Differences in muscle activity during hand-dexterity tasks between women with arthritis and a healthy reference group

Toward Early and Objective Hand Osteoarthritis Detection by Using EMG during Grasps

The early and objective detection of hand pathologies is a field that still requires more research. One of the main signs of hand osteoarthritis (HOA) is joint degeneration, which causes loss of strength, among other symptoms. HOA is usually diagnosed with imaging and radiography, but the disease is in an advanced stage when HOA is observable by these methods. Some authors suggest that muscle tissue changes seem to occur before joint degeneration. We propose recording muscular activity to look for indicators of these changes that might help in early diagnosis. Muscular activity is often measured using electromyography (EMG), which consists of recording electrical muscle activity. The aim of this study is to study whether different EMG characteristics (zero crossing, wavelength, mean absolute value, muscle activity) via collection of forearm and hand EMG signals are feasible alternatives to the existing methods of detecting HOA patients' hand function. We used surface EMG to measure the electrical activity of the dominant hand's forearm muscles with 22 healthy subjects and 20 HOA patients performing maximum force during six representative grasp types (the most commonly used in ADLs). The EMG characteristics were used to identify discriminant functions to detect HOA. The results show that forearm muscles are significantly affected by HOA in EMG terms, with very high success rates (between 93.3% and 100%) in the discriminant analyses, which suggest that EMG can be used as a preliminary step towards confirmation with current HOA diagnostic techniques. Digit flexors during cylindrical grasp, thumb muscles during oblique palmar grasp, and wrist extensors and radial deviators during the intermediate power-precision grasp are good candidates to help detect HOA.

Effect of task-oriented training on pain, functionality, and quality of life in rheumatoid arthritis

Objectives

The aim of this study was to demonstrate additional effects of task-oriented training (TOT) in patients with rheumatoid arthritis (RA) regarding pain, dexterity, muscle strength, and ability to perform activities of daily living (ADLs) within five weeks.

Patients and methods

Between June 2016 and February 2018, a total of 46 female RA patients (mean age: 51.17±7.9 years; range, 29 to 68 years) who were volunteer for participating in the study were randomized into two groups as follows: conventional exercise group (Group 1) and conventional + TOT group (Group 2). The exercises of Group 1 included passive range of motion (PROM), isometric grip strength exercises, and mobilization of metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints. In Group 2, in addition to conventional exercises, the patients completed an exercise program consisting of washing their faces, using forks, drinking water from a glass, sitting up, and putting on a shirt. Exercises were performed twice a week for a five-week period. Before and after the exercise programs, hand grip strength was assessed with a Jamar hand dynamometer, hand dexterity with Nine Hole Peg Test (NHPT), pain with Visual Analog Scale (VAS), and ADLs with Health Assessment Questionnaire (HAQ) and Duruöz Hand Index (DHI).

Results

There was no significant difference in NHPT and Jamar in both groups (p>0.05). Although a significant decrease was observed within the groups in VAS and HAQ scores before and after the exercise programs in both groups (p<0.05), no significant difference was found between the groups (p>0.05). The DHI showed a significant improvement in Group 2 and a significant difference was observed between the two groups (p<0.05).

Conclusion

This study shows that exercise programs may be beneficial in alleviating pain and performing daily activities. Also, adding task-oriented training to a program may facilitate ADLs in RA patients.

Acute Whole-Body Vibration Exercise Promotes Favorable Handgrip Neuromuscular Modifications in Rheumatoid Arthritis: A Cross-Over Randomized Clinical

Objective

Rheumatoid arthritis (RA) causes progressive changes in the musculoskeletal system compromising neuromuscular control especially in the hands. Whole-body vibration (WBV) could be an alternative for the rehabilitation in this population. This study investigated the immediate effect of WBV while in the modified push-up position on neural ratio (NR) in a single session during handgrip strength (HS) in women with stable RA.

Methods

Twenty-one women with RA (diagnosis of disease: ±8 years, erythrocyte sedimentation rate: ±24.8, age: 54± 11 years, BMI: 28 ± 4 kg·m⁻²) received three experimental interventions for five minutes in a randomized and balanced cross-over order: (1) control—seated with hands at rest, (2) sham—push-up position with hands on the vibration platform that remained disconnected, and (3) vibration—push-up position with hands on the vibration platform turned on (45 Hz, 2 mm, 159.73 m·s⁻²). At the baseline and immediately after the three experimental interventions, the HS, the electromyographic records (EMGrms), and range of motion (ROM) of the dominant hand were measured. The NR, i.e., the ratio between EMGrms of the flexor digitorum superficialis (FDS) muscle and HS, was also determined. The lower NR represented the greater neuromuscular efficiency (NE).

Results

The NR was similar at baseline in the three experimental interventions. Despite the nonsignificance of within-interventions (p = 0.0611) and interaction effect (p = 0.1907), WBV exercise reduced the NR compared with the sham and control (p = 0.0003, F = 8.86, η² = 0.85, power = 1.00).

Conclusion

Acute WBV exercise under the hands promotes neuromuscular modifications during the handgrip of women with stable RA. Thus, acute WBV exercise may be used as a preparatory exercise for the rehabilitation of the hands in this population. This trial is registered with trial registration 2.544.850 (ReBEC-RBR-2n932c).

Impairment of electrical activation of wrist flexor and extensor muscles during gripping and functional activities in the early stage of hand osteoarthritis: A cross-sectional study

STUDY DESIGN

This is a cross-sectional study.

INTRODUCTION

The wrist extensor muscles have a fundamental role in the stabilization of the wrist while performing manual activities. However, it is unknown if the clinical signs of hand osteoarthritis (HOA) cause impairment in the activation of these muscles PURPOSE OF THE STUDY: The purpose of this study was to investigate whether early-stage HOA affects the magnitude of activation and coactivation between the wrist extensor and flexor muscles METHODS: Thirty-two subjects were divided into two groups: control group (n = 16; 55 ± 7.42 years) and a group with HOA grades 2 or 3 (HOAG; n = 16; 57 ± 7.82 years). Muscle activation was measured in m. flexor digitorum superficialis, m. flexor carpi ulnaris (FCU) and extensors (EXT) during the evaluation of grip strength and three manual activities (write, cut a paper with scissors, and close and open a bottle). The coactivation index was calculated between the electromyography of the flexors (FCU and FSD) and wrist EXT.

RESULTS

HOAG presented reduced muscle activation in all tasks, with a statistical difference for the flexor digitorum superficialis and EXT in the scissors activity, and for the FCU in the bottle activity. No differences were found between groups for the coactivation index and grip strength.

DISCUSSION

The reduced muscle activity may be due to an inability of the patients of the HOAG to recruit all motor units or to an inhibition related to the presence of pain.

CONCLUSION

In the early stages of HOA, there is a functional deficit associated with a reduced muscle activity of the wrist muscles during manual activities.

Development and comprehensive evaluation of a new spring-steel-driven glove for grasping assistance during activities of daily living

Millions of people suffer from a decline in grip strength and hand function due to conditions such as chronic disease, injuries, and aging. Hand function decline results in difficulties with performing activities of daily living, where grasping, lifting, and releasing objects are essential. There is an increasing demand for assistive gloves to enhance users' hand function and improve their independence. This paper presents the design of a new bidirectional lightweight assistive glove and demonstrates its capabilities through comprehensive experiments using human subjects. The developed glove can provide adequate power augmentation for grasping and releasing objects due to its simple yet effective design using spring steel strips and linear actuators. The glove directly transfers assistive forces to users' fingertips without any complex intermediate mechanism, and its low weight of 196 g promotes its usability. The rigorous experiment design provided a thorough assessment of the developed glove by accounting for both parameters of size and weight of objects and by including subjects with different hand sizes. To quantify the glove's performance, the subjects' muscle activity, their finger and thumb joints' trajectories, and their grasping forces while using the glove were investigated. The glove could generate the necessary grasping forces to assist with lifting common-household objects. The subjects' muscle activity significantly decreased when using the glove for object manipulation. The trajectories of the index finger and thumb joints when using the glove were dependent on the size of objects similar to natural unassisted grasping. The obtained results demonstrate the glove's ability for grip power augmentation of individuals with declining hand strength.

Evaluation of Optical and Radar Based Motion Capturing Technologies for Characterizing Hand Movement in Rheumatoid Arthritis-A Pilot Study

In light of the state-of-the-art treatment options for patients with rheumatoid arthritis (RA), a detailed and early quantification and detection of impaired hand function is desirable to allow personalized treatment regiments and amend currently used subjective patient reported outcome measures. This is the motivation to apply and adapt modern measurement technologies to quantify, assess and analyze human hand movement using a marker-based optoelectronic measurement system (OMS), which has been widely used to measure human motion. We complement these recordings with data from markerless (Doppler radar) sensors and data from both sensor technologies are integrated with clinical outcomes of hand function. The technologies are leveraged to identify hand movement characteristics in RA affected patients in comparison to healthy control subjects, while performing functional tests, such as the Moberg-Picking-Up Test. The results presented discuss the experimental framework and present the limiting factors imposed by the use of marker-based measurements on hand function. The comparison of simple finger motion data, collected by the OMS, to data recorded by a simple continuous wave radar suggests that radar is a promising option for the objective assessment of hand function. Overall, the broad scope of integrating two measurement technologies with traditional clinical tests shows promising potential for developing new pathways in understanding of the role of functional outcomes for the RA pathology.

Identification of forearm skin zones with similar muscle activation patterns during activities of daily living

Background

A deeper knowledge of the activity of the forearm muscles during activities of daily living (ADL) could help to better understand the role of those muscles and allow clinicians to treat motor dysfunctions more effectively and thus improve patients’ ability to perform activities of daily living.

Methods

In this work, we recorded sEMG activity from 30 spots distributed over the skin of the whole forearm of six subjects during the performance of 21 representative simulated ADL from the Sollerman Hand Function Test. Functional principal component analysis and hierarchical cluster analysis (HCA) were used to identify forearm spots with similar muscle activation patterns.

Results

The best classification of spots with similar activity in simulated ADL consisted in seven muscular-anatomically coherent groups: (1) wrist flexion and ulnar deviation; (2) wrist flexion and radial deviation; (3) digit flexion; (4) thumb extension and abduction/adduction; (5) finger extension; (6) wrist extension and ulnar deviation; and (7) wrist extension and radial deviation.

Conclusion

The number of sEMG sensors could be reduced from 30 to 7 without losing any relevant information, using them as representative spots of the muscular activity of the forearm in simulated ADL. This may help to assess muscle function in rehabilitation while also simplifying the complexity of prosthesis control.

Electromyographic Activity of the Upper Limb in Three Hand Function Tests

Objective/Background

Occupational therapists usually assess hand function through standardised tests, however, there is no consensus on how the scores assigned to hand dexterity can accurately measure hand function required for daily activities and few studies evaluate the movement patterns of the upper limbs during hand function tests. This study aimed to evaluate the differences in muscle activation patterns during the performance of three hand dexterity tests.

Methods

Twenty university students underwent a surface electromyographic (sEMG) assessment of eight upper limb muscles during the performance of the box and blocks test (BEST), nine-hole peg test (9HPT), and functional dexterity test (FDT). The description and comparison of each muscle activity during the test performance, gender differences, and the correlation between individual muscles’ sEMG activity were analysed through appropriate statistics.

Results

Increased activity of proximal muscles was found during the performance of BEST (p < .001). While a higher activation of the distal muscles occurred during the FDT and 9HPT performance, no differences were found between them. Comparisons of the sEMG activity revealed a significant increase in the muscle activation among women (p = .05). Strong and positive correlations (r > .5; p < .05) were observed between proximal and distal sEMG activities, suggesting a coordinate pattern of muscle activation during hand function tests.

Conclusion

The results suggested the existence of differences in the muscle activation pattern during the performance of hand function evaluations. Occupational therapists should be aware of unique muscle requirements and its impact on the results of dexterity tests during hand function evaluation.

Intramuscular fat and physical performance at the Framingham Heart Study

Intramuscular fat may mediate associations between obesity and physical disability. We examined the associations between muscle attenuation, a proxy for intramuscular fat, and physical function. Paraspinous muscle computed tomography attenuation was obtained on a Framingham Heart Study subgroup (n = 1152, 56 % women, mean age 66 years). Regressions modeled cross-sectional associations between muscle attenuation and mobility disability, grip strength, and walking speed with standard covariates; models additionally adjusted for body mass index (BMI) and visceral adipose tissue (VAT). Separate models investigated associations between VAT and subcutaneous adipose tissue (SAT) and physical function. Per 1 standard deviation decrement in muscle attenuation (i.e., more muscle fat), we observed 1.29 (95 % CI = 1.11, 1.50; p = 0.0009) increased odds of walking speed ≤1 m/s in women and men. This persisted after separate BMI and VAT adjustments (p < 0.02). In men, there was a 1.29 kg (95 % CI = 0.57, 2.01; p = 0.0005) decrement in grip strength, which persisted after BMI and VAT adjustments (p ≤ 0.0004). For VAT and SAT, similar associations were not observed. Intramuscular fat is associated with increased odds of walking speed ≤1 m/s in both sexes and lower grip strength in men. There were no similar associations for VAT and SAT, highlighting the specificity of intramuscular fat in association with physical function.

Short- and Long-Intracortical Inhibition in Incomplete Spinal Cord Injury

BACKGROUND

Short- (SICI) and long-interval intracortical inhibition (LICI) are involved in the control of movement and movement initiation. Alterations to the two circuits can result in direct alterations to the physiology of the muscles and can be used to explain the physiological changes to individuals with spinal cord injury (SCI).

OBJECTIVE

To probe changes in GABAergic function by characterizing the recruitment curves of SICI and LICI interval intracortical inhibition in an upper limb muscle in chronic SCI participants with injury between C3 and C7.

METHODS

Recruitment curves were elicited with conditioning stimulus intensities determined as a percentage of active motor threshold (AMT) (SICI, 60% to 110% AMT; LICI, 90% to 130% AMT) and recorded from the flexor carpi radialis muscle during an isometric contraction equal to 15% to 20% of maximum voluntary contraction.

RESULTS

AMT was greater and motor-evoked potential sizes were lower in SCI compared with uninjured controls. SICI magnitude was not different between groups, although the range of conditioning stimulus intensities to evoke SICI was unique to each group. LICI was reduced in the control group during active contraction and remained present in SCI.

DISCUSSION

LICI was increased in the actively contracted flexor carpi radialis muscle in individuals with SCI compared with age-matched controls. These findings indicate that GABAB function mediating LICI is different in SCI versus controls.

CONCLUSIONS

Increased LICI in SCI may be attributed to the medication baclofen or to changes in the neural mechanisms controlling contraction-related modulation of the LICI circuit.