Quantitative assessment of finger motor performance: Normative data

Thumb Pronation Angle in Thumb Opposition Evaluated by the Nail Tip Angle of Thumb-Ring Finger Opposition

BACKGROUND

This study aimed to devise the method for the evaluation of the thumb pronation angle and calculate its reference value.

METHODS

The study was conducted from October 2021 to March 2022, and 600 hands of 300 healthy volunteers were included in this study. The participants were divided into 6 age groups with 50 participants each. In study 1, 12 participants from group 1 were randomly selected, which included 6 male and 6 female participants. We measured the thumb pronation angle using FASTRAK system and the nail tip angle of thumb-ring finger opposition (T-R angle) and also evaluated the relation between them. In study 2, we measured the T-R angle of 600 hands of 300 healthy volunteers. The T-R angle mean (SD) and 95% confidence interval (CI) of each age group were calculated as reference values.

RESULTS

The thumb pronation angle was correlated with the T-R angle. The T-R angle mean (SD) and 95% CI of the 6 groups were as follows: group 1, 142.5° (12.4) and 117.7 to 167.3; group 2, 139.9° (10.1) and 119.7 to 160.1; group 3, 142.3° (9.7) and 122.9 to 160.5; group 4, 140.2° (12.6) and 115.0 to 165.4; group 5, 138.3° (11.9) and 114.5 to 162.1; and group 6, 135.4° (13.0) and 109.4 to 161.4. The 95% CI tended to decrease with an increasing age.

CONCLUSIONS

The T-R angle was a suitable evaluation method for the thumb pronation angle, and it should be evaluated by age groups.

Hand-worn devices for assessment and rehabilitation of motor function and their potential use in BCI protocols: a review

Introduction

Various neurological conditions can impair hand function. Affected individuals cannot fully participate in activities of daily living due to the lack of fine motor control. Neurorehabilitation emphasizes repetitive movement and subjective clinical assessments that require clinical experience to administer.

Methods

Here, we perform a review of literature focused on the use of hand-worn devices for rehabilitation and assessment of hand function. We paid particular attention to protocols that involve brain-computer interfaces (BCIs) since BCIs are gaining ground as a means for detecting volitional signals as the basis for interactive motor training protocols to augment recovery. All devices reviewed either monitor, assist, stimulate, or support hand and finger movement.

Results

A majority of studies reviewed here test or validate devices through clinical trials, especially for stroke. Even though sensor gloves are the most commonly employed type of device in this domain, they have certain limitations. Many such gloves use bend or inertial sensors to monitor the movement of individual digits, but few monitor both movement and applied pressure. The use of such devices in BCI protocols is also uncommon.

Discussion

We conclude that hand-worn devices that monitor both flexion and grip will benefit both clinical diagnostic assessment of function during treatment and closed-loop BCI protocols aimed at rehabilitation.

Innovative Quantitative Assessment of Hand Function in Carpal Tunnel Syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) compromises fine sensorimotor function during activities of daily living and affects a large number of individuals with high burden costs for society. The purpose of this study was to quantitatively characterize fine movement skills in CTS patients preoperatively and at 1 month postoperatively by means of a sensor-engineered glove, in order to provide new insights for evaluative and finally therapeutic purposes.

METHODS

Forty-one CTS patients and 41 age- and gender-matched healthy controls (HC) were analyzed by adopting the engineered glove Hand Test System (HTS), which previously demonstrated its reliability and sensitivity to detect hands dysfunction in several neurological diseases. A sub-group of 11 CTS subjects was re-tested 1 month after surgery. Three parameters-touch duration (TD), inter-tapping interval (ITI), and movement rate (MR)-were considered to characterize hand function.

RESULTS

The affected hand of CTS patients generally showed worst finger opposition performances than HC. Comparing the dominant hand, all parameters were able to significantly discriminate CTS patients from HC. Considering the nondominant hand, the best performing parameter in discriminating CTS from HC was TD. The follow-up assessment at 1 month after surgery showed that considered parameters were able to monitor patients' recovery. In particular, the TD parameter recorded at the 3 different assigned task modalities resulted significantly enhanced.

CONCLUSIONS

Results of this pilot study proved the validity of the parameters obtained through the sensor-engineered glove to assess objectively hand functional status and surgical outcomes in CTS.

Engineered glove to evaluate hand disability in rheumatoid arthritis: A pilot-study

OBJECTIVE

The Hand Test System (HTS) is an engineered-sensorized glove that has been originally developed in the neuroscientific field for the evaluation of hand fingers' speed movement. This pilot-study aimed to evaluate the reproducibility of HTS analysis in rheumatoid arthritis (RA), correlating glove-derived parameters with clinical disease activity indexes, self-reported disability-related questionnaires and hand strength.

METHODS

Fifty-five RA patients and fifty age and sex matched healthy controls (HCs) performed HTS analysis. The glove recognized the touch speed between the finger tips during standard sequences of movements, providing three quantitative parameters: touch duration (TD), inter-tapping interval (ITI) and movement rate (MR). These variables were correlated with Health Assessment Questionnaire (HAQ), Health Assessment Questionnaire-Disease Index (HAQ-DI), Hand Disability Index (HDI), Hand Grip Strength (HGS), DAS28-CRP, CDAI and SDAI.

RESULTS

Intraclass correlation coefficient was 0.93 (CI: 0.92, 0.95). RA patients showed significantly slower TD, ITI and MR than HCs, for all classes of disease activity (P<0.001). All HTS parameters correlated significantly with HAQ, HAQ-DI, HDI, HGS, DAS28-CRP, SDAI, CDAI (between P<0.05 and P<0.001). Of note, also RA patients in clinical remission showed a significantly higher TD compared with HCs (P<0.001).

CONCLUSION

HTS seems a new safe and fast tool to evaluate rheumatoid hand's functionality, measuring the speed of finger movements. Furthermore, the HTS parameters significantly correlate with quality of life, disease activity, hand strength and perceived hand disability, evaluating also potential hand motor impairment in RA clinical remission.

Evaluation of Explicit Motor Timing Ability in Young Tennis Players

A crucial ability for athletes playing sports that involve coincidence timing actions is the motor timing ability. The efficiency of perceptual and motor processes underlying the motor timing ability has been related to the motor experience gained in interceptive sports, such as tennis. In the present study, the motor timing ability in young tennis players (TP) and age-matched control participants (CTRL) was compared by means of a synchronization paradigm. Participants were asked to perform finger-opposition movements in synch to a metronome beating 0.5 and 2 Hz in (1) a bimanual coordination test, which compared the performance of the dominant hand with that of the contralateral hand, and (2) a movement lateralization test, which compared the motor performance of the dominant hand during single-hand and bimanual tasks (BTs). The motor performance was evaluated through movement strategy [defined by touch duration (TD), inter-tapping interval (ITI), and movement frequency] and movement accuracy (temporal accuracy defined by the synchronization error and spatial accuracy defined by the percentage of correct touches—%CORR_SEQ). Results showed that motor expertise significantly influences movement strategy in the bimanual coordination test; TD of TP was significantly higher than those of CTRL, specifically at 0.5 Hz. Furthermore, overall ITI values of TP were lower than those of CTRL. Lastly, in the movement lateralization test, the %CORR_SEQ executed with the right dominant hand by TP in the BT was significantly higher than those of CTRL. A discussion about the role of motor expertise in the timing ability and the related neurophysiological adaptations is provided.

Multimodal Neurophysiological and Neuroimaging Evidence of Genetic Influence on Motor Control: A Case Report of Monozygotic Twins

Considering genetic influence on brain structure and function, including motor control, we report a case of right-handed monozygotic twins with atypical organization of fine motor movement control that might imply genetic influence. Structural and functional organization of the twins' motor function was assessed using transcranial magnetic stimulation (TMS), fMRI with a motor-task paradigm, and diffusion tensor imaging (DTI) tractography. TMS revealed that both twins presented the same unexpected activation and inhibition of both motor cortices during volitional unilateral fine hand movement. The right ipsilateral corticospinal tract was weaker than the left contralateral one. The motor-task fMRI identified activation in the left primary motor cortex and bilateral secondary motor areas during right-hand (dominant) movement and activation in the bilateral primary motor cortex and secondary motor areas during left-hand movement. Based on DTI tractography, both twins showed a significantly lower streamline count (number of fibers) in the right corticospinal tract compared with a control group, which was not the case for the left corticospinal tract. Neither twin reported any difficulty in conducting fine motor movements during their activities of daily living. The combination of TMS and advanced neuroimaging techniques identified an atypical motor control organization that might be influenced by genetic factors. This combination emphasizes that activation of the unilateral uncrossed pyramidal tract represents an alternative scheme to a "failure" of building a standard pattern but may not necessarily lead to disability.

Asymmetric transcallosal conduction delay leads to finer bimanual coordination

It has been theorized that hemispheric dominance and more segregated information processing have evolved to overcome long conduction delays through the corpus callosum (transcallosal conduction delay - TCD) but that this may still impact behavioral performance, mostly in tasks requiring high timing accuracy. Nevertheless, a thorough understanding of the temporal features of interhemispheric communication is lacking. Here, we aimed to assess the relationship between TCD and behavioral performance with a noninvasive directional cortical measure of TCD obtained from transcranial magnetic stimulation (TMS)-evoked potentials (TEPs) in the motor system. Twenty-one healthy right-handed subjects were tested. TEPs were recorded during an ipsilateral silent period (iSP) paradigm and integrated with diffusion tensor imaging (DTI) and an in-phase bimanual thumb-opposition task. Linear mixed models were applied to test relationships between measures. We found TEP indexes of transcallosal communication at ∼15 ms both after primary motor cortex stimulation (M1-P15) and after dorsal premotor cortex stimulation (dPMC-P15). Both M1-and dPMC-P15 were predicted by mean diffusivity in the callosal body. Moreover, M1-P15 was positively related to iSP. Importantly, M1-P15 latency was linked to bimanual coordination with direction-dependent effects, so that asymmetric TCD was the best predictor of bimanual coordination. Our findings support the idea that transcallosal timing in signal transmission is essential for interhemispheric communication and can impact the final behavioral outcome. However, they challenge the view that a short conduction delay is always beneficial. Rather, they suggest that the effect of the conduction delay may depend on the direction of information flow.

Effects of aging on finger movements in multiple sclerosis

BACKGROUND

People with multiple sclerosis (PwMS) report impaired hand movements and coordination. With an engineered glove we demonstrated altered finger movements in PwMS; increasing age resulted in decreased performance in healthy subjects (normative data). This study aims at investigating aging effects on finger motor performance in PwMS, in relation to disease duration and Expanded Disability Status Scale (EDSS).

METHODS

Ninety-six PwMS performed repetitive finger opposition movements with the dominant hand and both hands at maximal velocity or metronome-paced. Performance was compared with the norms, and correlation coefficients between finger motor parameters, age, disease duration and EDSS were calculated.

RESULTS

The majority of subjects was outside of the normal range according to age and probability increased with level of disability. Age significantly correlated with the glove parameters (r ranged in absolute value between 0.22-0.31; p-value in the range 0.002-0.049). Older subjects with lower disability showed worse performance than younger (p = 0.044 and 0.02), whilst younger subjects with higher disability performed similarly to older (p = 0.72 and 0.49).

CONCLUSION

Finger motor performance assessment provides important hints about upper limb disability, which should be evaluated in relation to age, disease duration and EDSS.

Quantitative Assessment of Finger Movement Profile in a Visual-Motor Task Based on a Tablet Computer: The Application in Parkinson's Disease

BACKGROUND/OBJECTIVE

Easily applicable, quantitative assessment of movement is widely needed in various clinical settings, especially in the evaluation of Parkinson's disease (PD).

METHODS

We developed a highly repeatable tablet computer-based finger movement assessment system (FMAS) to record finger movement profile in a visual-motor task both in PD (n = 217) and healthy participants (n = 221).

RESULTS

We found age-related declines in finger movement performance among the healthy participants but not in PD patients with the FMAS. Significant differences in movement time (MT) and latency/MT ratio but not in latency were observed in PD patients as compared with healthy subjects (P < 0.000). Meanwhile, we identified the latency/MT ratio as the optimal parameter to differentiate PD from age-matched healthy subjects in an age-independent manner (cut-off 1.08 with corresponding AUC = 0.861). In addition, a significant correlation was found between finger movement parameters and the Hoehn and Yahr scale (H-Y scale), UPDRS III score and the duration of the disease in PD patients (P < 0.01).

CONCLUSION

It was suggested that the tablet computer-based evaluation of finger movement provided an easily applicable quantitative method to assess the conditions of PD patients.

Thumbs up: movements made by the thumb are smoother and larger than fingers in finger-thumb opposition tasks

Background

In humans, the thumb plays a crucial role in producing finger opposition movements. These movements form the basis of several activities of the hand. Hence these movements have been used to study phenomena like prehension, motor control, motor learning, etc. Although such tasks have been studied extensively, the relative contribution of the thumb vis-à-vis the fingers in finger opposition tasks is not well understood. In this study, we investigated the kinematics of thumb and fingers in a simple finger opposition task. Further, we quantified the relative contribution and the movement smoothness aspects and compared these between fingers and thumb.

Methods

Eight, young healthy participants (four males and four females) were asked to perform a full finger to thumb opposition movement, where they were required to reach for different phalanges of the fingers. Position (X, Y and Z) of individual segments of the four fingers and the thumb were measured with reference to the wrist by a 16-sensor kinematics measurement system. Displacements and velocities were computed. An index, displacement ratio, that quantifies the relative contribution of thumb and fingers was computed from displacement data. Velocity data was used to quantify the smoothness of movement of thumb and fingers.

Results

The Displacement Ratio showed that contribution of the thumb is higher than contribution of any other target finger or target phalanges, except for the distal phalanx of the index and middle fingers. Smoothness of movement of the thumb was higher than all the finger phalanges in all cases.

Conclusion

We conclude that in the task considered (thumb opposition movements to different targets within the hand & fingers), the thumb made a greater relative contribution in terms of displacement ratio and also produced smoother movements. However, smoothness of thumb did not vary depending on the target. This suggests that the traditional notion of the thumb being a special digit when compared to other fingers is true at least for the opposition movements considered in this study.