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The corticospinal tract (CST) is the preeminent voluntary motor pathway that controls human movements. Consequently, long-standing interest has focused on CST location and function in order to understand both loss and recovery of neurological function after incomplete cervical spinal cord injury, such as traumatic central cord syndrome. The hallmark clinical finding is paresis of the hands and upper-extremity function with retention of lower-extremity movements, which has been attributed to injury and the sparing of specific CST fibers. In contrast to historical concepts that proposed somatotopic (laminar) CST organization, the current narrative summarizes the accumulated evidence that 1) there is no somatotopic organization of the corticospinal tract within the spinal cord in humans and 2) the CST is critically important for hand function. The evidence includes data from 1) tract-tracing studies of the central nervous system and in vivo MRI studies of both humans and nonhuman primates, 2) selective ablative studies of the CST in primates, 3) evolutionary assessments of the CST in mammals, and 4) neuropathological examinations of patients after incomplete cervical spinal cord injury involving the CST and prominent arm and hand dysfunction. Acute traumatic central cord syndrome is characterized by prominent upper-extremity dysfunction, which has been falsely predicated on pinpoint injury to an assumed CST layer that specifically innervates the hand muscles. Given the evidence surveyed herein, the pathophysiological mechanism is most likely related to diffuse injury to the CST that plays a critically important role in hand function.

This research is motivated by the problem in this study, namely weak hand muscle strength, muscle endurance and balance to shooting games, some UPGRIS students take part in Petanque UKM, some of them are students who have hand muscle strength, muscle endurance in throwing something is lacking and so is the balance of the body. The purpose of this study was to determine the effect of hand muscle strength, muscle endurance and balance on the accuracy of shooting games at UKM Petanque UPGRIS and to determine the causes of the lack of accuracy in the shooting game Petanque. The method used is quantitative research methods with the type of research model True-Experimental Design Pre-test Post-test Two Group design. The population and sample in this study were 10 petanque athletes at the PGRI University of Semarang. This sampling technique uses total sampling. The method of data analysis used paired sample test with a significance level of 5%. The results showed that there was an effect of hand muscle strength training, muscle endurance and balance on the accuracy of shooting game Petanque which was expressed through the results of hypothesis testing with paired sample t-test with count = -7.571 and t-table = 2.777. Then t_count> t-table so that Ho is rejected and Ha is accepted, while based on the significant value because the value is sig. = 0.002 with a confidence level of 95%, then Sig. > ? (0.05). So that Ho was rejected. This study concludes that there is an effect of hand muscle strength training, muscle endurance and balance on the accuracy of the Petanque shooting game at the UKM Petanque UPGRIS club. Suggestion, hand muscle strength training, muscle endurance and balance are used as training media so that they can help athletes improve shooting accuracy.

Purpose Cerebellar connectivity is thought to be abnormal in cervical dystonia (CD) and other dystonia subtypes, based on evidence from imaging studies and animal work. The authors investigated whether transcranial magnetic stimulation-induced cerebellar brain inhibition (CBI), a measure of cerebellar efficiency at inhibiting motor outflow, is abnormal in patients with CD and/or is associated with clinical features of CD. Because of methodological heterogeneity in CBI reporting, the authors deployed additional controls to reduce potential sources of variability in this study. Methods Cerebellar brain inhibition was applied in 20 CD patients and 14 healthy control subjects. Cerebellar brain inhibition consisted of a cerebellar conditioning stimulus delivered at four different interstimulus intervals (ISIs) before a test stimulus delivered to hand muscle representation in the motor cortex. The average ratio of conditioned to unconditioned motor evoked potential was computed for each ISI. Cervical dystonia clinical severity was measured using the Toronto Western Spasmodic Torticollis Rating Scale. Control experiments involved neuronavigated transcranial magnetic stimulation, neck postural control in patients, and careful screening for noncerebellar pathway inhibition via cervicomedullary evoked potentials. Results There was no difference between CBI measured in healthy control subjects and CD patients at any of the four ISIs; however, CBI efficiency was significantly correlated with worsening CD clinical severity at the 5 ms ISI. Conclusions Cerebellar brain inhibition is a variable measure in both healthy control subjects and CD patients; much of this variability may be attributed to experimental methodology. Yet, CD severity is significantly associated with reduced CBI at the 5 ms ISI, suggestive of cerebello-thalamo-cortical tract dysfunction in this disorder.

Our current understanding of synergistic muscle control is based on the analysis of muscle activities. Modules (synergies) in muscle coordination are extracted from electromyographic (EMG) signal envelopes. Each envelope indirectly reflects the neural drive received by a muscle; therefore, it carries information on the overall activity of the innervating motor neurons. However, it is not known whether the output of spinal motor neurons, whose number is orders of magnitude greater than the muscles they innervate, is organized in a low-dimensional fashion when performing complex tasks. Here, we hypothesized that motor neuron activities exhibit a synergistic organization in complex tasks and therefore that the common input to motor neurons results in a large dimensionality reduction in motor neuron outputs. To test this hypothesis, we factorized the output spike trains of motor neurons innervating 14 intrinsic and extrinsic hand muscles and analyzed the dimensionality of control when healthy individuals exerted isometric forces using seven grip types. We identified four motor neuron synergies, accounting for >70% of the variance of the activity of 54.1 ± 12.9 motor neurons, and we identified four functionally similar muscle synergies. However, motor neuron synergies better discriminated individual finger forces than muscle synergies and were more consistent with the expected role of muscles actuating each finger. Moreover, in a few cases, motor neurons innervating the same muscle were active in separate synergies. Our findings suggest a highly divergent net neural inputs to spinal motor neurons from spinal and supraspinal structures, contributing to the dimensionality reduction captured by muscle synergies. SIGNIFICANCE STATEMENT We addressed whether the output of spinal motor neurons innervating multiple hand muscles could be accounted for by a modular organization, i.e., synergies, previously described to account for the coordination of multiple muscles. We found that motor neuron synergies presented similar dimensionality (implying a >10-fold reduction in dimensionality) and structure as muscle synergies. Nonetheless, the synergistic behavior of subsets of motor neurons within a muscle was also observed. These results advance our understanding of how neuromuscular control arises from mapping descending inputs to muscle activation signals. We provide, for the first time, insights into the organization of neural inputs to spinal motor neurons which, to date, has been inferred through analysis of muscle synergies.

We call a hemiparetic hand with paralyzed finger extensors and volitional but spastic flexors a "spastic combination hand." Anecdotally, patients report hand-as-a-holder function with objects like pill bottles, motivating us to formally study spastic combination hand holding capacity using cylinders with different diameters. Nine participants with spastic hemiparesis and spastic combination hand more than 24 mos performed a standardized motor task with 10 cylinder diameters ranging between 1.3 and 9.5 cm and weighing 0.8 and 8.4 oz. Using the unaffected hand, participants attempted to insert a given cylinder into their spastic combination hand, holding it independently for 5 secs. Successful holds were counted during two sessions before and one session after botulinum toxin intervention of Ashworth 3 hand muscles. Findings revealed that a median capacity of six different cylinder diameters was successfully inserted into spastic combination hand at least once before block and a median capacity of 10 cylinders was inserted after block. A mixed-effect statistical model using fixed effects of cylinder diameter and session revealed that total number of successful holds was 43% higher after botulinum. We conclude that this proof-of-concept study does support the idea that spastic combination hand has holding capacity for cylindrical objects of specified diameter and weight and that botulinum neurotoxin offers potential for enlarging spastic combination hand capacity.

STUDY DESIGN This is a cross-sectional descriptive study. OBJECTIVES To quantify differences in hand muscle morphology between persons with cervical spinal cord injury (SCI) and uninjured adults. SETTING The study was performed at the Guangdong Work Injury Rehabilitation Hospital. METHODS We quantified hand muscle cross-sectional area (CSA), thickness, and echo intensity (EI) in 18 persons with subacute to chronic SCI and 23 controls using ultrasound imaging. RESULTS Mean SCI abductor pollicis brevis (APB), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) CSA were ~26%, 43%, and 37% smaller than the control means, the deficit in the APB being less than the ADM (P

Background: Literature shows that intensive Functional Electrical Stimulation facilitates upper limb motor recovery after Stroke. Aim: To assess the effects of 4 weeks of FES therapy on right upper limb motor functions in patient with Chronic Stroke. Materials and Methods: The participant was thirty year old male Right Hemiparesis who had experienced Chronic Ischemic Stroke. FES therapy was given for forty five minutes per session, three sessions a week for complete four weeks. The pre and post intervention score were measured with Fugl Meyer Assessment, Voluntary Control Grading and MAS. Results: The Fugl Meyer Assessment score for right upper limb showed improvement with progression in stage of VCG for right upper limb and hand. Also improved MAS score was noted for right shoulder, elbow and hand muscles. Conclusion: The current study confirms that application of FES therapy improves upper limb motor functions in Chronic stage of Stroke after 4 weeks.

Individuals with stroke show distinct differences in hand function impairment when the shoulder is in adduction, within the workspace compared to when the shoulder is abducted, away from the body. To better understand how shoulder position affects hand control, we tested the corticomotor excitability and intracortical control of intrinsic and extrinsic hand muscles important for grasp in twelve healthy individuals. Motor evoked potentials (MEP) using single and paired-pulse transcranial magnetic stimulation were elicited in extensor digitorum communis (EDC), flexor digitorum superficialis (FDS), first dorsal interosseous (FDI), and abductor pollicis brevis (APB). The shoulder was fully supported in horizontal adduction (ADD) or abduction (ABD). Separate mixed-effect models were fit to the MEP parameters using shoulder position (or upper-extremity [UE] side) as fixed and participants as random effects. In the non-dominant UE, EDC showed significantly greater MEPs in shoulder ABD than ADD. In contrast, the dominant side EDC showed significantly greater MEPs in ADD compared to ABD; %facilitation of EDC on dominant side showed significant stimulus intensity x position interaction, EDC excitability was significantly greater in ADD at 150% of the resting threshold. Intrinsic hand muscles of the dominant UE received significantly more intracortical inhibition (SICI) when the shoulder was in ADD compared to ABD; there was no position-dependent modulation of SICI on the non-dominant side. Our findings suggest that these resting-state changes in hand muscle excitabilities reflect the natural statistics of UE movements, which in turn may arise from as well as shape the nature of shoulder-hand coupling underlying UE behaviors.

Background: The manual muscle test (MMT) is the traditional method to assess the intrinsic hand muscle test. However, this test is qualitative and subjective. A device capable of rapidly measuring motor output along a linear scale may be of value in the evaluation of hand recovery from any neurological impairment. Objective: To demonstrate inter-rater reliability of the Peg Restrained Intrinsic Muscle Evaluator (PRIME) device for measuring intrinsic hand muscle strength in adults with impaired hand functions. Methods: 16 subjects (2 female, 14 male, mean age=47±15 years) with cervical spinal cord injury were enrolled. Intrinsic hand muscle strength of adults were performed by two-tester with use of PRIME device and manual muscle testing, within the same session. Inter-tester correlation was tested by Pearson's correlation and Intraclass correlation coefficient (ICC). Results: Intraclass correlation coefficients for hypothenar, first dorsal interosseous, abductor pollicis brevis and opponence pollicis muscles ranged from 0.7 to 0.8 with hypothenar muscle test being lowest ICC=0.7 and thumb opposition highest, ICC=0.81. Conclusion: Results from this study suggest that PRIME device demonstrates good reliability within testers for quantified measuring of intrinsic hand muscle strength. Further use of PRIME in clinic will aid in diagnostics, medical decision making and evaluation of rehabilitation progress in patients with cervical spinal cord injury.

A dynamic splint is superior to traditional static splint, offering more benefits such as reduced spasticity, allowing comfortable stretch, repositioning fingers in extension positions, and increasing hand performance. This paper suggested the development of a dynamic splint based on a pulley rotation with a locking system as a home rehabilitation device to reduce hand spasticity in stroke patients. Moreover, this study consisted of two main activities: simulation using finite element analysis and clinical experimental trials. Eight stroke patients participated in 4 weeks of intervention using the proposed dynamic splint for a combined total of least 3 hours per day at home. Outcome measures included Fugl-Meyer Assessment (FMA) and Modified Modified Ashworth Scale (MMAS) at baseline, 2 weeks, and 4 weeks. After 4 weeks of wearing, participants were also asked to fill out a satisfaction questionnaire. The results showed that wearing this proposed dynamic splint over 4 weeks, the hand function of participants increased significantly(p < 0.05), and the spasticity of the hand muscles decreased significantly(p < 0.05). With an overall rating of 8 out of 10 points, stroke participants had a high level of satisfaction with this home-use dynamic splint. The findings indicated that stroke patients who used this proposed splint showed substantial changes in hand function and reduced hand spasticity.

Objective. There is a debate over the relevance of ultrasound abnormalities to the pain, functional impairment, and radiologic severity in hand osteoarthritis (OA). This study aims to determine the association between ultrasound abnormalities and clinical, functional, and radiographic measures in hand OA. Methods. A total of 66 patients was consecutively enrolled. All patients with gray-scale synovitis, joint effusion, and osteophytes were examined by ultrasound for 20 hand joints. Radiographic changes in both hands were evaluated by the Kellgren-Lawrence (K-L) grading system and were described as total radiographic severity score and number of affected joints. Other measures were also assessed, including each patient’s visual analogue scale for pain, the Functional Index for Hand Osteoarthritis for functional disability, and grip and pinch strength for hand muscle strength. Results. In total, 10 patients with gray-scale synovitis, 35 with joint effusion, and 66 with osteophytes were detected in hand OA scans on ultrasound. Osteophytes on ultrasound were significantly associated with total radiographic severity score and number of affected joint (r=0.293, p=0.003 and r=0.336, p＜0.001, respectively). In addition, there were weak associations of synovitis and joint effusion with radiographic changes. Patients with higher total radiographic severity score showed larger number of ultrasound-detected abnormalities, such as synovitis, joint effusion, and osteophytes (p=0.011, p=0.002, and p＜0.001, respectively). Conclusion. This study shows that ultrasound findings, especially osteophytes, were associated with radiographic changes based on K-L grade, but not clinical and functional status in hand OA. (J Rheum Dis 2021;28:17-24)

Introduction: the aim of this study was to assess the relationship between ultrasonographic hand muscle thickness measurements and hand muscle strength in patients who underwent median or ulnar nerve reconstruction. Methods: in this prospective, cross-sectional study, intrinsic hand muscle thicknesses were measured using ultrasound with a 4- to 13-MHz linear-array probe. Measurements of hand strength were performed using a dynamometer and a pinchmeter. Results: in the median nerve group (n = 11), a moderate correlation (r = 0.694; P =.018) was observed between lateral pinch strength and transverse thenar thickness. In the ulnar nerve group (n = 11), longitudinal thenar thickness below the flexor pollicis longus tendon was moderate to highly correlated with pinch and handgrip strengths (r = 0.726-0.893; P, NA

This is a correlational research. The population of this research is all students participating in the badminton extracurricular at SMAN 06 Mukomuko 25 students. The sampling is done by using total sampling method which result in 25 male students. The data collection techniques are : 1) hand power is tested by one hand medicine ball put, 2) wrist flexibility is measured by using arc-ruler, 3) jumping smash hit skill is tested by using badminton court with grading boxes. The data is analysed by product moment correlation and dual correlation with α = 0.05 significance. The result of the data analysis are : 1) There is a significant relation between hand muscle power and students jumping smash hit skill in badminton extracurricular class at SMAN 06 Mukomuko, Bengkulu and the contribution is 39,19%, 2) There is significant relation between wrist flexibility and the students jumping smash hit skill and the contribution is 38,69%, 3) There is significant contribution of both muscle power and wrist flexibility to the students jumping smash hit skill as much as 55,65%.

Dari hasil observasi, ditemukan berbagai permasalahan yaitu, rendahnya kemampuan menulis peserta didik, kurang terlatihnya otot-otot tangan sehingga peserta didik cepat merasa letih ketika menulis. Tujuan dari penelitian ini adalah menganalisis data kuantitatif untuk mengetahui sejauhmana efektifitas metode graphomotor terhadap kemampuan menulis peserta didik. Jenis penelitian ini adalah penelitian kuantitatif eksperimen, dengan desain Pre Experimental Design. Hasil analisis data pre-test post-test dengan menggunakan rumus statistik uji t menunjukkan bahwa metode graphomotor efektif meningkatkan kemampuan menulis peserta didik. Ini terbukti setelah dianalisis dengan menggunakan rumus statistik uji t diperoleh harga thitung > ttabel yaitu 21,56 > 2,12 dengan db =17 pada taraf signifikan 5 %

Study Design Case report. Introduction A severe wrist fracture can cause permanent physical disabilities and deformities, leading to limit patients in their occupation and social environment. Purpose of the Study We aim at presenting a treatment protocol and the functional outcome of a patient with severe clinical state after a rare wrist fracture. Methods We provided physical therapy intervention associated with serious games for muscle strengthening. Results and Discussion There was an increase in strengthening and a decrease in Disability of the Arm, Shoulder and Hand score and Patient Rated Wrist Evaluation scores. The International Classification of Functioning scores have changed from severe to light or to absent in many of the domains. Conclusion The use of serious games combined with a conventional physical therapy intervention played a fundamental role in recovery and return to work activities, and there was also an important recovery of general health condition.

The study purpose: To determine the relationship between hand muscle strength and shoulder muscle strength with the ability to punch straight ahead of Karate extracurricular members at SDN 07 Cipinang Melayu. Materials and methods: This research is a correlation study AND the population of this study is 20 students. The instruments used in this research are hand muscle strength using hand grib dynamometer or handheld dynamometer, for shoulder muscle strength survey using Expanding Dynamometer, to survey strokes with inner tube rubber bearings. Results: There is a significant relationship between hand muscle strength and the ability to hit straight ahead with t count 3.163>ttable 1.729, there is a significant relationship between shoulder muscle strength and straight forward punch ability with t count 2, 874>ttable 1.729, there is a relationship which is significant between hand muscle strength, shoulder muscle strength with the ability of a straight forward punch t count 5,311> ttable 3,125. Conclusions: There is a significant relationship between hand muscle strength, shoulder muscle strength and the ability to punch straight ahead of the Karate extracurricular members at SDN 07 Cipinang Melayu.

Purpose Targeted muscle reinnervation (TMR) has emerged as a treatment for, and prevention of, symptomatic neuromas and has been reported to be of benefit in the hand. Anatomical studies establishing landmarks for consistent identification of the motor entry points (MEPs) to the intrinsic muscles have not been performed. The purpose of this study was to provide details regarding the MEPs to the intrinsic muscles, determine which MEPs are identifiable dorsally, and develop recommended sensory to MEP nerve coaptations for prophylactic TMR at the time of ray amputation or for management of symptomatic neuromas. Methods Motor entry points to the intrinsic hand muscles were dissected in 5 fresh latex-injected cadavers. Number of MEPs, diameter, surface of entry, and distance from dorsal (Lister tubercle) and volar (hamate hook) landmarks were recorded for each target muscle. The digital sensory nerve diameters were measured for size comparison. Results Motor entry points were identified to all 19 intrinsic muscles through a volar approach and 12 through a dorsal approach. For all fingers, at least 2 MEPs were consistently identified dorsally at the base of each amputation site innervating expendable muscles. Motor entry points to the thenar muscles were only reliably identified through a volar approach. Two recommended nerve coaptations for each digit amputation were identified. All had a favorable sensory-to-MEP diameter ratio less than 2:1. Conclusions The intrinsic hand muscles have MEPs at consistent distances from bony landmarks both dorsally and volarly. Clinical relevance These results can be applied clinically to assist surgeons in identifying the locations of MEPs to the intrinsic muscles when performing TMR in the hand for both neuroma treatment and prevention.

Objective To explore the diagnostic accuracy of the split-hand index (SHI) for amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) using sonographic assessment of muscle thickness. Methods We performed a prospective sonographic assessment of hand muscle thickness in 59 controls, 87 patients with ALS, and 33 patients with SMA. We determined the diagnostic accuracy of SHI for differentiating patients with ALS and SMA from controls. Results Patients with ALS and SMA had significantly lower muscle thickness and SHI values compared with controls. SHI showed excellent diagnostic accuracy for differentiating ALS from controls, and good diagnostic accuracy for differentiating SMA from controls. Conclusions SHI determined by sonographic measurement of hand muscle thickness seems to be a promising tool for the diagnosis of ALS and may be added easily when performing neuromuscular ultrasound. Significance SHI determined by sonographic measurement of hand muscle thickness can differentiate between healthy subjects and patients with ALS and SMA.

It is believed that exposure to whole-body vibration (WBV) may increase seated occupant drowsiness and seated. The purpose of this paper is to investigate the strength of the hand grip among the young adults in Malaysia. Also, to examine the correlation between anthropometry factors such as hand length (HL), hand breadth (HB), wrist circumference (WC) and body mass index (BMI) with average full hand grip strength of young adults. 40 Malaysian young adults with equal females and males and the range age of 23 to 28 years old voluntarily basis participated in this study. Three experiments were conducted in sitting position according to American Standard Hand Therapist (ASHT) with 45º, 90o and 135o of hand flexion using dynamometer. The results show the significant different full hand grip strength between Malaysian young adult females and females, the difference full hand grip strength for different hand flexion angles in sitting position and difference correlations between anthropometry factors and full hand grip strength for both young adult males and females.

Background: The sawmill or lumber mill industry is mainly known as important small-scale industries in India, where thousands of sawmillers suffered from musculoskeletal pain and other health-related problems. The primary aim of the current study is to find out the subjective assessment of musculoskeletal disorders (MSDs) and occupational related health disorders among sawmill workers in India. Materials and Methods: The current descriptive study was direct on 135 sawmillers and 130 control subjects from different region of the Hooghly district, in India. To this end, the Nordic Musculoskeletal Questionnaire (NMQ) was administered to estimate the subjective discomfort feeling and Handgrip Strength were also measured to estimate the power of the hand muscle among the sawmillers and compare with control groups. Posture adopted frequently during working of the sawmillers were also analyzed by the Ovako Working Analysis System (OWAS). Results: The data indicated that the sawmill workers complained of discomfort (pain) felt maximum in low back part of the body (91) followed by hands (80), shoulders (76), knees (64), and the upper back (58). This study indicated that the sawmillers had less handgrip strength than the control subjects due to performing more hand intensive jobs. Conclusions: The results of current study indicate that the sawmill workers suffered from MSD due to working in a stooped, squatting posture for a long duration, which adversely affected their health.

Introduction: The number of older people in Indonesia continues to rise. Aging process will cause changes in organ systems, one of which is changes in the musculoskeletal system. One of the significant weakening of function in the elderly is the degrading strength of the handheld muscles, which resulted in a decrease of functional abilities. One method which can be used to increase hand muscle grip strength is by doing rubber ball exercise. Aim: To analyze the difference of hand muscle grip strength on pre- and post- performing rubber ball exercises in elderlies at St. Joseph Nursing Home in Surabaya. Method: This study is a pre-experimental analytic research with one group pretest – posttest design approach. The sampling technique used consecutive sampling, with a total sample of 48 elderlies. The interventions for rubber ball exercises were carried out three times a week for one month. Instruments used for this study were the MMSE and MNA-SF questionnaires. The hand muscle grip strength was measured using the Handgrip Dynamometer. data analysis was done using the SPSS program and the Chi-Square test. Results: The mean total value of the muscle grip strength pre-exercises was 10,8 ± 3,9 kg. The mean total value of the hand muscle grip strength post exercises was 11,97 ± 4,08 kg. The data analysis results show that there was a significant difference between pre- and postperforming rubber ball exercises on the elderly at St. Joseph nursing home in Surabaya. (p=0,025). Conclusion: There is a significant contrast between pre and post-performing rubber ball exercises on the elderly at St. Joseph nursing home in Surabaya.

Voluntary force declines during sustained, maximal voluntary contractions (MVC) due to changes in muscle and central nervous system properties. Central fatigue, an exercise-induced reduction in voluntary activation, is influenced by multiple processes. Some may occur independently of descending voluntary drive. To differentiate the effects associated with voluntary drive from other central and peripheral influences, we measured voluntary activation and motoneuron excitability following fatiguing contractions produced voluntarily or by electrical stimulation. On two separate days, participants performed either a 2-min MVC of adductor pollicis muscle or received 2-min continuous supramaximal electrical stimulation of the ulnar nerve. In study 1 (n = 14), the superimposed twitch elicited by ulnar nerve stimulation during brief MVCs was increased, and, hence, voluntary activation was reduced, up to 240 s after the 2-min MVC [−20 ± 12% (SD), P = 0.002] but not the 2-min stimulated contraction (−4 ± 7%), despite large reductions in MVC force (voluntary, −54 ± 18%; stimulated, −46 ± 16%). In study 2 (n = 12), F-waves recorded from the adductor pollicis were reduced in area for 150 s following the 2-min MVC (−21 ± 16%, P = 0.007) but not after the stimulated contraction (5 ± 27%). Therefore, voluntary activation and motoneuron excitability decreased only when descending voluntary drive was present during the fatiguing task. The findings do not exclude a cortical or brain stem contribution to the reduced voluntary activation but suggest that neither sensory feedback from the fatigued muscle nor repetitive activation of motoneurons underlie the changes, whereas they are consistent with motoneuronal inhibition by released factors linked to voluntary drive. NEW & NOTEWORTHY We demonstrate that reductions in voluntary activation and motoneuron excitability following 2-min isometric maximal contractions in humans occur only when fatigue is produced through voluntary contractions and not through electrically stimulated contractions. This is contrary to studies that suggest that changes in the superimposed twitch and therefore voluntary activation are explained by changes in peripheral factors alone. Thus, the interpolated twitch technique remains a viable tool to assess voluntary activation and central fatigue.

To make robotic hand devices controlled by surface electromyography (sEMG) signals feasible and practical tools for assisting patients with hand impairments, the problems that prevent these devices from being widely used have to be overcome. The most significant problem is the involuntary amplitude variation of the sEMG signals due to the movement of electrodes during forearm motion. Moreover, for patients who have had a stroke or another neurological disease, the muscle activity of the impaired hand is weak and has a low signal-to-noise ratio (SNR). Thus, muscle activity detection methods intended for controlling robotic hand devices should not depend mainly on the amplitude characteristics of the sEMG signal in the detection process, and they need to be more reliable for sEMG signals that have a low SNR. Since amplitude-independent muscle activity detection methods meet these requirements, this paper investigates the performance of such a method on people who have had a stroke in terms of the detection of weak muscle activity and resistance to false alarms caused by the involuntary amplitude variation of sEMG signals; these two parameters are very important for achieving the reliable control of robotic hand devices intended for people with disabilities. A comparison between the performance of an amplitude-independent muscle activity detection algorithm and three amplitude-dependent algorithms was conducted by using sEMG signals recorded from six hemiparesis stroke survivors and from six healthy subjects. The results showed that the amplitude-independent algorithm performed better in terms of detecting weak muscle activity and resisting false alarms.

Using a cross-sectional design, we aimed to identify the effect of aging on sensorimotor function and cortical motor representations of two intrinsic hand muscles, as well as the course and timing of those changes. Furthermore, the link between cortical motor representations, sensorimotor function, and intracortical inhibition and facilitation was investigated. Seventy-seven participants over the full adult lifespan were enrolled. For the first dorsal interosseus (FDI) and abductor digiti minimi (ADM) muscle, cortical motor representations, GABAA-mediated short-interval intracortical inhibition (SICI), and glutamate-mediated intracortical facilitation (ICF) were assessed using transcranial magnetic stimulation over the dominant primary motor cortex. Additionally, participants' dexterity and force were measured. Linear, polynomial, and piecewise linear regression analyses were conducted to identify the course and timing of age-related differences. Our results demonstrated variation in sensorimotor function over the lifespan, with a marked decline starting around the mid-thirties. Furthermore, an age-related reduction in cortical motor representation volume and maximal MEP of the FDI, but not for ADM, was observed, occurring mainly until the mid-forties. Area of the cortical motor representation did not change with advancing age. Furthermore, cortical motor representations, sensorimotor function, and measures of intracortical inhibition and facilitation were not interrelated. This work was supported by the Research Fund KU Leuven (C16/15/070), the Research Foundation Flanders grant (G089818N), the Excellence of Science grant (EOS 30446199, MEMODYN) and the Hercules fund AUHL/11/01 (R-3987) and I005018N. The authors declare no competing financial interests. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Cuypers, K (reprint author), Katholieke Univ Leuven, Dept Movement Sci, Grp Biomed Sci, Movement Control & Neuroplastic Res Grp, Leuven, Belgium; Hasselt Univ, REVAL Res Inst, Agoralaan, Diepenbeek, Belgium. koen.cuypers@kuleuven.be

Bilateral voluntary contractions involve functional changes in both primary motor cortices. However how the unilateral voluntary contraction of hand muscles influences the contralateral corticomuscular synchronous oscillations mechanisms remains unclear. In the bimanual tasks, nine healthy subjects were instructed to generate force by abducting their left-hand index finger against a force sensor and simultaneously the right-hand precise pinch task with visual feedback. They were divided into four conditions according to the two contraction force levels of the left-hand muscles 5% and 50% maximal isometric voluntary contraction (MVC) and with/without visual feedback for the right hand. Corticomuscular synchronization of the right hand in the beta band was revealed when the subjects performed the bimanual exercise with 5% MVC of left-hand muscles, which is consistent with previous studies. As the contraction strength of the left-hand muscle increased to 50% MVC, the corticomuscular coherence (CMC) frequency of the right hand shifted to gamma band, and the CMC in beta band decreased significantly (P < 0.05) in the electroencephalography→electromyography direction. This phenomenon suggests that the corticomuscular synchronous oscillation will shift from beta band to higher frequencies (principally gamma) as the contraction force of the contralateral hand increases, which may be due to the changes in the subject's attention and more frequent synchronization of neuromuscular motor neurons oscillations. These findings will be helpful to explore the hand motion control and feedback mechanisms, and further provide a basis for the application of neuromuscular coupling in clinical rehabilitation evaluation.Video abstract: http://links.lww.com/WNR/A571.

Introduction. A distinctive feature of the modern lifestyle of children and adolescents is insufficient physical activity having a negative effect on their health. We conducted a physical activity survey for 997 schoolchildren and 597 students of the city of Ufa. Results. The results showed that 688 respondents (43.16%) did not do sport outside school or university. 272 people (17.06%) reported jogging and playing sports games on their own. 634 respondents (39.78%) attended sports clubs and sections on a regular basis. The survey demonstrated that physically inactive students and schoolchildren violated daily routine. Such schoolchildren spent significantly more leisure time on television viewing (52.78%) compared to their peers attending sports clubs (41.36%). The percentage of schoolchildren spending much time on the computer among those not doing sport was also higher (58.59% vs 41.47%). The same trend was observed in the students: 36.24% of the students not practicing sport spent most of their leisure time on the computer. Physically active students spent enough time outdoors as compared to those not doing sport (23.40% vs 11.15%). Conclusions. The surveyed schoolchildren and students revealed age and gender differences in sports patterns. The duration of training and the level of sportsmanship was higher in boys than in girls. We also observed the increase with age in the number and duration of training, as well as the level of sportsmanship. The health status analysis showed that the schoolchildren and students doing sport had significantly more harmonious physical development, while disharmonious physical development was more common among physically inactive persons. The pupils and students practicing sport regularly showed higher lung vital capacity, hand muscle strength, and a higher level of adaptation.

Introduction We sought to evaluate the reproducibility of the motor unit number index (MUNIX) and MScanFit motor unit number estimation (MScan) when recording was performed over intrinsic hand muscles. Methods The compound muscle action potential (CMAP) amplitude, MUNIX, and MScan were measured from the abductor pollicis brevis (APB), first dorsal interosseous (FDI), and abductor digit minimi (ADM) muscles from 15 healthy volunteers on three different occasions. Results The reproducibility of CMAP amplitudes was excellent, with intraclass correlation coefficients (ICC) of 0.86 (APB), 0.90 (FDI), and 0.96 (ADM). Motor unit number index (ICCAPB 0.73, ICCFDI 0.85, ICCADM 0.85) and MScan (ICCAPB 0.86, ICCFDI 0.83, ICCADM 0.81) were highly reproducible across the three muscles. There were no significant correlations between MUNIX and MScan coefficients of variation (CV) and CMAP amplitude CVs. Discussion Reproducibility of MUNIX and MScan was not significantly different across the intrinsic hand muscles and was independent of CMAP amplitude variability.

Background: Functional abnormalities in multiple sclerosis may be due to a decrease in the level of physical activity of MS patients compared to healthy People. Exercise activity as a non-pharmacological method can have beneficial effects on the rehabilitation of these patients. Therefore, the purpose of present study was to investigate the effect of eight weeks of combined training on some indicators of physical and mental function in women with multiple sclerosis. Methods: Twenty women with multiple sclerosis were randomly divided into experimental and control group that only 16 subjects (8 in the training group and 8 in the control group) were able to complete all stages of this study. The training group participated in eight weeks and three days per week in combined training program (contains rhythmic aerobic and resistance training by bodyweight, Theraband, and TRX). Muscles strength, endurance and speed of walking, and psychological induces were evaluated in pre- test and post-test. Independent and paired samples T-test were used for data analysis. Results: Combined training resulted in a significant increase in quadriceps and hand muscles strength, endurance and speed of walking, and also significant decrease in depression and anxiety levels (P˂0.05). However, no significant difference was observed in the fingers strength (P˃0.05). Conclusion: It seems that combined training used in present study can be effective in increasing muscle strength, motor function, and decreasing depression and anxiety in women with multiple sclerosis. Therefore, the use of this training method at the club and home is recommended for these patients.

Handgrip Dynamometer is a tool used to view the strength of the hand muscles post-stroke patients. In this study Handgrip Dynamometer created to look at the hand grip strength in real time and find out the hand grip strength criteria, there are three indicators: the criteria of mild, moderate or strong. Handgrip dynamometer using the Arduino Uno control over the entire system and Load Cell as a sensor. Load Cell Output will be boosted by Analog Signal conditioner HX711 and then processed in the microcontroller, then will be displayed on the LCD. Berdasarlan weight measurement results obtained by the result of error by 0% By comparison to using weights, sehingga can be concluded that the tool can be used according to its function.

Mechanical perturbations in one upper limb often elicit corrective responses in both the perturbed as well as its contralateral and unperturbed counterpart. These crossed corrective responses have been shown to be sensitive to the bimanual requirements of the perturbation, but crossed responses (CRs) in hand muscles are far less well studied. Here, we investigate corrective CRs in an intrinsic hand muscle, the first dorsal interosseous (1DI), to clockwise and anticlockwise mechanical perturbations to the contralateral index finger while participants performed a bimanual finger abduction task. We found that the CRs in the unperturbed 1DI were sensitive to the direction of the perturbation of the contralateral index finger. However, the size of the CRs was not sensitive to the amplitude of the contralateral perturbation nor its context within the bimanual task. The onset latency of the CRs was too fast to be purely transcortical ( NEW & NOTEWORTHY An intrinsic hand muscle shows a crossed response to a perturbation of the contralateral index finger. The crossed response is dependent on the direction of the contralateral perturbation but not on the amplitude or the bimanual requirements of the movement, suggesting a far less flexible control policy than those governing crossed responses in more proximal muscles. The crossed response is too fast to be purely mediated by transcortical pathways, suggesting subcortical contributions.

In this study, we address the issue of whether vibrotactile feedback can enhance the motor cortex excitability translated into the plastic changes in local cortical areas during motor imagery (MI) BCI-based training. For this purpose, we focused on two of the most notable neurophysiological effects of MI – the event-related-desynchronization (ERD) level and the increase in cortical excitability assessed with navigated transcranial magnetic stimulation (nTMS). For TMS navigation, we used individual high-resolution 3D brain MRIs. Ten BCI-naive and healthy adults participated in this study. The MI (rest or left/right hand imagery using Graz-BCI paradigm) tasks were performed separately in the presence and absence of feedback. To investigate how much the presence/absence of vibrotactile feedback in MI BCI-based training could contribute to the sensorimotor cortical activations, we compared the MEPs amplitude during MI after training with and without feedback. In addition, the ERD levels during MI BCI-based training were investigated. Our findings provide evidence that applying vibrotactile feedback during MI training leads to (i) an enhancement of the desynchronization level of mu-rhythm EEG patterns over the contralateral motor cortex area corresponding to the MI of the non-dominant hand; (ii) an increase in motor cortical excitability in hand muscle representation corresponding to a muscle engaged by the MI.

Hand movement is controlled by a large number of muscles acting on multiple joints in the hand and forearm. In a forearm amputee the control of a hand prosthesis is traditionally depending on electromyography from the remaining forearm muscles. Technical improvements have made it possible to safely and routinely implant electrodes inside the muscles and record high-quality signals from individual muscles. In this study, we present a database of intramuscular EMG signals recorded with fine-wire electrodes alongside recordings of hand forces in an isometric setup and with the addition of spike-sorted metadata. Six forearm muscles were recorded from twelve able-bodied subjects and nine forearm muscles from two subjects. The fully automated recording protocol, based on command cues, comprised a variety of hand movements, including some requiring slowly increasing/decreasing force. The recorded data can be used to develop and test algorithms for control of a prosthetic hand. Assessment of the signals was done in both quantitative and qualitative manners., Measurement(s)muscle electrophysiology trait • muscle contractionTechnology Type(s)micro electrode • strain gaugesFactor Type(s)age • muscleSample Characteristic - OrganismHomo sapiens Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11310011

The first aim of this study was to compare an incidence of sarcopenia in patients with chronic obstructive pulmonary disease (COPD) when using updated (2018) the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm compared to the previous version (2010). The second aim was to determine relationships between clinical and functional parameters of COPD and parameters of sarcopenia. Methods . The study involved 86 stable COPD patients (68 males; mean age, 66.6 ± 8.7 years). The diagnosis of COPD was made according to GINA 2019. Sarcopenia was diagnosed according to EWGSOP guidelines 2010 and 2018. Muscle mass was assessed using dual-energy Xray absorptiometry (DXA). Results . Walking speed was measured in all patients according to EWGSOP guideline 2010. Additionally, hand muscle strength was measured in patients with walking speed > 0.8 m/s (n = 25). DXA was required to 72% of patients to confirm the diagnosis of sarcopenia. Sarcopenia was defined in 38 (44.1%) patients including severe sarcopenia in 20 (23.3%). According to results of SARC-F questionnaire, further hand muscle strength measurement was required to 64 patients and DXA was required to 51 (59.3%) patients. As a result, sarcopenia was confirmed in 38 (44.1%) patients including severe sarcopenia in 34 (39.5%) patients. The incidence of sarcopenia was higher in patients with more severe symptoms of COPD and more severe bronchial obstruction ( р = 0.001), and in patients with emphysema ( р < 0.03). Conclusion . The incidence of sarcopenia in COPD patients did not differ when used different diagnostic algorithms (EWGSOP, 2010 vs 2018) and was 44.1%. The need in additional tests, including expensive tests, was lower and the incidence of sarcopenia was higher (39.5% vs 23.3%) following the EWGSOP algorithm, 2018, compared to that of 2010. The incidence of sarcopenia increased in more severe COPD, in patients with emphysema, severe clinical symptoms, severe and very severe bronchial obstruction. The incidence of sarcopenia was not related to the patient’s age.

Background: Parkinson’s disease (PD) is the third most common neurodegenerative disease in the central nervous system. It is a degenerative and slowly progressive disease. PD patients have difficulty at the beginning of the movement, at the path of movement, and at the end of the movement. PD consists of 5 main stages. Methods: The purpose of this study was to diagnose PD type 1 and 2 on the electrical activity of shoulder muscle during isometric contraction with and without intellectual activity. In the same way, the electrical activity of the 2 right anterior deltoid muscles and the right upper trapezium by electromyographic apparatus in 4 conditions: (1) Resting, (2) Resting with intellectual activity, (3) performing an isometric movement in the hands, and (4) performing a movement Isometric in hand with an intellectual activity evaluated. The statistical population of the study consisted of 20 patients as experimental group (10 patients in the first stage and 10 patients in the second stage of PD) and ten healthy subjects as the control group as the statistical population. Shapiro-Wilk test was used to determine the normal distribution of data. Averages of variables were compared using the ANOVA test at a significant level of 5%. All statistical methods were performed using SPSS software. Results: The results of this study showed that the electrical activity of the shoulder belt muscles is significantly different during and after the isometric contraction with and without mental activity in PD type I and II. Conclusion: As a result, a non-invasive approach to assessing the electrical activity of shoulder muscle can be used to determine the first and second stages of PD. Research shows that PD is a chronic and progressive complication that most affects older people. Also, according to the results, Parkinson’s patients have weaker performance in cognitive functions than healthy people.

Introduction. Coexistent involvement of upper and lower motor neurons is a characteristic feature of amyotrophyc lateral syndrome (ALS) necessary for the diagnosis. Diagnosis of upper motor neuron involvement in ALS is based solely on clinical features, which may not be detected at the disease onset and in rare forms manifesting clinically as the local lower motor neuron syndrome (LLMNS). The main method of assessment of the functional state of the upper motor neuron in ALS is transcranial magnetic stimulation (TMS). It allows assessing the excitability of motor cortex, corticospinal path function, and mapping of cortical representation of the muscles. In patients with ALS changes of various indicators demonstrating hyperexcitability as well as degenerative lesions of the motor cortex and the corticospinal tracts are recorded on TMS. Objective: to discuss changes in the TMS in patients with LAS, pathophysiological mechanisms of their formation and possible diagnostic value. Results. In 22 patients with LLMNS, navigation TMS revealed disturbances of intracortical suppression on paired stimulation with recording period of silence, increase of motor threshold in dominant hemisphere, decrease of the weighted square and reorganization of cortical representations of the hand muscles. Conclusion. The data obtained allow to consider navigation TMS as a promising technology for identifying upper motor neuron involvement in patients with ALS., №2 (2018)