surface were inserted into flexors pollicis longus (FPL) and brevis (FPB), extensors pollicis longus (EPL) and brevis (EPB), abductors pollicis longus (APL) and brevis (APB), opponens pollicis (OPP), adductor that the highest ...

muscles during the pinch force generation. Extensor Digitorium (ED), Abductor Pollicis Longus (APL), Flexor Digitorum Superficialis (FDS), Dorsal Interosseous (DI), Abductor Pollicis Brevis (APB), Flexor Pollicis Brevis (FPB), and Adductor ...

and extrinsic hand extensors included abductor pollicis longus (AbPL) and extensors carpi radialis brevis (ECRB (ED45), and carpi ulnaris (ECU). Wrist and extrinsic hand flexors included palmaris longus (PLPB), adductor pollicis (AdP), opponens pollicis (OP), and flexors ...

were placed in abductor pollicis brevis, opponens digiti minimi, extensor carpi ulnaris, and flexor pollicis longus. For the muscles mediating proximal forelimb movements, injections were placed in shoulder

targeted to obtain the activities of the Extensor Digitorium (ED), Abductor Pollicis Longus (APL), Flexor, the flexor digitorum superficialis (FDS), an extrinsic flexor muscle, is normally connected to the MCP joints Digitorum Superficialis (FDS), Dorsal Interosseous (DI), Abductor Pollicis ...

We conducted this study to establish reliability and normative values for abductor pollicis brevis strength. A portable microprocessor-controlled hand-held device was used for testing. Twelve healthy subjects were used for intrarater and interrater reliability testing. Intraclass correlation coefficients were 0.92 for intrarater ...

Complete absence or variations of extensor pollicis brevis and abductor pollicis longus; absence of the extrinsic extensors, abductor pollicis longus, thenar muscles along with congenital hypoplasia of the thumb; absence of flexor pollicis ...

Intersection syndrome of the forearm is a painful condition in the area where the muscle bellies of the abductor pollicis longus and extensor pollicis brevis cross the common wrist extensors. A similar case of the foot with marked fibrosis at the interconnection of flexor hallucis longus and flexor digitorum ...

and flexor pollicis longus muscles were recorded in addition to APB. In another subject right and left pollicis brevis, EPB: extensor pollicis brevis, FPL: flexor pollicis longus, FPB: flexor pollicis brevis, A extensor ...

BackgroundThe development of osteoarthritis (OA) in the hand results in increased joint stiffness, which in turn affects the grip strength. The goal of the present study is to theoretically analyze the muscle forces in a thumb in response to the increased joint stiffness.MethodsThe thumb was modeled as a linkage system consisting of a trapezium, a metacarpal bone, a proximal and a distal phalanx. ...

This work presents a study on the influence of the aqueous environment on the surface EMG (sEMG) signal recorded in bipolar montage from the abductor pollicis brevis muscle, when only the forearm is immersed in water. Ten men, 30.1+/-4.0 (mean +/- SD) years old, performed ten 2-s 40% MVC isometric contractions of the ...

Electromyography (EMG) studies are useful in the anatomical localization of nerve injuries and, in most cases, isolating lesions to a single nerve root level. Their utility is important in identifying specific nerve-root-level injuries where surgical or interventional procedures may be warranted. In this case report, an individual presented with right upper extremity radicular symptoms consistent ...

A study has been made of the effect of voluntary contraction on the `late' responses which can be recorded in muscles after indirect stimulation. Two late responses have been described of which the first was shown to consist mainly of a potentiated H-reflex. The potentiation of this wave was greatest in the abductor pollicis brevis ...

The description of a bilaterally well developed, bicipital and bipennate accessory extensor carpi radialis muscle is reported. The muscle arose between the origins of the long and short radial carpal extensor muscles and inserted by 2 tendons into the 1st 2 metacarpal bones. The ulnar tendinous insertion was simultaneously the origin of abductor pollicis ...

The function of the radial sesamoid bone (RS) in the giant panda (Ailuropoda melanoleuca) was examined by macroscopic study of RS-related bones and muscles. The RS was observed to be connected to the scapholunar and the 1st metacarpal bones. A joint cavity was present between the proximal surface of the RS and the distal area of the scapholunar bone but the RS possessed a fibrous joint connecting ...

This study discusses the force-generating capacity of thumb muscles during jar-opening tasks using two grip patterns: the power grip and the precision grip. This study develops a three-dimensional biomechanical model of the thumb to predict muscle forces in jar-opening activities based on external forces measured by a custom-designed jar device. Ten healthy subjects participated in the study. Each ...

superficialis; EDC, extensor digitorum communis; E45, extensor digiti 4,5; AbPL, abductor pollicis longus; Ad communis and quarti et quinti proprius (EDC, E45); abductor pollicis longus (AbPL); adductor pollicis (Ad, triceps; Bic, biceps; Pro, pronator teres; Brd, brachioradialis; FCR, flexor ...

A 39-year-old patient suffered a stab wound of the right thenar prominence after an accident with a screwdriver. In the first hospital the deep wound was irrigated with octenidine dihydrochloride/2-phenoxyethanol and closed by suture. During the further course pressure pain and numbness of the right thenar and swelling of the right hand occurred. Three weeks after the accident an operative ...

Six variations of opponensplasty were biomechanically studied to determine if there is a significant difference in the amount of opposition produced by altering the insertion site of the tendon transfer while keeping the tendon source and pulley location constant. Five cadaveric arms were used to simulate six described insertion sites for opponensplasty tendon transfers. The arms were mounted ...

The manipulation mechanism of the giant panda (Ailuropida melanoleuca) was examined by means of CT (computed tomography) and 3-dimensional (3-D) Volume Rendering techniques. In the 3-D images of the giant panda hand, not only the bones but also the muscular system was visualised. Sections of the articulated skeleton were obtained. It was demonstrated that the hand of the panda is equipped with ...

Using Hiranuma's classification, we carefully examined anatomical variations in the first compartments of 246 human wrist joints from 124 cadavers. Morphological examinations were conducted to determine the number of accessory tendons and the existence of dissepiments for the extensor pollicis brevis (EPB) and abductor ...

The authors report five cases of ulnar dislocation of the Extensor pollicis longus caused by rupture of the hood at the metacarpophalangeal of joint the thumb. This rarely described lesion is well known in long fingers but seems to be less common in the thumb and no previous series can be found in the literature. This dislocation gives a deficit on active extension of the ...

The physiological behavior of the abductor pollicis brevis (APB) muscle during early stage of fatigue is important as a reference for future clinical assessment of a pathologically altered muscle, as e.g. in carpal tunnel syndrome. The purpose of this study was to assess changes of force and surface electromyograms (sEMG) during early ...

The purpose of this study was to analyze how the frequency of the Piper rhythm of the abductor pollicis brevis muscle (APB) and thus of the rhythmic synchronization of motor units changes with fatigue. Fourteen subjects participated in the study. The EMG signals were measured during maximum voluntary contractions, and a mimicked motor ...

Interventional paired associative stimulation (IPAS) to the contralateral peripheral nerve and cerebral cortex can enhance the primary motor cortex (M1) excitability with two synchronously arriving inputs. This study investigated whether dopamine contributed to the associative long-term potentiation-like effect in the M1 in Parkinson's disease (PD) patients. Eighteen right-handed PD patients and ...

The objective of this study was to investigate three-dimensional thumb joint movements produced by individual extrinsic thumb muscles. Ten cadaveric arms were dissected to expose the musculotendinous junctions of the flexor pollicis longus (FPL), abductor pollicis longus (APL), extensor pollicis ...

Despite its abundance in Latin America, and its remarkable ability to use tools, there are only a few myological studies on the capuchin monkey, Cebus libidinosus. In the present study, we dissected the forearm extensor muscles of six adult males and two adult females of this species. We describe these muscles and compare them with those of other primates dissected by us and by other authors. The ...

), the extensor carpi radialis (ECR), the extensor carpi ulnaris (ECU), and the abductor pollicis longus (APL), the extensor carpi radialis (ECR), the extensor carpi ulnaris (ECU), and the abductor pollicis longus (APL related to the production of the wrist movements above were selected: the flexor carpi ulnaris ...

Flexion is produced by the flexor pollicis longus and brevis,. (Figure 4) with the adductor and opponeus acting in a somewhat ...

Carpal tunnel syndrome is a common condition affecting 1% of the population. Open carpal tunnel release is the most commonly performed procedure for this condition. About 70-90% of patients have good to excellent long-term outcomes with open carpal tunnel release. The remainder have poor outcomes. An understanding of factors which predict a poor outcome following open carpal tunnel release would ...

BackgroundSevere cases of cubital tunnel syndrome do not always result in functional recovery after surgical decompression of the ulnar nerve. A combined operation of tendon transfer to restore index finger abduction and decompression of the ulnar nerve was performed for patients with severe cubital tunnel syndrome who required powerful pinch strength and whose preoperative compound muscle action ...

We tested whether task-dependent modulation of inhibition within the motor cortex is impaired in patients with dystonia. Paired-pulse transcranial magnetic stimulation (TMS) at an interstimulus interval of 2 msec was used to measure the effect of two different tasks on short ISI intracortical inhibition (SICI) in dystonic and normal subjects. In two experiments, SICI of the fourth dorsal ...

We tested whether task-dependent modulation of inhibition within the motor cortex is impaired in patients with dystonia. Paired-pulse transcranial magnetic stimulation (TMS) at an interstimulus interval of 2 ms was used to measure the effect of two different tasks on cortical inhibition (SICI) in dystonic and normal subjects. In two experiments, SICI of the fourth dorsal interosseus (4DIO) and ...

Patients with writer's cramp (WC) show abnormalities of sensorimotor integration possibly contributing to their motor deficit. We studied sensorimotor integration by determining short-latency afferent inhibition (SAI) in 12 WC patients and 10 age-matched healthy controls. A conditioning electrical median nerve stimulus was followed 14 to 36 msec later by transcranial magnetic stimulation of the ...

Previous work has suggested that there may be a widespread disturbance of motor control mechanisms in patients with cervical dystonia. In the present study, we used transcranial magnetic stimulation to investigate the topography of the corticomotor projection to the abductor pollicis brevis (APB) muscle in 10 subjects with idiopathic ...

Eleven patients over 40 years old, with median nerve lesions at the wrist, were operated on an average of 5 months after their injury. In six patients, the median nerve was repaired using a polypropylene mesh applied to secure the nerve stumps in contact, thereby allowing for direct repair with microsutures. Six patients had their median nerve repaired with sural grafts. The average gap length was ...

Both the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) possess a 'false-thumb', actually an enlarged radial sesamoid bone, which contributes to the gripping action of the hand. These species are not closely related, however, as one is an ursid and the other an ailurid, so the fact that they share this adaptation implies a remarkable convergence. We studied the functional ...

Baseline and synchronous evoked EMG activity were studied in wrist muscles of human subjects under conditions of transcranial magnetic stimulation of the motor cortex during the performance of different motor tasks. During recording, a subject had to hold a loaded handle with the thumb and index finger. When a subject increased the grip force (intentionally or under conditions of increasing handle ...

Electromyogram recordings revealed a concurrent contraction of the orbicularis oris, the primary articulator for bilabial stops, when participants executed a precision grip contracting the abductor pollicis brevis, a point motor act contracting the extensor indicis proprius or a curl motor act contracting the flexor sublimis digitorum ...

A temporal pattern coding, synchronization and rhythmicity form an integral part of central nervous system information controlling the muscle activation. Rhythmic oscillations of muscles at frequencies of 35-60 Hz were already noted in the electromyograms by Piper (1907). The purpose of this study was to resolve the Piper rhythm in the EMG of the APB muscle and report the pacing frequencies of the ...

The aim of the study was to assess if the observation of single or more complex muscle movements activates the premotor cortex in man. We stimulated by transcranial magnetic stimulation the right and left motor cortex recording from the abductor pollicis brevis of eight normal subjects, during observation of different movements ...

Both the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) possess a �false-thumb�, actually an enlarged radial sesamoid bone, which contributes to the gripping action of the hand. These species are not closely related, however, as one is an ursid and the other an ailurid, so the fact that they share this adaptation implies a remarkable convergence. We studied the ...

rotation of the hand. EMG was recorded from the first dorsal 149interosseus, flexor pollicis brevis, flexor), flexor digitorum superficialis (FDS), flexor pollicis brevis (FPB) and first dorsal interosseus (1DI digitorum superficialis, 150extensor carpi radialis longus and biceps muscles of the right hand. 151The ...

radialis longus (ECRL), flexor digitorum superficialis (FDS), flexor pollicis brevis (FPB) and first dorsal the first dorsal interosseus, flexor pollicis brevis, flexor digitorum superficialis, extensor carpi radialis longus and biceps muscles of the right arm. The EMG was recorded using custom-built active bipolar

This study investigated the psychophysiological patterns associated with cell phone text messaging (texting). Twelve college students who were very familiar with texting were monitored with surface electromyography (SEMG) from the shoulder (upper trapezius) and thumb (abductor pollicis brevis/opponens pollicis); ...

DeQuervain's tendonitis is an inflammation of two tendons: the extensor pollicis brevis and the abductor pollicis longus as they cross in the first dorsal compartment of the wrist. Symptoms include pain, swelling along the radial aspect of the wrist, and a decrease in thumb motion. A positive Finkelstein's test at ...

De Quervain's disease has been described as an entrapment of the extensor pollicis brevis and abductor pollicis tendons in the first dorsal compartment of the wrist is a common cause of wrist and hand pain. Currently, intrasheath corticosteroid injections have been reported to be successful as well as surgical ...

Dystonia is a set of disorders characterized by abnormal postures and unwanted muscle spasms that interfere with motor performance. Focal dystonias, the most common, affect just 1 body part. A 25-year-old woman had a focal hand dystonia with pain and muscle spasms in the right hand after surgical treatment for thumb duplication. According to Wassel's classification, she was type II, with ...

Between November 2001�and January 2008, 56�patients (68�hands) out of 110�patients operated for spastic hand deformities, presented with spasticity of the intrinsic muscles of the long fingers (interosseii and the abductor pollicis brevis). All patients were adults (mean age 42.1�years). The surgical indication was discussed ...

Neuronal plasticity is to be kept within operational limits to serve its purpose as a safe memory system that shapes and focuses sensory and motor representations. Temporal and spatial properties of motor cortical plasticity were assessed in patients with writer's cramp using a model of long-term potentiation (LTP) and long-term depression (LTD) of synaptic efficacy. Paired associative stimulation ...

In normal subjects short interval intracortical inhibition (SICI) is topographically modulated by cutaneous input, which may be important for focusing muscle activation during tasks. In patients with writer's cramp, a task-specific focal dystonia characterized by inappropriate and excessive muscle activation of the upper limb during certain motor tasks, intracortical inhibition is reduced at rest ...

In focal hand dystonia, long-term potentiation (LTP) and depression (LTD)-like neuronal plasticity, as assessed by paired associative stimulation (PAS) targeting the hand-associated motor cortex, is enhanced and the topographic organization of plasticity is lost. However, if any of these abnormalities alone is sufficient to cause focal dystonia (FD) remains unknown. Ten patients with cervical ...

Background and PurposeCervical radiculopathy is a pathological process involving a nerve root of the cervical spine. The most common causes of radiculopathy are cervical disc herniation followed by cervical spondylosis. The aim of this study was to determine the effect of dropped shoulder as a cause of lower cervical radiculopathy.MethodsIn total, 132 patients, comprising 105 women (79.5%) and 27 ...

OBJECTIVE: Threshold tracking allows the non-invasive assessment of axonal excitability. This study aimed to determine whether axonal excitability of the motor axons of the median nerve (to APB) and ulnar nerve (to ADM) to the small muscles of the hands is sufficiently similar to be interchangeable; confirm the feasibility and reproducibility of ulnar studies and obtain control data for a young ...

Intracortical inhibition and facilitation in different representations of the human motor cortex. J. Neurophysiol. 80: 2870-2881, 1998. Intracortical inhibition (ICI) and intracortical facilitation (ICF) of the human motor cortex can be studied with paired transcranial magnetic stimulation (TMS). Plastic changes and some neurological disorders in humans are associated with changes in ICI and ICF. ...

Study Objectives:The aim of our study was to determine which muscle or combination of muscles (either axial or limb muscles, lower or upper limb muscles, or proximal or distal limb muscles) provides the highest rates of rapid eye movement (REM) sleep phasic electromyographic (EMG) activity seen in patients with REM sleep behavior disorder (RBD).Setting:Two university hospital sleep disorders ...

brevus posterior (flexors, plantar flexors) superficial gastrocnemius (medial and lateral heads digitorum brevis extensor hallicis brevis deep dorsal interossei plantar (superficial to deep; lateral to medial) superficial plantar aponeurosis (most superficial) abductor digiti V flexor digitorum brevis

A 15-year-old pitcher on a boys� Little League baseball team suffered spontaneous rupture of the extensor pollicis brevis (EPB) tendon. Since the EPB tendon was, at surgery, found hypoplastic and non-functional, transfer of the extensor indicis proprius (EIP) tendon was carried out. After a 6-month period of rehabilitation and follow-up, the patient was ...

with surface electrodes placed over the flexor pollicis brevis, first dorsal interosseus, biceps brachii, flexor carpi radialis, pronator teres, extensor carpi ulnaris, and extensor carpi radialis longus muscles of the right hand. Because flexor pollicis brevis is relatively small, the electrode overlying the ...

- ductor pollicis longus (AbPL), extensor digitorum communis (EDC), extensor digiti secundi and tertiiP), opponens pollicis (OpP), flexor digiti quinti brevis manus (F5B), and opponens digiti quinti manus (Op5 that the upper end pointed toward the monkey's right (see Fig. 1C). We used digital video footage taken

With C7-T1 brachial plexus injuries, finger motion is absent while shoulder, elbow and wrist function are largely preserved. Previously, we have reconstructed finger flexion by transferring the brachialis muscle to the flexor digitorum profundus and flexor pollicis longus; and we have restored extension of thumb and finger by transferring the motor nerve to the supinator to ...

Anatomic variation of the trapeziometacarpal joint stabilizing structures is one of the concepts proposed to explain the pathogenesis of trapeziometacarpal arthritis. We undertook this study to test the hypothesis that septation of the first extensor compartment or variation of the abductor pollicis longus (APL) tendon (supernumerary insertions) are more ...

PurposeA common treatment of arthritis of the first carpometacarpal joint requires all or a portion of the flexor carpi radialis tendon (FCR) to be used as an interpositional graft. The purpose of this study was to examine the in vitro tendon forces in six wrist flexor and extensors to determine if their force contribution changes during different dynamic wrist motions along with a specific ...

Oxaliplatin is first-line chemotherapy for colorectal cancer, but produces dose-limiting neurotoxicity. Acute neurotoxicity following infusion produces symptoms including cold-triggered fasciculations and cramps, with subsequent chronic neuropathy developing at higher cumulative doses. Axonal excitability studies were undertaken in 15 oxaliplatin-treated patients before and immediately after ...

Electromyographic (EMG) activity from voluntarily contracting hand muscles undergoes transient suppression following nociceptive fingertip stimulation. This suppression is mediated by a spinal inhibitory reflex designated the cutaneous silent period (CSP). The CSP is abolished or altered in a variety of myelopathic conditions. However, before the CSP can gain acceptance as an aid in the diagnosis ...

ObjectiveThe aim of this study was to further characterize surround inhibition (SI) in the primary motor cortex (M1) by comparing its magnitude and time course during a simple reaction time task (SRT) and a choice reaction time task (CRT).MethodsIn both the SRT and the CRT, subjects performed the same right index finger flexion in response to an acoustic signal. For CRT, the alternative choice was ...

The objective of the present study was to assess the spatiotemporal scenario of brain activity associated with sensory stimulation of the abductor pollicis brevis muscle. Spatiotemporal dipole models, using realistic individual boundary element head models, were built from somatosensory evoked potentials (SEPs; 64 Ch. EEG) to ...

In patients with focal hand dystonia (FHD), pathological overflow activation occurs in muscles not involved in the movement. Surround inhibition is a neural mechanism that can sharpen desired movement by inhibiting unwanted movement in adjacent muscles. To further establish the phenomenon of surround inhibition and to determine whether short intracortical inhibition (SICI) reflecting inhibition ...

Brain plasticity refers to changes in the organization of the brain as a result of different environmental stimuli. The aim of this study was to assess the genetic variation of brain plasticity, by comparing intrapair differences between monozygotic (MZ) and dizygotic (DZ) twins. Plasticity was examined by a paired associative stimulation (PAS) in 32 healthy female twins (9 MZ and 7 DZ pairs, aged ...

Cortico-muscular coherence (CMC) reflects interactions between muscular and cortical activities as detected with EMG and EEG recordings, respectively. Most previous studies utilized EMG rectification for CMC calculation. Yet, recent modeling studies predicted that EMG rectification might have disadvantages for CMC evaluation. In addition, previously the effect of rectification on CMC was estimated ...

Task-specific focal dystonia is thought to have a neurological basis where stereotypical synchronous inputs and maladaptive plasticity play a role. As afferent input is a powerful driver of cortical reorganization, we propose that a period of asynchronous afferent stimulation may reverse maladaptive cortical changes and alleviate symptoms. Using transcranial magnetic stimulation (TMS), 3 hand ...

The motor threshold (MT) is a fundamental parameter for evaluating cortical excitability in transcranial magnetic stimulation (TMS) despite remarkable variation, both within, and between subjects. We intended to test whether the variation could be reduced by targeting the stimulation on-line and modeling the TMS-induced electric field on individual MR images. Navigated TMS was used to map the ...

Purpose: Given that SCI leads to substantial changes in biomechanical properties of the body and to widespread postlesional reorganization of the motor system as determined by functional imaging studies, we sought to identify neurophysiological correlations and time course of reorganization affecting muscles more distant to a SCI. Methods: Two arm muscles distant to a SCI (T2-L3), M.biceps brachii ...

The aetiology of idiopathic scoliosis (IS) remains unknown; however, there is a growing body of evidence suggesting that the spine deformity could be the expression of a subclinical nervous system disorder. A defective sensory input or an anomalous sensorimotor integration may lead to an abnormal postural tone and therefore the development of a spine deformity. Inhibition of the motor ...

The aetiology of idiopathic scoliosis (IS) remains unknown; however, there is a growing body of evidence suggesting that the spine deformity could be the expression of a subclinical nervous system disorder. A defective sensory input or an anomalous sensorimotor integration may lead to an abnormal postural tone and therefore the development of a spine deformity. Inhibition of the motor ...

Recent evidence indicates that regular physical activity enhances brain plasticity (i.e. the ability to reorganise neural connections) and improves neurocognitive function. However, the effect of regular physical activity on human motor cortex function is unknown. The purpose of this study was to examine motor cortex plasticity for a small hand muscle in highly active and sedentary individuals. ...

BackgroundBreathing in humans is dually controlled for metabolic (brainstem commands) and behavioral purposes (suprapontine commands) with reciprocal modulation through spinal integration. Whereas the ventilatory response to chemical stimuli arises from the brainstem, the compensation of mechanical loads in awake humans is thought to involve suprapontine mechanisms. The aim of this study was to ...

Previous studies have shown that intracortical inhibition (ICI) plays an important role in shaping the output from primary motor cortex, and that ICI may be impaired in people with Focal Hand Dystonia (FHD). This study explored the muscle-specificity and temporal modulation of ICI during the performance of a phasic index finger flexion task. Eight control subjects and seven with FHD were asked to ...

There is evidence of a strong capacity for functional and structural reorganization in the human motor system. However, past research has focused mainly on complex movement sequences over rather short training durations. In this study we investigated changes in corticospinal excitability associated with longer training of elementary, maximum-speed tapping movements. All participating subjects were ...

Sports concussions affect thousands of individuals every year and are a major public health concern. Still, little is known about the long-term and cumulative effects of concussions on brain neurophysiology. The principal objective of this study was to investigate the long-lasting effects of multiple sports concussions on sensorimotor integration and somatosensory processing in a sample of 12 ...

Although pathological muscle pain involves a significantly larger population than any other pain condition, the central mechanisms are less explored than those of cutaneous pain. The aims of the study were to establish the pain matrix for muscle pain in the full head volume and, further, to explore the possibility of a functional segregation to nonpainful and painful stimuli within the area of the ...

Recently, 2 physiologically distinct phases of short-interval intracortical inhibition (SICI) have been identified, a larger phase at interstimulus interval (ISI) 3 ms and a smaller phase at ISI 1 ms. While the former is mediated by synaptic processes, the mechanisms underlying the first phase of SICI remain a matter of debate. Separately, it is known that fatiguing hand exercise reduces SICI, a ...

Recently, 2 physiologically distinct phases of short-interval intracortical inhibition (SICI) have been identified, a larger phase at interstimulus interval (ISI) 3 ms and a smaller phase at ISI 1 ms. While the former is mediated by synaptic processes, the mechanisms underlying the first phase of SICI remain a matter of debate. Separately, it is known that fatiguing hand exercise reduces SICI, a ...

A previous study suggested that axonal hyperpolariza tion produced by maximal voluntary contraction could accentuate conduction block in symptomatic patients with chronic inflammatory demyelinating polyneuropathy (CIDP). If this is so, conduction block should occur with hyperpolarization due to other causes such as the release of ischaemia. The effects of ischaemia on axonal excitability and on ...

We used multi-channel surface electromyograms (EMGs) to examine if electrode location influences coherence measures derived from pairs of EMGs recorded from two hand muscles during a pinch task. A linear probe of 16 electrodes was used to estimate the location of the innervation zone in first dorsal interosseous (FDI) and abductor pollicis ...

Plastic neural changes have been documented in relation to different types of physical activity, but little is known about central nervous system plasticity accompanying reduced physical activity and immobilization. In the present study we investigated whether plastic neural changes occur in relation to 1 wk of immobilization of the nondominant wrist and hand and a corresponding period of recovery ...

BackgroundStudying the changes that occur in motor unit potential trains (MUPTs) may provide insight into the extent of motor unit loss and neural re-organization resulting from nerve compression injury. The purpose of this study was to determine the feasibility of using decomposition-based quantitative electromyography (DQEMG) to study the pathophysiological changes associated with compression ...

Age-related declines in central processing may delay the facilitation of corticospinal (CS) tracts that underlie emergence of voluntary responses to external stimuli. To explore this effect, single pulse transcranial magnetic stimulation (TMS) was applied to the left motor cortex at different latencies from the go-signal (auditory tone) during a simple reaction time (SRT) task with the right or ...

The present study was undertaken to evaluate the role of Na[superscript +]/K[superscript +] pump dysfunction in the development of diabetic neuropathy (DN). Nerve excitability techniques, which provide information about membrane potential and axonal ion channel function, were undertaken in 15 patients with established DN and in 10 patients with diabetes who had no evidence of neuropathy (DWN). ...

Motor cortex stimulus-response (S/R) curves are an indication of cortical excitability and are of relevance to topographical mapping. The aims of this study were to compare two different methods of collecting data to construct a S/R curve for transcranial magnetic stimulation (TMS) in the upper limbs, to identify reliable summary statistics for the S/R curve, and to determine whether S/R curves ...

It has been postulated that sensorimotor integration is abnormal in dystonia. We investigated changes in motor cortical excitability induced by peripheral stimulation in patients with focal hand dystonia (12 patients with hand cramps) and with cervical dystonia (nine with spasmodic torticollis) compared with 16 age-matched normal controls. Motor evoked potentials (MEP) to focal (figure-of-eight ...

Experimental evidence suggests impairment of inhibitory intracortical circuits in migraine, while not much is known about activity of facilitatory intracortical circuits. In the present work we evaluated the effects of high frequency-repetitive transcranial magnetic stimulation (hf-rTMS) on the activity of facilitatory circuits of motor cortex in 18 patients affected by migraine with aura and 18 ...

Paired-pulse transcranial magnetic stimulation (TMS) was used to assess the effectiveness of intracortical inhibition (ICI) acting on corticospinal neurons controlling three intrinsic hand muscles in humans. We hypothesised that the suppression of ICI with selective activation of a muscle would be restricted to corticospinal neurons controlling the muscle targeted for activation. Surface EMG was ...

... M. flexor digitorum longus pars profundus. 36. M. flexor carpi radialis. 37. M. pronator teres. 38. M. pronatoraccesorius. 39. M. extensor carpi ulnaris. 40. M. abductor pollicis longus. 41. M. extensor ca...

. Then, for each muscle contraction, four muscles were selected by palpation: the flexor carpi ulnaris (FCU), the extensor carpi radialis (ECR), the ex- tensor carpi ulnaris (ECU), and the abductor pollicis longus (APL) [11]. Because quadriplegic patients (with a C7 and C8 functional level) can still weakly

it is wrapped in black cloth in order to provide optical shielding. #12;159 Flexors Abductor pollicis longus Ulna on the left is a strain gauge used in finger flexor experiments. 8.3.1 Absolute images 8.3.1.1 Introduction in order to better represent the subtle variations in the absorption maps. #12;161 8.3.2 Finger flexor

and flexor carpi radialis (ECU, FCU, ECR, and FCR), and the palmaris longus (Pal). � The common digit muscles profundus (FDP). � The intrinsic hand muscles: the flexor pollicis brevis (FPB) and the first dorsal controlling the level of contrac- tion of four flexor muscles. Two monkeys used the system to control

Damage to the dorsolateral prefrontal cortex (DLPFC) impairs gating of irrelevant sensory information at early cortical processing stages. We investigated how transient inhibition of DLPFC impacts early event-related potentials (ERPs) arising from relevant or irrelevant vibrotactile stimuli to the fingertips. Specifically, we hypothesized that suppression of DLPFC using continuous theta burst ...

The afferent volley generated during neuromuscular electrical stimulation (NMES) can increase the excitability of human corticospinal (CS) pathways to muscles of the leg and hand. Over time, such increases can strengthen CS pathways damaged by injury or disease and result in enduring improvements in function. There is some evidence that NMES affects CS excitability differently for muscles of the ...

ABSTRACT Twenty lead-exposed men were selected on the basis of a maximum level of lead in the blood of 70-140 ?g/100 ml within the past year. There was no clinical evidence of neuropathy attributable to lead and haemoglobin levels were normal. In individuals, maximum motor and sensory conduction and the amplitude of the evoked potentials were normal or borderline in the median, peroneal and sural ...

The mechanisms underlying spinal shock have not been clearly defined. At present, clinical assessment remains the mainstay to describe progression through spinal shock following traumatic spinal cord injury. However, nerve excitability studies in combination with conventional nerve conduction and clinical assessments have the potential to investigate spinal shock at the level of the peripheral ...

The purpose of this study was to investigate the muscle activation and the muscle frequency response of the dominant arm muscles (flexor carpi radialis and extensor digitorum) and hand muscles (abductor pollicis and first dorsal interosseous) during robotic surgical skills training in a virtual environment. The virtual surgical training tasks consisted of ...

Interposition grafting material is used frequently to treat osteoarthritis of the base of the thumb or tendinous and ligamentous injuries of the hand. The observation of duplicated tendons in the first dorsal compartment of the hand prompted us to explore the possibility of using the accessory abductor pollicis longus (AAPL) tendon as grafting material. ...

A case of severe degloving injury to the left hand with complete destruction of the extensor apparatus of the thumb and exposure of the IP joint is presented. The damaged area was resurfaced with the use of the Integra template and the abductor pollicis longus tendon, lengthened with a tendon graft provided by the extensor indicis, and used to restore ...

A modification of the Eaton and Littler technique for reconstructing ligaments and restoring stability of the carpometacarpal joint of the thumb is described. We use a strip from the flexor carpi radialis tendon, which is split down to the crest of the trapezium. The tendon strip is led beneath the ligaments and the abductor pollicis longus insertion, ...

Compression syndromes of the ulnar nerve are more often located proximally in the cubital tunnel than distally in Guyon's canal. In many cases anatomic structures can be found that induce compression. These may be ganglia, tumours, vascular abnormalities, crossing fibrous bands or accessory muscles. The ulnar nerve has therefore to be revised all along its passage through Guyon's canal. When other ...

The aim of this study was to evaluate thumb postures, thumb movements and muscle activity when using mobile phones for SMS messaging and to determine whether there were differences in these exposures (a) across various mobile phone tasks, (b) between gender and (c) between subjects with and without musculoskeletal symptoms in shoulders and upper extremities. Fifty-six young adults (15 healthy and ...

This paper describes a clinical case study in which a chitosan/polyglycolic acid nerve guidance conduit (chitosan-PGA NGC) was utilized to repair a 30 mm long median nerve defect in the right distal forearm of a 55 year-old male patient. Thirty-six months after the nerve repair, the palm abduction of the thumb and the thumb-index digital opposition recovered, facilitating the patient to accomplish ...

Thirty-seven cases of ligament reconstruction of the nonarthritic thumb carpometacarpal joint were performed in 35 patients, 29 female and 6 male, between 1980 and 1996. Follow-up ranged from 1 to 17 years with an average of 5.2 years. The procedure described by Eaton and Littler in which a slip of the flexor carpi radialis (FCR) weaved through the first metacarpal and around the ...

The operative treatment of thumb carpometacarpal joint arthritis may include resection-suspension-interposition-arthroplasty. Although quite a technically demanding procedure, a suspension arthroplasty using a strip of the flexor carpi radialis tendon is quite a popular technique. Other techniques, which use the abductor pollicis longus (APL) tendon, is ...

BACKGROUND: The aim of this study was to determine the difference in activation patterns of the plantar intrinsic foot muscles during two quiet standing tasks with increasing postural difficulty. We hypothesised that activation of these muscles would increase with increasing postural demand and be correlated with postural sway. METHODS: Intra-muscular electromyographic (EMG) activity was recorded ...

The systemic injection of L-Acetylcarnitine (L-Ac) induces a reversible increase in recurrent inhibition. In addition, L-Ac potentiation of recurrent inhibition has been found to increase the synchronous activity of single motor units, as detected by traditional linear analysis in the time domain. This result has been recently confirmed using a nonlinear method based on the analysis of embedded ...

Torque motor produced stretch of upper limb muscles results in two distinct reflex peaks in the EMG activity. While the short latency reflex (SLR) response is mediated largely by the spinal monosynaptic reflex pathway, the longer latency reflex (LLR) is suggested to involve a transcortical loop. For the SLRs, patterns of heteronymous monosynaptic Ia connections have been well studied for a large ...

A traumatic fat effusion in a tendon sheath is an unreported entity. We report on the clinical and imaging features, including radiography and computed tomography (CT), of a fat-density effusion in the wrist joint and tendon sheaths of the extensor pollicis longus, extensor carpi radialis longus, and extensor carpi radialis brevis in a 28-year-old patient ...

The hypothenar eminence is of great surgical interest yet its complex anatomy is yet to be fully discovered. This review focuses on: the osteoligamentous floor and topography of the Guyon's canal and the carpal ulnar neurovascular space. The canal under the Pisohamate ligament must be individualized. It corresponds to the zone 2 of Shea and McClain where the deep branch of the ulnar nerve is ...

Active pronation is important for many activities of daily living. Loss of median nerve function including pronation is a rare sequela of humerus fracture. Tendon transfers to restore pronation are reserved for the obstetrical brachial plexus palsy patient. Transfer of expendable motor nerves is a treatment modality that can be used to restore active pronation. Nerve transfers are advantageous in ...