The aging hand

A Usability Pilot Study of a Sensor-Guided Interactive System for Dexterity Training in Parkinson's Disease

This pilot study aimed to evaluate the usability of a new, feedback-based dexterity training system in people with Parkinson's disease (PwPD) and healthy adults. Seven PwPD and seven healthy adults participated in the study. The System Usability Scale (SUS) and the Post-Study System Usability Questionnaire Version 3 (PSSUQ) were used to assess usability. Additionally, the feedback shown as a counter, detected through newly developed algorithms, was evaluated by comparing the device-detected repetitions during six exercises to those counted by a supervisor. High median SUS scores of 92.5 were obtained in both PwPD (IQR = 81.25-98.75) and healthy adults (IQR = 87.5-93.75, maximum score 100, minimum score 0). Similarly, high PSSUQ median scores were achieved after the session (1.14, IQR = 1.00-1.33, PD; 1.08, IQR = 1.00-1.58, healthy adults, maximum score 1, minimum score 7). PwPD completed 648 repetitions, with 551 (85%) correctly recognized by the system. For healthy adults, 883 out of 913 (97%) repetitions were classified as right. The present study showed high usability and high perceived user satisfaction for the new training system in all study participants. The system effectively detects exercise repetition rates but requires further refinement to enhance accuracy for specific pinch grip exercises.

Reliability and Optimal Cut-Off Points of the Test for Upper Limb Apraxia (TULIA) for Spanish-Speaking Post-Stroke Patients

OBJECTIVE

To evaluate the reliability, identify the optimal cut-off points, and determine the diagnostic accuracy of the TULIA Apraxia test in a sample of Spanish-speaking post-stroke patients.

DESIGN

Cross-sectional.

SETTING

Public primary care.

PARTICIPANTS

201 post-stroke patients.

MAIN MEASURES

Reliability was assessed using Cronbach's alpha. Cut-off points were identified for each TULIA Apraxia sub-test and stratified for age (≤65 years, > 65 years) using ROC curve analysis, area under the curve, and Youden index. Diagnostic accuracy was evaluated using sensitivity, specificity, and predictive values.

RESULTS

Cronbach's alpha of the sub-tests varied from 0.716 (95% CI 0.653-0.772) for pantomime intransitive to 0.824 (95% CI 0.784-0.858) for imitation non-symbolic. Cut-off points ranged from ≤25 to ≤35 points. For individuals aged ≤65 years, the cut-offs that best balanced sensitivity and specificity were ≤25 points for detecting alterations in imitation transitive and ≤33 points for pantomime non-symbolic. For individuals over 65 years, the imitation transitive cut-off (≤26 points) presented the most adjusted balance. The minimum positive predictive value was 0.667 (95% CI 0.542-0.777), indicating that the TULIA Apraxia tests correctly classified more than 67% of patients with apraxia. The minimum negative predictive value was 0.763 (95% CI 0.644-0.859), showing that the test accurately identified more than 76% of patients without apraxia.

CONCLUSIONS

The TULIA Apraxia test is reliable in Spanish-speaking post-stroke patients. Optimal cut-off points, along with their respective sensitivity and specificity values, exhibit adequate test accuracy. Predictive values indicate that the test correctly identifies individuals with and without apraxia.

Age-related differences in eye movements and the association with Archimedes spiral tracing performance in young and older adults

Age-related hand motor impairments may critically depend on visual information though few studies have examined eye movements during tasks of hand function in older adults. The purpose of this study was to assess eye movements and their association with performance while tracing on a touchscreen in young and older adults. Eye movements of 21 young (age 20-38 years; 12 females, 9 males) and 20 older (65-85 years; 10 females, 10 males) adults were recorded while performing an Archimedes spiral tracing task, a common clinical assessment sensitive to age-associated impairments in hand function. Participants traced an Archimedes spiral template on a touchscreen as accurately as possible under three conditions, using (1) a stylus, (2) the index finger, and (3) the index finger while performing a visuospatial dual task. Older adults made fewer total fixations than young adults, and participants made fewer fixations when tracing parts of the spiral where vision of the spiral template was likely more obstructed by the hand. Inter-fixation distance and inter-fixation distance variability were greater in older compared to young adults. A relationship between increased inter-fixation distance and increased spiral tracing error demonstrates the association between age-related changes in eye movements and spiral tracing performance in older adults. Results contribute novel findings of age-associated changes in ocuomotor behavior during a common clinical assessment and offer insight into motor control in older adults.

Which motor-cognitive abilities underlie the digital Trail-Making Test? Decomposing various test scores to detect cognitive impairment in Parkinson's disease-Pilot study

Since Parkinson's disease (PD) is a heterogeneous disorder with symptoms, such as tremors, gait and speech disturbances, or memory loss, individualized diagnostics are needed to optimize treatment. In their current form, the typical paper-pencil methods traditionally used to track disease progression are too coarse to capture the subtleties of clinical phenomena. For this reason, digital biomarkers that capture, for example, motor function, cognition, and behavior using apps, wearables, and tracking systems are becoming increasingly established. However, given the high prevalence of cognitive impairment in PD, digital cognitive biomarkers to predict mental progression are important in clinical practice. This pilot study aimed to identify those components of our digital version of the TMT (dTMT) that allow discrimination between PD patients with and without cognitive deficits. A total of 30 healthy control (age 66.3 ± 8.61) and 30 participants with PD (age 68.3 ± 9.66) performed the dTMT using a touch-sensitive tablet to capture enhanced performance metrics, such as the speed between and inside circles. The decomposition of cognitive abilities based on integrating additional variables in the dTMT revealed that the Parkinson's disease group was significantly more sensitive to parameters of inhibitory control. In contrast, the mild cognitive impairment group was sensitive to parameters of cognitive flexibility and working memory. The dTMT allows objective, ecologically valid, and long-term cognitive and fine-motor performance tracking, suggesting its potential as a digital biomarker in neurodegenerative disorders.

You Are as Old as the Connectivity You Keep: Distinct Neurophysiological Mechanisms Underlying Age-Related Changes in Hand Dexterity and Strength

BACKGROUND

Aging can lead to a decline in motor control. While age-related motor impairments have been documented, the underlying changes in cortico-cortical interactions remain poorly understood.

METHODS

We took advantage of the high temporal resolution of dual-site transcranial magnetic stimulation (dsTMS) to investigate how communication between higher-order rostral premotor regions and the primary motor cortex (M1) influences motor control in young and elderly adults. We assessed the dynamics of connectivity from the inferior frontal gyrus (IFG) or pre-supplementary motor area (preSMA) to M1, by testing how conditioning of the IFG/preSMA affected the amplitude of motor evoked potentials (MEPs) induced by M1 stimulation at different temporal intervals. Moreover, we explored how age-related changes in premotor-M1 interactions relate to motor performance.

RESULTS

Our results show that both young and elderly adults had excitatory IFG-M1 and preSMA-M1 interactions, but the two groups' timing and strength differed. In young adults, IFG-M1 interactions were early and time-specific (8 ms), whereas in older individuals, they were delayed and more prolonged (12-16 ms). PreSMA-M1 interactions emerged early (6 ms) and peaked at 10-12 ms in young individuals but were attenuated in older individuals. Critically, a connectivity profile of the IFG-M1 circuit like that of the young cohort predicted better dexterity in older individuals, while preserved preSMA-M1 interactions predicted greater strength, suggesting that age-related motor decline is associated with specific changes in premotor-motor networks.

CONCLUSIONS

Preserving youthful motor network connectivity in older individuals is related to maintaining motor performance and providing information for interventions targeting aging effects on behavior.

The Relationship Between Reduced Hand Dexterity and Brain Structure Abnormality in Older Adults

BACKGROUND

Hand dexterity is affected by normal aging and neuroinflammatory processes in the brain. Understanding the relationship between hand dexterity and brain structure in neurotypical older adults may be informative about prodromal pathological processes, thus providing an opportunity for earlier diagnosis and intervention to improve functional outcomes.

METHODS

this study investigates the associations between hand dexterity and brain measures in neurotypical older adults (≥65 years) using the Nine-Hole Peg Test (9HPT) and magnetic resonance imaging (MRI).

RESULTS

Elastic net regularized regression revealed that reduced hand dexterity in dominant and non-dominant hands was associated with an enlarged volume of the left choroid plexus, the region implicated in neuroinflammatory and altered myelination processes, and reduced myelin content in the left frontal operculum, the region implicated in motor imagery, action production, and higher-order motor functions. Distinct neural mechanisms underlying hand dexterity in dominant and non-dominant hands included the differences in caudate and thalamic volumes as well as altered cortical myelin patterns in frontal, temporal, parietal, and occipital regions supporting sensorimotor and visual processing and integration, attentional control, and eye movements. Although elastic net identified more predictive features for the dominant vs. non-dominant hand, the feature stability was higher for the latter, thus indicating higher generalizability for the non-dominant hand model.

CONCLUSIONS

Our findings suggest that the 9HPT for hand dexterity might be a cost-effective screening tool for early detection of neuroinflammatory and neurodegenerative processes. Longitudinal studies are needed to validate our findings in a larger sample and explore the potential of hand dexterity as an early clinical marker.

Difficulties in Manipulating the Female Artificial Urinary Sphincter Pump: Prevalence and Management

PURPOSE

While pump manipulation is rarely problematic in male patients with artificial urinary sphincters (AUSs), the situation may differ in female patients due to anatomical or cultural factors. This study aimed to evaluate the prevalence of difficulties in pump manipulation among female AUS patients, identify associated risk factors, and explore management strategies for this challenging issue.

METHODS

Data were collected from all female patients who underwent a robotic AUS implantation at a single academic center between 2014 and 2022. The primary endpoint was temporary difficulties, defined by at least one other short hospitalization to learn pump manipulation.

RESULTS

Out of the 88 female AUS patients included in the study, 20 experienced initial difficulties manipulating the pump, accounting for 22.7% of the group. Temporary difficulties were reported by 16 patients (18.2%), while 4 patients (4.5%) had their devices permanently deactivated. Surgical reoperations to reposition the pump were necessary for 5 patients, representing 5.6% of the sample. The only variables significantly associated with temporary difficulties were longer operative time (183.4 minutes vs. 159.1 minutes, P=0.04) and the overall experience of the center (32 vs. 50, P=0.04). The sole variable significantly linked to serious difficulties was the overall experience of the center (11 vs. 47, P=0.004). Although the median age and body mass index were higher in the group with temporary difficulties, these differences were not statistically significant.

CONCLUSION

Difficulties in manipulating the pump are relatively common among female AUS patients. Most of these difficulties can be resolved through repeated patient education and careful follow-up. However, some may lead to serious complications. Raising awareness of this issue, along with ongoing patient education and meticulous follow-up, may help to minimize these consequences.

Association of handgrip strength weakness and asymmetry with low physical performance among Chinese older people

BACKGROUND

Handgrip strength (HGS) weakness and asymmetry are both abnormal conditions of upper-limb muscle strength. The association between HGS weakness and physical performance is controversial, and the link between HGS asymmetry and physical performance remains unclear.

AIMS

This study aimed to investigate the associations of HGS weakness and asymmetry separately and concurrently with low physical performance among Chinese older people.

METHODS

The study used two waves of data from China Health and Retirement Longitudinal Study (CHARLS) in 2013 and 2015. HGS weakness and asymmetry were defined according to the maximal HGS and the HGS ratio, respectively. Participants were classified into 4 groups according to HGS status: normal, asymmetry only, weakness only, and concurrent weakness and asymmetry. The logistic regression model was used to investigate the cross-sectional association between low physical performance and each of maximal HGS, HGS ratio, and HGS status, as well as the prospective association between baseline HGS status and new-onset physical performance decline after two years.

RESULTS

Participants with HGS asymmetry only, weakness only, and two abnormalities showed a higher prevalence of low physical performance when asymmetry defined as an HGS ratio exceeding 1.20 and 1.30 (all, p < 0.001), with the greatest odds in those with two abnormalities (20% threshold: OR 3.83; 30% threshold: OR 5.41). The longitudinal analysis found that HGS weakness can predict the new-onset low physical performance over a two-year period, with concurrent HGS asymmetry further increased the future risk of physical performance decline.

CONCLUSIONS

Both HGS weakness and asymmetry were associated with a higher prevalence of low physical performance, in an additive way. This study will help screen older people with low physical performance more efficiently, and identify those at higher risk of developing new-onset physical performance decline within two years.

Grip and pinch strength prediction models based on hand anthropometric parameters: an analytic cross-sectional study

BACKGROUND

Hand grip strength (HGS) and pinch strength are important clinical measures for assessing the hand and overall health.

OBJECTIVE

The aim of the present study is to predict HGS and pinch strength based on 1 hand anthropometry, and (2) body anthropometric parameters using machine learning.

METHODS

A Secondary analysis was conducted on 542 participant aged 30-60 years from the Persian Organizational Cohort study in Mashhad University of Medical Sciences. Artificial Neural Network (ANN) were fitted as prediction model. The dataset was divided into two sets: a training set, which comprised 70% of the data, and a test set, which comprised 30% of the data. Various combinations of the hand anthropometric, demographic, and body anthropometric parameters were used to determine the most accurate model.

RESULTS

The optimal HGS model, using the input of gender, body mass, and hand anthropometric parameters of length (both total length and palm), maximum width, maximum breadth, and hand shape index, achieved nearly equal accuracy to the model that incorporated all variables (RMSE = 5.23, Adjusted R2 = 0.67). As for pinch strength, gender, hand length (both total length and palm), maximum width, maximum breadth, hand shape index, hand span, and middle finger length came closest to the model incorporating all variables (RMSE = 1.20, Adjusted R2 = 0.52).

CONCLUSION

This ANN model showed that hand anthropometric parameters of total length, palm length, maximum width, maximum breadth, and the hand shape index, emerge as optimal predictors for both HGS and HPS. Body anthropometric factors (e.g., body mass) play roles as predictors for HGS, whereas their influence on pinch strength appears to be less pronounced.

LEVEL OF EVIDENCE

Level III (Diagnosis).

TRIAL REGISTRATION

Not applicable.

Remote dried blood spot collection for inflammatory markers in older adults is feasible, reliable, and valid

Dried blood spots (DBS) provide a minimally invasive method to assess inflammatory markers and can be collected remotely at-home or in-person in the lab. However, there is a lack of methodological information comparing these different collection methods and in older adults. We investigated the feasibility (including adherence, yield, quality, and participant preferences) and measurement properties (reliability, validity) of remotely collected DBS inflammatory markers in older adults. Participants (N = 167, mean age = 72, range: 60-96 years) collected their own DBS (finger prick on filter paper) during three remote interviews over ∼ 6 months. Within 4-5 days on average of their last remote interview, a subset of 41 participants also attended an in-person lab visit that included a researcher-collected DBS sample, venous blood draw, and survey to assess participant preferences of DBS collection. DBS and venous blood were assayed for CRP, IL-6, and TNF-α. Adherence: 98% of expected DBS samples (493 out of 501) were completed and mailed back to the lab. Yield: 97% of DBS samples were sufficient for all assays. Quality: On average, 0.80 fewer optimal spots (60uL of blood that filled the entire circle) were obtained remotely vs. in-person (p = 0.013), but the number of useable or better spots (at least 30-40uL of blood) did not differ (p = 0.89). Preference: A slight majority of participants (54%) preferred in-person DBS collection. Reliability: DBS test-retest reliabilities were good: CRP (ICC = 0.74), IL-6 (ICC = 0.76), and TNF-α (ICC = 0.70). Validity: Inflammatory levels from DBS correlated strongly with levels from venous blood (r = 0.60-0.99) and correlated as expected with sociodemographic and physical health and function variables. Older adults can remotely collect their own DBS to acquire reliable and valid inflammatory data. Remote DBS collection is highly feasible and may allow for inflammatory markers to be assessed in larger, more representative samples than are possible with lab- or clinic-based research designs.

Finger-Individuating Exoskeleton System with Non-Contact Leader-Follower Control Strategy

This paper proposes a novel finger-individuating exoskeleton system with a non-contact leader-follower control strategy that effectively combines motion functionality and individual adaptability. Our solution comprises the following two interactive components: the leader side and the follower side. The leader side processes joint angle information from the healthy hand during motion via a Leap Motion Controller as the system input, providing more flexible and active operations owing to the non-contact manner. Then, as the follower side, the exoskeleton is driven to assist the user's hand for rehabilitation training according to the input. The exoskeleton mechanism is designed as a universal module that can adapt to various digit sizes and weighs only 40 g. Additionally, the current motion of the exoskeleton is fed back to the system in real time, forming a closed loop to ensure control accuracy. Finally, four experiments validate the design effectiveness and motion performance of the proposed exoskeleton system. The experimental results indicate that our prototype can provide an average force of about 16.5 N for the whole hand during flexing, and the success rate reaches 82.03% in grasping tasks. Importantly, the proposed prototype holds promise for improving rehabilitation outcomes, offering diverse options for different stroke stages or application scenarios.

Racial/Ethnic Differences in Self-Reported Upper Limb Limitations Among U.S. Older Adults

BACKGROUND

The development of disability related to activities of daily living (ADL) is of great concern in the aging population, particularly for Hispanic and Non-Hispanic (NH) Black older adults, where disability prevalence is greater compared to NH Whites. ADL-disability is typically measured across many functional tasks without differentiating upper- versus lower-limb limitations, hindering our understanding of disability burden. Despite the importance of the upper limbs for completing ADL and known age-related declines in function, racial/ethnic differences in upper limb function remain largely unknown.

METHODS

We identified 4 292 NH White, NH Black, and Mexican American older adults (≥65) from the 2011-2018 waves of the National Health and Nutrition Examination Survey (NHANES). We classified participants as having a limitation based on their ability to complete 5 upper-limb tasks (preparing meals, eating, dressing, reaching overhead, and grasping small objects) and compared limitation rates across racial/ethnic groups.

RESULTS

Compared to NH Whites, NH Black older adults had significantly greater odds of reporting difficulties preparing meals (odds ratio [OR]: 1.36, 95% confidence interval [95% CI]: 1.01, 1.86) and dressing (OR: 1.55, 95% CI: 1.19, 2.02), while Mexican Americans had greater difficulty preparing meals (OR: 1.70, 95% CI: 1.12, 2.58), dressing (OR: 1.63, 95% CI: 1.12, 2.36), and grasping small objects (OR: 1.48, 95% CI: 1.06, 2.07).

CONCLUSIONS

Our results demonstrate differences in self-reported upper limb ADL-disability across racial/ethnic groups, particularly for Mexican American older adults. Such findings underscore the need for routine monitoring of upper limb function throughout adulthood to identify limitations and target therapeutic interventions before independence is compromised.

The influence of food packaging on independent eating in individuals with hand impairments

PURPOSE

Hand function plays a major role in the successful performance of activities of daily living (ADLs), such as eating. There is a lack of data exploring how persons with hand impairment manage food packaging and its impact on eating.

METHODS

A convenience sample of 12 inpatients with hand impairments undergoing rehabilitation participated in a qualitative interview where they were asked questions about their experiences with food packaging and independent eating, and asked to open a set of commonly available hospital food packages, first without any tools/aids, and then with tools/aids if they desired to use them. Audio data were transcribed and cross-referenced with video data. Data were analyzed using codebook thematic analysis.

RESULTS

An overarching theme of "Messiness" along with four major themes were identified: a) Inaccessibility of food packaging; b) Lack of control; c) Eating avoidance; and d) Preferred packaging and strategies.

CONCLUSIONS

Inpatients with a hand impairment often experience several challenges with independent eating while in hospital as a result of their difficulties with hard to open food packaging. A greater consideration of universal design principles may be relevant for designers to make packaging more accessible.

Age-related differences in finger interdependence during complex hand movements

The well-known decrease in finger dexterity during healthy aging leads to a significant reduction in quality of life. Still, the exact patterns of altered finger kinematics of older adults in daily life are fairly unexplored. Finger interdependence is the unintentional comovement of fingers that are not intended to move, and it is known to vary across the lifespan. Nevertheless, the magnitude and direction of age-related differences in finger interdependence are ambiguous across studies and tasks and have not been explored in the context of daily life finger movements. We investigated five different free and daily-life-inspired finger movements of the right, dominant hand as well as a sequential finger tapping task of the thumb against the other fingers, in 17 younger (22-37 yr) and 17 older (62-80 yr) adults using an exoskeleton data glove for data recording. Using inferential statistics, we found that the unintentional comovement of fingers generally decreases with age in all performed daily-life-inspired movements. Finger tapping, however, showed a trend towards higher finger interdependence for older compared with younger adults. Using machine learning, we predicted the age group of a person from finger interdependence features of single movement trials significantly better than chance level for the daily-life-inspired movements, but not for finger tapping. Taken together, we show that for specific tasks, decreased finger interdependence (i.e., less comovement) could potentially act as a marker of human aging that specifically characterizes older adults' complex finger movements in daily life.NEW & NOTEWORTHY Kinematic finger movement data were analyzed with regard to age-related differences. Extensive analyses of complex and daily-life-inspired movements reveal that the direction of age effects is not uniform but task-dependent: Although older adults generally show more finger interdependence than younger adults in a simple finger tapping task, this effect is reversed for daily-life-inspired movement tasks. For these tasks, finger interdependence indices offer potential new markers to predict the age group of an individual using machine learning approaches.

Exploratory analysis using machine learning algorithms to predict pinch strength by anthropometric and socio-demographic features

Objectives. This study examines the role of different machine learning (ML) algorithms to determine which socio-demographic factors and hand-forearm anthropometric dimensions can be used to accurately predict hand function. Methods. The cross-sectional study was conducted with 7119 healthy Iranian participants (3525 males and 3594 females) aged 10-89 years. Seventeen hand-forearm anthropometric dimensions were measured by JEGS digital caliper and a measuring tape. Tip-to-tip, key and three-jaw chuck pinches were measured using a calibrated pinch gauge. Subsequently, 21 features pertinent to socio-demographic factors and hand-forearm anthropometric dimensions were used for classification. Furthermore, 12 well-known classifiers were implemented and evaluated to predict pinches. Results. Among the 21 features considered in this study, hand length, stature, age, thumb length and index finger length were found to be the most relevant and effective components for each of the three pinch predictions. The k-nearest neighbor, adaptive boosting (AdaBoost) and random forest classifiers achieved the highest classification accuracy of 96.75, 86.49 and 84.66% to predict three pinches, respectively. Conclusions. Predicting pinch strength and determining the predictive hand-forearm anthropometric and socio-demographic characteristics using ML may pave the way to designing an enhanced tool handle and reduce common musculoskeletal disorders of the hand.

Effect of digital game intervention on cognitive functions in older adults: a multiple baseline single case experimental design study

BACKGROUND

Residents in nursing homes are prone to cognitive decline affecting memory, visuospatial cognition, and executive functions. Cognitive decline can lead to dementia, necessitating prioritized intervention.

METHODS

The current study aimed to investigate whether an intervention using a digital game was effective for preserving and improving the cognitive function of residents in nursing homes. An intervention study was conducted using a single-case AB design with multiple baselines. The participants in the study were five older adults aged 65 and over who do not play digital games regularly. The study ran for 15 weeks, including a baseline (phase A) and an intervention phase (phase B). Phase A had five baselines (5 to 9 weeks) with random participant assignment. In phase B, participants engaged in a digital game (Space Invaders) individually. Cognitive function was assessed as the outcome, measured using the Brain Assessment (performed on a tablet through the Internet) at 16 measurement points. Four of five participants (two female and two male) were included in the analysis, using visual inspection and Bayesian statistics with multi-level modeling.

RESULTS

Visual inspection of the graphs revealed cognitive function score improvements after the intervention for most layers in terms of memory of numbers, memory of words, mental rotation test (visuospatial ability), and total scores in the Brain Assessment. These effects were also significant in the analysis by multi-level modeling.

CONCLUSIONS

The results suggest that the use of digital games may be effective for preserving and improving cognitive function among residents of nursing home.

TRIAL REGISTRATION

This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000048677; public title: Effect of a Digital Game Intervention for Cognitive Functions in Older People; registration date: August 30, 2022).

A machine-learning method isolating changes in wrist kinematics that identify age-related changes in arm movement

Normal aging often results in an increase in physiological tremors and slowing of the movement of the hands, which can impair daily activities and quality of life. This study, using lightweight wearable non-invasive sensors, aimed to detect and identify age-related changes in wrist kinematics and response latency. Eighteen young (ages 18-20) and nine older (ages 49-57) adults performed two standard tasks with wearable inertial measurement units on their wrists. Frequency analysis revealed 5 kinematic variables distinguishing older from younger adults in a postural task, with best discrimination occurring in the 9-13 Hz range, agreeing with previously identified frequency range of age-related tremors, and achieving excellent classifier performance (0.86 AUROC score and 89% accuracy). In a second pronation-supination task, analysis of angular velocity in the roll axis identified a 71 ms delay in initiating arm movement in the older adults. This study demonstrates that an analysis of simple kinematic variables sampled at 100 Hz frequency with commercially available sensors is reliable, sensitive, and accurate at detecting age-related increases in physiological tremor and motor slowing. It remains to be seen if such sensitive methods may be accurate in distinguishing physiological tremors from tremors that occur in neurological diseases, such as Parkinson's Disease.

The rules of mature sex: Sexual scripts and the global challenge of rising STIs

Sexual health continues to be a socially complex problem globally with rising rates of sexually transmitted infections (STIs) despite extensive government and health marketing initiatives. In particular, STIs are rising at a greater rate in mature consumers than any other age group with the main reason cited as lack of condom use. The rules around condom use are based on sexual scripts or internalised guidelines and thus a key step in developing social marketing initiatives to increase condom use and address this global challenge is identifying the sexual scripts that motivate and inhibit condom use by mature consumers. Using sexual script theory, this research involves interviews with 24 mature single heterosexual Australian consumers to identify the sexual scripts that can be leveraged in health marketing to address the grand challenge of increasing mature consumer participation in protective sexual health behaviours.

LSTM-CNN: An efficient diagnostic network for Parkinson's disease utilizing dynamic handwriting analysis

BACKGROUND AND OBJECTIVES

Dynamic handwriting analysis, due to its noninvasive and readily accessible nature, has emerged as a vital adjunctive method for the early diagnosis of Parkinson's disease (PD). An essential step involves analysing subtle variations in signals to quantify PD dysgraphia. Although previous studies have explored extracting features from the overall signal, they may ignore the potential importance of local signal segments. In this study, we propose a lightweight network architecture to analyse dynamic handwriting signal segments of patients and present visual diagnostic results, providing an efficient diagnostic method.

METHODS

To analyse subtle variations in handwriting, we investigate time-dependent patterns in local representation of handwriting signals. Specifically, we segment the handwriting signal into fixed-length sequential segments and design a compact one-dimensional (1D) hybrid network to extract discriminative temporal features for classifying each local segment. Finally, the category of the handwriting signal is fully diagnosed through a majority voting scheme.

RESULTS

The proposed method achieves impressive diagnostic performance on the new DraWritePD dataset (with an accuracy of 96.2%, sensitivity of 94.5% and specificity of 97.3%) and the well-established PaHaW dataset (with an accuracy of 90.7%, sensitivity of 94.3% and specificity of 87.5%). Moreover, the network architecture stands out for its excellent lightweight design, occupying a mere 0.084M parameters, with only 0.59M floating-point operations. It also exhibits nearly real-time CPU inference performance, with the inference time for a single handwriting signal ranging from 0.106 to 0.220 s.

CONCLUSIONS

We present a series of experiments with extensive analysis, which systematically demonstrate the effectiveness and efficiency of the proposed method in quantifying dysgraphia for a precise diagnosis of PD.

Backward logistic regression analysis of the determinants of the hand function among patients with leprosy: A cross-sectional study

Introduction

The hands are the most common site of disability in leprosy. Hand dysfunction could result in difficulty performing activities of daily living. Therefore, hand function should be regularly assessed to ensure that any decrease in hand function could be diagnosed earlier.

Methods

This study included 110 patients with leprosy from Likupang and Lembata, Indonesia. Hand function was assessed using the modified Jebsen test to measure hand function respective of the dominance. The grip and pinch strength were used as objective measures of clinical arm function. The World Health Organization (WHO) hand disability grade were used to determine the degree of impairment. Other factors such as age, sex and the type of leprosy were also considered. All factors were analysed using backward logistic regression.

Results

Among the 110 participants, a decrease in the dominant (48.2%) and non-dominant (50.9%) hand functions were found. Pinch strength (OR: 3.39; 95% CI: 1.13-10.19) and age (OR: 4.91; 95% CI: 1.72-14.03) were significantly associated with hand function irrespective of the dominance. Conversely, the WHO hand disability grade (OR: 2.97; 95% CI: 1.10-8.04) and type of leprosy (OR: 0.34; 95% CI: 0.12-0.97) were significantly associated with only function of the dominant hand.

Conclusion

There is a significant association of age and pinch strength with hand function regardless of the hand dominance. In contrast, the WHO hand disability grade and type of leprosy are significantly associated with the function of the dominant hand only.

Association of handgrip strength asymmetry and weakness with functional disability among middle-aged and older adults in China

Background

Little is known about the association of handgrip strength (HGS) asymmetry with functional disability in China. We aimed to examine the individual and combined association of HGS asymmetry and weakness with functional disability among middle-aged and older Chinese adults.

Methods

We included participants aged ≥45 years from two waves of the China Health and Retirement Longitudinal Study (2011 and 2015). HGS weakness was defined as the maximal HGS<28 kg for men and <18 kg for women. HGS asymmetry was measured by dividing the maximal nondominant HGS (kg) by the maximal dominant HGS (kg), with the value <0.90 or >1.10 considered as asymmetry. Functional disability was assessed by activities of daily living (ADL) and instrumental activities of daily living (IADL) and was defined as encountering difficulty in completing one or more ADL/IADL tasks. The logistic regression models were used to explore the association between HGS measures and functional disability.

Results

11 950 (mean age 59.2 ± 9.6 years, 47.9% males) and 7540 (mean age 57.5 ± 8.6 years, 50.1% males) participants were included in the cross-sectional and prospective study, respectively. HGS asymmetry and weakness, individually or simultaneously, were associated with an increased prevalence of functional disability. During the four-year follow-up, 1822 (24.2%) participants had incident functional disability. The separate exposure to HGS asymmetry (odds ratio (OR) = 1.18; 95% confidence interval (CI) = 1.05-1.32) or weakness (OR = 1.59; 95% CI = 1.30-1.95) was independently associated with functional disability. For combined associations, those with both weakness and asymmetry showed the greatest risk of new-onset functional disability (OR = 1.91; 95% CI = 1.45-2.52).

Conclusions

HGS asymmetry and weakness were associated with a higher risk of functional disability. Assessing HGS asymmetry together with weakness may help to better identify those at risk of functional disability to enable early interventions.

Predicting human chronological age via AI analysis of dorsal hand versus facial images: A study in a cohort of Indian females

Predicting a person's chronological age (CA) from visible skin features using artificial intelligence (AI) is now commonplace. Often, convolutional neural network (CNN) models are built using images of the face as biometric data. However, hands hold telltale signs of a person's age. To determine the utility of using only hand images in predicting CA, we developed two deep CNNs based on 1) dorsal hand images (H) and 2) frontal face images (F). Subjects (n = 1454) were Indian women, 20-80 years, across three geographic cohorts (Mumbai, New Delhi and Bangalore) and having a broad variation in skin tones. Images were randomised: 70% of F and 70% of H were used to train CNNs. The remaining 30% of F and H were retained for validation. CNN validation showed mean absolute error for predicting CA using F and H of 4.1 and 4.7 years, respectively. In both cases correlations of predicted and actual age were statistically significant (r(F) = 0.93, r(H) = 0.90). The CNNs for F and H were validated for dark and light skin tones. Finally, by blurring or accentuating visible features on specific regions of the hand and face, we identified those features that contributed to the CNN models. For the face, areas of the inner eye corner and around the mouth were most important for age prediction. For the hands, knuckle texture was a key driver for age prediction. Collectively, for AI estimates of CA, CNNs based solely on hand images are a viable alternative and comparable to CNNs based on facial images.

Older adults are impaired in the release of grip force during a force tracking task

Age-related changes in force generation have been implicated in declines in older adult manual dexterity. While force generation is a critical aspect of the successful manipulation of objects, the controlled release of force represents the final component of dexterous activities. The impact of advancing age on the release of grip force has received relatively little investigation despite its importance in dexterity. The primary aim of this project was to determine the effects of age on the control of force release during a precision grip tracking task. Young adults (N = 10, 18-28 years) and older adults (N = 10, 57-77 years) completed a ramp-hold-release (0-35% of maximum grip force) force tracking task with their dominant hand. Compared to young adults, older adults were disproportionately less accurate (i.e., less time within target range) and had more error (i.e., greater relative root mean squared error) in the release of force, compared to generation of grip force. There was a significant difference between groups in two-point discrimination of the thumb, which was moderately correlated to force control across all phases of the task. The decline in force release performance associated with advanced age may be a result of sensory deficits and changes in central nervous system circuitry.

A Personalised 3D-Printed Dental Plaque Removal Mouthguard for Older Adults

OBJECTIVES

The aim of the present study was to examine the plaque removal effectiveness of a personalised 3D-printed dental plaque removal mouthguard device in a clinical trial setting.

METHODS

A personalised 3D-printed mouthguard was developed to clean dental plaque using micro-mist. A clinical trial was conducted to examine the plaque removal effectiveness of this device. The clinical trial recruited 55 participants (21 males and 34 females) with an average age of 68.4 years (range, 60-81 years). Dental plaque was dyed by plaque disclosing liquid (Ci). Turesky Modification of the Quigley-Hein Plaque Index (TMQHPI) was used to evaluate the level and rate of plaque formation on the tooth surface. The TMQHPI was recorded and intraoral photos were taken before and after mouthguard cleaning. The plaque removal rate was calculated based on TMQHPI and intraoral photos (pixel-based method) before and after cleaning.

RESULTS

The personalised 3D-printed micro-mist injection mouthguard can be effective in dental plaque removal on tooth and gingiva, and the effectiveness lies between that of a manual toothbrush and a mouth rinse. The newly proposed pixel-based method can be a practical, high sensitive tool to evaluate the level of plaque formation.

CONCLUSIONS

Under the conditions of the present study, we conclude that the personalised 3D-printed micro-mist injection mouthguard can be useful in reducing dental plaque and may be especially suitable for older adults and disabled people.

Bringing the Walk with Ease Programme to the UK: a mixed-methods study to assess the relevance, acceptability, and feasibility of implementation for people with arthritis and musculoskeletal conditions

Developed in the United States (US), Walk With Ease (WWE) is a popular evidence-based, 6-week community walking programme for adults with arthritis, delivered in either an instructor-led or self-directed format. While WWE has expanded into communities across the USA, it is relatively unknown in other countries across the globe. This study, in collaboration with community and patient partners, aimed to examine the relevance, acceptability and feasibility of introducing WWE into a UK context. After initial cultural adaptation, participants were recruited into the study. Eligible (≥18 years, doctor diagnosed arthritis (confirmed or self-report), self-reported joint symptoms in last 30 days, BMI ≥25 kg/m2, and <150 min/week of moderate/vigorous PA) and consented participants were randomized into two groups: WWE programme or usual care. A mixed-methods analysis approach integrated quantitative data (physical performance assessment; baseline and post-six week programme questionnaire) and qualitative data (narrative interviews exploring participants' pre- and post-WWE experiences and stakeholders' perceptions). Of 149 participants, the majority were women (70%) aged ≥60 years (76%). Among the 97 receiving the programme, 52 chose instructor-led; 45 chose self-directed. Participants found WWE relevant and acceptable-99% indicating they would recommend WWE to family/friends. Within both WWE formats, mixed differences representing improvement were observed at 6 weeks from baseline for physical performance and arthritis symptoms. Emergent themes included improved motivation, health, and social well-being. WWE is a relevant and acceptable walking programme with scope for wider implementation to support UK health and well-being policy strategies.

Handgrip strength asymmetry as a new biomarker for sarcopenia and individual sarcopenia signatures

BACKGROUND

Although handgrip strength (HGS) asymmetry has clinical screening utility, its relevance to sarcopenia is unknown. This study examined the relationship between HGS asymmetry and sarcopenia signatures, and explored the relevance of circulating neural/neuromuscular markers.

METHODS

9403 individuals aged 18-92 years participated in this study. Maximal HGS and skeletal muscle index (SMI) were determined using hand dynamometry and DXA. Sarcopenia was diagnosed upon the presence of low HGS and low SMI, according to cohort-specific thresholds. Plasma biomarkers were measured by ELISA in a sub-group of 269 participants aged 50-83 years. Asymmetry was determined as the highest recorded HGS divided by the highest recorded HGS of the opposite hand. Individuals with a ratio > 1.10 were classified as having asymmetrical HGS.

RESULTS

Subjects with asymmetrical HGS had significantly lower SMI (7.67 kg/m2 vs 7.71 kg/m2, p = 0.004) and lower HGS (37.82 kg vs 38.91 kg, p < 0.001) than those with symmetrical HGS. In those aged ≥ 50 years asymmetrical HGS was associated with 2.67 higher odds for sarcopenia [95% confidence interval: (CI) = 1.557-4.561, p < 0.001], 1.83 higher odds for low HGS only (CI 1.427-2.342, p < 0.001), and 1.79 higher odds for low SMI only (CI 1.257-2.554, p = 0.001). HGS asymmetry demonstrated acceptable diagnostic accuracy for sarcopenia (AUC = 0.727, CI 0.658-0.796, p < 0.001). Plasma neural cell adhesion molecule concentrations were 19.6% higher in individuals with asymmetrical HGS (185.40 ng/mL vs 155.00 ng/mL, p < 0.001) than those with symmetrical HGS.

DISCUSSION

Our findings demonstrate the utility of HGS asymmetry as a screening tool that may complement existing strategies seeking to combat sarcopenia. Biomarker analyses suggest that heightened denervation may be an important aetiological factor underpinning HGS asymmetry.

Skin Sensitivity Assessment Using Smartphone Haptic Feedback

Goal: This work presents a smartphone application to assess cutaneous sensory perception by establishing Vibrational Perception Thresholds (VPTs). Cutaneous sensory perception diagnostics allow for the early detection and symptom tracking of tactile dysfunction. However, lack of access to healthcare and the limited frequency of current screening tools can leave skin sensation impairments undiscovered or unmonitored. Methods: A 23-participant cross-sectional study in subjects with a range of finger sensation tests Smartphone Established VPTs (SE-VPTs) by varying device vibrational intensity. These are compared against monofilament test scores, a clinical measure of skin sensitivity. Results: We find a strong positive correlation between SE-VPTs and monofilament scores ([Formula: see text] = 0.86, p = 1.65e-07). Conclusions: These results demonstrate the feasibility of using a smartphone as a skin sensation screening tool.

Understanding data collection strategies for the ethical inclusion of older adults with disabilities in transitional care research: A scoping review protocol

INTRODUCTION

A growing body of evidence suggests that older adults are particularly vulnerable to poor care as they transition across care environments. Thus, they require transitional care services as they transition across healthcare settings. To help make intervention research meaningful to the older adults the intervention aims to serve, many researchers aim to study their experiences, by actively involving them in research processes. However, collecting data from older adults with various forms of disability often assumes that the research methods selected are appropriate for them. This scoping review will map the evidence on research methods to collect data from older adults with disabilities within the transitional care literature.

METHODS

The proposed scoping review follows the framework originally described by the Joanna Briggs Institute (JBI) Manual: (1) developing a search strategy, (2) evidence screening and selection, (3) data extraction; and (4) analysis. We will include studies identified through a comprehensive search of peer-reviewed and empirical literature reporting on research methods used to elicit the experiences of older adults with disabilities in transitional care interventions. In addition, we will search the reference lists of included studies. The findings of this review will be narratively synthesized. The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews will guide the reporting of the methods and results.

DISCUSSION

The overarching goal of this study is to develop strategies to assist the research community in increasing the inclusion of older adults with disabilities in transitional care research. The findings of this review will highlight recommendations for research to inform data collection within future intervention research for older adults with disabilities. Study findings will be disseminated via a publication and presentations.

A hybrid linear discriminant analysis and genetic algorithm to create a linear model of aging when performing motor tasks through inertial sensors positioned on the hand and forearm

BACKGROUND

During the aging process, cognitive functions and performance of the muscular and neural system show signs of decline, thus making the elderly more susceptible to disease and death. These alterations, which occur with advanced age, affect functional performance in both the lower and upper members, and consequently human motor functions. Objective measurements are important tools to help understand and characterize the dysfunctions and limitations that occur due to neuromuscular changes related to advancing age. Therefore, the objective of this study is to attest to the difference between groups of young and old individuals through manual movements and whether the combination of features can produce a linear correlation concerning the different age groups.

METHODS

This study counted on 99 participants, these were divided into 8 groups, which were grouped by age. The data collection was performed using inertial sensors (positioned on the back of the hand and on the back of the forearm). Firstly, the participants were divided into groups of young and elderly to verify if the groups could be distinguished through the features alone. Following this, the features were combined using the linear discriminant analysis (LDA), which gave rise to a singular feature called the LDA-value that aided in verifying the correlation between the different age ranges and the LDA-value.

RESULTS

The results demonstrated that 125 features are able to distinguish the difference between the groups of young and elderly individuals. The use of the LDA-value allows for the obtaining of a linear model of the changes that occur with aging in the performance of tasks in line with advancing age, the correlation obtained, using Pearson's coefficient, was 0.86.

CONCLUSION

When we compare only the young and elderly groups, the results indicate that there is a difference in the way tasks are performed between young and elderly individuals. When the 8 groups were analyzed, the linear correlation obtained was strong, with the LDA-value being effective in obtaining a linear correlation of the eight groups, demonstrating that although the features alone do not demonstrate gradual changes as a function of age, their combination established these changes.

Quantifying Hand Strength and Isometric Pinch Individuation Using a Flexible Pressure Sensor Grid

Modulating force between the thumb and another digit, or isometric pinch individuation, is critical for daily tasks and can be impaired due to central or peripheral nervous system injury. Because surgical and rehabilitative efforts often focus on regaining this dexterous ability, we need to be able to consistently quantify pinch individuation across time and facilities. Currently, a standardized metric for such an assessment does not exist. Therefore, we tested whether we could use a commercially available flexible pressure sensor grid (Tekscan F-Socket [Tekscan Inc., Norwood, MA, USA]) to repeatedly measure isometric pinch individuation and maximum voluntary contraction (MVC) in twenty right-handed healthy volunteers at two visits. We developed a novel equation informed by the prior literature to calculate isometric individuation scores that quantified percentage of force on the grid generated by the indicated digit. MVC intra-class correlation coefficients (ICCs) for the left and right hands were 0.86 (p < 0.0001) and 0.88 (p < 0.0001), respectively, suggesting MVC measurements were consistent over time. However, individuation score ICCs, were poorer (left index ICC 0.41, p = 0.28; right index ICC -0.02, p = 0.51), indicating that this protocol did not provide a sufficiently repeatable individuation assessment. These data support the need to develop novel platforms specifically for repeatable and objective isometric hand dexterity assessments.

Association of Handgrip Strength Weakness and Asymmetry With Incidence of Motoric Cognitive Risk Syndrome in the China Health and Retirement Longitudinal Study

BACKGROUND AND OBJECTIVES

Motoric cognitive risk (MCR) syndrome is a type of pre-dementia. It is defined as the co-occurrence of subjective cognitive complaints and a slow gait speed. A recent study found that handgrip strength (HGS) asymmetry is associated with an increased risk of neurodegenerative disorders. We aimed to investigate the associations of HGS weakness and asymmetry separately and together with MCR incidence among older Chinese adults.

METHODS

Data from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study were used. HGS values <28 kg for male participants and <18 kg for female participants were considered HGS weaknesses. HGS asymmetry was assessed by the ratio of nondominant to dominant HGS. We used 3 different cutoff values of HGS ratio to define asymmetry, including 10%, 20%, and 30%. Specifically, HGS ratios <0.90 or >1.10 (10%), <0.80 or >1.20 (20%), and <0.70 or >1.30 (30%) were classified as asymmetry. The participants were classified into 4 groups: neither weakness nor asymmetry (neither), asymmetry only, weakness only, and weakness and asymmetry (both). The association between baseline HGS status and 4-year incidence of MCR was examined using logistic regression analyses.

RESULTS

A total of 3,777 participants 60 years and older were included in the baseline analysis. The prevalence of MCR at the baseline was 12.8%. Participants with asymmetry only, weakness only, and both showed significantly increased risk of MCR. After excluding participants with MCR at baseline, 2,328 participants were included in the longitudinal analysis. There were 111 MCR cases (4.77%) over the 4-year follow-up period. Participants with HGS weakness and asymmetry together at baseline had increased odds of incident MCR (HGS ratio at 10%: odds ratio [OR] 4.48, p < 0.001; HGS ratio at 20%: OR 5.43, p < 0.001; HGS ratio at 30%: OR 6.02, p < 0.001).

DISCUSSION

These results show that the presence of both HGS asymmetry and weakness is associated with MCR incidence. The early recognition of HGS asymmetry and weakness may be helpful in the prevention and treatment of cognitive dysfunction.

Neurophysiological Markers of Premotor-Motor Network Plasticity Predict Motor Performance in Young and Older Adults

Aging is commonly associated with a decline in motor control and neural plasticity. Tuning cortico-cortical interactions between premotor and motor areas is essential for controlling fine manual movements. However, whether plasticity in premotor-motor circuits predicts hand motor abilities in young and elderly humans remains unclear. Here, we administered transcranial magnetic stimulation (TMS) over the ventral premotor cortex (PMv) and primary motor cortex (M1) using the cortico-cortical paired-associative stimulation (ccPAS) protocol to manipulate the strength of PMv-to-M1 connectivity in 14 young and 14 elderly healthy adults. We assessed changes in motor-evoked potentials (MEPs) during ccPAS as an index of PMv-M1 network plasticity. We tested whether the magnitude of MEP changes might predict interindividual differences in performance in two motor tasks that rely on premotor-motor circuits, i.e., the nine-hole pegboard test and a choice reaction task. Results show lower motor performance and decreased PMv-M1 network plasticity in elderly adults. Critically, the slope of MEP changes during ccPAS accurately predicted performance at the two tasks across age groups, with larger slopes (i.e., MEP increase) predicting better motor performance at baseline in both young and elderly participants. These findings suggest that physiological indices of PMv-M1 plasticity could provide a neurophysiological marker of fine motor control across age-groups.

The Purdue Pegboard Test: Normative Data From 1,355 Healthy People From Austria

IMPORTANCE

The Purdue Pegboard Test (PPT) is widely used as a measure of manual dexterity. Declining manual dexterity may predict cognitive decline among elderly people, but normative data for this population are scarce.

OBJECTIVE

To identify demographic and clinical predictors of PPT results in normal middle-aged and elderly Austrian people and to provide norms stratified by significant determinants.

DESIGN

A prospective, community-based cohort study using baseline data of participants from two study panels (1991-1994 and 1999-2003).

SETTING

Monocentric study Participants: 1,355 healthy, randomly selected, community-dwelling people ages 40 to 79 yr.

METHOD

Extensive clinical examination, including completion of the PPT.

OUTCOMES AND MEASURES

The number of pegs placed within a 30-s time limit on four subtests: using the right hand, left hand, both hands, and assembly (within 60 s), respectively. Demographic outcomes were the highest grade achieved.

RESULTS

For all four subtests, increasing age (βs = -0.400 to -0.118, SEs = 0.006 to 0.019, p < .001) and male sex (βs = -1.440 to -0.807, SEs = 0.107 to 0.325, p < .001) was related to worse test results. Among vascular risk factors, diabetes (βs = -1.577 to -0.419, SEs = 0.165 to 0.503, p < .001) was related to worse test results but explained only a small portion (0.7%-1.1%) of the variability in PPT performance.

CONCLUSIONS AND RELEVANCE

We provide age- and sex-specific norms of the PPT for a middle-aged and elderly population. The data represent useful reference values when assessing manual dexterity in older age groups. What This Article Adds: Advancing age and male sex relate to worse performance on the PPT in a community-dwelling cohort without signs and symptoms of neurological disease. Vascular risk factors explain only very little of the variance of test results in our population. Our study adds to the limited age- and sex-specific norms of the PPT among middle-aged and older people.

Effects of home-based manual dexterity training on cognitive function among older adults: a randomized controlled trial

BACKGROUND

The relationship between manual dexterity and cognitive function among older adults is well known; however, few studies have focused on manual dexterity training that confirms cognitive load of training in older adults through functional near-infrared spectroscopy (fNIRS) and verifies the effect of training. This study examined the effects of home-based manual dexterity training on cognitive function in older adults using a digital trail-making peg test device combining two conventional assessment tools namely, the peg and trail-making tests.

METHODS

For 12 weeks, 57 healthy older adults aged 65-88 years participated in a parallel-group, randomized controlled trial, wherein home-based manual dexterity training was performed for approximately 20 min daily. To quantify the cognitive load in different manual dexterity conditions, we assessed the cortical activation patterns of the prefrontal cortex via a wearable four-channel fNIRS device. Participants in the control group were asked to continue their usual daily routines during the intervention period. Cognitive function was assessed using the Stroop Color and Word and Cognitive Impairment Tests. Manual dexterity was assessed using the Purdue Pegboard Test. All outcomes were estimated before and after the intervention.

RESULTS

We observed significant differences in prefrontal cortical activation between the different manual dexterity conditions. Only the intervention group showed a significant improvement in Stroop interference (169.0-108.9 ms, p = 0.032) and an executive function and assembly task of the Purdue Pegboard Test (22.5-26.4 counts, p < 0.001). Additionally, except the clock drawing task, cognitive function had a larger effect size (Cohen's d) in the intervention group (d = 0.26-0.45) than in the control group (d = 0.11-0.28).

CONCLUSIONS

Home-based manual dexterity training can improve performance in a complex manual dexterity task and executive functioning in older adults.

TRIAL REGISTRATION

UMIN-CTR Clinical Trial, UMIN000047203. Registered 17 March 2022 - Retrospectively registered, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&recptno=R000053844&type=summary&language=E.

Quantitative assessments of finger individuation with an instrumented glove

BACKGROUND

In clinical and research settings, hand dexterity is often assessed as finger individuation, or the ability to move one finger at a time. Despite its clinical importance, there is currently no standardized, sufficiently sensitive, or fully objective platform for these evaluations.

METHODS

Here we developed two novel individuation scores and tested them against a previously developed score using a commercially available instrumented glove and data collected from 20 healthy adults. Participants performed individuation for each finger of each hand as well as whole hand open-close at two study visits separated by several weeks. Using the three individuation scores, intra-class correlation coefficients (ICC) and minimal detectable changes (MDC) were calculated. Individuation scores were further correlated with subjective assessments to assess validity.

RESULTS

We found that each score emphasized different aspects of individuation performance while generating scores on the same scale (0 [poor] to 1 [ideal]). These scores were repeatable, but the quality of the metrics varied by both equation and finger of interest. For example, index finger intra-class correlation coefficients (ICC's) were 0.90 (< 0.0001), 0.77 (< 0.001), and 0.83 (p < 0.0001), while pinky finger ICC's were 0.96 (p < 0.0001), 0.88 (p < 0.0001), and 0.81 (p < 0.001) for each score. Similarly, MDCs also varied by both finger and equation. In particular, thumb MDCs were 0.068, 0.14, and 0.045, while index MDCs were 0.041, 0.066, and 0.078. Furthermore, objective measurements correlated with subjective assessments of finger individuation quality for all three equations (ρ = - 0.45, p < 0.0001; ρ = - 0.53, p < 0.0001; ρ = - 0.40, p < 0.0001).

CONCLUSIONS

Here we provide a set of normative values for three separate finger individuation scores in healthy adults with a commercially available instrumented glove. Each score emphasizes a different aspect of finger individuation performance and may be more uniquely applicable to certain clinical scenarios. We hope for this platform to be used within and across centers wishing to share objective data in the physiological study of hand dexterity. In sum, this work represents the first healthy participant data set for this platform and may inform future translational applications into motor physiology and rehabilitation labs, orthopedic hand and neurosurgery clinics, and even operating rooms.

Lipid Differences and Related Metabolism Present on the Hand Skin Surface of Different-Aged Asiatic Females-An Untargeted Metabolomics Study

This cross-sectional study aimed to investigate differences in skin surface lipids (SSL) and explore related metabolic pathways among females of different ages in Henan Province. Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to determine the lipid composition of the skin surface of 58 female volunteers who were divided into three age groups. Statistical analysis was performed using Progenesis QI, Ezinfo, and MetaboAnalyst. Multivariate and enrichment analysis were used to identify the different SSL among the groups. A total of 530 lipid entities were identified and classified into eight classes. Among these, 63 lipids were significantly different between the groups. Lower levels of glycerolipids (GLs) and sphingolipids (SPs) were observed in the middle-aged group, while higher levels of GLs were found in the elder group. GLs belonged to the largest and statistically significant enrichment of lipid metabolic pathways, and the lipid individuals enriched to the sphingoid bases metabolism were the most and statistically significant. These findings suggest that there are differences in hand SSL among females of different ages, which may be related to GLs and sphingoid bases metabolism.

Hand Dexterity Is Associated with the Ability to Resolve Perceptual and Cognitive Interference in Older Adults: Pilot Study

The relationship between hand dexterity and inhibitory control across the lifespan is underexplored. In this pilot study, we examined inhibitory control using a modified Simon task. During the task, participants were presented with right- and left-pointing arrows located either on the right or the left parts of the screen. In the congruent trials, the arrow location and direction matched. In the incongruent trials, they mismatched, thus creating cognitive interference. In 50% of trials, the arrow presentation was accompanied by a task-irrelevant but environmentally meaningful sound that created perceptual interference. Hand dexterity was measured with the 9-hole peg test. Significantly faster reaction time (RT) on the modified Simon task (p < 0.001) was observed in younger adults, trials with concurrent sound stimuli, and congruent trials. Older adults who reported recent falls had greater difficulty resolving cognitive interference than older adults without recent falls. Hand dexterity significantly moderated the effect of sound on RT, but only in the group of older individuals. Interestingly, older individuals with reduced hand dexterity benefited from concurrent sounds more than those with better hand dexterity. Our findings suggest that task-irrelevant but environmentally meaningful sounds may increase alertness and enhance stimulus perception and recognition, thus improving motor performance in older individuals.

Home calligraphic exercises as manual dexterity training in patients with Parkinson's disease: a pilot feasibility study

PURPOSE

To assess the feasibility and effects on manual dexterity and the quality of life (QoL) of a 12-week home calligraphic training program in patients with Parkinson's disease (PD).

METHODS

A pilot study with participants recruited from the Movement Disorders consultation at the Hospital 12 de Octubre (Madrid). The main outcome, manual dexterity, was assessed using the Purdue Pegboard Test (PPT). Secondary outcomes included clinical rating scales that contemplate aspects related to manual dexterity (DextQ-24, UPDRSII, UPDRSIII), and QoL (PDQ-39 and EuroQoL-5D).

RESULTS

Thirty PD patients (57% males) with a mean age of 66.11 (9.76) years and 93% adherence rate. The PPT scores improved significantly (p < 0.0001) from T0 (start of the study) to T1 (after 24 weeks). No statistically significant change was found in DextQ-24, UPDRS-II and UPDRS-III, but a clear improvement was observed in the QoL measurement: EuroQoL-5D (p < 0.0001), PDQ-39 (p < 0.0001) and modified PDQ-39 (p = 0.022).

CONCLUSIONS

This is the first study to demonstrate the feasibility and improvement in hand dexterity assessed by the PPT for patients diagnosed with PD after a 12-week home calligraphic training program. A significant improvement was noted in the QoL measurements, such as the PDQ-39, modified PDQ-39, and EuroQoL-5D.Implications for RehabilitationMost patients with Parkinson's disease suffer from impaired manual dexterity, making it difficult to perform activities of daily living such as eating, buttoning, or shaving.A 12-week home calligraphic training program could improve hand dexterity in these patients.The advantage of this home calligraphic trainingis is that it is an easy-to-perform, low-cost and no side effects.This training also improves their quality of life.

Decreased nerve conduction velocity may be a predictor of fingertip dexterity and subjective complaints

We examined the causes of decreased fingertip dexterity in elderly individuals with an aim to improve their quality of life by improving their activities of daily living. We calculated nerve conduction velocity, absolute error during force adjustment tasks, and fingertip dexterity test scores for 30 young (21-34 years old) and 30 elderly (60-74 years old) participants to identify age-related changes. We also assessed subjective complaints of pain, motor function, and numbness. Motor nerve (young: 55.8 ± 3.7 m/s; elderly: 52.2 ± 5.0 m/s) and sensory nerve (young: 59.4 ± 3.4 m/s; elderly: 55.5 ± 5.3 m/s) conduction velocities decreased in an age-dependent manner. Moreover, the decrease of motor nerve conduction velocity was associated with decreased fingertip dexterity (objective index), while the decrease of sensory nerve conduction velocity was associated with subjective complaints of pain and motor function (subjective index).

Trajectories of mobility difficulty and falls in community-dwelling adults aged 50 + in Taiwan from 2003 to 2015

BACKGROUND

A decline in mobility leads to fall occurrence and poorer performance in instrumental activities of daily living, which are widely proved to be associated with older adults' health-related quality of life. To inform potential predicaments faced by older adults at different age levels, predictors of this mobility change and falls along with the ageing process need to be further evaluated. Therefore, this study examined the risk factors associated with the longitudinal course of mobility difficulty and falls among community-dwelling middle-aged and older adults in the Taiwanese community.

METHODS

We evaluated data for the period between 2003 and 2015 from the Taiwan Longitudinal Study on Aging; the data cover 5267 community-based middle-aged and older adults with approximately 12 years of follow-up. In terms of mobility, the participants self-reported difficulties in mobility tasks (eg, ambulation) and whether they used a walking device. We employed linear mixed-effects regression models and cumulative logit models to examine whether personal characteristics are associated with mobility difficulty and falls.

RESULTS

Mobility difficulty significantly increased over time for the participants aged ≥ 60 years. Perceived difficulties in standing, walking, squatting, and running became apparent from a younger age than limitations with hand function. The probability of repeated falls increased significantly with older age at 70 (p = .002), higher level of mobility difficulty (p < .0001), lower cognitive status (p = .001), living alone (p = .001), higher number of comorbid illnesses (p < .001), walking device use (p = .003), longer time in physical activities (p < .011), and elevated depressive symptoms (p = .006). Although walking aid use increased the probability of falls, individuals with mobility difficulty had a reduced probability of repeated falls when using a walking device (p = .02).

CONCLUSION

Community-dwelling Taiwanese adults face an earlier mobility difficulty starting in 60 years old. Individuals with more leisure and physical activities in daily life were more likely to maintain mobility and walking safety. Long-term, regular, social, and physical activity could be a referral option for falls prevention program. The use of a walking device and safety precautions are warranted, particularly for individuals with walking difficulties.

A Biopsychosocial Model of Mealtime Management in Persons with Dementia, an Asset-Based Approach to Patient-Centered Care

Considering the rapid increase in the population over the age of 65, there is increasing need to consider models of care for persons with dementia (PWD). One common deficit associated with dementia progression is difficulty with successful participation in mealtimes. Difficulty participating in mealtimes in PWD is not the result of one factor, but rather a confluence of biological, psychological, and social characteristics common in dementia. Factors leading to mealtime difficulties for PWD may include changes in cognitive status, altered sensorimotor functioning, and increased reliance on caregiver support. The complex nature of biological, psychological, and social factors leading to mealtime difficulty highlights the need for a pragmatic model that caregivers can utilize to successfully support PWD during mealtimes. Existing models of dementia and mealtime management were reviewed and collated to create a model of mealtime management that considers this complex interplay. The Biopsychosocial Model of Mealtime Management builds on past research around patient-centered care and introduces an asset-based approach to capitalize on a PWD's retained capabilities as opposed to compensating for disabilities associated with dementia. We hope this model will provide a framework for caregivers to understand what factors impact mealtime participation in PWD and provide appropriate means on intervention.

Hand dexterity, daily functioning and health-related quality of life in kidney transplant recipients

Impaired interplay between sensory and motor function may be an important, often overlooked cause of the decreased daily functioning and impaired health-related quality of life (HRQoL) of kidney transplant recipients (KTR). We assessed this interplay using a hand dexterity test, and investigated its potential associations with daily functioning and HRQoL among KTR enrolled at the TransplantLines Biobank and Cohort Study. A total of 309 KTR (58% male, mean age 56 ± 13 years) at median 4 [IQR: 1-11] years after transplantation were included. Impaired hand dexterity, as defined by a test performance slower than the 95th percentile of an age- and sex-specific reference population, was observed in 71 (23%) KTR. Worse hand dexterity was independently associated with worse performance on almost all measures of physical capacity, activities of daily living and societal participation. Finally, hand dexterity was independently associated with physical HRQoL (standardized beta - 0.22, 95%CI - 0.34 to - 0.09, P < 0.001). In conclusion, impaired interplay between sensory and motor function, as assessed by hand dexterity, is prevalent among KTR. In addition, poor hand dexterity was associated with impaired daily functioning and limited physical HRQoL. Impaired interplay between sensory and motor function may be therefore an important, hitherto overlooked, phenomenon in KTR.

Validation of a graphic test to quantitatively assess the dominant hand dexterity

Dexterity dysfunction is a key feature of disability in many neurological and non-neurological diseases. The Nine-Hole Peg Test (NHPT) is the most used test to assess hand dexterity in clinical practice but presents limitations. A new graphic test to enhance objective evaluation of the of the dominant hand dexterity is proposed. The task consists in drawing a continuous line in paths composed by a part with multiple orthogonal changes of direction ('meander'), and a second part derived from the Archimedean spiral ('spiral'). The test was validated in 200 healthy controls and 93 neurological patients. 48 patients performed also the NHPT. Several parameters were analyzed, among which total time, total length, number of touches and number of crossings. Healthy subjects display statistically significant differences with respect to pathological subjects in the case of total time, number of touches, and number of crossings (p<0.001), but not in the case of total length (p = 0.27) needed to complete the second sheet. Moreover, healthy controls display a learning effect, the time needed to complete the second sheet was significantly lower than for the first sheet (p<0.001), and an inverse correlation with age was observed (r = 0.56, p<0.001). The comparison between the NHPT and the new test showed a strong positive correlation (r = 0.71, p<0.001) whereas touches and crossing a weak positive one (r = 0.35, p = 0.01). The new test distinguishes between a slow but precise performance and a fast but imprecise performance, thus providing additional information with respect to NHPT.

Accessible and Inclusive Cyber Security: A Nuanced and Complex Challenge

It has been argued that human-centred security design needs to accommodate the considerations of three dimensions: (1) security, (2) usability and (3) accessibility. The latter has not yet received much attention. Now that governments and health services are increasingly requiring their citizens/patients to use online services, the need for accessible security and privacy has become far more pressing. The reality is that, for many, security measures are often exasperatingly inaccessible. Regardless of the outcome of the debate about the social acceptability of compelling people to access public services online, we still need to design accessibility into these systems, or risk excluding and marginalising swathes of the population who cannot use these systems in the same way as abled users. These users are particularly vulnerable to attack and online deception not only because security and privacy controls are inaccessible but also because they often struggle with depleted resources and capabilities together with less social, economic and political resilience. This conceptual paper contemplates the accessible dimension of human-centred security and its impact on the inclusivity of security technologies. We scope the range of vulnerabilities that can result from a lack of accessibility in security solutions and contemplate the nuances and complex challenges inherent in making security accessible. We conclude by suggesting a number of avenues for future work in this space.

Human vulnerability and variability in the cold: Establishing individual risks for cold weather injuries

Human tolerance to cold environments is extremely limited and responses between individuals is highly variable. Such physiological and morphological predispositions place them at high risk of developing cold weather injuries [CWI; including hypothermia and/or non-freezing (NFCI) and freezing cold injuries (FCI)]. The present manuscript highlights current knowledge on the vulnerability and variability of human cold responses and associated risks of developing CWI. This review 1) defines and categorizes cold stress and CWI, 2) presents cold defense mechanisms including biological adaptations, acute responses and acclimatization/acclimation and, 3) proposes mitigation strategies for CWI. This body of evidence clearly indicates that all humans are at risk of developing CWI without adequate knowledge and protective equipment. In addition, we show that while body mass plays a key role in mitigating risks of hypothermia between individuals and populations, NFCI and FCI depend mainly on changes in peripheral blood flow and associated decrease in skin temperature. Clearly, understanding the large interindividual variability in morphology, insulation, and metabolism is essential to reduce potential risks for CWI between and within populations.

Sensorimotor Synchronization in Healthy Aging and Neurocognitive Disorders

Sensorimotor synchronization (SMS), the coordination of physical actions in time with a rhythmic sequence, is a skill that is necessary not only for keeping the beat when making music, but in a wide variety of interpersonal contexts. Being able to attend to temporal regularities in the environment is a prerequisite for event prediction, which lies at the heart of many cognitive and social operations. It is therefore of value to assess and potentially stimulate SMS abilities, particularly in aging and neurocognitive disorders (NCDs), to understand intra-individual communication in the later stages of life, and to devise effective music-based interventions. While a bulk of research exists about SMS and movement-based interventions in Parkinson's disease, a lot less is known about other types of neurodegenerative disorders, such as Alzheimer's disease, vascular dementia, or frontotemporal dementia. In this review, we outline the brain and cognitive mechanisms involved in SMS with auditory stimuli, and how they might be subject to change in healthy and pathological aging. Globally, SMS with isochronous sounds is a relatively well-preserved skill in old adulthood and in patients with NCDs. At the same time, natural tapping speed decreases with age. Furthermore, especially when synchronizing to sequences at slow tempi, regularity and precision might be lower in older adults, and even more so in people with NCDs, presumably due to the fact that this process relies on attention and working memory resources that depend on the prefrontal cortex and parietal areas. Finally, we point out that the effect of the severity and etiology of NCDs on sensorimotor abilities is still unclear: More research is needed with moderate and severe NCD, comparing different etiologies, and using complex auditory signals, such as music.

Effectiveness of elongation band exercise on the upper limb strength and range of motion among older adults

An elongation band (EB) is used to improve the physical strength of older adults. However, the evidence of its effect on the upper limb is a deficiency. This study investigated the effectiveness of EB exercises on upper limb function in the elderly. Participants were divided into two groups: EB (n=16) and control (n=14). The EB group performed exercises in a sitting position using an EB while the control group performed active stretching exercises without bands. The exercise regimen consisted of four shoulder joint movements. Each group performed the exercise for 20 min per day, 5 days per week over a period of 2 months. Measurements included upper limb muscle strength, shoulder joint range of motion, and grip strength. Measurements were performed at baseline, and 1 and 2 months after the intervention. Analysis of covariance was used to compare differences between the groups. The EB group demonstrated significant increases in muscle strength (upper trapezius, deltoid, middle trapezius muscle), shoulder joint range of motion (right shoulder flexion, internal rotation, external rotation, left shoulder joint extension), and grip strength. In conclusion, EB exercises increased upper limb muscle strength, shoulder joint range of motion, and grip strength in older adults.

Handgrip strength asymmetry is associated with the risk of neurodegenerative disorders among Chinese older adults

BACKGROUND

Neurodegenerative disorders, as the irreversible condition, have a long, silent preclinical period. Recognition of early physical signs of neurodegenerative disorders had important practical implications for identifying at-risk population. The aim of this study was to investigate whether handgrip strength (HGS) asymmetry was associated with the incidence of neurodegenerative disorders among Chinese older adults.

METHODS

This study used the data of participants aged 60 years and over from three waves (2011-2015) of China Health and Retirement Longitudinal Study. HGS asymmetry was measured with HGS ratio (maximal non-dominant HGS/maximal dominant HGS), with the value less than 0.9 or more than 1.1 considered as HGS asymmetry. Physician-diagnosed neurodegenerative disorders were identified by self-reported or proxy-reported information. Competing risk analysis was conducted to examine the association between HGS asymmetry and incident neurodegenerative disorders, with mortality treated as the competing event.

RESULTS

A total of 4925 participants were included in the analysis [mean (SD) age: 68.1(6.68); female: 49.7%]. Eight hundred and eighty-eight (18.0%) participants had low HGS and 2227 (45.2%) had HGS asymmetry. During the 4 years of follow-up, there were 156 cases of neurodegenerative disorders and 422 cases of mortality. The incidence of neurodegenerative disorders was 8.7 per 1000 person-years [95% confidence interval (CI): 7.4-10.2], and the incidence of mortality was 23.5 per 1000 person-years (95% CI: 21.4-25.9). Both the cause-specific model and the Fine-Gray subdistribution hazard model showed that participants with HGS asymmetry had increased hazard of neurodegenerative disorders [hazard ratio (HR) = 1.66, P = 0.002, 95% CI: 1.202-2.297; subdistribution hazard ratio (SHR) = 1.65, P = 0.002, 95% CI: 1.202-2.285]. Low HGS, but not HGS asymmetry, was related to the higher hazard of mortality (HR = 1.61, P < 0.001, 95% CI: 1.297-1.995; SHR = 1.58, P < 0.001, 95% CI: 1.286-1.951).

CONCLUSIONS

Handgrip strength asymmetry was associated with the future risk of neurodegenerative disorders among Chinese older adults. Public healthcare providers could consider examining HGS asymmetry along with the maximal HGS as a way to identify those at elevated risk of neurodegenerative disorders.

A novel tablet-based application for assessment of manual dexterity and its components: a reliability and validity study in healthy subjects

BACKGROUND

We developed five tablet-based tasks (applications) to measure multiple components of manual dexterity.

AIM

to test reliability and validity of tablet-based dexterity measures in healthy participants.

METHODS

Tasks included: (1) Finger recognition to assess mental rotation capacity. The subject taps with the finger indicated on a virtual hand in three orientations (reaction time, correct trials). (2) Rhythm tapping to evaluate timing of finger movements performed with, and subsequently without, an auditory cue (inter-stimulus interval). (3) Multi-finger tapping to assess independent finger movements (reaction time, correct trials, unwanted finger movements). (4) Sequence tapping to assess production and memorization of visually cued finger sequences (successful taps). (5) Line-tracking to assess movement speed and accuracy while tracking an unpredictably moving line on the screen with the fingertip (duration, error). To study inter-rater reliability, 34 healthy subjects (mean age 35 years) performed the tablet tasks twice with two raters. Relative reliability (Intra-class correlation, ICC) and absolute reliability (Standard error of measurement, SEM) were established. Task validity was evaluated in 54 healthy subjects (mean age 49 years, range: 20-78 years) by correlating tablet measures with age, clinical dexterity assessments (time taken to pick-up objects in Box and Block Test, BBT and Moberg Pick Up Test, MPUT) and with measures obtained using a finger force-sensor device.

RESULTS

Most timing measures showed excellent reliability. Poor to excellent reliability was found for correct trials across tasks, and reliability was poor for unwanted movements. Inter-session learning occurred in some measures. Age correlated with slower and more variable reaction times in finger recognition, less correct trials in multi-finger tapping, and slower line-tracking. Reaction times correlated with those obtained using a finger force-sensor device. No significant correlations between tablet measures and BBT or MPUT were found. Inter-task correlation among tablet-derived measures was weak.

CONCLUSIONS

Most tablet-based dexterity measures showed good-to-excellent reliability (ICC ≥ 0.60) except for unwanted movements during multi-finger tapping. Age-related decline in performance and association with finger force-sensor measures support validity of tablet measures. Tablet-based components of dexterity complement conventional clinical dexterity assessments. Future work is required to establish measurement properties in patients with neurological and psychiatric disorders.

The senile hand: age effects on intrinsic hand muscle CMAP amplitudes influence split-hand index calculations

INTRODUCTION/AIMS

Age can affect hand muscles non-uniformly. We investigated the influence of age on the compound muscle action potential (CMAP) amplitude of the hand muscles and the derived split-hand index (SHI).

METHODS

We studied 244 subjects investigated for myasthenia gravis but without neuromuscular disorders. Abductor pollicis brevis (APB), first dorsal interosseous (FDI), and abductor digiti minimi (ADM) CMAPs were obtained by supramaximal stimulation at the wrist, recording with surface electrodes while checking the best recording site. We applied Tukey's HSD and Kruskal-Wallis one-way analysis of variance for comparing age groups defined by median and inter-quantile ranges (IQR). Spearman's rank correlation coefficient and linear regression were used for testing age-dependence of measurements.

RESULTS

Median age was 61.5 years (1st IQR 44.5, 3rd IQR 72.0, range 18-89). Age and neurophysiological measurements were similar between genders. APB_CMAP , FDI_CMAP , ADM_CMAP and SHI were correlated with age (p < 0.001). Median and cut-off values were significantly different between age groups. APB_CMAP , FDI_CMAP and ADM_CMAP decreased by 0.8/0.7/0.3 mV/year, respectively, and SHI decreased 0.15/year.

DISCUSSION

The CMAP amplitudes of hand muscles and derived SHI were strongly age-dependent, although this effect was less in ADM. This represents a physiological phenomenon. Future studies using the SHI should consider age effects. This article is protected by copyright. All rights reserved.