Age-related changes in bilateral upper extremity coordination

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.

Correlation between kinetic and kinematic measures, clinical tests and subjective self-evaluation questionnaires of the affected upper limb in people after stroke

Introduction

Assessment of stroke recovery should include multiple sources of information in order to obtain a complete understanding of the individual's rehabilitation progress. Self-evaluation questionnaires' scores do not always correspond to the scores of commonly used clinical evaluation tools. The purpose of this study was to assess the relationship between self-evaluation questionnaires, clinical tests, and kinematic and kinetic analyses of the affected upper limb after stroke, and to determine the correlation between these measures and self-reported general function 2-4 years after the stroke.

Methods

Twenty-six subjects recovering from stroke were included in the study. Spearman's correlation coefficient was used to measure the correlation between Stroke Impact Scale (SIS), Motor activity Log (MAL), Fugl-Meyer Assessment (FMA) and Action Reach Arm Test (ARAT) scores, and kinematic and kinetic analyses. A logistic regression was used to assess the extent to which these measures may predict the participants' functional self-reported status 2-4 years post stroke.

Results

Sections regarding hand function, hand force and general ADL of the self-evaluation questionnaires correlated with kinematic variables. However, only questionnaires that focus on hand function correlated with clinical tests. Mean and maximal hand velocity had the strongest correlations with self-evaluation questionnaires and with the clinical tests, more than other kinematic variables. Self-evaluation questionnaires and clinical tests were found to be correlated with hand kinetic metrics force-to-time ratio and number of force peaks. SIS hand force domain, mean velocity and maximal velocity predicted self-reported general function 2-4 years after the stroke.

Conclusion

Self-evaluation questionnaires should be considered for wider use in the clinical evaluation of a patient's stroke recovery, since they add important information on the individual's functional status, which is not reflected in the clinical tests.

Using Electronic Handgrip Dynamometry and Accelerometry to Examine Multiple Aspects of Handgrip Function in Master Endurance Athletes: A Pilot Study

ABSTRACT

Klawitter, LA, Hackney, KJ, Christensen, BK, Hamm, JM, Hanson, M, and McGrath, R. Using electronic handgrip dynamometry and accelerometry to examine multiple aspects of handgrip function in master endurance athletes: A Pilot Study. J Strength Cond Res 37(9): 1777-1782, 2023-Electronic handgrip dynamometry and accelerometry may provide novel opportunities to comprehensively measure muscle function for human performance, especially for master athletes. This investigation sought to determine the multivariate relationships between maximal strength, asymmetry, rate of force development, fatigability, submaximal force control, bimanual coordination, and neuromuscular steadiness to derive one or more handgrip principal components in master-aged endurance athletes. We included n = 31 cyclists and triathletes aged 35-70 years. Maximal strength, asymmetry, rate of force development, fatigability, submaximal force control, bimanual coordination, and neuromuscular steadiness were measured twice on each hand using electronic handgrip dynamometry and accelerometry. The highest performing measures were included in the analyses. A principal component analysis was conducted to derive a new collection of uncorrelated variables from the collected handgrip measurements. Principal components with eigenvalues >1.0 were kept, and individual measures with a factor loading of |>0.40| were retained in each principal component. There were 3 principal components retained with eigenvalues of 2.46, 1.31, and 1.17. The first principal component, "robust strength," contained maximal strength, rate of force development, submaximal force control, and neuromuscular steadiness. The second principal component, "bilateral synergy," contained asymmetry and bimanual coordination, whereas the third principal component, "muscle conditioning," contained fatigability. Principal components 1, 2, and 3 explained 44.0, 31.6, and 24.4% of the variance, respectively. Different dimensions of muscle function emerged from our findings, suggesting the potential of a muscle function battery. Further research examining how these measures are associated with appropriate human performance metrics and lower extremity correlates is warranted.

Bimanual coordination during reach-to-grasp actions is sensitive to task goal with distinctions between left- and right-hemispheric stroke

The perceptual feature of a task such as how a task goal is perceived influences performance and coordination of bimanual actions in neurotypical adults. To assess how bimanual task goal modifies paretic and non-paretic arm performance and bimanual coordination in individuals with stroke affecting left and right hemispheres, 30 participants with hemispheric stroke (15 right-hemisphere damage-RHD); 15 left-hemisphere damage-LHD) and 10 age-matched controls performed reach-to-grasp and pick-up actions under bimanual common-goal (i.e., two physically coupled dowels), bimanual independent-goal (two physically uncoupled dowels), and unimanual conditions. Reach-to-grasp time and peak grasp aperture indexed motor performance, while time lags between peak reach velocities, peak grasp apertures, and peak pick-up velocities of the two hands characterized reach, grasp, and pick-up coordination, respectively. Compared to unimanual actions, bimanual actions significantly slowed non-paretic arm speed to match paretic arm speed, thus affording no benefit to paretic arm performance. Detriments in non-paretic arm performance during bimanual actions was more pronounced in the RHD group. Under common-goal conditions, movements were faster with smaller peak grasp apertures compared to independent-goal conditions for all groups. Compared to controls, individuals with stroke demonstrated poor grasp and pick-up coordination. Of the patient groups, patients with LHD showed more pronounced deficits in grasp coordination between hands. Finally, grasp coordination deficits related to paretic arm motor deficits (upper extremity Fugl-Meyer score) for LHD group, and to Trail-Making Test performance for RHD group. Findings suggest that task goal and distinct clinical deficits influence bimanual performance and coordination in patients with left- and right-hemispheric stroke.

Development and Psychometric Testing of the Bimanual Assessment Measure for People With Chronic Stroke

IMPORTANCE

Few tools are available to assess bimanual deficits after stroke.

OBJECTIVE

To develop the Bimanual Assessment Measure (BAM), which assesses a person's hand coordination in both preferred and prestroke roles (i.e., stabilizer or manipulator).

DESIGN

Development and psychometric testing of the BAM.

SETTING

Research laboratory.

PARTICIPANTS

People with chronic stroke (n = 24), age-matched controls (n = 23), and occupational therapists (n = 40).

OUTCOMES AND MEASURES

We assessed the BAM's internal consistency, reliability, and face and known-groups validity.

RESULTS

Items were selected as meaningful tasks that represented a range of bimanual coordination requirements (e.g., symmetrical forces and timing, asymmetrical forces and timing, time-limited reactive movement). Focus groups of people with stroke and occupational therapists provided input into BAM development. The BAM was found to have excellent reliability and internal consistency and face and known-groups validity.

CONCLUSIONS AND RELEVANCE

The BAM is a valid, reliable measure for people with chronic stroke that identifies bimanual coordination deficits beyond unimanual impairments and the potential capacity for people to return to prestroke hand roles (i.e., as a manipulator). What This Article Adds: This article introduces the BAM as a new assessment measure of bimanual functioning with the potential capacity to restore prestroke hand roles as either a manipulator or a stabilizer among people with chronic stroke.

Task selection for a sensor-based, wearable, upper limb training device for stroke survivors: a multi-stage approach

PURPOSE

Post-stroke survivors report that feedback helps to increase training motivation. A wearable system (M-MARK), comprising movement and muscle sensors and providing feedback when performing everyday tasks was developed. The objective reported here was to create an evidence-based set of upper-limb tasks for use with the system.

MATERIALS AND METHODS

Data from two focus groups with rehabilitation professionals, ten interviews with stroke survivors and a review of assessment tests were synthesized. In a two-stage process, suggested tasks were screened to exclude non-tasks and complex activities. Remaining tasks were screened for suitability and entered into a categorization matrix.

RESULTS

Of 83 suggestions, eight non-tasks, and 42 complex activities were rejected. Of the remaining 33 tasks, 15 were rejected: five required fine motor control; eight were too complex to standardize; one because the role of hemiplegic hand was not defined and one involved water. The review of clinical assessment tests found no additional tasks. Eleven were ultimately selected for testing with M-Mark.

CONCLUSIONS

Using a task categorization matrix, a set of training tasks was systematically identified. There was strong agreement between data from the professionals, survivors and literature. The matrix populated by tasks has potential for wider use in upper-limb stroke rehabilitation. IMPLICATIONS FOR REHABILITATIONRehabilitation technologies that provide feedback on quantity and quality of movements can support independent home-based upper limb rehabilitation.Rehabilitation technology systems require a library of upper limb tasks at different levels for people with stroke and therapists to choose from.A user-defined and evidence-based set of upper limb tasks for use within a wearable sensor device system have been developed.

Correlations between Hand Dexterity and Bimanual Coordination on the Activities of Daily Living in Older Adults with Mild Cognitive Impairment

Background/Aims

Many motor impairments are present in older adults with cognitive decline. One of them is the impairment of hand dexterity and bimanual coordination that result in poor functional ability in the activities of daily living (ADL). This study investigated the effects of hand dexterity and bimanual coordination declination on the sub-domains of ADL in older adults with mild cognitive impairment (MCI).

Methods

Thirty-one senior individuals with MCI were recruited in this study. The Purdue Pegboard Test was used to measure hand dexterity, and bimanual coordination was assessed by the continuous circle-drawing task. Their ADL were assessed with the General Activity Daily Living questionnaire.

Results

The correlations analysis showed an association between the dominant hand and bimanual dexterity with the domestic domain of ADL and all conditions of hand dexterity with the complex domain of ADL. Moreover, the multiple regression analysis showed that the predictor of the greatest effect for domestic and complex domains was dominant hand dexterity.

Discussion/Conclusion

These results revealed that dominant hand dexterity strongly affected domestic and complex ADL in older adults with MCI. There were age-related changes regarding lateral asymmetrical motor reduction, especially in cognitive tasks. However, complex tasks involving cognitive function may need dominant, nondominant and bimanual hand dexterity.

Assessing Additional Characteristics of Muscle Function With Digital Handgrip Dynamometry and Accelerometry: Framework for a Novel Handgrip Strength Protocol

Maximal handgrip strength (HGS) is a convenient and reliable, but incomplete, assessment of muscle function. Although low HGS is a powerful predictor of poor health, several limitations to maximal HGS exist. The predictive value of HGS is restricted because low HGS is associated with a wide range of unspecified health conditions, and other characteristics of muscle function aside from strength capacity are not evaluated. Current HGS protocol guidelines emphasize the ascertainment of maximal force, which is only a single muscle function characteristic. Muscle function is intrinsically multivariable, and assessing other attributes in addition to strength capacity will improve screenings for age-related disabilities and diseases. Digital handgrip dynamometers and accelerometers provide unique opportunities to examine several aspects of muscle function beyond strength capacity, while also maintaining procedural ease. Specifically, digital handgrip dynamometry and accelerometry can assess the rate of force development, submaximal force steadiness, fatigability, and task-specific tremoring. Moreover, HGS protocols can be easily refined to include an examination of strength asymmetry and bilateral strength. Therefore, evaluating muscle function with new HGS technologies and protocols may provide a more comprehensive assessment of muscle function beyond maximal strength, without sacrificing feasibility. This Special Article introduces a novel framework for assessing multiple attributes of muscle function with digital handgrip dynamometry, accelerometry, and refinements to current HGS protocols. Such framework may aid in the discovery of measures that better predict and explain age-related disability, biological aging, and the effects of comorbid diseases that are amenable to interventions. These additional HGS measures may also contribute to our understanding of concepts such as resilience. Using sophisticated HGS technologies that are currently available and modernizing protocols for developing a new muscle function assessment may help transform clinical practice by enhancing screenings that will better identify the onset and progression of the disabling process.

Impact of Sensory Deficits on Upper Limb Motor Performance in Individuals with Cerebral Palsy: A Systematic Review

People living with cerebral palsy (CP) exhibit motor and sensory impairments that affect unimanual and bimanual functions. The importance of sensory functions for motor control is well known, but the association between motor and sensory functions remains unclear in people living with CP. The objective of this systematic review was to characterize the relationship between sensory deficits and upper limb motor function in individuals living with CP.

METHODS

Five databases were screened. The inclusion criteria were: (1) including people living with CP, (2) reporting measurements of upper limb motor and sensory functions. A qualitative analysis of the studies' level of evidence was done.

RESULTS

Thirty-three articles were included. Twenty-five articles evaluated tactile functions, 10 proprioceptive functions and 7 visual functions; 31 of the articles reported on unimanual functions and 17 of them reported on bimanual functions. Tactile functions showed a moderate to high association; it was not possible to reach definitive conclusions for proprioceptive and visual functions.

CONCLUSIONS

The heterogeneity of the results limits the ability to draw definitive conclusions. Further studies should aim to perform more comprehensive assessments of motor and sensory functions, to determine the relative contribution of various sensory modalities to simple and more complex motor functions.

Contraction Phase and Force Differentially Change Motor Evoked Potential Recruitment Slope and Interhemispheric Inhibition in Young Versus Old

Interhemispheric interactions are important for arm coordination and hemispheric specialization. Unilateral voluntary static contraction is known to increase bilateral corticospinal motor evoked potential (MEP) amplitude. It is unknown how increasing and decreasing contraction affect the opposite limb. Since dynamic muscle contraction is more ecologically relevant to daily activities, we studied MEP recruitment using a novel method and short interval interhemispheric inhibition (IHI) from active to resting hemisphere at 4 phases of contralateral ECR contraction: Rest, Ramp Up [increasing at 25% of maximum voluntary contraction (MVC)], Execution (tonic at 50% MVC), and Ramp Down (relaxation at 25% MVC) in 42 healthy adults. We analyzed the linear portion of resting extensor carpi radialis (ECR) MEP recruitment by stimulating at multiple intensities and comparing slopes, expressed as mV per TMS stimulation level, via linear mixed modeling. In younger participants (age ≤ 30), resting ECR MEP recruitment slopes were significantly and equally larger both at Ramp Up (slope increase = 0.047, p < 0.001) and Ramp Down (slope increase = 0.031, p < 0.001) compared to rest, despite opposite directions of force change. In contrast, Active ECR MEP recruitment slopes were larger in Ramp Down than all other phases (Rest:0.184, p < 0.001; Ramp Up:0.128, p = 0.001; Execution: p = 0.003). Older (age ≥ 60) participants’ resting MEP recruitment slope was higher than younger participants across all phases. IHI did not reduce MEP recruitment slope equally in old compared to young. In conclusion, our data indicate that MEP recruitment slope in the resting limb is affected by the homologous active limb contraction force, irrespective of the direction of force change. The active arm MEP recruitment slope, in contrast, remains relatively unaffected. Older participants had steeper MEP recruitment slopes and less interhemispheric inhibition compared to younger participants.

The probability of choosing both hands depends on an interaction between motor capacity and limb-specific control in chronic stroke

A goal of rehabilitation after stroke is to promote pre-stroke levels of arm use for every day, frequently bimanual, functional activities. We reasoned that, after a stroke, the choice to use one or both hands for bimanual tasks might depend not only on residual motor capacity, but also the specialized demands imposed by the task on the paretic hand. To capture spontaneous, task-specific choices, we covertly observed 50 pre-stroke right-handed chronic stroke survivors (25 each of left, LHD, and right-hemisphere damage, RHD) and 11 age-similar control adults and recorded their hand use strategies for two pairs of bimanual tasks with distinct demands: one with greater precision requirements (photo-album tasks), and another with greater stabilization requirements (letter-envelope tasks). The primary outcome was the choice to use one or both hands. Logistic regression was used to test the two hypotheses that the probability of choosing a bimanual strategy would be greater in those with less severe motor impairment and also in those with LHD. When collapsed across the four tasks, we found support for these hypotheses. Notably, however, the influence of these factors on bimanual choice varied based on task demands. For the photo-album pair, the probability of a bimanual strategy was greater for those with LHD compared to RHD, regardless of the degree of motor impairment. For the letter-envelope pair, we found a significant interaction between impairment and side of lesion in determining the likelihood of choosing both hands. Therefore, the manner in which side of lesion moderates the effect of impairment on hand use depends on the task.

Effectiveness of bimanual coordination tasks performance in improving coordination skills and cognitive functions in elderly

Background

The purpose of the study was to determine the impact of the performance of bimanual coordination tasks with specific characteristics on the changes in quality of coordination, musculoskeletal load of the upper limbs and cognitive functions.

Methods and findings

A group of 26 people aged 60–67 years performed 6 sessions of bimanual coordination training. Each session included set of tasks that varied depending on the shape in which the cursor moved, the coordination mode (in-phase, anti-phase, complex) and the tracking mode (imposed or freely chosen speed). Performance was assessed by: Error, Variability and Execution. The load of upper limb muscles was expressed with the value of the normalized EMG amplitude. Cognitive functions were evaluated using the Vienna Test System. The Variability and Error values obtained during the sixth training session decreased by more than 50% of the initial values. Tasks with freely chosen speed showed changes from 15% to 34% for Error and from 45% to 50% for Variability. For tasks with imposed speed and coordination mode anti-phase or complex it was between 51% and 58% for Error and between 58% and 68% for Variability. Statistically significant differences between load during the sixth training session compared to the first session occurred in three out of four muscles and were between 9% to 39%. There were statistically significant differences in motor time and no differences in variables describing attention and working memory.

Conclusions

Coordination mode is meaningful for improving coordination skills; tasks in the anti-phase and complex are recommended. Tracking mode also plays a role, tasks with an imposed cursor movement speed have greater potential to improve coordination skills than tasks with freely chosen. Improved control skills resulted in the reduction of upper limb musculoskeletal load. It can be assumed that an increase in coordination skills with the use of appropriate training can help to reduce musculoskeletal load.

Age-related deficits in bilateral motor synergies and force coordination

Background

Ageing may cause impairments in executing bilateral movement control. This study investigated age-related changes in interlimb force coordination across multiple trials by quantifying bilateral motor synergies based on the uncontrolled manifold hypothesis. Participants completed the trials with and without visual feedback.

Methods

Twenty healthy individuals (10 older adults and 10 young adults) performed 12 isometric force control trials for the two vision conditions at 5% of maximal voluntary contraction. All dependent variables were analyzed in two-way mixed model (Group × Vision Condition; 2 × 2) ANOVAs with repeated measures on the last factor.

Results

The analyses revealed that older adults had greater mean force produced by two hands in both vision conditions (i.e., yes and no visual feedback). Across both vision conditions, the older adult group showed greater asymmetrical force variability (i.e., standard deviation of non-dominant hand > standard deviation of dominant hand) and revealed more positive correlation coefficients between forces produced by two hands as compared with the young adult group. Finally, an index of bilateral motor synergies was significantly greater in young adults than older adults when visual feedback was available.

Conclusion

The current findings indicate that deficits in interlimb force coordination across multiple trials appeared in older adults.

The effects of speed of execution on upper-limb kinematics in activities of daily living with respect to age

In this study, 26 young, 16 older adults ≤ 66a, and 22 older adults ≥ 67a were examined in a set of neuropsychological tests and the kinematics in two different activities of daily living (ADL) were assessed. Half of the participants performed the ADL in a natural speed, the other half as fast as possible. The performance in the Trail Making Task B revealed an increased slope after 67 years of age. When executed in a natural speed, ADL kinematics were comparable. When executed as fast as possible, almost all kinematic parameters showed significant group and speed differences and revealed group × speed interactions. Models of multiple linear regression predicting ADL trial durations showed similar strategies in the young and older adults < 67a. Factors were the general movement speed, the travelled path lengths, and the simultaneous use of both hands. In the older adults ≥ 67a, factors were the general movement speed, the travelled path length, and the activity level (during the task execution). A principal component analysis supported these findings by revealing two underlying components: movement strategy and age-dependent decline in primarily executive functions, where the ADL trial duration had comparable loadings on both components. These results in association with the accelerated decline in executive functions found in the oldest group suggest that deterioration of ADL with age is particularly caused by specific age-dependent changes in cognitive capacities.

Handedness results from complementary hemispheric dominance, not global hemispheric dominance: evidence from mechanically coupled bilateral movements

Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g., bread) with one hand while applying forces to the object (e.g., slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand while moving the other hand to a target. Thus the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right-hand reach and left-hand stabilize; left-hand reach and right-hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction such that the right hand showed straighter reaching performance whereas the left hand showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks. NEW & NOTEWORTHY We provide evidence for interlimb differences in bilateral coordination of reaching and stabilizing functions, demonstrating an advantage for the dominant and nondominant arms for distinct features of control. These results provide the first evidence for complementary specializations of each limb-hemisphere system for different aspects of control within the context of a complementary bilateral task.

Age-related changes in hand dominance and functional asymmetry in older adults

The aim of the study was to investigate fine motor performance and ascertain age-related changes in laterality between the dominant and non-dominant hand. A representative sample of 635 adults (144 males and 491 females) aged 50 years and over completed a test battery MLS (Motor Performance Series) to assess a broad range of hand functions. Functional asymmetry was observed in all four motor tests (postural tremor, aiming, tapping, and inserting long pins). Significant differences between the dominant and non-dominant hand were obtained in both sexes across all age groups, except in the oldest female group (age >70) for the aiming (number of hits and errors) and postural tremor (number of errors) tasks. These differences in age-related changes may be attributed to hemispheric asymmetry, environmental factors, or use-dependent plasticity. Conflicting evidence in the literature warrants additional research to better explain age-related alterations of hand dominance and manual performance in old age.