Query: extension finger

title: An Attention Controlled Hand Exoskeleton for the Rehabilitation of Finger Extension and Flexion Using a Rigid Soft Combined Mechanism
abstract: Hand rehabilitation exoskeletons are in need of improving key features such as simplicity, compactness, bi directional actuation, low cost, portability, safe human robotic interaction, and intuitive control. This article presents a brain controlled hand exoskeleton based on a multi segment mechanism driven by a steel spring. Active rehabilitation training is realized using a threshold of the attention value measured by an electroencephalography (EEG) sensor as a brain controlled switch for the hand exoskeleton. We present a prototype implementation of this rigid soft combined multi segment mechanism with active training and provide a preliminary evaluation. The experimental results showed that the proposed mechanism could generate enough range of motion with a single input by distributing an actuated linear motion into the rotational motions of finger joints during finger flexion/extension. The average attention value in the experiment of concentration with visual guidance was significantly higher than that in the experiment without visual guidance. The feasibility of the attention based control with visual guidance was proven with an overall exoskeleton actuation success rate of 95.54% (14 human subjects) In the exoskeleton actuation experiment using the general threshold, it performed just as good as using the customized thresholds; therefore, a general threshold of the attention value can be set for a certain group of users in hand exoskeleton activation.

title: Real time isometric finger extension force estimation based on motor unit discharge information.
abstract: The goal of this study was to perform real time estimation of isometric finger extension force using discharge information of motor units (MUs)  A real time electromyogram (EMG) decomposition method based on the fast independent component analysis (FastICA) algorithm was developed to extract MU discharge events from high density (HD) EMG recordings. The decomposition was first performed offline during an initialization period, and the obtained separation matrix was then applied to new data samples in real time. Since MU pool discharge probability reflects the neural drive to spinal motoneurons, individual finger forces were estimated based on a firing rate force model established during the initialization, termed neural drive method. Conventional EMG amplitude based method was used to estimate the forces as a comparison, termed EMG amplitude method. Simulated HD EMG signals were first used to evaluate the accuracy of the real time decomposition. Experimental EMG recordings of 5 minute isometric finger extension with pseudorandom force levels were used to assess the performance of force estimation over time.  The simulation results showed that the accuracy of real time decomposition was 86% compared with an offline accuracy of 94% However, the real time decomposition accuracy was stable over time. Experimental results showed that the neural drive method had a significantly smaller root mean square error (RMSE) of the force estimation compared with the EMG amplitude method, and the estimation delay was also smaller, which was consistent across fingers. Additionally, the RMSE of the neural drive method was stable until 230 s, while the RMSE of the EMG amplitude method increased progressively over time.  The neural drive method on real time finger force estimation was more accurate over time compared with the conventional EMG amplitude method during prolonged muscle contractions. The outcomes can potentially offer a more accurate and robust neural interface technique for reliable neural machine interactions based on MU pool discharge information.

title: Excellent functional recovery after Kirschner wire extension blocking technique for displaced closed bony mallet finger injuries; results of 36 cases.
abstract: Bony mallet finger injuries comprise 30% of all mallet injuries. Operative treatment of bony mallet fingers injuries still remains controversial. The aim of this study was to describe the k wire extension blocking technique and the functional results using the PRWHE questionnaire. A single center retrospective observational cohort of 36 patients was defined between January 2010 and December 2015. Inclusion criteria for this study were acute fractures with 1) persistent displacement of more than 3 mm in extension splint, 2) palmar subluxation of the distal phalanx or 3) fracture fragments consisting of more than one third of the joint surface. According to the PRWHE questionnaire, excellent results were observed with a mean follow up period of 32 months of all patients. Two patients developed a clinically relevant superficial wound infection and one patient developed a nail deformity. In conclusion, the k wire extension blocking technique is safe and results in excellent mid term functional outcome.

title: Ultrasound guided selective nerve blocks for trigger finger surgeries to maintain flexion/extension of fingers Case series
abstract: A patient's ability to move his/her fingers during hand surgery may be helpful to surgeons because it allows the effectiveness of the intervention evaluation and prediction of hand function in the postoperative period. The purpose of this case series is to demonstrate the efficacy of an ultrasound guided peripheral nerve block technique to maintain the hand flexor and extensor muscles motor function and discuss the benefits of the technique for trigger finger surgery. Case report Ten patients scheduled to undergo trigger finger surgery were selected. The goal was to maintain flexion and extension of the fingers during the procedure. Thus, ultrasound guided ulnar, radial, and medial nerve block was performed in the distal third of the forearm, at 5 7 cm proximal to the wrist. The block was performed with 5 mL of 0.375% bupivacaine on each nerve. All procedures were uneventfully performed maintaining the flexion and extension of the fingers. In two cases, it was observed that the motricity maintenance and the patients' ability to move their fingers when requested allowed the success of the surgical procedure after the third intraoperative evaluation.  This case series shows that it is possible to maintain the motor function of the hand flexor and extensor muscles to perform finger trigger surgeries using specific ultrasound guided distal blocks.

title: Elicited Finger and Wrist Extension Through Transcutaneous Radial Nerve Stimulation
abstract: Individuals with neurological disorders, such as stroke or spinal cord injury, often have weakness and/or spasticity in their hand and wrist muscles, which can lead to impaired ability to extend their fingers and wrists. Functional electrical stimulation can help to restore these motor functions. However, the conventional stimulation method can lead to fast muscle fatigue and limited movements due to a non physiological recruitment of motor units and a limited recruitment of deep muscles. In this paper, we investigated the feasibility of eliciting various hand opening and wrist extension movement patterns through a transcutaneous electrical stimulation array, which targeted the proximal segment of the radial nerve bundle proximal to the elbow. The wrist and finger joint kinematics were used to classify the different movement patterns through a cluster analysis, and electromyogram signals from the wrist and finger extensors were recorded to investigate the muscle activation patterns. The results showed that the finger and wrist motions can be elicited both independently and in a coordinated manner, by changing the stimulation intensity and stimulation location. H reflex activity was also observed, which demonstrated the potential of recruiting motor units in a physiological order. Our approach could be further developed into a rehabilitative/assistive tool for individuals with impaired hand opening and/or wrist extension.

title: The addition of the MEP amplitude of finger extension muscles to clinical predictors of hand function after stroke; a prospective cohort study.
abstract: Within the first 72 hours after stroke, active finger extension is a strong predictor of long term dexterity. Transcranial magnetic stimulation may add prognostic value to clinical assessment, which is especially relevant for patients unable to follow instructions.  The current prospective cohort study aims at determining whether amplitude of motor evoked potentials of the extensor digitorum communis (EDC) can improve clinical prediction after stroke when added to clinical tests. METHODS the amplitude of motor evoked potentials of the affected EDC muscle at rest was measured in 18 participants within 4 weeks after stroke, as were the ability to perform finger extension and the Fugl Meyer Motor Assessment of the upper extremity (FMA_UE) These three determinants were related to the FMA_UE at 26 weeks after stroke (FMA_UE26) both directly, and via the proportional recovery prediction model. The relation between amplitude of the motor evoked potentials and FMA_UE26 was evaluated for EDC. For comparison, also the MEP amplitudes of biceps brachii and adductor digiti minimi muscles were recorded.  Patients' ability to voluntarily extend the fingers was strongly related to FMA_UE26, in our cohort there were no false negative results for this predictor. Our data revealed that the relation between amplitude of motor evoked potential of EDC and FMA_UE26 was significant, but moderate (rs 0.58) without added clinical value. The other tested muscles did not correlate significantly to FMA_UE26.  Our study demonstrates no additional value of motor evoked potential amplitude of the affected EDC muscle to the clinical test of finger extension, the latter being more strongly related to FMA_UE26.

title: [Ultrasound guided selective nerve blocks for trigger finger surgeries to maintain flexion/extension of fingers Case series]
abstract: A patient's ability to move his/her fingers during hand surgery may be helpful to surgeons because it allows the effectiveness of the intervention evaluation and prediction of hand function in the postoperative period. The purpose of this case series is to demonstrate the efficacy of an ultrasound guided peripheral nerve block technique to maintain the hand flexor and extensor muscles motor function and discuss the benefits of the technique for trigger finger surgery.  Ten patients scheduled to undergo trigger finger surgery were selected. The goal was to maintain flexion and extension of the fingers during the procedure. Thus, ultrasound guided ulnar, radial, and medial nerve block was performed in the distal third of the forearm, at 5 7cm proximal to the wrist. The block was performed with 5mL of 0.375% bupivacaine on each nerve. All procedures were uneventfully performed maintaining the flexion and extension of the fingers. In two cases, it was observed that the motricity maintenance and the patients' ability to move their fingers when requested allowed the success of the surgical procedure after the third intraoperative evaluation.  This case series shows that it is possible to maintain the motor function of the hand flexor and extensor muscles to perform finger trigger surgeries using specific ultrasound guided distal blocks.

title: Trigger Finger at the Distal A2 Pulley with Extension Locking of Proximal Interphalangeal Joint: Category of the Idiopathic Trigger Finger by the Location of Pathologic Lesion
abstract: Category of the Idiopathic Trigger Finger by the Location of Pathologic Lesion.  Surg J 2(1) 16 21.  Category of the Idiopathic Trigger Finger by the Location of Pathologic Lesion

title: Finger extension weakness and downbeat nystagmus motor neurone disease (FEWDON MND)
abstract: Atypical motor neurone disease (MND) represents a challenging and expanding group of neurodegenerative disorders involving the upper or lower motor neurones, and rarely both. Neuro ophthalmological disturbances such as gaze evoked downbeat nystagmus are extremely rare in the context of typical and atypical MND. Finger extension weakness and downbeat nystagmus motor neurone disease (FEWDON MND) syndrome has been recently recognised as a distinct syndromic phenotype of MND, with a characteristic clinical picture. We describe a 63 year old woman with long standing lower motor neurone involvement of the upper limbs, who on examination had gaze evoked downbeat nystagmus. After extensive negative investigation for secondary causes of MND and downbeat nystagmus, we diagnosed FEWDON MND syndrome.

title: Finger Extension Weakness and Downbeat Nystagmus Motor Neuron Disease Syndrome: A Series of Two Cases.
abstract: E ye movement abnormalities are rare in motor neuron disease (MND) Ophthalmoparesis is eventually found in patients with amyotrophic lateral sclerosis (ALS) who chose invasive ventilation, but is otherwise typically not observed. There are a few case reports documenting slowing of vertical saccades, gaze evoked horizontal or rotatory nystagmus, impairment of smooth pursuit, and progressive ophthalmoplegia and eyelid apraxia (1 4) These eye movement abnormalities are typically seen in ALS patients with bulbar onset or frontal lobe impairment. In 2006, Thakore et al (5) reported 3 cases of a novel MND with early and disproportionately severe involvement of finger and wrist extensors, downbeat nystagmus (DBN) relative sparing of bulbar and respiratory musculature, prolonged survival, and lack of family history. In 2016, they described an additional 3 patients with the same clinical phenotype, and designated the disorder as Finger Extension Weakness and Downbeat Nystagmus Motor Neuron Disease Syndrome with an acronym of FEWDON MND (6) We document 2 patients with FEWDON MND adding clinical and genetic insights into this novel entity. A 31 year old woman reported an eleven year history of slowly progressive left hand weakness years after the onset of left hand weakness, she experienced oscillopsia worse with downgaze, and 3 years after that cramping in her calves and left forearm muscles with generalized intermittent fasciculations. There were no associated sensory symptoms. Her medical history was significant for anxiety, and she was on sertraline and oral contraceptive pill. There was no family history of neurological or neuromuscular disorders. On examination, visual acuity was 20/20 in each eye with intact pupillary responses and color vision. Ocular motility showed full versions and ductions with DBN in primary gaze, which worsened with lateral gaze  and downgaze. Pursuit was interrupted by DBN, which did not dampen with convergence. Automated visual fields and the appearance of the anterior and posterior segments of both eyes were normal. Neurological examination revealed tongue fasciculations and atrophy without slowing of speech or dysarthria. There were both upper and lower motor neuron signs present in the limbs with predominant finger extensor weakness bilaterally. Nerve conduction studies (NCS) showed a reduced right peroneal motor amplitude, and needle electromyography (EMG) revealed large motor units and reduced recruitment in the left cervical and lumbosacral myotomes with fibrillations. MRI brain showed a Chiari I malformation without cerebellar atrophy, and MRI of the cervical spine was unremarkable. A 39 year old woman experienced oscillopsia at the age of 18 years. Nine years later, after her second pregnancy, she developed persistent fatigue. At age 32 years, the patient presented to our clinic with slowly progressive weakness. She had no significant medical history and was not taking any medications. There was no family history of neurological or neuromuscular disorders. On examination, visual acuity was 20/20 in the right eye and 20/30 in the left eye. Pupillary responses and color vision were normal. Ocular motility showed full versions and ductions with DBN in primary gaze, worsened with lateral gaze and downgaze, and slightly decreased in upgaze. Pursuit was interrupted by the DBN, which did not dampen with convergence. Automated perimetry, slitlamp examination, and funduscopy were normal. Neurological examination revealed both upper and lower motor neuron signs in the limbs with predominant finger extensor weakness bilaterally. NCS were normal and needle EMG showed very large motor units with reduced recruitment typical of a very longstanding slowly progressive neurogenic process. Brain MRI was normal. A trial of 3, 4 diaminopyridine had resulted in some symptomatic relief. However, she independently stopped this medication. Department of Neurology (AM) University of Toronto, Toronto, Canada; Department of Neurology (LZ, ANES) Sunnybrook Health Sciences Centre, Toronto, University of Toronto, Canada; Department of Neurology (PA) Toronto Western Hospital, University of Toronto, Toronto, Canada; and Department of Ophthalmology and Vision Sciences (ANES) University of Toronto, Toronto, Canada.