Fine Motor Control Task Research Articles

A novel biomechanical model of the mouse forelimb predicts muscle activity in optimal control simulations of reaching movements.

Mice are key model organisms in genetics, neuroscience and motor systems physiology. Fine motor control tasks performed by mice have become widely used in assaying neural and biophysical motor system mechanisms, including lever or joystick manipulation, and reach-to-grasp tasks (Becker et al., 2019; Bollu et al., 2019; Conner at al., 2021). Although fine motor tasks provide useful insights into behaviors which require complex multi-joint motor control, there is no previously developed physiological biomechanical model of the adult mouse forelimb available for estimating kinematics (including joint angles, joint velocities, fiber lengths and fiber velocities) nor muscle activity or kinetics (including forces and moments) during these behaviors. Here we have developed a musculoskeletal model based on high-resolution imaging and reconstruction of the mouse forelimb that includes muscles spanning the neck, trunk, shoulder, and limbs using anatomical data. Physics-based optimal control simulations of the forelimb model were used to estimate in vivo muscle activity present when constrained to the tracked kinematics during mouse reaching movements. The activity of a subset of muscles was recorded via electromyography and used as the ground truth to assess the accuracy of the muscle patterning in simulation. We found that the synthesized muscle patterning in the forelimb model had a strong resemblance to empirical muscle patterning, suggesting that our model has utility in providing a realistic set of estimated muscle excitations over time when provided with a kinematic template. The strength of the resemblance between empirical muscle activity and optimal control predictions increases as mice performance improves throughout learning of the reaching task. Our computational tools are available as open-source in the OpenSim physics and modeling platform (Seth et al., 2018). Our model can enhance research into limb control across broad research topics and can inform analyses of motor learning, muscle synergies, neural patterning, and behavioral research that would otherwise be inaccessible.

Writing in two different scripts promotes fine motor control

Biscriptuality is the ability to write in two different scripts. Achieving handwriting expertise in a single script demands years of intensive practice, and these demands are even stronger when two scripts must be mastered. Biscriptuality could thus impact the cognitive and motor skills underlying graphomotor control. Here, we aimed at establishing that biscriptuality enhances graphomotor control, and at testing whether biscriptuals have better fine motor skills and working memory performance compared to Latin monoscriptuals.We found that biscriptuals perform better than monoscriptuals on graphomotor tasks, and on 3 types of fine motor control tasks indexing dexterity, motor timing under spatial constraints, and spontaneous motor tempo; the two groups did not significantly differ in their working memory performance. These results demonstrate that writing expertise widely impacts the organization of the motor system.

Tracking dynamic flow: Decoding flow fluctuations through performance in a fine motor control task

Tracking dynamic flow: Decoding flow fluctuations through performance in a fine motor control task

An Intention Prediction Based Shared Control System for Point-to-Point Navigation of a Robotic Wheelchair

Shared control approaches for robotic wheelchairs aim to provide navigation assistance to humans by utilizing robot’s intelligence in environment perception and motion planning. They can be broadly classified into two categories based on human intention prediction. Without human intention prediction, control authority lies with humans and assistance is provided only to avoid collisions. This can cause difficulty in cases where fine motor control is required, such as when entering narrow doorways, especially for users with severe upper limb disability. Intention prediction based approaches are able to better assist with such tasks but do not give enough control authority to the user as possible user intentions are pre-defined. In this work, we present an intention prediction based shared control system for point-to-point navigation of wheelchair which gives control authority to the user and also assists in fine motor control tasks. We compute various possible user intentions online using generalized Voronoi diagram, link them across time steps using their <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">homotopy class</i> and thus are able to calculate their probability given user input history. A shared local path planner then steers user towards the most likely path. This allows the user to follow any path. Our simulation experiments with 18 healthy subjects and both simulation and real wheelchair experiments, with 2 Cerebral Palsy (CP) subjects, show that our system can improve navigation outcome for people with disability and in general leads to around 10% faster completion of the task for even healthy people as compared to a local obstacle avoidance system while allowing users to follow their desired path with similar accuracy.

Quantifying upper-limb motor impairment in people with multiple sclerosis: A physiological profiling approach.

. Upper-limb sensory and motor impairments are common in people with multiple sclerosis (MS), yet the current gold standard criteria for documenting functional impairment largely focuses on mobility, balance and postural stability. . We aimed to determine the validity of the upper-limb Physiological Profile Assessment (PPA) in people with MS by investigating whether the included domains of muscle strength, dexterity, arm stability, position sense, skin sensation and bimanual coordination 1) are sensitive in differentiating people with MS from healthy controls and 2) correlate with a validated measure of upper-limb function and a scale for quantifying disability in MS. . In a cross-sectional study, 40 participants with MS and 80 healthy controls completed all 13 of the upper-limb PPA tests within a single session. . People with MS were impaired across all physiological domains tested. Performance in 4 of the 13 tests was correlated with a validated measure of self-reported upper-limb function (Pearson's r or Spearman's rho -0.333-0.441), whereas 3 tests were associated with the degree of MS-specific disability (Spearman's rho -0.318; 0.456). . The upper-limb PPA offers a valid and clinically suitable assessment of upper-limb function in people with MS. Clinicians should prioritize assessments of motor speed, fine motor control and functional tasks in their assessment of upper-limb function in people with MS because these domains are the most commonly and significantly impaired.

Oral Fine Motor Control of Teeth Treated with Endodontic Microsurgery: A Single-Blinded Case-control Study

IntroductionPeriodontal mechanoreceptors (PMRs) are refined neural receptors present in abundance at the root apex and have a pivotal role in oral fine motor control. This case-control study aimed to evaluate the oral fine motor control of teeth treated with endodontic microsurgery (EMS) in comparison with the control teeth using a standardized behavioral biting task. MethodsFourteen eligible participants performed 5 trials of an oral fine motor control task that involved holding and splitting half of a peanut positioned on a force transducer with their EMS treated tooth and its contralateral control incisor tooth (28 teeth in total). The outcome variables were the mean food holding force, intra- and intertrial variability of the holding force, food splitting force, splitting duration, and the frequency of the stepwise splitting phase. The data were analyzed with parametric and nonparametric tests. ResultsThe results showed no statistically significant differences in the holding force, inter- and intratrial variability of the holding force, splitting force, or splitting duration between the teeth treated with EMS and the control (P > .05). However, there was a significantly higher frequency of stepwise ramp increase during the splitting phase with EMS treated teeth compared with the control (48% and 37%, respectively; P < .05). ConclusionsEMS treated teeth showed similar force regulation and oral fine motor control as the contralateral control. The findings of this study suggest that EMS treatment does not perturb the sensory information of PMRs and maintains the force regulation and oral fine motor control of the teeth.

Repetitive finger movement and circle drawing in persons with Parkinson's disease.

Little is known regarding how repetitive finger movement performance impacts other fine motor control tasks, such as circle drawing, in persons with Parkinson’s disease (PD). Previous research has shown that impairments in repetitive finger movements emerge at rates near to and above 2 Hz in most persons with PD. Thus, the purpose of this study was to compare circle drawing performance in persons with PD that demonstrate impairment in repetitive finger movement and those that do not. Twenty-two participants with PD and twelve healthy older adults completed the study. Only participants with PD completed the repetitive finger movement task. From the kinematic data for the repetitive finger movement task, participants were grouped into Hasteners and Non-Hasteners. Participants with PD and the healthy older adults completed a series of circle drawing tasks at two different target sizes (1 cm and 2 cm) and three pacing conditions (Self-paced, 1.25 Hz, and 2.5 Hz). Kinematic and electromyography data were recorded and compared between groups. Results revealed that, in general, persons with PD demonstrate impairments in circle drawing and associated electromyography activity compared to healthy older adults. Moreover, persons with PD that hasten during repetitive finger movements demonstrate significantly increased movement rate during circle drawing, while those persons with PD that do not hasten demonstrate a significant increase in width variability. This suggests that differing motor control mechanisms may play a role in the performance of fine motor tasks in persons with PD. Continued research is needed to better understand differences in circle drawing performance among persons with PD to inform future development of patient-centered treatments.

Acute Exercise as an Intervention to Trigger Motor Performance and EEG Beta Activity in Older Adults.

Acute bouts of exercise have been shown to improve fine motor control performance and to facilitate motor memory consolidation processes in young adults. Exercise effects might be reflected in EEG task-related power (TRPow) decreases in the beta band (13–30 Hz) as an indicator of active motor processing. This study aimed to investigate those effects in healthy older adults. Thirty-eight participants (65–74 years of age) were assigned to an experimental (EG, acute exercise) or a control group (CG, rest). Fine motor control was assessed using a precision grip force modulation (FM) task. FM performance and EEG were measured at (1) baseline (immediately before acute exercise/rest), (2) during practice sessions immediately after, (3) 30 minutes, and (4) 24 hours (FM only) after exercise/rest. A marginal significant effect indicated that EG revealed more improvement in fine motor performance immediately after exercise than CG after resting. EG showed enhanced consolidation of short-term and long-term motor memory, whereas CG revealed only a tendency for short-term motor memory consolidation. Stronger TRPow decreases were revealed immediately after exercise in the contralateral frontal brain area as compared to the control condition. This finding indicates that acute exercise might enhance cortical activation and thus, improves fine motor control by enabling healthy older adults to better utilize existing frontal brain capacities during fine motor control tasks after exercise. Furthermore, acute exercise can act as a possible intervention to enhance motor memory consolidation in older adults.

Reproducibility of standardized fine motor control tasks and age effects in healthy adults

Graphical tasks can provide objective measures of important motor symptoms of movement disorders such as Parkinson’s disease (PD). These tasks could potentially be useful in clinical settings for (early) diagnosis and monitoring of such diseases. However, before such tasks can be used clinically, reproducibility needs to be investigated. The present study assesses the reproducibility of these graphical tasks including age-effects in healthy adults. Overall, performance on circle, spiral and zigzag tracing tasks and a writing task showed good reproducibility (intraclass correlation coefficients (ICC)>0.7). Reproducibility was similar to the reproducibility of the Purdue pegboard task, which is an already validated fine motor control task. Reproducibility for the modified Fitts’ task was moderate (ICC=0.6). Reproducibility was higher in older participants compared to younger participants. To conclude, performance on graphical tasks, especially tracing and writing tasks, was reproducible in healthy adults, which is essential for future diagnostic and monitoring purposes in patients.

Smoothness of surgical tool tip motion correlates to skill in endovascular tasks

Current performance assessment techniques in endovascular surgery are subjective or limited to grading scales based solely on an expert's observation of a novice's task execution. Since most endovascular procedures involve performing fine motor control tasks that require complex dexterous movements, this paper evaluates objective and quantitative metrics of performance that capture movement quality through the computation of tool tip movement smoothness. An experiment was designed that involved recording the catheter tip movement from 20 subjects performing four fundamental endovascular tasks in each of three sessions using manual catheterization on a physical model and in a simulation environment. Several motion-based performance measures that have been shown to reliably assess skill in other domains were computed and tested for correlation with subjective data that were simultaneously obtained from the global rating scale assessment tool. Metrics that captured movement smoothness produced statistically significant correlations with the observation-based assessment metrics and were able to differentiate skill among participants. In particular, submovement analysis led to metrics that captured statistically significant differences across ability group, session, experimental platform, and task. Objective and quantitative metrics that capture movement smoothness could be incorporated into future training protocols to provide detailed feedback on trainee performance.

Effect of Active Workstation Use on Workload, Task Performance, and Postural and Physiological Responses

OCCUPATIONAL APPLICATION: We assessed workload and performance when using two active workstations. Our results, consistent with earlier evidence, indicates that active workstations do not increase physical activity at the expense of reduced performance and operator workload, if these workstations are used for simple tasks that do not require great attention or fine motor control. Active workstations also allowed for more variability in posture and reduced static posture. However, reinforcement of ergonomics recommendations in terms of reducing non-neutral postures may be necessary.TECHNICAL ABSTRACT Background: Over the past 30 years, work has become more sedentary due to increased computer desk work, which has led to the development of major health consequences such as obesity and diabetes. One promising intervention for decreasing sedentariness is the incorporation of active workstations. Objective: We investigated the impact of two active workstations (standing and walking) on workload, task performance, and postural and physiological responses during standard office work tasks. Methods: Using a counterbalanced, within-subjects design, 30 subjects (aged 23.2 [3.1] years) were tested in three workstations: sitting, standing, and walking. A battery of simulated office tasks, including mousing, keyboarding, and cognition tasks, were presented in a randomized order during each trial. Subjective workload was assessed using the NASA-Task Load Index. Performance outcomes included reaction time, number of errors, and total task time. Physiological responses included percent heart rate reserve and heart rate variability. Neck, trunk, and shoulder inclination angles were analyzed to identify differences between workstations with respect to working posture. Results: Compared to sitting, standing and walking both resulted in significantly higher objective measures of workload. While use of walking workstation led to significantly decreased performance on fine motor control tasks, standing did not reduce performance and resulted in improved mousing performance. Both standing and walking allowed for more variability in posture. There was also an indication of more deviation from idle sitting posture while standing and walking compared to sitting. Conclusions: This study contributes to the guidance needed for the use of active workstations, to take advantage of the potential health benefits without sacrificing performance or substantially increasing workload. A standing workstation, properly adjusted based on user anthropometry and ergonomics recommendations, decreased sedentary time, allowed for more postural variability, and enhanced performance on some mousing and cognition tasks, while perceived workload remained consistent with levels while seated.

Grip force modulation characteristics as a marker for clinical disease progression in individuals with Parkinson disease: case-control study.

Upper extremity deficits are prevalent in individuals with Parkinson disease (PD). In the early stages of PD, such deficits can be subtle and challenging to document on clinical examination. The purpose of this study was to use a novel force sensor system to characterize grip force modulation, including force, temporal, and movement quality parameters, during a fine motor control task in individuals with early stage PD. A case-control study was conducted. Fourteen individuals with early stage PD were compared with a control group of 14 healthy older adults. The relationship of force modulation parameters with motor symptom severity and disease chronicity also was assessed in people with PD. Force was measured during both precision and power grasp tasks using an instrumented twist-cap device capable of rotating in either direction. Compared with the control group, the PD group demonstrated more movement arrests during both precision and power grasp and longer total movement times during the power grasp. These deficits persisted when a concurrent cognitive task was added, with some evidence of force control deficits in the PD group, including lower rates of force production during the precision grasp task and higher peak forces during the power grasp task. For precision grasp, a higher number of movement arrests in single- and dual-task conditions as well as longer total movement times in the dual-task condition were associated with more severe motor symptoms. The sample was small and consisted of individuals in the early stages of PD with mild motor deficits. The group with PD was predominantly male, whereas the control group was predominantly female. The results suggest that assessing grip force modulation deficits during fine motor tasks is possible with instrumented devices, and such sensitive measures may be important for detecting and tracking change early in the progression of PD.

Age-related differences in finger force control are characterized by reduced force production

It has been repeatedly shown that precise finger force control declines with age. The tasks and evaluation parameters used to reveal age-related differences vary between studies. In order to examine effects of task characteristics, young adults (18-25years) and late middle-aged adults (55-65years) performed precision grip tasks with varying speed and force requirements. Different outcome variables were used to evaluate age-related differences. Age-related differences were confirmed for performance accuracy (TWR) and variability (relative root mean square error, rRMSE). The task characteristics, however, influenced accuracy and variability in both age groups: Force modulation performance at higher speed was poorer than at lower speed and at fixed force levels than at force levels adjusted to the individual maximum forces. This effect tended to be stronger for older participants for the rRMSE. A curve fit confirmed the age-related differences for both spatial force tracking parameters (amplitude and intercept) and for one temporal parameter (phase shift), but not for the temporal parameter frequency. Additionally, matching the timing parameters of the sine wave seemed to be more important than matching the spatial parameters in both young adults and late middle-aged adults. However, the effect was stronger for the group of late middle-aged, even though maximum voluntary contraction was not significantly different between groups. Our data indicate that changes in the processing of fine motor control tasks with increasing age are caused by difficulties of late middle-aged adults to produce a predefined amount of force in a short time.

Schizotypal trait in healthy women is associated with a shift away from dextrality on a spatial motor control task, but not on a force control task

It is generally acknowledged that schizophrenia and schizotypy lie on the same continuum, while there is an ongoing debate as to whether schizotypy represents true dimension or quasi-dimension. Evidence suggests that reduced hemispheric lateralization and mixed handedness are associated with both schizophrenia and schizotypy. However, the possible relationship of schizotypy with laterality as assessed with motor function tasks has not been well documented. A few studies using fine motor control tasks have demonstrated the relationship between schizotypy and reduced laterality among student populations, yet little has been done in community samples. Here we employed 249 healthy women and examined the association between schizotypal traits assessed with the Schizotypal Personality Questionnaire and motor functions assessed with the Purdue Pegboard test (as a measure of spatial motor control) and a handgrip force test. Correlational and categorical analyses both showed that schizotypal traits were significantly associated with leftward and bilateral bias in the fine motor control task, but not in the handgrip force test. Schizotypy did not significantly affect the performance level on either of these tasks. These results indicate that schizotypal traits in healthy women are associated with a shift away from dextrality, supporting the fully dimensional model of schizotypy.

Relationship between reaction time, fine motor control, and visual–spatial perception on vigilance and visual-motor tasks in 22q11.2 Deletion Syndrome

22q11.2 Deletion Syndrome (22q11DS) is a common microdeletion disorder associated with mild to moderate intellectual disability and specific neurocognitive deficits, particularly in visual-motor and attentional abilities. Currently there is evidence that the visual-motor profile of 22q11DS is not entirely mediated by intellectual disability and that these individuals have specific deficits in visual-motor integration. However, the extent to which attentional deficits, such as vigilance, influence impairments on visual motor tasks in 22q11DS is unclear. This study examines visual-motor abilities and reaction time using a range of standardised tests in 35 children with 22q11DS, 26 age-matched typically developing (TD) sibling controls and 17 low-IQ community controls. Statistically significant deficits were observed in the 22q11DS group compared to both low-IQ and TD control groups on a timed fine motor control and accuracy task. The 22q11DS group performed significantly better than the low-IQ control group on an untimed drawing task and were equivalent to the TD control group on point accuracy and simple reaction time tests. Results suggest that visual motor deficits in 22q11DS are primarily attributable to deficits in psychomotor speed which becomes apparent when tasks are timed versus untimed. Moreover, the integration of visual and motor information may be intact and, indeed, represent a relative strength in 22q11DS when there are no time constraints imposed. While this may have significant implications for cognitive remediation strategies for children with 22q11DS, the relationship between reaction time, visual reasoning, cognitive complexity, fine motor speed and accuracy, and graphomotor ability on visual-motor tasks is still unclear.

The Kløve–Matthews Static Steadiness Test Compared with the DPD TREMOR: Comparison of a Fine Motor Control Task with Measures of Tremor in Smokers and Manganese-Exposed Workers

The aim of this study was to compare two tests for tremor/fine motor control as regards their sensitivity in relation to effects on tremor of exposure to manganese and cigarette smoke. One hundred manganese-exposed workers were compared with 100 age-matched referents. The subjects were tested with the Kløve–Matthews static steadiness test (hole tremormeter) and the DPD TREMOR (accelerometer). The manganese-exposed subjects showed increased postural tremor compared to the referents. The tremor had a larger frequency dispersion among the exposed subjects than among the referents as assessed by the TREMOR 7.0 test system, indicating that the tremor had a pattern where the power was burned at a wider spectre of frequencies among the exposed subjects than among the referents. The two tests differed in their ability to demonstrate tremor, depending of the type of exposure (manganese or cigarette smoke). The static steadiness test was better than the TREMOR at discriminating between manganese-exposed subjects and referents while the TREMOR was better at discriminating between smokers and non-smokers than the static steadiness test. The tests also differed in their ability to demonstrate tremor depending on the frequency of tremor. The Tremor Intensity I was higher for subjects with higher tremor frequency, while no such effect was found for the static steadiness test parameters. When studying the effects of exposures where the quality of the tremor is unknown, it is suggested to include at least two tremor tests, one based on acceleration and the other on displacement.

Effects of prolonged mental work on functional brain topography

Topographic patterns of event-related covariance between electrodes were measured from subjects performing a difficult memory and fine-motor control task for 10–14 h. Striking changes occured in the patterns after subjects performed the task for an average of 7–9 h, but before performance deteriorated. Pattern strength was reduced in a fraction-of-a-second-long response preparation interval over midline precentral areas and over the entire left hemisphere. By contrast, pattern strength in a succeeding response inhibition interval was reduced over all areas. The pattern changed least in an intervening interval associated with visual-stimulus processing. This suggests that, in addition to the well-known global reduction in neuroelectric signal strength, functional neural networks are selectively affected by sustained mental work in specific fraction-of-a-second task intervals.