hand dexterity

Occupations including first responders and military require manual tasks; therefore changes in hand strength and dexterity could affect performance. We hypothesised that pinch strength, grip strength, and dexterity will change after unloaded and loaded exercise. Twenty-four male (25 ± 4.0 yrs; 86.3 ± 9.3 kg) and 10 female (25 ± 6.0 yrs; 62.1 ± 5.9 kg) participants completed 3 conditions for 5 minutes: (1) no exercise (2) run with no load at 3...

Teaching microsurgery is limited by the availability of appropriate training models. In-vivo models, such as rats, remain the gold standard, but ethical and economic limitations restrict their use for initial training. This study investigated the feasibility of using egg membrane as an inert model, an accessible and economical alternative for introduction to microsurgery. The specifications for inert models include ease of access, low cost, high reproducibility and realistic reproduction of relevant characteristics...

BACKGROUND: Spinal epidural abscess (SEA) is a rare condition that may result in catastrophic outcomes. On the other hand, calcium pyrophosphate (CPP) deposition disease (CPPD) causes inflammatory arthritis. Spinal involvement of a crystal-induced inflammation caused by CPPD is also common. Surgery is a common risk factor for both SEA and CPPD; however, the postoperative acute onset of SEA complicated with CPPD is extremely rare. CASE DESCRIPTION: A man in his 70s presented to our hospital, complaining of right upper limb weakness, loss of dexterity, and gait disturbance...

BACKGROUND: Knowing how impaired manual dexterity and finger proprioception affect upper limb activity capacity is important for delineating targeted post-stroke interventions for upper limb recovery. OBJECTIVES: To investigate whether impaired manual dexterity and finger proprioception explain variance in post-stroke activity capacity, and whether they explain more variance than conventional clinical assessments of upper limb sensorimotor impairments. METHODS: Activity capacity and hand sensorimotor impairments were assessed using clinical measures in N = 42 late subacute/chronic hemiparetic stroke patients...

OBJECTIVE: Hand clumsiness and reduced hand dexterity can signal early signs of degenerative cervical myelopathy (DCM). While the 10-second grip and release (10-s G&R) test is a common clinical tool for evaluating hand function, a more accessible method is warranted. This study explores the use of deep learning-enhanced hand grip and release test (DL-HGRT) for predicting DCM and evaluates its capability to reduce the duration of the 10-s G&R test. METHODS: The retrospective study included 508 DCM patients and 1,194 control subjects...

Existing electromyographic (EMG) based motor intent detection algorithms are typically user-specific, and a generic model that can quickly adapt to new users is highly desirable. However, establishing such a model remains a challenge due to high inter-person variability and external interference with EMG signals. In this study, we present a feature disentanglement approach, implemented by an autoencoder-like architecture, designed to decompose user-invariant, motor-task-sensitive high-level representations from user-sensitive, task-irrelevant representations in EMG amplitude features...

BACKGROUND AND OBJECTIVE: Motor function plays a critical role in everyday activities, from basic self-care tasks to complex activities that require precision and dexterity. This study was conducted to investigate the effects of transcranial direct current stimulation (tDCS) on grip strength and hand dexterity in healthy individuals. METHOD: We conducted a double-blind randomized clinical trial with two groups of sham and active tDCS. The anode was fixed over the primary motor cortex area M1 on the C3 point...

INTRODUCTION: The red nucleus is part of the motor system controlling limb movements. While this seems to be a function common in many vertebrates, its organization and circuitry have undergone massive changes during evolution. In primates, it is sub-divided into the magnocellular and parvocellular parts that give rise to rubrospinal and rubro-olivary connection, respectively. These two subdivisions are subject to striking variation within the primates and the size of the magnocellular part is markedly reduced in bipedal primates including humans...

The human hand possesses both consolidated motor skills and remarkable flexibility in adapting to ongoing task demands. However, the underlying mechanisms by which the brain balances stability and flexibility remain unknown. In the absence of external input or behavior, spontaneous (intrinsic) brain connectivity is thought to represent a prior of stored memories. In this study, we investigated how manual dexterity modulates spontaneous functional connectivity in the motor cortex during hand movement. Using magnetoencephalography (MEG), in 47 human participants (both sexes) we examined connectivity modulations in the alpha and beta frequency bands at rest and during two motor tasks ( i...

Sinaflex robotic telesurgery system has been introduced recently to provide ergonomic postures for the surgeon along with dexterous workspace for robotic telesurgery. The robot is described, and the forward and inverse kinematics are derived and validated by an experiment. The robot and operational workspaces and their dexterity are investigated and compared using the data collected during a dog vasectomy robotic telesurgery by Sinaflex . According to the simulation results, the workspace of the end effector is as large as 914...

INTRODUCTION: Cerebral palsy (CP) is the predominant cause of children disability. It is characterized by motor, sensory, and postural deficits due to a non-progressive injury to the developing central nervous system. In recent years, new rehabilitation techniques targeting the central representations of motor patterns have been introduced: the most used are action observation therapy (AOT), motor imagery (MI), and mirror therapy (MT). Aim of this study is to assess the effectiveness of these cognitive strategies on the recovery of upper limb motor functions in children with CP...

BACKGROUND: Recent technological advancements present promising opportunities to enhance the frequency and objectivity of functional assessments, aligning with recent stroke rehabilitation guidelines. Within this framework, we designed and adapted different manual dexterity tests in extended reality (XR), using immersive virtual reality (VR) with controllers (BBT-VR-C), immersive VR with hand-tracking (BBT-VR-HT), and mixed-reality (MD-MR). OBJECTIVE: This study primarily aimed to assess and compare the validity of the BBT-VR-C, BBT-VR-HT and MD-MR to assess post-stroke manual dexterity...

OBJECTIVES: To evaluate the most effective method for mechanical inter-dental plaque removal between inter-dental brushes (IDB) and dental floss (DF), in addition to toothbrushing in patients affected by peri-implant mucositis (PIM); to identify possible factors related to the patient or to the single implant-supported element that could influence plaque accumulation and inflammation of peri-implant tissues. METHODS: Forty patients with PIM were recruited. They were randomly assigned to two different groups depending on inter-dental device used (IDB or DF)...

OBJECTIVE: The course of cognitive aging is influenced by multiple health factors. This cross-sectional study investigated the interactive relations between body mass index (BMI), maximum oxygen consumption (VO2max), and sex on neuropsychological outcomes in community-dwelling predominantly older adults. METHODS: Participants were 164 healthy adults [M (SD) = 64.6 (12.5) years, 56% men, 87% white] who participated in an investigation of cardiovascular risk factors and brain health...

OBJECTIVE: Musician's focal hand dystonia is a painless task-specific focal dystonia, which presents with involuntary movements, abnormal postures, and loss of fine motor dexterity. We report here the case of a 63-year-old male, percussionist, with african ethnicity, with musician's focal hand dystonia who was treated with botulinum toxin, and describe the results at 4-weeks follow up. METHODS: Clinical examination and video analysis revealed abnormal flexion of the 3rd finger, followed by flexion of the 4th and 5th fingers while playing the congas...

Primate brain evolution has involved prominent expansions of the cerebral cortex, with largest effects observed in the human lineage. Such expansions were accompanied by fine-grained anatomical alterations, including increased cortical folding. However, the molecular bases of evolutionary alterations in human sulcal organization are not yet well understood. Here, we integrated data from recently completed large-scale neuroimaging genetic analyses with annotations of the human genome relevant to various periods and events in our evolutionary history...

Touch sensation from the glabrous skin of the hand is essential for precisely controlling dexterous movements, yet the neural mechanisms by which tactile inputs influence motor circuits remain largely unexplored. By pairing air-puff tactile stimulation on the hand's glabrous skin with transcranial magnetic stimulation (TMS) over the primary motor cortex (M1), we examined the effects of tactile stimuli from single or multiple fingers on corticospinal excitability and M1's intracortical circuits. Our results showed that when we targeted the hand's first dorsal interosseous (FDI) muscle with TMS, homotopic (index finger) tactile stimulation, regardless of its point (fingertip or base), reduced corticospinal excitability...

INTRODUCTION: Although clinical and functional impairments in the lower limbs have been extensively studied in patients with MS, the upper limb (UL) are also frequently affected. Clinical impairment of the UL in patients with MS is very common with muscle strength and hand dexterity as critical factors in maintaining functional activities that are the basis for independence and quality of life in people with MS. OBJECTIVE: To investigate the effects of a training protocol using the Powerball® system in combination with conventional physiotherapy on muscle strength, coordination, fatigue, functionality, and quality of life in persons with MS over an 8-week period...

BACKGROUND: Decreased endogenous melatonin concentrations in people with multiple sclerosis (PwMS) are associated with fatigue and pain that impair postural balance and muscle strength. Melatonin ingestion had analgesic and anti-fatigue effects. However, the acute effect of exogenous melatonin on dynamic postural stability and muscle strength has not been studied yet in PwMS. This study aimed to investigate the safety and the efficacy of a nighttime melatonin intake on dynamic postural balance and lower-extremity muscle strength the following morning in PwMS...

INTRODUCTION: The sensorimotor integrations subserving object-oriented manipulative actions have been extensively investigated in non-human primates via direct approaches, as intracortical micro-stimulation (ICMS), cytoarchitectonic analysis and anatomical tracers. However, the understanding of the mechanisms underlying complex motor behaviors is yet to be fully integrated in brain mapping paradigms and the consistency of these findings with intraoperative data obtained during awake neurosurgical procedures for brain tumor removal is still largely unexplored...