Age and grip strength predict hand dexterity in adults

Age- and sex-related changes in motor functions: a comprehensive assessment and component analysis

Age-related motor impairments often cause caregiver dependency or even hospitalization. However, comprehensive investigations of the different motor abilities and the changes thereof across the adult lifespan remain sparse. We, therefore, extensively assessed essential basic and complex motor functions in 444 healthy adults covering a wide age range (range 21 to 88 years). Basic motor functions, here defined as simple isolated single or repetitive movements in one direction, were assessed by means of maximum grip strength (GS) and maximum finger-tapping frequency (FTF). Complex motor functions, comprising composite sequential movements involving both proximal and distal joints/muscle groups, were evaluated with the Action Research Arm Test (ARAT), the Jebsen-Taylor Hand Function Test (JTT), and the Purdue Pegboard Test. Men achieved higher scores than women concerning GS and FTF, whereas women stacked more pins per time than men during the Purdue Pegboard Test. There was no significant sex effect regarding JTT. We observed a significant but task-specific reduction of basic and complex motor performance scores across the adult lifespan. Linear regression analyses significantly predicted the participants' ages based on motor performance scores (R2 = 0.502). Of note, the ratio between the left- and right-hand performance remained stable across ages for all tests. Principal Component Analysis (PCA) revealed three motor components across all tests that represented dexterity, force, and speed. These components were consistently present in young (21-40 years), middle-aged (41-60 years), and older (61-88 years) adults, as well as in women and men. Based on the three motor components, K-means clustering analysis differentiated high- and low-performing participants across the adult life span. The rich motor data set of 444 healthy participants revealed age- and sex-dependent changes in essential basic and complex motor functions. Notably, the comprehensive assessment allowed for generating robust motor components across the adult lifespan. Our data may serve as a reference for future studies of healthy subjects and patients with motor deficits. Moreover, these findings emphasize the importance of comprehensively assessing different motor functions, including dexterity, force, and speed, to characterize human motor abilities and their age-related decline.

Pre-acquired Functional Connectivity Predicts Choice Inconsistency

Economic choice theories usually assume that humans maximize utility in their choices. However, studies have shown that humans make inconsistent choices, leading to suboptimal behavior, even without context-dependent manipulations. Previous studies showed that activation in value and motor networks are associated with inconsistent choices at the moment of choice. Here, we investigated if the neural predispositions, measured before a choice task, can predict choice inconsistency in a later risky choice task. Using functional connectivity (FC) measures from resting-state functional magnetic resonance imaging (rsfMRI), derived before any choice was made, we aimed to predict subjects' inconsistency levels in a later-performed choice task. We hypothesized that rsfMRI FC measures extracted from value and motor brain areas would predict inconsistency. Forty subjects (21 females) completed a rsfMRI scan before performing a risky choice task. We compared models that were trained on FC that included only hypothesized value and motor regions with models trained on whole-brain FC. We found that both model types significantly predicted inconsistency levels. Moreover, even the whole-brain models relied mostly on FC between value and motor areas. For external validation, we used a neural network pretrained on FC matrices of 37,000 subjects and fine-tuned it on our data and again showed significant predictions. Together, this shows that the tendency for choice inconsistency is predicted by predispositions of the nervous system and that synchrony between the motor and value networks plays a crucial role in this tendency.

Manual Dexterity Predictors of Artificial Urinary Sphincter Success

OBJECTIVE

To determine better in-office measures for artificial urinary sphincter outcomes, we investigated the ability of preoperative timed peg-transfer, pinch strength, grip strength, and Disabilities of the Arm Shoulder and Hand Outcome questionnaire in predicting postoperative satisfaction, confidence, and ease of use of artificial urinary sphincter placement for stress urinary incontinence.

MATERIALS AND METHODS

A timed 9-hole peg test, pinch and grip strength assessment, and upper extremity questionnaire were administered during the preoperative visit before sphincter placement. In addition to standard preoperative workup, short-form International Consultation of Incontinence Questionnaire and physician handshake were recorded. Activation occurred 6 weeks after surgery along with assessment of adequacy of pump placement. Three months from surgery a repeat incontinence questionnaire and a survey measuring satisfaction, difficulty of use, and confidence were given. Correlation between preoperative assessment variables and the postoperative questionnaire was assessed.

RESULTS

Thirty-nine patients were included. Average age and body mass index were 68.8 years and 28.8 kg/m2, respectively. Prior prostatectomy accounted for 92.3% of patients, and 46.2% had prior pelvic radiation. Postoperatively, 59.0% of patients were very satisfied; 64.1% of patients reported no difficulty of use; 53.8% felt confidence within 1 day; and 66.7% had much better bladder control. Average pad improvement count was 5.3. Pinch test was associated with satisfaction (P = .011) while peg test was associated with confidence (P = .049). Handshake and upper extremity questionnaire were not significant.

CONCLUSION

The pinch and 9-hole peg transfer tests are cost-effective and easily performed adjuncts that could be used during artificial urinary sphincter evaluation for patients with unclear manual functional status.

Older and younger adults differ in time course of skill acquisition but not in overall improvement in a bimanual visuomotor tracking task

Manual motor performance declines with age, but the extent to which age influences the acquisition of new skills remains a topic of debate. Here, we examined whether older healthy adults show less training-dependent performance improvements during a single session of a bimanual pinch task than younger adults. We also explored whether physical and cognitive factors, such as grip strength or motor-cognitive ability, are associated with performance improvements. Healthy younger (n = 16) and older (n = 20) adults performed three training blocks separated by short breaks. Participants were tasked with producing visually instructed changes in pinch force using their right and left thumb and index fingers. Task complexity was varied by shifting between bimanual mirror-symmetric and inverse-asymmetric changes in pinch force. Older adults generally displayed higher visuomotor force tracking errors during the more complex inverse-asymmetric task compared to younger adults. Both groups showed a comparable net decrease in visuomotor force tracking error over the entire session, but their improvement trajectories differed. Young adults showed enhanced visuomotor tracking error only in the first block, while older adults exhibited a more gradual improvement over the three training blocks. Furthermore, grip strength and performance on a motor-cognitive test battery scaled positively with individual performance improvements during the first block in both age groups. Together, the results show subtle age-dependent differences in the rate of bimanual visuomotor skill acquisition, while overall short-term learning ability is maintained.

Deficits in force production during multifinger tasks demarcate cognitive dysfunction

BACKGROUND

The multifinger force deficit (MFFD) is the decline in force generated by each finger as the number of fingers contributing to an action is increased. It has been shown to associate with cognitive status.

AIMS

The aim was to establish whether a particularly challenging form of multifinger grip dynamometry, that provides minimal tactile feedback via cutaneous receptors and requires active compensation for reaction forces, will yield an MFFD that is more sensitive to cognitive status.

METHODS

Associations between measures of motor function, and cognitive status (Montreal Cognitive Assessment [MoCA]) and latent components of cognitive function (derived from 11 tests using principal component analysis), were estimated cross-sectionally using generalized partial rank correlations. The participants (n  =  62) were community dwelling, aged 65-87.

RESULTS

Approximately half the participants were unable to complete the dynamometry task successfully. Cognitive status demarcated individuals who could perform the task from those who could not. Among those who complied with the task requirements, the MFFD was negatively correlated with MoCA scores-those with the highest MoCA scores tended to exhibit the smallest deficits, and vice versa. There were corresponding associations with latent components of cognitive function.

DISCUSSION

The results support the view that neurodegenerative processes that are a feature of normal and pathological aging exert corresponding effects on expressions of motor coordination-in multifinger tasks, and cognitive sufficiency, due to their dependence on shared neural systems.

CONCLUSIONS

The outcomes add weight to the assertion that deficits in force production during multifinger tasks are sensitive to cognitive dysfunction.

An ergonomic study of arborist work activities

Arborists work in high-risk environments, particularly when climbing trees, where a combination of grip strength and resistance to psychological stress are important attributes for safety. This study investigated the physical and cognitive activities of arborists combined with selected workload factors such as blood pressure, pulse, handgrip strength, and other anthropometric measurements, including manual dexterity and spatial awareness. The sample included 10 participants aged 17-48 years. Blood pressure was negatively correlated with handgrip strength after the activity had been performed. Different types of arborist activities led to various types of physiological feedback, as shown by the analysis of variance. According to our results, there is a difference between physical workloads, associated with activities such as tree felling, tree climbing, or chainsaw maintenance, and cognitive workloads, such as supervision or observation, in relation to blood pressure. Blood pressure was higher for activities that involved a cognitive workload. Before and after any activity, handgrip strength was positively associated with hand size. After any activity, greater changes in handgrip strength of the participant's right hand were associated with needing more time to successfully complete a peg test, which represents a greater cognitive burden. Our results suggest that arborists deal with physical activities such as tree felling, tree climbing, working with a chainsaw, and mental activities (supervising or observing) which were identified as two different groups correlated with hand grip strength, blood pressure, manual dexterity, and spatial awareness. In conclusion, the tree-climbing activity appeared to be the least stressful, and psychological stress appeared to have a greater impact on the health of observers and supervisors in the study group. This can be applied to other professions in many fields, including industries where workers face both physical and cognitive workloads.

Effects of noninvasive neuromodulation targeting the spinal cord on early learning of force control by the digits

AIMS

Control of finger forces underlies our capacity for skilled hand movements acquired during development and reacquired after neurological injury. Learning force control by the digits, therefore, predicates our functional independence. Noninvasive neuromodulation targeting synapses that link corticospinal neurons onto the final common pathway via spike-timing-dependent mechanisms can alter distal limb motor output on a transient basis, yet these effects appear subject to individual differences. Here, we investigated how this form of noninvasive neuromodulation interacts with task repetition to influence early learning of force control during precision grip.

METHODS

The unique effects of neuromodulation, task repetition, and neuromodulation coinciding with task repetition were tested in three separate conditions using a within-subject, cross-over design (n = 23).

RESULTS

We found that synchronizing depolarization events within milliseconds of stabilizing precision grip accelerated learning but only after accounting for individual differences through inclusion of subjects who showed upregulated corticospinal excitability at 2 of 3 time points following conditioning stimulation (n = 19).

CONCLUSIONS

Our findings provide insights into how the state of the corticospinal system can be leveraged to drive early motor skill learning, further emphasizing individual differences in the response to noninvasive neuromodulation. We interpret these findings in the context of biological mechanisms underlying the observed effects and implications for emerging therapeutic applications.

Resistance band training with functional electrical stimulation improves force control capabilities in older adults: a preliminary study

Resistance band training (RBT) with functional electrical stimulation (FES) may be an effective exercise regimen for improving age-related motor impairments. This preliminary study investigated the potential effects of bimanual RBT with FES on upper limb motor functions in older adults. This study randomly assigned 22 elderly people to the bimanual RBT with FES (Bi-RBT+FES) group and the RBT without FES (Bi-RBT) group. All participants performed isometric hand-grip force control tasks in unimanual (dominant and non-dominant) and bimanual conditions before and after four weeks of exercise for each group. We quantified the mean force, force accuracy, force variability, and force regularity at two targeted force levels (i.e., 10 % and 40 % of maximum voluntary contraction; MVC) to estimate changes in force control capabilities. The results revealed that the Bi-RBT+FES group demonstrated a greater force accuracy in the dominant hand at 10 % of MVC after training. Non-dominant hands in the Bi-RBT+FES group increased force accuracy at 40 % of MVC and reduced force variability collapsed across two targeted force levels. Both groups showed a decrease in force regularity after training. These preliminary results indicate that Bi-RBT+FES may be a viable option to facilitate functional recovery of the upper limbs in older adults.

Handgrip strength and upper limb functional performance measures in people over 18 years old: Analysis of relationships and influencing factors

BACKGROUND

Handgrip strength is a common, simple, and inexpensive method to measure muscle strength. On the other hand, the functional performance measurement involves a usual task which implies repeating elements between the individuals' interaction and the environment. This is fundamental for projecting their results to daily life situation.

PURPOSE

To explore the relationship between grip strength and measures of functional performance of the upper limbs (ULs) in people over 18 years of age, and to determine the influence of sociodemographic and anthropometric variables on the relationship.

STUDY DESIGN

A cross-sectional study was conducted under the analytical empirical approach, using linear associations between handgrip strength and functional performance measurement tests (correspondence analysis).

METHODS

Three hundred sixty-two male and female individuals between 18 and 91 years of age from 4 Colombian cities participated. The grip strength of both ULs measured with a digital dynamometry was associated with the Box and Block Test (BBT, manual dexterity), Nine-Hole Peg Test (NHPT, daily living tasks), and Jebsen-Taylor Hand Function Test (JJT, ability to grasp, pick up, and place). Multiple linear regression analyzes were performed to assess possible explanatory factors of a sociodemographic and anthropometric order.

RESULTS

A significant association was found between the grip strength of dominant and non-dominant ULs with all functional performance tests (ρ > 0.27 and p < .001), except for the writing and simulated feeding subtests of the JJT (ρ ≤ 0.16). An interactive effect of age was found in the relationship between grip strength and the 3 functional performance tests.

CONCLUSIONS

These results support the association between grip strength with the NHPT, JJT, and BBT measures and the interactive effect of age on the performance of all tests.

A Polysomnographic Study of Effects of Sleep Deprivation on Novice and Senior Surgeons during Simulated Vitreoretinal Surgery

PURPOSE

To assess the impact of a 3-hour polysomnography (PSG)-recorded night of sleep deprivation on next-morning simulated microsurgical skills among vitreoretinal (VR) surgeons with different levels of surgical experience and associate the sleep parameters obtained by PSG with Eyesi-generated performance.

DESIGN

Self-controlled cohort study.

PARTICIPANTS

Eleven junior VR surgery fellows with < 2 years of surgical experience and 11 senior surgeons with > 10 years of surgical practice.

METHODS

Surgical performance was assessed at 7am after a 3-hour sleep-deprived night using the Eyesi simulator and compared with each subject's baseline performance.

MAIN OUTCOME MEASURES

Changes in Eyesi-generated score (0-700, worst to best), time for task completion (minutes), tremor-specific score (0-100, worst to best), and out-of-tolerance tremor percentage. Polysomnography was recorded during sleep deprivation.

RESULTS

Novice surgeons had worse simulated surgical performance after sleep deprivation compared with self-controlled baseline dexterity in the total score (559.1 ± 39.3 vs. 593.8 ± 31.7; P = 0.041), time for task completion (13.59 ± 3.87 minutes vs. 10.96 ± 1.95 minutes; P = 0.027), tremor-specific score (53.8 ± 19.7 vs. 70.0 ± 15.3; P = 0.031), and out-of-tolerance tremor (37.7% ± 11.9% vs. 28.0% ± 9.2%; P = 0.031), whereas no performance differences were detected in those parameters among the senior surgeons before and after sleep deprivation (P ≥ 0.05). Time for task completion increased by 26% (P = 0.048) in the post-sleep deprivation simulation sessions for all participants with a high apnea-hypopnea index (AHI) and by 37% (P = 0.008) among surgeons with fragmented sleep compared with those with normal AHI and < 10 arousals per hour, respectively. Fragmented sleep was the only polysomnographic parameter associated with a worse Eyesi-generated score, with a 10% (P = 0.005) decrease the following morning.

CONCLUSIONS

This study detected impaired simulated surgical dexterity among novice surgeons after acute sleep deprivation, whereas senior surgeons maintained their surgical performance, suggesting that the impact of poor sleep quality on surgical skills is offset by increased experience. When considering the 2 study groups together, sleep fragmentation and AHI were associated with jeopardized surgical performance after sleep deprivation.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Average Scleral Lens Replacement Period at a Tertiary Care Hospital

OBJECTIVE

To evaluate the average scleral lens replacement period at a tertiary care hospital.

METHODS

Patients were identified retrospectively through electronic medical records. Inclusion criteria included scleral lens patients treated at the USC Department of Ophthalmology who had reordered a scleral lens at least once in one eye. Lens order histories were evaluated, and statistical analysis included a multivariable, mixed-methods, linear, regression model.

RESULTS

Two hundred fifty-one patients (120 men and 131 women; average age 57.1±17.4 years, range 9-93 years) and a total of 445 eyes (227 OD, 218 OS; 199 irregular corneas, 246 ocular surface disease) were included. The average replacement period for a scleral lens was 23.9±14.3 months (range 5-2,617 days). Patients with greater scleral lens experience had a statistically significant increase in their average scleral lens replacement period; for every one year of additional experience wearing scleral lenses, average replacement period increased by 30.7 days ( P =0.001). There was no statistically significant correlation between average scleral lens replacement period and sex, diagnosis, prior outside scleral lens treatment, lens brand, or lens diameter.

CONCLUSION

The average scleral lens replacement period in this patient cohort at a tertiary care hospital was 23.9±14.3 months (1.99±1.19 years). Further studies are needed to better understand the impact of scleral lens age on ocular health and vision. Certainly, proper scleral lens training and education are essential to ensure optimal lens condition and treatment outcomes.

A Computer Interface Controlled by Upper Limb Muscles: Effects of a Two Weeks Training on Younger and Older Adults

As the population worldwide ages, there is a growing need for assistive technology and effective human-machine interfaces to address the wider range of motor disabilities that older adults may experience. Motor disabilities can make it difficult for individuals to perform basic daily tasks, such as getting dressed, preparing meals, or using a computer. The goal of this study was to investigate the effect of two weeks of training with a myoelectric computer interface (MCI) on motor functions in younger and older adults. Twenty people were recruited in the study: thirteen younger (range: 22-35 years old) and seven older (range: 61-78 years old) adults. Participants completed six training sessions of about 2 hours each, during which the activity of right and left biceps and trapezius were mapped into a control signal for the cursor of a computer. Results highlighted significant improvements in cursor control, and therefore in muscle coordination, in both groups. All participants with training became faster and more accurate, although people in different age range learned with a different dynamic. Results of the questionnaire on system usability and quality highlighted a general consensus about easiness of use and intuitiveness. These findings suggest that the proposed MCI training can be a powerful tool in the framework of assistive technologies for both younger and older adults. Further research is needed to determine the optimal duration and intensity of MCI training for different age groups and to investigate long-term effects of training on physical and cognitive function.

Influences of Psychomotor Behaviors on Learning Swimming Styles in 6-9-Year-Old Children

The aim of this study was to identify the existence of some relationships between certain psychomotor behaviors, which we consider specific to swimming, and learning to execute the technique of some swimming styles (front crawl and backstroke). The study was carried out for 10 months and included 76 children (40 boys and 36 girls) aged between 6 and 9 years who practice recreational swimming in a city in Romania. Several tools were used: the Tapping test for manual dexterity, the Goodenough test for body schema, the Flamingo test for static balance, and the horizontal buoyancy test for body balance on the water. The results indicated better ratings on all psychomotor behaviors analyzed according to gender (in favor of girls compared to boys). The levels of all analyzed psychomotor behaviors have a direct relationship to the subjects' age. Also, we identified moderate positive correlations for manual dexterity (rs = 0.63 in the front crawl style; rs = 0.57 in the backstroke style) and strong correlations for body schema, static balance and buoyancy, coordination with the learning of the two swimming styles (r or rs between 0.77 and 0.85). In conclusion, psychomotor behaviors can be predictors for learning swimming styles.

Aging reduces manual dexterity and force production asymmetries between the hands

Age-related effects on motor asymmetry provide insight into changes in cortical activation during aging. To investigate potential changes in manual performance associated with aging, we conducted the Jamar hand function test and the Purdue Pegboard test on young and older adults. All tests indicated reduced motor asymmetry in the older group. Further analysis suggested that a significant decline in dominant (right) hand function resulted in less asymmetric performance in older adults. The finding is inconsistent with the application of the HAROLD model in the motor domain, which assumes improved performance in the non-dominant hand, leading to a reduction of motor asymmetry in older adults. Based on the manual performance in young and older adults, it is suggested that aging reduces manual asymmetry in both force production and manual dexterity due to the reduced performance of the dominant hand.

Normative Performance Profiles of College Aged Esport Athletes in a Pilot Study

Aims

This study aimed to holistically assess the physical and cognitive attributes of esport athletes.

Methods and Results

Forty-six adults between 18 and 32 years old with experience playing videogames were enrolled in this study. Participants completed assessments in five areas: demographics, self-report questionnaires, cognitive performance, physical performance, and gaming performance. Participants self-reported Overwatch ranking and physical activity participation (Pediatric Physical Activity Measure), and grip strength was measured with a handheld dynamometer. Seven domains of physical, mental, and social health and well-being were measured with the Patient Reported Outcomes Measurement Information System (PROMIS-29). The List Sorting Working Memory Test and Picture Sequence Memory Test from the National Institutes of Health (NIH) Toolbox Cognition Batteries were used to measure cognitive performance. Finally, esports performance was measured using a series of tasks through Alienware Academy and AIM Booster to record accuracy, reaction time, and targets hit. Participants were separated into high and low ranking groups for comparisons. This sample of esport athletes was similar to the general population for grip strength, each of the PROMIS-29 metrics, the List Sorting Working Memory Test, and the Picture Sequence Memory Test. Reaction time was the variable with the only significant difference between ranking groups.

Conclusion

This study represents a primary investigation of esport athletes using a holistic approach. By incorporating physical and cognitive components, the most important factors to esport athletes' health and performance can be better understood and applied.

Comparing the effect of rhythmic stabilization and combination of isotonic technique on grip strength, pinch strength and dexterity of hand among middle aged healthy individuals - a randomized clinical trial

Purpose: The aim of the study was to evaluate and compare the effects of Rhythmic Stabilization and a combination of isotonic technique on grip  strength, pinch strength, and dexterity of hand among middle aged healthy individuals. Methods Forty middle aged healthy individuals were selected on the basis of inclusion and exclusion criteria. Participants were randomly allocated to two groups, with 20 in group A (Rhythmic Stabilization) and 20 in group B (Combination of Isotonic Technique). Treatment was given for 4 weeks, thrice a week. Outcome measures: grip strength, pinch strength, and dexterity were assessed by the Jamar hand dynamometer, the Pinch gauge, and the Perdue peg board, respectively. Outcome measures were assessed at baseline and after 4 weeks of treatment. Results Notably, Group A participants showed a significant improvement in all outcome measures compared to Group B (p<0.05) when compared. Both the interventions were effective for dexterity outcome in both groups (p<0.05).  Conclusion: This study provides evidence that application of Rhythmic Stabilization improves grip strength and pinch strength.  This suggests that static Proprioceptive Neuromuscular Facilitation (PNF) exercises performed on the fingers can improve dexterity, grip strength, and pinch strength in the middle-aged population. Highlights As age increases, there is decrease in grip strength and dexterity of a person. The grip strength, finger strength and dexterity are inter-related. The Proprioceptive Neuromuscular Facilitation increases strength of muscles. The static PNF exercises are more effective than the dynamic PNF exercises to improve strength of grip strength, finger strength and dexterity.

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.

Protective gloves, hand grip strength, and dexterity tests: A comprehensive study

Protective gloves can affect hand performance indicators (HPIs) like manual dexterity and hand grip. The present study was conducted to comprehensively and comparatively investigate several types of protective gloves and HPI assessment tools. Seventeen healthy men participated in this study. Four types of protective gloves, two structural firefighting and two general protective gloves, were investigated using four different dexterity tests and the bulb dynamometer. Structural firefighting gloves were significantly different in terms of dexterity, while there was no significant difference between general protective gloves. In contrast, firefighting gloves were not significantly different in terms of hand grip strength, while general protective gloves were significantly different in this regard. Among the four investigated tests, the hand tool dexterity test had the highest discrimination power. The negative effects of structural firefighting gloves on HPIs were higher than those of general protective gloves. A trade-off between safety requirements and hand performance is needed.

Functional Aging: Integrating Functionality to a Multidimensional Assessment of Healthy Aging

Worldwide, the number of old adults will peak in the coming decades. Relying solely on the chronological age to make treatment decisions and shape general or specific societal and medical considerations may reinforce ageism and lead to flawed reasoning. Defining physiological age using biological markers is not yet reliable, and an approach based on comorbidities without considering their impact on quality of life is inadequate. A multidimensional approach with strong integration of functionality is presented here to draw a real-world aging approach, easily accessible, clinically relevant, and of societal value.

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).

Seven-month wintertime supplementation of 1200 IU vitamin D has no effect on hand grip strength in young, physically active males: A randomized, controlled study

Background

Study Design

Methods

Results

Conclusion

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.

Stroke-Related Sarcopenia among Two Different Developing Countries with Diverse Ethnic Backgrounds (Cross-National Study in Egypt and China)

The prevalence of stroke-related sarcopenia differs according to the diagnostic criteria, the cut-off point for assessment, and ethnicity. Egypt and China are developing countries with different races where no research concerning stroke-related sarcopenia has been performed yet. We aimed to evaluate the prevalence of possible sarcopenia and confirmed sarcopenia among Egyptian and Chinese stroke survivors using the Asian Working Group of Sarcopenia (AWGS-2019) criteria and to assess the variables associated with the prevalence rate. A prospective cross-sectional study was carried out among 200 Egyptian and 195 Chinese stroke survivors from 2019 to 2021 using a structural health questionnaire. A hand-held dynamometer was used to measure grip strength. Anthropometric measures were used to estimate muscle mass. Data were analyzed using SPSS statistics version 20. p-values < 0.05 were considered statistically significant. The prevalence of possible sarcopenia ranged from 20.0% to 34.4% among Egyptian and Chinese groups, except for the Egyptian females where it was 52.0%. The prevalence of sarcopenia in both populations ranged from 13.6% to 18.6%. Pre-stroke independent variables that accelerated possible sarcopenia were age, history of dyslipidemia, diabetes mellitus, and ischemic heart disease, but stroke severity was a post-stroke risk factor. Age was the only pre-stroke variable for sarcopenia, while quitting smoking and having good nutritional status were variables for the reduction of possible sarcopenia. Quitting smoking, having a good nutritional status, and early rehabilitation reduced sarcopenia development. Controlling vascular risk factors, enhancing rehabilitation, and nutritional therapy are protective measures against sarcopenia. Longitudinal studies are required to identify further risk factors.

Unilateral hand force control impairments in older women

Older women may experience deficits in sensorimotor control at their upper limb because of aging progress compromising the motor system. This study aimed to investigate whether younger and older women differ in sensorimotor capabilities assessed by unilateral force control performances at a lower targeted force level. Twenty-one older and 21 younger women performed isometric unilateral force control tasks at 10 % of maximum voluntary contraction for each hand, respectively. Purdue Pegboard Test (PPT) was used to measure unilateral hand dexterity. Five force control variables (i.e., maximal and submaximal force, force error, variability, and regularity) and PPT scores were analyzed in two-way mixed ANOVAs (Group × Hand Condition), respectively. The absolute force power was analyzed in three-way mixed ANOVA (Group × Hand Condition × Frequency Band). The findings revealed that older women produced less maximal and submaximal unilateral forces than in younger women. Greater variability, regularity, and force frequency oscillations below 4 Hz were observed in older women as compared with those in younger women. Force error in the dominant hand was greater in older women than those in younger women. Finally, older women showed lower PPT scores than younger women. These findings suggested that older women may have deficits in unilateral force control capabilities as well as motor dexterity.

Association of total lifetime breastfeeding duration with midlife handgrip strength: findings from Project Viva

BACKGROUND

Lactation has long term effects on maternal health, but the relationship between lactation and long-term handgrip strength, a marker of musculoskeletal function and healthy aging, has not been explored.

OBJECTIVE

Examine the relationship between total lifetime breastfeeding duration (BFD) and midlife handgrip strength.

METHODS

We measured handgrip strength as a marker of overall strength among 631 women in the Project Viva cohort. At the same visit, women reported their BFD for each birth, and we derived total lifetime BFD. We used multivariable linear regression models to estimate associations of lifetime BFD in months with midlife handgrip strength in kilograms, adjusted for race/ethnicity, education, marital status, household income, age at first pregnancy and age at handgrip strength assessment.

RESULTS

Mean (standard deviation) age was 50.7 (5.1) years, lifetime BFD was 21.6 (19.5) months, and handgrip strength was 28.0 kg (6.0) in the dominant and 26.0 kg (5.6) in the non-dominant hand. In fully adjusted models, each 3-month increment in lifetime BFD was associated with 0.10 kg (95% CI 0.02, 0.18) higher handgrip strength for the dominant hand and 0.10 kg (95% CI 0.03, 0.18) for the nondominant hand. Results were similar in models examining mean BFD per pregnancy rather than total BFD. There was no evidence of effect modification by race/ethnicity.

CONCLUSIONS

Our study suggests that there is a small beneficial effect of lifetime BFD on handgrip strength. Future studies can explore mechanisms by which BFD affects body composition and associations with other outcomes related to lean mass such as sarcopenia.

Finger dexterity in well-functioning cohort of office workers in Macau

Aim

The study aimed to describe the finger dexterity in office workers of an Asian population.

Methods

One hundred twenty-seven right-handed office workers, aged 21–50 with a similar split of male and female, were recruited with finger dexterity measured by the O’Connor Finger Dexterity Test. The grip strength, tip and lateral pinch strength of both hands were also measured.

Results

This study provided the percentile score of the O’Connor Finger Dexterity Test of both males and females in the Asian population. Raw scores of below 218 and 213 seconds in male and female participants respectively reach the 90th percentile, and above 237 and 235 seconds in male and female below the 10th percentile. Results showed no significant difference in local mean scores across different age groups, between male and female and with varying hours of working in typing, filing, and writing. A significant difference was only found in finger dexterity and years of working as office workers. No significant correlation was found between the finger dexterity with grip strength, tip and lateral pinch of the dominant right hand. The results were similar to the original normative score with similar work skills and demands.

Conclusion

The mean scores could be used as a valid reference for local occupational therapists to evaluate the finger dexterity of office workers. However, caution has to be taken that conclusions drawn can be biased because of the relatively small sample size, and the results cannot be generalized to represent a wider Asian population.

Metabolomic signatures for the longitudinal reduction of muscle strength over 10 years

Background

Skeletal muscles are essential components of the neuromuscular skeletal system that have an integral role in the structure and function of the synovial joints which are often affected by osteoarthritis (OA). The aim of this study was to identify the baseline metabolomic signatures for the longitudinal reduction of muscle strength over 10 years in the well-established community-based Tasmanian Older Adult Cohort (TASOAC).

Methods

Study participants were 50–79 year old individuals from the TASOAC. Hand grip, knee extension, and leg strength were measured at baseline, 2.6-, 5-, and 10-year follow-up points. Fasting serum samples were collected at 2.6-year follow-up point, and metabolomic profiling was performed using the TMIC Prime Metabolomics Profiling Assay. Generalized linear mixed effects model was used to identify metabolites that were associated with the reduction in muscle strength over 10 years after controlling for age, sex, and BMI. Significance level was defined at α=0.0004 after correction of multiple testing of 129 metabolites with Bonferroni method. Further, a genome-wide association study (GWAS) analysis was performed to explore if genetic factors account for the association between the identified metabolomic markers and the longitudinal reduction of muscle strength over 10 years.

Results

A total of 409 older adults (50% of them females) were included. The mean age was 60.93±6.50 years, and mean BMI was 27.12±4.18 kg/m² at baseline. Muscle strength declined by 0.09 psi, 0.02 kg, and 2.57 kg per year for hand grip, knee extension, and leg strength, respectively. Among the 143 metabolites measured, 129 passed the quality checks and were included in the analysis. We found that the elevated blood level of asymmetric dimethylarginine (ADMA) was associated with the reduction in hand grip (p=0.0003) and knee extension strength (p=0.008) over 10 years. GWAS analysis found that a SNP rs1125718 adjacent to WISP1gene was associated with ADMA levels (p=4.39*10^-8). Further, we found that the increased serum concentration of uric acid was significantly associated with the decline in leg strength over 10 years (p=0.0001).

Conclusion

Our results demonstrated that elevated serum ADMA and uric acid at baseline were associated with age-dependent muscle strength reduction. They might be novel targets to prevent muscle strength loss over time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13395-022-00286-9.

The Precision of the Human Hand: Variability in Pinch Strength and Manual Dexterity

Changes in hand morphology throughout human evolution have facilitated the use of forceful pad-to-pad precision grips, contributing to the development of fine motor movement and dexterous manipulation typical of modern humans. Today, variation in human hand function may be affected by demographic and/or lifestyle factors, but these remain largely unexplored. We measured pinch grip strength and dexterity in a heterogeneous cross-sectional sample of human participants (n = 556) to test for the potential effects of sex, age, hand asymmetries, hand morphology, and frequently practiced manual activities across the lifespan. We found a significant effect of sex on pinch strength, dexterity, and different directional asymmetries, with the practice of manual musical instruments, significantly increasing female dexterity for both hands. Males and females with wider hands were also stronger, but not more precise, than those with longer hands, while the thumb-index ratio had no effect. Hand dominance asymmetry further had a significant effect on dexterity but not on pinch strength. These results indicate that different patterns of hand asymmetries and hand function are influenced in part by life experiences, improving our understanding of the link between hand form and function and offering a referential context for interpreting the evolution of human dexterity.

Normative Static Grip Strength of Saudi Arabia's Population and Influences of Numerous Factors on Grip Strength

Most daily tasks require exerting static grip strength which can be challenging for the elderly as their strength diminishes with age. Moreover, normative static grip strength data are important in ergonomics and clinical settings. The goal of this study is to present the gender, age-specific, hand-specific, and body-mass-index-specific handgrip strength reference of Saudi males and females in order to describe the population's occupational demand and to compare them with the international standards. The secondary objective is to investigate the effects of gender, age group, hand area, and body mass index on the grip strength. A sample of 297 (146 male and 151 female) volunteers aged between 18 and 70 with different occupations participated in the study. Grip strength data were collected using a Jamar dynamometer with standard test position, protocol, and instructions. The mean maximum voluntary grip strength values for males were 38.71 kg and 22.01 kg, respectively. There was a curvilinear relationship of grip strength to age; significant differences between genders, hand area, and some age groups; and a correlation to hand dimensions depending on the gender.

Beyond the Finish Line: The Impact and Dynamics of Biomarkers in Physical Exercise-A Narrative Review

The research of biomarkers continues to emerge as a developing academic field which is attracting substantial interest. The study of biomarkers proves to be useful in developing and implementing new screening methods for a wide variety of diseases including in the sports area, whether for leisure activities or professional sports. Novel research has brought into question the immune system and the limitations it may impose on sports practicing. As the well-being of athletes is a priority, the state of their immune function offers valuable information regarding their health status and their ability to continue training. The assessment of various biomarkers may contribute to a more accurate risk stratification and subsequent prevention of some invalidating or even fatal pathologies such as the sudden cardiac death. Therefore, we have reviewed several studies that included sports-related pathology or specific morphofunctional alterations for which some immune biomarkers may represent an expression of the underlying mechanism. These include the defensins, immunoglobulin A (IgA), interleukin-6 (IL-6), the tumoral necrosis factor α (TNF-α), and the white blood cells (WBC) count. Similarly, also of significant interest are various endocrine biomarkers, such as cortisol and testosterone, as well as anabolic or catabolic markers, respectively. Literature data highlight that these values are greatly influenced not only by the duration, but also by the intensity of the physical exercise; moderate training sessions actually enhance the immune function of the body, while a significant increase in both duration and intensity of sports activity acts as a deleterious factor. Therefore, in this paper we aim to highlight the importance of biomarkers’ evaluation in connection with sports activities and a subsequent more adequate approach towards personalized training regimens.

Geriatric nutritional risk index in prediction of muscular strength of elderly patients undergoing hemodialysis

PURPOSE

Geriatric nutritional risk index (GNRI) is one of the new tools to determine nutritional status in the elderly. This study assessed the association between GNRI and muscular strength through handgrip strength (HGS) in patients undergoing hemodialysis.

METHODS

This cross-sectional analytical study assessed 110 hemodialysis patients at Guilan, North of Iran, (mean age of 70.3 ± 6.93), 57 men and 53 women through simple random sampling. Demographic characteristics, GNRI, and HGS of patients were determined. Data were analyzed using descriptive and inferential statistics, including independent t test, AVOVA, Pearson correlation, and linear multiple regression tests.

RESULTS

The mean values of the GNRI and HGS were 93.90 ± 11.06 and 14.82 ± 3.72, respectively. Finally, it was identified that there is a direct and significant association between GNRI and HGS (p = 0.001, r = 0.734). Linear multiple regression showed that GNRI is an independent predictor of HGS (Adj.R² = 0.67, β_GNRI = 8.13).

CONCLUSION

GNRI can be used as a predictor of muscular strength in hemodialysis patients.

Development of a Mitochondrial Myopathy-Composite Assessment Tool

BACKGROUND

'Mitochondrial Myopathy' (MM) refers to genetically-confirmed Primary Mitochondrial Disease (PMD) that predominantly impairs skeletal muscle function. Validated outcome measures encompassing core MM domains of muscle weakness, muscle fatigue, imbalance, impaired dexterity, and exercise intolerance do not exist. The goal of this study was to validate clinically-meaningful, quantitative outcome measures specific to MM.

METHODS

This was a single centre study. Objective measures evaluated included hand-held dynamometry, balance assessments, Nine Hole Peg Test (9HPT), Functional Dexterity Test (FDT), 30 second Sit to Stand (30s STS), and 6-minute walk test (6MWT). Results were assessed as z-scores, with < -2 standard deviations considered abnormal. Performance relative to the North Star Ambulatory Assessment (NSAA) of functional mobility was assessed by Pearson's correlation.

RESULTS

In genetically-confirmed MM participants [n = 59, mean age 21.6 ± 13.9 (range 7 - 64.6 years), 44.1% male], with nuclear gene aetiologies, n = 18/59, or mitochondrial (mtDNA) aetiologies, n = 41/59, dynamometry measurements demonstrated both proximal [dominant elbow flexion (-2.6 ± 2.1, mean z-score ± standard deviation, SD), hip flexion (-2.5 ± 2.3), and knee flexion (-2.8 ± 1.3)] and distal muscle weakness [wrist extension (-3.4 ± 1.7), palmar pinch (-2.5 ± 2.8), and ankle dorsiflexion (-2.4 ± 2.5)]. Balance [Tandem Stance (TS) Eyes Open (-3.2 ± 8.8, n = 53) and TS Eyes Closed (-2.6 ± 2.7, n = 52)] and dexterity [FDT (-5.9 ± 6.0, n = 44) and 9HPT (-8.3 ± 11.2, n = 53)] assessments also revealed impairment. Exercise intolerance was confirmed by strength-based 30s STS test (-2.0 ± 0.8, n = 38) and mobility-based 6MWT mean z-score (-2.9 ± 1.3, n = 46) with significant decline in minute distances (slope -0.9, p = 0.03, n = 46). Muscle fatigue was quantified by dynamometry repetitions with strength decrement noted between first and sixth repetitions at dominant elbow flexors (-14.7 ± 2.2%, mean ± standard error, SEM, n = 21). All assessments were incorporated in the MM-Composite Assessment Tool (MM-COAST). MM-COAST composite score for MM participants was 1.3± 0.1(n = 53) with a higher score indicating greater MM disease severity, and correlated to NSAA (r = 0.64, p < 0.0001, n = 52) to indicate clinical meaning. Test-retest reliability of MM-COAST assessments in an MM subset (n = 14) revealed an intraclass correlation coefficient (ICC) of 0.81 (95% confidence interval: 0.59-0.92) indicating good reliability.

CONCLUSIONS

We have developed and successfully validated a MM-specific Composite Assessment Tool to quantify the key domains of MM, shown to be abnormal in a Definite MM cohort. MM-COAST may hold particular utility as a meaningful outcome measure in future MM intervention trials.

Correlation between the Ability to Manipulate a Touchscreen Device and Hand Strength and Manual Dexterity among Community-Living Older Individuals

Information regarding the relationship between the degree of hand function among the elderly as measured by traditional assessments and the ability to manipulate touchscreens is lacking. This study aimed to examine the correlation between the ability to manipulate a touchscreen device, as assessed using the touchscreen assessment tool (TATOO) (University of Haifa, Israel & Universetiy of Bologna, Italy), and hand strength and manual dexterity among independent community-living older individuals. Thirty-four community-living older adults (average age 79.4 ± 6.7 years) participated in single-session assessments lasting 45 min each. The assessment included hand strength measurement using the manual hand dynamometry and hydraulic pinch gauge, a functional dexterity test (FDT), and TATOO. No significant correlations were observed between most of the TATOO items (22 out of 26) and handgrip strength, pinch strength, and FDT results. Moderately significant correlations were demonstrated between the number of drag attempts in the “Drag to different directions” task and handgrip strength and manual dexterity (r value: −0.39, p value: 0.02; r value: 0.36, p value: 0.04, respectively). In addition, a moderately significant correlation was noted between the number of double taps and manual dexterity (r value: 0.32, p value: 0.07). These results indicate that more complex gestures that require greater accuracy (dragging task) or rapid movements (double tapping) are related to hand strength and manual dexterity. These results suggest that the manual gestures necessary for touchscreen operation entail unique and specific capabilities that are generally not captured by traditional tools. The clinical implication is that the hand function assessment toolbox should be expanded. Tools such as the TATOO should be used to capture skills required for touchscreen manipulation in the context of the modern digital milieu.

Influence of aging, disease, exercise, and injury on human hand movements: A systematic review

The human hand is a versatile organ that performs a variety of activities in daily life. The coordination of digits allows them to deal with objects of various sizes and shapes with an appropriate range of motions (ROM). A systematic literature review was performed to identify the clinical and non-clinical factors which affected the normal ROM, grip strength (GS), and dexterity of hand. The overall outcomes of the systematic review showed that: the performance of the individual declined as the age progressed; the performance of the dominant hand (DH) of an individual was better compared to his/her non-dominant hand (NDH); the tasks performed by a healthy hand was more efficient compared to a diseased one; appropriate rehabilitation programs/exercise techniques after a disease or injury improved the ROM, GS, and dexterity of hand post-surgery on par to a healthy hand.

Right-left asymmetry in corticospinal tract microstructure and dexterity are uncoupled in late adulthood

Ageing leads to a decline in white matter microstructure and dexterous function of the hand. In adolescents, it has previously been shown that the degree of right-left asymmetry in the corticospinal tract (CST) is linearly related with right-left asymmetry in dexterity. Here, we tested whether this association is also expressed in older adults. Participants completed a simple circle drawing task with their right and left hand as a measure of dexterity and underwent whole-brain diffusion weighted imaging at 3 Tesla (n = 199; aged 60-72 years). Fractional anisotropy and mean diffusivity of right and left CST were extracted from a manually defined region-of-interest. Linear regression analyses were computed to replicate the analyses in adolescents. Frequentist analyses were complemented with a Bayesian analytical framework. Outcome measures were compared with those previously reported in adolescents (aged 11-16 years). Asymmetries in white matter microstructure of the CST were evident and comparable to the degree of lateralisation observed in adolescence. Similarly, asymmetries in dexterity were evident, but to a lesser degree than in adolescents. Unlike in adolescents, we found no evidence of a linear relationship between asymmetries in CST microstructure and dexterity. Complementary Bayesian regression analysis provided moderate evidence in favour of the null hypothesis, pointing towards a lack of association between the structural and functional measures of right-left asymmetry. Our findings are compatible with the notion that, by late adulthood, a diverging impact of age on white matter structure and dexterous hand function dilutes the structure-function relationship between CST microstructure and manual proficiency that has been reported in adolescents.

Adherence to CPAP therapy for sleep apnea in patients aged over 70 years old

Purpose

Adherence to continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA) syndrome has not been established in patients over 70 years of age, whereas several studies have reported adherence below that age. This trial was designed to address this evidence gap.

Methods

Consecutive senior (> 70 years) patients with OSA, mean respiratory event index (REI) 34/h, body mass index (BMI) 31 kg/m², and junior (< 50 years) patients (REI 37/h, BMI 31 kg/m²) were included.

Results

At year follow-up among 72 senior patients (35 women) and 71 junior patients (17 women), there was no difference in the percentage of patients abandoning CPAP (senior 47% vs. junior 43%) or in CPAP daily use (4:53 ± 2:44 hh:min vs. 4:23 ± 3:00 hh:min).

Conclusions

CPAP adherence in senior patients with OSA was not poorer than that of a younger group of OSA patients. Advanced age should not be an obstacle to CPAP initiation.

What does hand motor function tell us about our aging brain in association with WMH?

Background

White matter hyperintensities (WMH) are a common cerebral finding in older people. WMH are usually asymptomatic, but excessive WMH are associated with cognitive decline and dementia. WMH are also among the neurological findings most consistently associated with declining motor performance in healthy ageing.

Aims

To determine if WMH load is associated with simple and complex motor movements in dominant and non-dominant hands in cognitively intact older subjects.

Methods

Hand motor performance was assessed with the Purdue Pegboard and Finger-tapping tests on 44 healthy right-handed participants, mean age 70.9 years (range 59–84 years). Participants also underwent magnetic resonance (MR) imaging, which were used to quantify WMH volume. The effect of WMH on the motor parameters was assessed via mediation analyses.

Results

WMH load increased significantly with age, while the motor scores decreased significantly with age. WMH load mediated only the relationship between age and left-hand pegboard scores.

Discussion

WMH mediated only the more complex Purdue Pegboard task for the non-dominant hand. This is likely because complex movements in the non-dominant hand recruit a larger cerebral network, which is more vulnerable to WMH.

Conclusions

Complex hand movements in the non-dominant hand are mediated by WMH. Subtle loss of motor movements of non-dominant hand might predict future excessive white matter atrophy.

Visualizing and Evaluating Finger Movement Using Combined Acceleration and Contact-Force Sensors: A Proof-of-Concept Study

The 10-s grip and release is a method to evaluate hand dexterity. Current evaluations only visually determine the presence or absence of a disability, but experienced physicians may also make other diagnoses. In this study, we investigated a method for evaluating hand movement function by acquiring and analyzing fingertip data during a 10-s grip and release using a wearable sensor that can measure triaxial acceleration and strain. The subjects were two healthy females. The analysis was performed on the x-, y-, and z-axis data, and absolute acceleration and contact force of all fingertips. We calculated the variability of the data, the number of grip and release, the frequency response, and each finger’s correlation. Experiments with some grip-and-release patterns have resulted in different characteristics for each. It was suggested that this could be expressed in radar charts to intuitively know the state of grip and release. Contact-force data of each finger were found to be useful for understanding the characteristics of grip and release and improving the accuracy of calculating the number of times to grip and release. Frequency analysis suggests that knowing the periodicity of grip and release can detect unnatural grip and release and tremor states. The correlations between the fingers allow us to consider the finger’s grip-and-release characteristics, considering the hand’s anatomy. By taking these factors into account, it is thought that the 10-s grip-and-release test could give us a new value by objectively assessing the motor functions of the hands other than the number of times of grip and release.

User-Centric Approach to Specifying Technical Attributes of Drug Delivery Devices: Empirical Study of Autoinjector-Cap Removal Forces

PURPOSE

The subcutaneous delivery of biologics using pre-filled autoinjector devices continues to attract broad scholarly interests. However, research still lacks a detailed understanding of user perceptions as the basis for specifying the clinically relevant technical attributes of a device, such as the cap-removal force. Therefore, this article studies the ability of users to remove the autoinjector cap, as well as the effects of the cap-removal force and user characteristics on the perceived ease of decapping.

PATIENTS AND METHODS

Forty-two participants among patients, caregivers, and healthcare professionals removed the protective cap using non-functional devices with different target cap-removal forces between 25 N and 55 N. Data were collected on the ability of the users to effectively decap the device and their perceived ease of decapping. Linear regression was then applied to quantify the impact of the decapping force and patient characteristics on the perceived ease of decapping.

RESULTS

The participants of the study effectively decapped all autoinjector devices irrespective of age, sex, and dexterity impairments. Moreover, the study reveals that the perceived ease of decapping decreases significantly with increasing decapping force and participants' dexterity impairments.

CONCLUSION

The study provides initial empirical evidence on the ability of users to decap autoinjector devices and shows how increasing the cap-removal force and dexterity impairments reduce the perceived ease of decapping.

Evaluating Additional Aspects of Muscle Function with a Digital Handgrip Dynamometer and Accelerometer for Cognitive Functioning in Older Adults: A Pilot Study

Handgrip dynamometers are used to assess handgrip strength (HGS), and low HGS is linked to poor cognitive function. Although HGS is a reliable measure of muscle function, it is only measuring maximal grip force. Other aspects of muscle function such as force control, fatigability, and steadiness are unaccounted for in current HGS protocols. This pilot study sought to determine the role of maximal HGS, submaximal HGS force control, HGS fatigability, and HGS neuromuscular steadiness on cognitive function in older adults. Our findings indicate that these additional HGS measurements could factor into detecting poorer cognitive functioning, while also evolving HGS protocols.

Evaluation of upper extremity function and its relation to curve pattern in female adolescents with idiopathic scoliosis: a pilot study

STUDY DESIGN

Cross-sectional and clinical measurement.

OBJECTIVE

To evaluate upper extremity function and its relation to the curve pattern in idiopathic scoliosis. Postural alterations and trunk distortions-caused by three-dimensional deformity itself in idiopathic scoliosis-may lead to functional changes in the upper extremity of subjects.

METHODS

Handgrip, pulp and lateral pinch strengths, hand dexterity, hand reaction time, coordination of upper extremity, upper extremity performance, throwing accuracy, and self-reported upper extremity disability were evaluated in 96 subjects. These subjects were divided into 3 groups: 47 with main thoracic curve pattern scoliosis (Lenke type 1), 31 with thoracolumbar/lumbar curve pattern scoliosis (Lenke type 5), and 18 unaffected (healthy control). Comparisons were performed between these three groups.

RESULTS

The thoracic scoliosis group showed a significant decrease in concave lateral pinch strength, concave hand dexterity of turning, coordination of the upper extremities, and concave hand reaction time than the thoracolumbar/lumbar scoliosis group (p < 0.05). Bilateral handgrip strengths decreased in thoracic scoliosis group when compared to healthy controls. Healthy individuals demonstrated greater throwing accuracy than individuals with scoliosis.

CONCLUSIONS

Upper extremity function was found to be affected based on the curve pattern. Individuals with main thoracic curves are likely to have deteriorated upper extremity function, especially for hand-specific motor skills, on the concave side, when compared to lumbar curves and healthy controls.

LEVEL OF EVIDENCE

Level III.

Associations between hand function and electrophysiological measurements in hand osteoarthritis patients of different ages with or without carpal tunnel syndrome

Osteoarthritis is a common degenerative disease that most frequently involves the hand. The objective was to compare clinical functional outcome measures including hand grip, pinch strength, and dexterity with various electrophysiological measures in patients of different ages with hand osteoarthritis with or without the presence of carpal tunnel syndrome (CTS). Patients with hand osteoarthritis (208 patients, 404 hands) who underwent hand-function tests and motor and sensory nerve conduction studies (NCS) between June 2015 and June 2016 were enrolled. The patients' hands were assigned to carpal tunnel syndrome (CTS) (206 hands; mean age, 56.37 ± 10.52; male:female, 46:160) or control groups (198 hands; mean age, 57.88 ± 9.68; male:female, 55:143). The strength of hand grip and lateral pinch, the time required to complete the nine-hole pegboard test (9HPT), and motor and sensory nerve conduction parameters were measured and compared across age groups and between hands with or without CTS. The CTS group showed significantly lower hand grip and lateral pinch strength, and a longer time to complete the 9HPT in comparison with the control group. Female patients showed significantly lower hand grip and lateral pinch strength than male patients. However, there was no difference in the 9HPT completion time between genders. Multivariate regression analysis identified the amplitude of the median compound muscle action potential (CMAP), age, and male gender as independent predictors of grip strength (adjusted R₂ = 0.679), and amplitude of median CMAP and male gender as independent predictors of KP strength (adjusted R₂ = 0.603). Velocity of median CMAP, amplitude of median sensory nerve action potential, and age were identified as independent predictors of 9HPT time (adjusted R₂ = 0.329). Nerve conduction measurements were significantly related to hand-function test results, and CTS induced significant deficits in strength and performance of the affected hand.

Population based norms for the box and blocks test in healthy right-handed Taiwanese adults

BACKGROUND

This study establishes norms for the Box and Block Test (BBT) in healthy Taiwanese adults between 15 and 75 years of age.

METHODS

621 right-handed healthy adults (296 males and 325 females) completed the study. All participants performed the BBT following the standard protocol. An age by gender by testing hand analysis of variance (ANOVA) was performed to determine differences for the variables of interest.

RESULTS

On average, females performed better on the BBT than males by approximately 2 points (p < 0.001). Across all participants, dominant hand performance was 2.8 points higher than non-dominant hand performance (p < 0.001). Significant changes of BBT scores across life span were observed at the ages of 30, 45 and 60 years old. Average scores across all age groups are at least one standard deviation below the previously established American norms for each corresponding age group.

CONCLUSION

When using the BBT test with adult Taiwanese clients, clinical practitioners should strongly consider using right-handed normative data from Taiwanese individuals as the norms for this population differ from the previously established norms from American adult participants.

Hand function assessment in peritoneal dialysis patient: a pilot study

BACKGROUND

There is variability among centres regarding the utilization of assisted peritoneal dialysis (PD). Functional impairment is one of the leading causes of assisted PD. Tools to assess the patient's ability to manipulate PD devices are required. The objective of this study was to evaluate the feasibility of hand function evaluation in PD patients and to test the association between hand function estimation and assisted PD.

METHODS

This was a pilot study of adults treated with PD in a dialysis unit in January 2019. Hand function was evaluated by Purdue Pegboard, Jebsen, Jamar and pinch tests. Relative risks were calculated with a Cox model to evaluate the association between each test and assisted PD.

RESULTS

Among the 43 PD patients included, 16 were autonomous and 27 were assisted in performing dialysis. The Jebsen and Purdue Pegboard tests were completed by 41 patients (95.3%). All patients succeeded in performing the Jamar and pinch tests. The median time to complete all tests was 22 min. After adjustment based on the Charlson comorbidity index, the assembly test of the Purdue Pegboard (RR 0.92 [95% confidence interval (CI) 0.86-0.98]), total Jebsen (RR 1.01 [95% CI 1.00-1.01]) and Jamar test (RR 0.94 [95% CI 0.90-0.99] with the dominant hand; OR 0.94 [95% CI 0.88-0.98] with the non-dominant hand) scores were associated with assisted PD.

CONCLUSION

The evaluation of hand function of PD patients is feasible in daily practice using the Jebsen, Purdue Pegboard, pinch and Jamar tests and may support choosing the appropriate utilization of assisted PD.

Can Resistance Training Improve Upper Limb Postural Tremor, Force Steadiness and Dexterity in Older Adults? A Systematic Review

BACKGROUND

The ageing process and several health conditions may increase tremor and reduce force steadiness and dexterity, which can severely impact on function and quality of life. Resistance training can evoke a range of neuromuscular adaptions that may significantly reduce tremor and/or increase force steadiness and/or dexterity in older adults, irrespective of their health condition.

OBJECTIVES

The objective of this study was to systematically review the literature to determine if a minimum of 4 weeks' resistance training can reduce postural tremor and improve force steadiness and/or dexterity in older adults, defined as aged 65 years and over.

METHODS

An electronic search using Ovid, CINAHL, SPORTDiscus and EMBASE was performed. Risk of bias was assessed using the Cochrane Risk of Bias Tool.

RESULTS

Fourteen studies met the eligibility criteria, including six randomised controlled trials and two quasi-randomised controlled trials. All eight studies that recruited healthy older adults reported significant reductions in postural tremor and/or improvements in force steadiness and dexterity. Five out of seven studies that examined older adults with a particular health condition reported some improvements in force steadiness and/or dexterity. Specifically, significant benefits were observed for older adults with chronic obstructive pulmonary disease and essential tremor; however, small or no changes were observed for individuals with osteoarthritis or stroke.

CONCLUSIONS

Resistance training is a non-pharmacological treatment that can reduce tremor and improve force steadiness and dexterity in a variety of older adult populations. Future research should employ randomised controlled trials with larger sample sizes, better describe training programme methods, and align exercise prescription to current recommendations for older adults.

Normative reference values on handgrip strength among healthy adults of Dhulikhel, Nepal: A cross-sectional study

Context

Handgrip strength (HGS) is the amount of static force that the hand can generate around the dynamometer and can be defined as the ability of the hand to hold the objects between the thumb and fingers. Handgrip measurement is simple but also a valid measure of overall muscle strength and also provides an objective index of functional integrity of upper extremity.

Aims

To provide population-based HGS reference values for Nepalese adults from 19 to 70 years of age.

Settings and Design

A cross-sectional study was conducted in Dhulikhel community among 526 participants.

Methods and Materials

Jamar Dynamometer was used for measuring HGS based on the recommendation provided by the American Society of Hand Therapists.

Statistical Analysis Used

Data were analyzed using STATA version 14.

Results

Men exhibited higher HGS compared to women with maximum grip strength observed in age group of 19-29 which were 47.24 kg and 32.51 kg for men and women, respectively. HGS decreases with increasing age in both dominant and nondominant hands.

Conclusions

The normative reference values provided in this study may serve as a guide for interpreting grip-strength measurements obtained from tested individuals.

Recovery, age, and gender effects on hand dexterity after a distal radius fracture. A 1-year prospective cohort study

STUDY DESIGN

A prospective cohort study.

INTRODUCTION

Physical factors that predict hand dexterity and the recovery of hand dexterity after a distal radius fracture (DRF) have not yet been examined.

PURPOSE OF THE STUDY

The first objective was to evaluate the recovery of hand dexterity comparing the injured and uninjured hands during the year after a DRF. The second objective was to determine the effect of age and sex on hand dexterity of the injured hand.

METHODS

Hand dexterity was examined bilaterally for the manipulation of 3 different sized objects (small, medium, and large) using the NK hand dexterity test. The measurements took place at 3, 6, and 12 months after DRF. Generalized linear modeling was performed, with age and sex as covariates, to assess changes over time, and between sides.

RESULTS

Overall, 242 patients with DRF (45 males and 197 females) with a mean age of 60.2 years with SD of 11.26, participated in the study. Statistical differences in hand dexterity were found between the injured and uninjured hands across all time intervals (P < .001). The effect size for the deficit between the injured and uninjured hands decreased across the time intervals and ranged from 0.19 to 0.38 for large objects, from 0.17 to 0.25 for medium objects, and from 0.11 to 0.32 for small objects. For each 1-year increase in age, hand dexterity scores were 0.3-0.4 seconds slower. Sex had much less effect, with annual increases of 0.1 seconds in hand dexterity scores.

CONCLUSIONS

Scores on the NK dexterity test improved between 3 and 6 months and then worsened between 6 and 12 months; at no point did dexterity equal the uninjured side. Greater attention to measuring and treating dexterity may be needed to provide a complete recovery after DRF. Scores will be affected by age and sex.

LEVEL OF EVIDENCE

Prognosis, 2a.