous literature, derived from measures of dexterity (pegboard task, marking squares and sorting matches) and strength (grip strength), available in a range of N = 6664–8069 children from the ALSPAC cohort. Although all indexes identified a higher proportion of individuals performing better with their right hand, they showed low correlation with each other (0.08–0.3). Left handers were less consistent compared to right handers in performing better with their dominant hand, but that varied across indexes, i.e. 13% of left handers performed better with their right hand on marking squares compared to 48% for sorting matches and grip strength. Analysis of sex effects on the laterality indexes showed that males and females tend to be, on all measures, more left- and right-lateralized, respectively. Males were also over-represented among the individuals performing equally with both hands suggesting they had a higher tendency to be weakly lateralized. This study shows that different handedness measures tap into different dimensions of laterality and cannot be used interchangeably. The trends observed across indexes for males and females suggest that sex effects should be taken into account in handedness and laterality studies.

Influence of Acetazolamide on Hand Strength and Manual Dexterity During a 30-h Simulated High Altitude Exposure.

High altitude missions pose significant challenges to Warfighter medical readiness and performance. Decreased circulating oxygen levels cause a decrease in exercise performance and can cause debilitating symptoms associated with acute mountain sickness, especially with rapid ascent. Acetazolamide (AZ) is known to minimize symptoms of acute mountain sickness, but it is unknown whether this medication alters hand strength and manual dexterity during altitude exposure. Ten male volunteers (22±4yr, 75.9±13.7kg, 174.9±9.3cm) participated in two separate 30h simulated altitude exposures (496mmHg, equivalent to 3,500m, 20°C, 20% RH) in a hypobaric chamber. Participants were given either a placebo or 250mg of AZ twice daily for 3.5d (2 sea-level [SL] days + the 30h altitude exposure) in a randomized, single-blind, crossover design. During SL and both altitude (ALT) exposures, hand function tests were performed, including hand grip and finger pinch strength tests, as well as the Purdue Pegboard (PP) and magazine loading tests to assess manual dexterity. Paired T tests and two-way repeated measure analysis of variance were used as appropriate to evaluate the effects of AZ and ALT. The value of p<0.05 was accepted for statistical significance. There were no influences of acute ALT exposure or AZ treatment on hand strength (eg, grip strength; SL: 39.2±5.5kg vs. ALT: 41.5±6.9kg, p>0.05) or dexterity (eg, PPassembly; placebo: 35.5±5.3 vs. AZ: 34.3±4.6, p>0.05) in our volunteers. Two dexterity tests (PPsum and magazine loading) showed improvements over time at ALT, regardless of treatment, where scores were improved after 10h of exposure compared to at 1h (eg, magazine loading: 56±12 vs. 48±10, p<0.001). This pattern was not seen in the PPassembly test or any strength measurements. Our results suggest that 500mg/d of AZ does not influence hand strength or manual dexterity during a 30h exposure to 3,500m simulated ALT. Acute ALT exposure (1h) did not influence dexterity or strength, although some measures of dexterity showed improvements as exposure time increased. We conclude that use of AZ to optimize medical readiness at ALT is unlikely to impair the Warfighter's ability to complete mission tasks that depend on hand function.

Neurocognitive Functioning in Early School-age Children With Intestinal Failure.

Little is known about school-age functioning in children with intestinal failure (IF). This study examines neurocognitive outcomes of children with IF at ages 4 to 8 years treated at a single centre, along with relevant medical and demographic variables. Between 2012 and 2016, neurocognitive assessments were administered to 28 children receiving treatment in our IF rehabilitation program, and included measures of intelligence, academics, learning/memory, language, visual-motor integration, and fine-motor dexterity. DSM-IV/V criteria were used to diagnose Learning Disability, Intellectual Disability, and/or Attention Deficit/Hyperactivity Disorder. Intellectual functioning ranged from extremely low to superior (Full Scale IQ range 53-123, mean = 89). Forty-six percentage received a cognitive/learning DSM diagnosis. Total number of first-year septic episodes correlated with poorer outcomes on the most cognitive measures. Adjusting for gestational age (61% were born <37 weeks), number of first-year septic episodes negatively predicted working memory, visual-motor integration, and visual memory scores. Additional factors correlating with poorer outcomes on ≥2 cognitive measures included length of first-year admissions, necrotizing enterocolitis diagnosis, and first-year sustained conjugated hyperbilirubinemia. Having ≥2 first-year septic episodes increased the likelihood of poorer outcome. Having a sibling was a significant positive predictor of working memory, processing speed, reading, and verbal learning skills. Our data provides preliminary evidence that children with IF are at risk of neurocognitive problems at early school age. Managing septic events during the first year is one strategy that may help reduce long-term neurocognitive risks in this population.

Recovery of cognitive function after relapse in multiple sclerosis

Background: Cognitive impairment is common in multiple sclerosis (MS) but its manifestation as acute disease activity is underappreciated. Objective: The aim of this study is to examine recovery after MS relapse on multiple tests of cognitive and motor function and explore correlates of change with Expanded Disability Status Scale (EDSS), magnetic resonance imaging (MRI), and cognitive reserve. Methods: Fifty relapsing group (RG) and matched stable participants were examined at baseline, during relapse, and at 3-month follow-up. Tests of cognitive processing speed (Symbol Digit Modalities Test (SDMT)) and consensus opinion measures of memory, ambulation, and manual dexterity were administered. All RG patients were treated with a 5-day course of Acthar Gel (5 mL/80 IU). Results: In RG patients, SDMT declined from 55.2 to 44.6 at relapse and recovered to 51.7, a slope differing from stable controls (p = 0.001). A statistical trend (p = 0.07) for the same effect was observed for verbal memory and was significant for ambulation (p = 0.03). The Cerebral Function Score from the EDSS also changed in the RG and recovered incompletely relative to controls (p = 0.006). Conclusion: These results replicate earlier reports of cognitive worsening during relapse in MS. Clinically meaningful improvements followed relapse on SDMT and ambulation. Cognitive decline during relapse can be appreciated on neurological exam but not patient-reported outcomes.

Brain magnetic resonance imaging is a predictor of bimanual performance and executive function in children with unilateral cerebral palsy.

To examine the association between brain magnetic resonance imaging (MRI) characteristics and executive function and bimanual performance in children with unilateral cerebral palsy (CP). Clinical MRI brain scans were classified as: (1) predominant pathological pattern (normal, white matter injury [WMI]; grey matter injury; focal vascular insults [FVI]; malformations; or miscellaneous); and (2) focal lesions (frontal, basal ganglia, and/or thalamus). Assessments included: (1) bimanual performance; (2) unimanual dexterity; and (3) executive function tasks (information processing, attention control, cognitive flexibility, and goal setting) and behavioural ratings (parent). From 131 recruited children, 60 were ineligible for analysis, leaving 71 children (47 males, 24 females) in the final sample (mean age 9y [SD 2y], 6y-12y 8mo). Brain MRIs were WMI (69%) and FVI (31%); and frontal (59%), thalamic (45%), basal ganglia (37%), and basal ganglia plus thalamic (21%). Bimanual performance was lower in FVI versus WMI (p<0.003), and with frontal (p=0.36), basal ganglia (p=0.032), and thalamic/basal ganglia lesions (p=0.013). Other than information processing, executive function tasks were not associated with predominant pattern. Frontal lesions predicted attention control (p=0.049) and cognitive flexibility (p=0.009) but not goal setting, information processing, or behavioural ratings. Clinical brain MRI predicts cognitive and motor outcomes when focal lesions and predominate lesion patterns are considered. What this paper adds Early brain magnetic resonance imaging (MRI) predicts bimanual performance and cognitive outcomes. Brain MRI may identify children requiring targeted interventions. Basal ganglia with/without thalamic lesions predicted bimanual performance. Frontal lesions were associated with attention control and cognitive flexibility. Brain MRI predominant patterns predicted motor, not cognitive outcomes, other than information processing.

Construct validity of the 9-Hole Peg Test and Purdue Pegboard Test in people with mild to moderately severe Parkinson’s disease

ObjectivesTo evaluate the construct validity of two dexterity measures, the 9-Hole Peg Test (9HPT) and Purdue Pegboard Test (PPT) in people with Parkinson’s disease (PD). DesignCross-sectional observational study. SettingTesting was conducted at the university or in participants’ homes. ParticipantsThirty community dwelling people with mild to moderately severe PD and no major upper limb comorbidities or cognitive impairments. InterventionsPegboard tests were administered in the ‘on’ and ‘end-of-dose’ phases of participants’ PD medication cycles. Participants rated hand function with two self-report questionnaires – the Manual Ability Measure-36 (MAM-36) and a subset of upper limb items from the MDS-UPDRS. To explore construct validity, we compared ‘on’ phase pegboard scores with normative values for unimpaired men and women and investigated relationships between pegboard scores and hand function questionnaires. ResultsIn the ‘on’ phase, pegboard scores were poorer than normative values. Differences in individual subtest scores ranged between 10 and 41%. Correlations between self-reported hand function and pegboard scores were weak to moderately strong in the ‘on’ phase (r=0.21–0.51), and weak at ‘end-of-dose’ (r=0.13–0.22). Higher correlation coefficients were observed between hand function and PPT subtest scores than with hand function and 9HPT scores. Most participants reported difficulty with daily hand tasks. ConclusionsWe found evidence for construct validity supporting the use of the 9HPT and PPT to evaluate people with mild to moderately severe PD when ‘on’, but not at the ‘end-of-dose’. Results also suggest that the PPT may be more sensitive to PD-related changes in dexterity than the 9HPT.

Performance-Based Outcome Measures of Dexterity in Hand and Wrist Injuries: A Structured Review of Measured Constructs

Dexterity impairments are common and disabling. To date, there is no consensus on an operational definition to measure dexterity. This review aims to provide an overview of constructs measured by performance-based outcome measures of dexterity and hand function (PBOMD) validated for use in persons with hand and upper limb conditions (HULC).

Kinematic analysis and dimensional optimization of a 2R2T parallel manipulator

The need of a device providing two-translational and two-rotational movements led us to design a 3UPS–1RPU parallel manipulator. The manipulator consisted of a mobile platform connected to a base through one central leg and three external legs located at the same radial distance. By studying different locations of the legs anchoring point, we improved the first layout design, yet not the optimal one. On this basis, this paper focuses on the optimal dimensional design of the manipulator. To this end, we put forward the kinematics equations of the manipulator in accordance with the anchoring points coordinates. Through a numerical approach, the equations allowing to find the manipulator workspace are developed. Also, we find a global manipulability index using a local dexterity measure. The latter index serves as an optimal function. The optimization process considers joint constraints. Thus, we built a nonlinear optimization problem solved through sequential quadratic programming algorithms. We start by optimizing only a small set of parameters rather than the entire set, which gives us insights into the initial guess to optimize using the entire set. Findings show that the optimal design approach improves the dexterity of the manipulator and reduces the number of singular configurations while having almost the same workspace as the original layout.

Medical robotics simulation framework for application-specific optimal kinematics

Abstract Most kinematic structures in robot architectures for medical tasks are not optimal. Further, the workspace and payloads are often oversized which results in high product prices that are not suitable for a clinical technology transfer. To investigate optimal kinematic structures and configurations, we have developed an adaptive simulation framework with an associated workflow for requirement analyses, modelling and simulation of specific robot kinematics. The framework is used to build simple and cost effective medical robot designs and was evaluated in a tool manipulation task where medical instruments had to be positioned precisely and oriented on the patient's body. The model quality is measured based on the maximum workspace coverage according to a configurable scoring metric. The metric generalizes among different human body shapes that are based on anthropometric data from UMTRI Human Shape. This dexterity measure is used to analyze different kinematic structures in simulations using the open source simulation tool V-REP. Therefor we developed simulation and visualization procedures for medical tasks based on a patchwork of size-variant anatomical target regions that can be configured and selectively activated in a motion planning controller. In our evaluations we compared the dexterity scores of a commercial lightweight robot arm with 7 joints to optimized kinematic structures with 6, 7 and 8 joints. Compared to the commercial hardware, we achieved improvements of 59% when using an optimized 6- dimensional robot arm, 64% with the 7-dimensional arm and 96% with an 8-dimensional robot arm. Our results show that simpler robot designs can outperform the typically used commercial robot arms in medical applications where the maximum workspace coverage is essential. Our framework provides the basis for a fully automatic optimization tool of the robot parameters that can be applied to a large variety of problems.

Role of Interhemispheric Cortical Interactions in Poststroke Motor Function

Background/Objective. We investigated interhemispheric interactions in stroke survivors by measuring transcranial magnetic stimulation (TMS)–evoked cortical coherence. We tested the effect of TMS on interhemispheric coherence during rest and active muscle contraction and compared coherence in stroke and older adults. We evaluated the relationships between interhemispheric coherence, paretic motor function, and the ipsilateral cortical silent period (iSP). Methods. Participants with (n = 19) and without (n = 14) chronic stroke either rested or maintained a contraction of the ipsilateral hand muscle during simultaneous recordings of evoked responses to TMS of the ipsilesional/nondominant (i/ndM1) and contralesional/dominant (c/dM1) primary motor cortex with EEG and in the hand muscle with EMG. We calculated pre- and post-TMS interhemispheric beta coherence (15-30 Hz) between motor areas in both conditions and the iSP duration during the active condition. Results. During active i/ndM1 TMS, interhemispheric coherence increased immediately following TMS in controls but not in stroke. Coherence during active cM1 TMS was greater than iM1 TMS in the stroke group. Coherence during active iM1 TMS was less in stroke participants and was negatively associated with measures of paretic arm motor function. Paretic iSP was longer compared with controls and negatively associated with clinical measures of manual dexterity. There was no relationship between coherence and. iSP for either group. No within- or between-group differences in coherence were observed at rest. Conclusions. TMS-evoked cortical coherence during hand muscle activation can index interhemispheric interactions associated with poststroke motor function and potentially offer new insights into neural mechanisms influencing functional recovery.

Personalized collaborative plans for robot-assisted dressing via optimization and simulation

Robots could be a valuable tool for helping with dressing but determining how a robot and a person with disabilities can collaborate to complete the task is challenging. We present task optimization of robot-assisted dressing (TOORAD), a method for generating a plan that consists of actions for both the robot and the person. TOORAD uses a multilevel optimization framework with heterogeneous simulations. The simulations model the physical interactions between the garment and the person being dressed, as well as the geometry and kinematics of the robot, human, and environment. Notably, the models for the human are personalized for an individual’s geometry and physical capabilities. TOORAD searches over a constrained action space that interleaves the motions of the person and the robot with the person remaining still when the robot moves and vice versa. In order to adapt to real-world variation, TOORAD incorporates a measure of robot dexterity in its optimization, and the robot senses the person’s body with a capacitive sensor to adapt its planned end effector trajectories. To evaluate TOORAD and gain insight into robot-assisted dressing, we conducted a study with six participants with physical disabilities who have difficulty dressing themselves. In the first session, we created models of the participants and surveyed their needs, capabilities, and views on robot-assisted dressing. TOORAD then found personalized plans and generated instructional visualizations for four of the participants, who returned for a second session during which they successfully put on both sleeves of a hospital gown with assistance from the robot. Overall, our work demonstrates the feasibility of generating personalized plans for robot-assisted dressing via optimization and physics-based simulation.

Measuring Hand Dexterity in People With Parkinson's Disease: Reliability of Pegboard Tests.

Knowledge regarding the reliability of pegboard tests when used to measure dexterity in people with Parkinson's disease (PD) is currently limited. To examine the test-retest and interrater reliability of the 9-Hole Peg Test (9HPT) and Purdue Pegboard Test (PPT) in people with PD. Cross-sectional observational study. For test-retest reliability, tests were completed on 2 days, 1 wk apart, in the "on" phase and "end-of-dose" period of participants' medication cycle. For interrater reliability, occupational therapists and physical therapists rated prerecorded pegboard test performance of participants with PD. Test-retest reliability was determined in participants' homes or in a university department. Interrater reliability was determined in a university department or a hospital setting. Test-retest reliability was determined with volunteers diagnosed with PD (N = 30). Interrater reliability was determined with a convenience sample of occupational and physical therapists (N = 11). The 9HPT and PPT are commonly used measures of manual dexterity. PPT subtests showed higher test-retest reliability (intraclass correlation coefficients [ICCs] ≥ .90) in both phases of the medication cycle compared with the 9HPT (ICCs = .70-.81). Minimal detectable change scores indicated acceptable measurement error for both tools. Interrater reliability for recorded performance of each measure was very good (ICCs > .99), with no calculable measurement error. Although both tools showed adequate test-retest and interrater reliability, results suggest that the PPT may be a more reliable measure of dexterity loss in people with PD. This study informs the clinical measurement of the loss of manual dexterity in people with PD, a frequent problem reported by people living with this disorder.

P74-T Reduced hand dexterity in Parkinson’s disease correlates with the level of short-latency intracortical inhibition impairment

Background In Parkinson’s disease (PD), primary motor cortex (M1) shows number of impairments in excitability and plasticity. However, there has been scarce attempts to check whether there is a link between these impairments and impaired hand dexterity in PD. Methods In a group of 29 PD patients (Hoehn & Yahr stage range 1–4), measures of M1 excitability (short latency intracortical inhibition [SICI] and intracortical facilitation [ICF], and plasticity (paired associative stimulation [PAS] protocol) were collected. They were correlated with results on the Perdue pegboard task (PPT), as a measure of hand dexterity, as well as with scores on a standard clinical scale (motor section of the Unified Parkinson’s Disease Scale [UPDRS]). Patients were tested off medication, after an overnight withdrawal. All measurements were carried out on the worst affected hand. Results Increase in MEP size immediately after and 30 min after the PAS protocol did not correlate with either PPT score or UPDRS motor cores and two derived scores, lateralised UPDRS and bradykinesia score (for the worst affected side). Same was with ICF. However, there was a significant correlation between amount of SICI and PPT score (Spearman R = 0.42, p = 0.023) – the larger the inhibition the higher the PPT scores; SICI did not correlate with other clinical measures. Conclusion It seems that in untreated PD patients there is a direct link between intracortical inhibition and hand dexterity. Lack of adequate short-latency intracortical inhibition most likely interferes with fine selection of movements which is of crucial importance for hand dexterity.