Extensor Carpi Radialis Longus Research Articles

Fatigue Alleviation by Low-Level Laser Pre-Exposure in Ischemic Neuromuscular Electrical Stimulation.

Despite its susceptibility to muscle fatigue, combined neuromuscular electrical stimulation (NMES) and blood flow restriction (BFR) is an effective regimen for managing muscle atrophy when traditional resistance exercises are not feasible. This study investigated the potential of low-level laser therapy (LLLT) in reducing muscle fatigue after the application of combined NMES and BFR. Thirty-six healthy adults were divided into control and LLLT groups. The LLLT group received 60 J of 850 nm wavelength LLLT before a training program of combined NMES and BFR of the non-dominant extensor carpi radialis longus (ECRL). The control group followed the same protocol but received sham laser therapy. Assessments included maximal voluntary contraction (MVC), ECRL mechanical properties, and isometric force-tracking for wrist extension. The LLLT group exhibited a smaller normalized difference in MVC decrement (-4.01 ± 4.88%) than the control group (-23.85 ± 7.12%) (P < .001). The LLLT group demonstrated a smaller decrease in muscle stiffness of the ECRL compared to the control group, characterized by the smaller normalized changes in frequency (P = .002), stiffness (P = .002), and relaxation measures (P = .011) of mechanical oscillation waves. Unlike the control group, the LLLT group exhibited a smaller post-test increase in force fluctuations during force-tracking (P = .014), linked to the predominant recruitment of low-threshold MUs (P < .001) without fatigue-related increases in the discharge variability of high-threshold MUs (P > .05). LLLT pre-exposure reduces fatigue after combined NMES and BFR, preserving force generation, muscle stiffness, and force scaling. The functional benefits are achieved through fatigue-resistant activation strategies of motor unit recruitment and rate coding.

Arthroscopic Hemitrapeziectomy and Extensor Carpis Radialis Longus Suspensioplasty With Intermetacarpal Ligament Reconstruction for Thumb Carpometacarpal Joint Osteoarthritis: Surgical Technique.

Level IV.

Surgical Technique: Brachioradialis to Extensor Carpi Radialis Longus and Brevis Nerve Transfers for Tetraplegia.

Improving upper extremity function in high cervical spinal cord injury (SCI) patients with tetraplegia is a challenging task owing to the limited expendable donor muscles and nerves that are available. Restoring active wrist extension for these patients is critical because it allows for tenodesis grasp. This is classically achieved with brachioradialis (BR) to extensor carpi radialis brevis (ECRB) tendon transfer, but outcomes are suboptimal because BR excursion is insufficient and its origin proximal to the elbow further limits the functionality of the tendon transfer, particularly in the absence of elbow extension. As an alternative approach to restore wrist extension in patients with ICSHT group 1 SCI, we present the first clinical report of the BR to extensor carpi radialis longus (ECRL) and BR to ECRB nerve transfers.

A Fresh Cadaver Study on the Innervation of Brachioradialis and Extensor Carpi Radialis Longus Muscles

Distal nerve transfers have revolutionized peripheral nerve surgery by allowing the transfer of healthy motor nerves to paralyzed ones without causing additional morbidity. Radial nerve branches to the brachialis (Ba), brachioradialis (Br), and extensor carpi radialis longus (ECRL) muscles have not been investigated in fresh cadavers. The radial nerve and its branches were dissected in 34 upper limbs from 17 fresh cadavers. Measurements were taken to determine the number, origin, length, and diameter of the branches. Myelinated fiber counts were obtained through histological analysis. The first branch of the radial nerve at the elbow was to the Ba muscle, followed by the branches to the Br and ECRL muscles. The Ba and Br muscles consistently received single innervation. The ECRL muscle showed varying innervation patterns, with one, two, or three branches. The branches to the Br muscles originated from the anterior side of the radial nerve, whereas the branches to the Ba and ECRL muscles originated from the posterior side. The average myelinated fiber counts favored the nerve to Br muscle over that to the ECRL muscle, with counts of 542 versus 350 and 568 versus 302 observed in hematoxylin and eosin and neurofilament staining, respectively. This study provides detailed anatomical insights into the motor branches of the radial nerve to the Ba, Br, and ECRL muscles. Understanding the anatomy of the radial nerve branches at the elbow is of utmost importance when devising a reconstructive strategy for upper limb paralysis. These findings can guide surgeons in selecting appropriate donor or recipient nerves for nerve transfer in cases of high tetraplegia and lower-type brachial plexus injuries.

Prevalence, evaluation, and clinical implications of a reticular tunnel formed by uncharacteristic distal fibers of the abductor pollicis longus

IntroductionVariations in muscles of the pollex are common, and some can elicit significant clinical implications. The abductor pollicis longus (APL) frequently exhibits non-typical morphologies; however, descriptions of uncharacteristic distal fibers from APL (APLudf) that form a reticular tunnel around the tendons of extensor carpi radialis longus (ECRL) and brevis (ECRB) are scarce in current literature. The objective of this study is to investigate the prevalence of APLudf with concurrent report of in situ and cross-sectional gross imaging. MethodsThe distal aspect of 110 APL muscles was examined for APLudf and reticular tunnel formation. Reticular tunnel length was measured over the long axis of the underlying ECRL tendon, and APLudf pennation angle was recorded. Characteristic APL and APLudf examples were photographed in situ, and one example of APLudf was cross-sectioned to show the bony attachment of the atypical fibers in relation to contiguous anatomy. A unique finding of an APLudf accessory tendon inserting onto an accessory abductor pollicis brevis muscle was removed, splayed, and photographed. ResultsAPLudf were present in 65 (59.1%) of upper limbs. The APLudf originated from a free origin over the ECRL and ECRB tendons and a fixed origin from the lateral margin of the distal radius and inserted onto the main APL tendon or an accessory tendon, creating a distinct reticular tunnel around the ECRL and ECRL with a mean length of 20.25 ± 5.55 mm (range = 11.09 mm–36.09 mm) and 12.99° ± 1.44° pennation. All APL muscles displayed one main tendon and at least one accessory tendon which originated solely from APLudf on 43 (39.1%) of the specimens. ConclusionsThe present study suggests the prevalence of APLudf is 59.1% and often occurs bilaterally. The restriction of intersecting movements within the APLudf reticular tunnel could cause ECRL and ECRB tendon inflammation (i.e., intersection syndrome), directly affect respective functions (e.g., radial extension of the wrist, abduction and extension of the thumb), and complicate surgical management in the region. This report may inform educators and healthcare providers when deliberating diagnosis, treatment, and healing of associated forearm, wrist, and pollex conditions.

Comparing the remote effects of dry needling and ischemic pressure on pain intensity and threshold of the myofascial trigger points in women: A Single Blinded Randomized Clinical Trial

ObjectiveThe current study aimed to investigate the remote effects of upper trapezius (UT) Dry needling (DN) and ischemic pressure (IP) on the pain intensity and threshold of the MTrPs in the extensor carpi radialis longus (ECRL) and the first dorsal interosseous (FDI) muscles. MethodsTwenty-eight subjects were allocated into two groups in a randomized clinical trial study undergoing DN and IP interventions on the MTrPs of the UT muscle for 3 sessions. Pressure pain intensity was assessed by visual analog scale (VAS) and pressure pain threshold (PPT) before and after interventions. Upper limb functions were evaluated by the disabilities of the arm, shoulder, and hand (DASH) questionnaire. ResultsThere were significant interactions between muscle, group, and time for PPT, muscle and group, group and time, and muscle and time for VAS (P < 0.05). In DN group, PPTs and VAS of the ECRL and FDI were changed after treatment in all sessions (P < 0.05). In ECRL and FDI muscles, the DN was more effective than IP (P < 0.05). Comparing the pain intensity and threshold of the ECRL, FDI, and UT muscles it was revealed that the improvement in symptoms of the ECRL muscle was the most in the DN group (P < 0.05). There was a significant interaction between group and time for DASH (P < 0.05). In both groups, the DASH score was reduced (P < 0.001). ConclusionsUT muscle DN demonstrated significantly better remote effects in alleviating symptoms of the ipsilateral distal muscles than IP. Both interventions were effective in improving the upper limb function in myofascial pain syndrome patients. Implications for practice•This study evaluated the remote effects of most common treatments on myofascial trigger points.•Dry needling showed therapeutic effects on pain alleviation in terms of both immediate and short term in the extensor carpi radialis longus muscle.•First dorsal interosseous pain threshold and intensity improved following dry needling of the upper trapezius while it is not connected to the upper trapezius muscle myofascially.

US-guided percutaneous irrigation of extra-shoulder calcific tendinitis.

To investigate the efficacy and safety of ultrasound-guided percutaneous irrigation of calcific tendinopathy (US-PICT) applied out of the shoulder, comparing its effectiveness to US-PICT of the rotator cuff. Patients subjected to US-PICT for extra-shoulder calcific tendinitis (Case Group) were compared to those subjected to US-PICT of the rotator cuff (Control Group). We had pre-procedure Visual Analogue Scale (VAS) pain score, 1- and 3-month VAS of patients of the Case Group, pre-procedure and 3-month VAS of patients of the Control Group. The Case Group consisted of 41 patients (27 women; mean age: 45 ± 9years): 26 gluteus medius, 5 patellar tendon, 3 rectus femoris, 2 gluteus maximus, 2 common extensor tendon, 1 extensor carpi radialis longus, 1 pes anserinus, and 1 peroneus longus. The Control Group included 41 patients (27 women; mean age: 47 ± 11 years). The mean pre-procedure VAS of the Case Group was 8.8 ± 0.7 with a significant (P < .001) drop at 1 month (4.5 ± 0.6) and 3 months (3.6 ± 0.6). The mean pre-procedure VAS of the Control Group was 8 ± 1.4 and dropped to 3.1 ± 1.6 after 3 months (P < .001). Post-treatment VAS at 3 months was not significantly different between two Groups (P = 0.134). Similarly, the decrease of VAS from baseline to 3 months was not significantly different between the two Groups (P = 0.264). US-PICT is a safe and effective procedure that can be used out of the shoulder. This study demonstrated the safety and effectiveness of US-PICT as a valuable therapeutic option for extra-shoulder calcific tendinitis, with similar clinical outcome to the same procedure performed in the rotator cuff. The technique must be adapted in some deeply located calcifications by means of the use of different needles and by thoroughly planning the access point for the procedure.

Optimization of Muscle Selection for Needle Electromyography in Isolated C6 Root Lesion: A Prospective Chart Review Study.

The aim of the study is to evaluate muscles with more prominent needle electromyographic findings to optimize needle electromyography screening of isolated C6 radiculopathy in patients with C6 root lesions. This prospective clinical study was performed on 39 patients with isolated and unilateral cervical radiculopathy selected from all referrals of 1733 patients to the electrodiagnosis unit of the physical medicine and rehabilitation department of a tertiary medical center (from April 2021 to December 2021). The presence of fibrillation potentials, positive sharp waves, and/or neurogenic motor action potentials that occurred in isolation or combination with selected muscles was considered an abnormal finding. Of 1733 referrals, 39 patients (18 males [46.1%] and 21 females [53.8%]), with a mean age of 49.7 ± 9.6 yrs, were found eligible. According to needle electromyography findings, the most involved muscles in C6 root lesion were pronator teres (100%), followed by extensor carpi radialis longus (94.8%), flexor carpi radialis (89.7%), brachioradialis (82%), infraspinatus (82%), supraspinatus (79.4%), deltoid (74.3%), biceps brachii (64.1%), extensor digitorum communis (33.3%), and triceps brachii (15.3%) muscles. The pronator teres is the most involved muscle of patients diagnosed with C6 radiculopathy. It might be considered the key muscle for screening and accurate diagnosis of C6 root involvement.

Scapholunate and lunotriquetral joint dynamic stabilizers and their role in wrist neuromuscular control and proprioception

Recent research interest has grown in exploring the role of muscles, isometric contraction, proprioception, and neuromuscular control in addressing dynamic scapholunate and lunotriquetral joint instability, marking a shift in the understanding of wrist stability. To present a comprehensive review of the carpal ligaments anatomy and wrist biomechanics, with a particular focus on the role of proprioception in dynamic carpal stability and their role in managing scapholunate (SL) and lunotriquetral (LTq) dynamic instabilities. We conducted a systematic search of the literature and review of the most relevant papers published and indexed in pubmed, related to wrist biomechanics, proprioception and its contribution to carpal dynamic stability. The study involved a comprehensive review of neuromuscular mechanisms in dynamic stabilization of the carpus, based on cadaver studies. The 3D position of the scaphoid, triquetrum, and capitate was monitored before and after tendon loading. The extensor carpi ulnaris (ECU) and the flexor carpi radialis (FCR) are identified as the primary pronators of the midcarpal joint. The ECU's pronation effect can potentially strain the scapholunate ligament, while the supinator muscles, the abductor pollicis longus (APL), the extensor carpi radialis longus (ECRL), and the flexor carpi ulnaris (FCU), have a protective role, particularly in cases of scapholunate ligament dysfunctions. The FCR, despite being a pronator of the distal row, has a beneficial effect as it provokes supination of the scaphoid. Comprehending carpal dysfunctions and instabilities hinges on understanding carpal anatomy and normal biomechanics. Proprioception, encompassing joint position sensation and neuromuscular control, is pivotal for stability. Biomechanical research informs tailored muscle strengthening for specific carpal issues. Supinator muscles should be strengthened for SL injuries, and ECU-focused strengthening and proprioceptive training are key for dynamic LTq instabilities. Ongoing research should delve into the intricate relationship between carpal ligaments, muscles, and proprioception to enhance wrist stability.

Exercise-based intervention as a nonsurgical treatment for patients with carpal instability: A case series

BackgroundAlthough the important roles of proprioception and neuromuscular control in carpal instabilities under laboratory conditions have been recognized, only a few studies have translated this knowledge into a routine clinical practice. PurposeThis study aimed to evaluate the results of a personalized rehabilitation in patients with carpal instability on functionality and pain intensity. Study designThis was a case series study. MethodsThis case series included 39 adults (mean age: 38.2 ± 14.0 years; 16/23 females/males) diagnosed with carpal instability (radial or ulnar) with indication for orthopedic treatment. The disabilities of the arm, shoulder, and hand questionnaire was used to assess upper limb functionality. Pain perception was assessed using a visual analog scale. Exercise-based physiotherapy interventions were performed according to the clinical needs of the patients for at least 6 weeks (2-3 sessions per week). For the treatment of radial instability (n = 13), strengthening exercises of the abductor pollicis longus, extensor carpi radialis longus, flexor carpi radialis, and pronator quadratus muscles were prescribed. For the treatment of ulnar instability (n = 24), extensor carpi ulnaris and pronator quadratus were trained. All patients underwent proprioceptive training in open kinetic chain and closed kinetic chain, as well as strengthening of the unaffected hand. Changes before and after treatment were compared using the nonparametric Wilcoxon signed rank test. ResultsA significant improvement with a large effect size in disabilities of the arm, shoulder, and hand (P < .001; d = 2.9) and visual analog scale (P < .001; d = 3.2) scores were obtained after treatment. Moreover, the changes were greater than the minimal clinically important difference of 10.8 and 1.4, respectively. Similar results were found when patients with radial instability and ulnar instability were analyzed separately. ConclusionsPersonalized training with specific proprioception and strengthening exercises produces improvements in functionality and pain perception in our cohort of people with carpal instability. These results highlight the importance of multicomponent exercise in the treatment of wrist instability. Future randomized clinical trials should further investigate the effectiveness of this protocol.

Deficits in neuromuscular control of increasing force in patients with chronic lateral epicondylitis.

Objective: This study investigated the neuromuscular control of increasing and releasing force in patients with chronic lateral epicondylitis (CLE). Methods: Fifteen patients with CLE (10 males, 5 females, 46.5 ± 6.3years) and fifteen healthy participants (9 males, 6 females, 45.3 ± 2.5years) participated in this study. In addition to power grip and maximal voluntary contraction (MVC) of wrist extension, force fluctuation dynamics and characteristics of inter-spike intervals (ISI) of motor units (MUs) with various recruitment thresholds in the extensor carpi radialis brevis (ECRB) and extensor carpi radialis longus (ECRL) during a designated force-tracking task with a trapezoidal target (0%-75%-0% MVC) were assessed. Results: Besides a smaller MVC of wrist extension, the patients exhibited significantly greater task errors (p = 0.007) and force fluctuations (p = 0.001) during force increment than the healthy counterparts. Nevertheless, no force variables significantly differed between groups during force release (p > 0.05). During force increment, the amplitudes of the motor unit action potential of the ECRB and ECRL muscles of the patients were smaller than those of the heathy counterparts (p < 0.001). The patient group also exhibited a higher percentage of motor units (MU) with lower recruitment threshold (<5% MVC) in the ECRL/ECRB muscles and a lower percentage of MU with higher recruitment threshold (>40% MVC) in the ECRB muscle, compared to the healthy group. During force increment, the patient group exhibited a higher rate of decrease in inter-spike intervals (ISIs) of motor units with lower recruitment thresholds (<10% MVC) in the ECRB and ECRL muscles, compared to the control group (p < 0.005). Conclusion: The patients with CLE exhibited more pronounced impairment in increasing force than in releasing force. This impairment in increasing force is attributed to deficits in tendon structure and degenerative changes in the larger motor units of the wrist extensors. To compensate for the neuromuscular deficits, the rate of progressive increase in discharge rate of the remaining smaller motor units (MUs) is enhanced to generate force. Significance: The deficits in neuromuscular control observed in CLE with degenerative changes cannot be fully explained by the experimental pain model, which predicts pain-related inhibition on low-threshold motor units.

Upper Extremity Electromyography During Bouldering: Research Report

Background: Despite the growing popularity of bouldering, little is known about the degree and variabilityof muscle activation that occurs while solving bouldering problems. The purpose of this study was to explorethe electromyography of eight upper extremity and trunk muscles during a session of indoor bouldering whilecompleting four different problems.Methods: Eleven climbers with self-reported ability to climb a V-scale V4 problem grade or higher and regularlyboulder at least two days/week for at least six months participated in this study. Electromyography was used torecord muscle activity of the flexor digitorum superficialis, extensor carpi radialis longus, biceps brachii, tricepsbrachii, anterior deltoid, middle deltoid, posterior deltoid, and latissimus dorsi.Conclusion: The highest average EMG across all four climbs occurred in the flexor digitorum superficialis,latissimus dorsi, and extensor carpi radialis brevis. Significant differences in muscle activity were noted betweenthe anterior deltoid and latissimus dorsi, flexor digitorum superficialis and biceps brachii, triceps brachii andflexor digitorum superficialis, posterior deltoid and latissimus dorsi, and triceps brachii and latissimus dorsi.This information may be useful in developing a strength and conditioning program for

Muscle assessment in brachial plexus injury: A reliability study

PurposeMotor outcome following a brachial plexus injury is frequently measured to evaluate the success of surgical interventions. We aimed to identify whether the manual muscle testing using the Medical Research Council (MRC) method in adults with C5/6/7 motor weakness was reliable and whether its results correlated with functional recovery. MethodsTwo experienced clinicians examined 30 adults with C5/6/7 weakness following proximal nerve injury. The examination included using the modified MRC to assess motor outcome in the upper limb. Kappa statistics were calculated to evaluate inter-tester reliability. Correlation coefficients was calculated to explore the correlation between the MRC and the Disabilities of the Arm Shoulder and Hand (DASH) score and each EQ5D domain. ResultsWe found that grades 3–5 of the modified and unmodified MRC motor rating scales have poor inter-rater reliability when assessing C5/6/7 innervated muscles in adults with a proximal nerve injury. The Deltoid Posterior and the Extensor Carpi Radialis Longus were the only muscles (using the modified MRC) to achieve a Kappa over 0.6 indicating substantial reliability. Higher combined MRC scores correlated significantly with a lower DASH and vice versa. Similarly, higher combined scores of MRC correlated significantly with a higher rating of overall health on the EQ5D VAS. ConclusionsThis study demonstrates that the MRC motor rating scale has poor inter-rater reliability when assessing C5/C6/C7 innervated muscles in adults following proximal nerve injury. Other methods of assessing motor outcome following proximal nerve injury need to be considered.

Anatomy of the Superficial Radial Nerve and Its Target Nerves for Targeted Muscle Reinnervation: An Anatomical Cadaver Study.

Targeted muscle reinnervation (TMR) is a surgical procedure for treating symptomatic neuroma, in which the neuroma is removed and the proximal nerve stump is coapted to a donor motor branch innervating a nearby muscle. This study aimed to identify optimal motor targets for TMR of the superficial radial nerve (SRN). Seven cadaveric upper limbs were dissected to describe the course of the SRN in the forearm and motor nerve supply-number, length, diameter, and entry points in muscle of motor branches-for potential recipient muscles. The radial nerve provided three (three of six) motor branches, two (two of six) motor branches, or one (one of six) motor branch to the brachioradialis muscle, entering the muscle 21.7 ± 17.9 to 10.8 ± 15 mm proximal to the lateral epicondyle. One (one of seven), two (three of seven), three (two of seven), or four (one of seven) motor branches innervated the extensor carpi radialis longus muscle, with entry points 13.9 ± 16.2 to 26.3 ± 14.9 mm distal from the lateral epicondyle. In all specimens, the posterior interosseous nerve gave off one motor branch to the extensor carpi radialis brevis, which divided into two or three secondary branches. The distal anterior interosseus nerve was assessed as a potential recipient for TMR coaptation and had a freely transferable length of 56.4 ± 12.7 mm. When considering TMR for neuromas of the SRN in the distal third of the forearm and hand, the distal anterior interosseus nerve is a suitable donor target. For neuromas of the SRN in the proximal two-thirds of the forearm, the motor branches to the extensor carpi radialis longus, extensor carpi radialis brevis, and brachioradialis are potential donor targets.

A Novel Passive Implantable Differential Mechanism to Restore Individuated Finger Flexion during Grasping following Tendon Transfer Surgery: A Pilot Study

Tendon transfer surgery is often used to restore hand grasp function following high median-ulnar nerve palsy. This surgery typically reroutes and sutures the tendon of the extensor carpi radialis longus (ECRL) muscle to all four flexor digitorum profundus (FDP) tendons of the hand, coupling them together. This makes it difficult to grasp irregularly shaped objects. We propose inserting a novel implantable passive device between the FDP tendons to surgically construct a differential mechanism, enabling the fingers to individually adapt to the irregular contours during grasping. These passive implants with no moving parts are fabricated from biocompatible materials. We tested the implants’ ability to create differential flexion between the index and middle fingers when actuated by a single muscle in two human cadaver hands using a computerized closed-loop control paradigm. In these cadaveric models, the implants enabled significantly more differential flexion between the index and middle fingers for a wide range of donor tendon tensions. The implants also redistributed fingertip forces between fingers. When grasping uneven objects, the difference in contact forces between fingers reduced by nearly 23% compared to the current suture-based surgery. These results suggest that self-adaptive grasp is possible in tendon transfers that drive multiple distal flexor tendons.

Understanding the biomechanics of the forearm during the dart thrower's motion.

This study investigated the contribution of different forearm muscles, namely the flexor carpi ulnaris, extensor carpi radialis longus and brevis, extensor carpi ulnaris and flexor carpi radialis, during the dart thrower's motion. Thirteen healthy participants were recruited. The forearm muscle activation patterns during the dart thrower's motion were measured using surface electromyography. The average root mean square for the extensor carpi ulnaris was found to be the highest during the dart thrower's motion. Muscle activations during the dart thrower's motion were heterogeneous among the participants. The results suggest the rehabilitation protocol for patients with wrist injuries should be reconsidered.

Probing motor dynamics at the muscle level-Acoustic myography in Parkinson's disease.

Acoustic myography (AMG) noninvasively probes muscle activity. We explored whether AMG captures abnormal motor activity in patients with Parkinson's disease (PD) and how this activity is modulated by antiparkinsonian medication. Twenty patients with PD underwent AMG of the biceps, triceps, extensor carpi radialis longus, and adductor policis muscles of the more affected arm during active and passive movements, using a mobile AMG device (CURO, Denmark). AMG and assessment of motor symptoms were performed in a pragmatic off-medication state, as well as one and 3 h after oral intake of 200 mg levodopa. Three AMG parameters were calculated using the CURO analysis system. Motor efficiency was expressed by the E-score, muscle fiber recruitment by the temporal T-score, spatial summation by the S-score, and S/T ratio. Twenty age- and sex-matched healthy subjects served as controls. Group mean values were statistically compared using unpaired two-tailed adjusted t-test and ANOVA with Tukey´s correction for multiple comparison (p≤ 0.05). For the biceps and extensor carpi radialis longus muscles, the active movement S:T ratio was lower in PD relative to healthy controls. The E-score was also lower during active and passive flexion/extension movements in the off-medication state. No significant between-group differences in the AMG scores were noted for the triceps muscle during active or passive movements. The active S:T ratio and the E-score during active elbow flexion and extension may offer a useful means to quickly assess abnormal motor activity and the effect of drug treatment in PD.

Influence of a Hybrid Manual–Electric Wheelchair Propulsion System on the User’s Muscular Effort

Abstract Self-propelled wheelchairs favour the rehabilitation process, forcing the user to be physically active. Unfortunately, in most cases, the manual propulsion is not adapted to the individual needs and physical capabilities of the user. This paper presents the results of operational tests of a wheelchair equipped with a hybrid propulsion system in which the muscle strength generated by the user is assisted by two independent electric motors. The research aimed to investigate the influence of the applied control algorithm and the assistance factor (W) on the value of the muscular effort (MA) while propelling the wheelchair with the use of push rims. A modified ARmedical AR-405 wheelchair equipped with two MagicPie 5 electric motors built into the wheelchair’s hubs with a power of 500 W was used in this research. The tests were carried out on a wheelchair test bench simulating the moment of resistance within the range of 8–11 Nm. Surface electromyography was employed for the measurement of MA, specifically, a four-channel Noraxon Mini DTS apparatus. The research was carried out on five patients from the group of C50 anthropometric dimensions. The effort was measured for four muscles: deltoid–anterior part, deltoid–posteriori part, and triceps brachii and extensor carpi radialis longus. The effectiveness of the hybrid propulsion system was observed based on the extensor carpi radialis longus muscle. In this case, for the standard wheelchair, the MA ranged from 93% to 123%. In contrast, for a wheelchair equipped with the hybrid propulsion system, at W = 70%, the MA was within the range of 43%–75%.

Repetitive Peripheral Magnetic Stimulation Combined with Motor Imagery Changes Resting-State EEG Activity: A Randomized Controlled Trial.

Repetitive peripheral magnetic stimulation is a novel non-invasive technique for applying repetitive magnetic stimulation to the peripheral nerves and muscles. Contrarily, a person imagines that he/she is exercising during motor imagery. Resting-state electroencephalography can evaluate the ability of motor imagery; however, the effects of motor imagery and repetitive peripheral magnetic stimulation on resting-state electroencephalography are unknown. We examined the effects of motor imagery and repetitive peripheral magnetic stimulation on the vividness of motor imagery and resting-state electroencephalography. The participants were divided into a motor imagery group and motor imagery and repetitive peripheral magnetic stimulation group. They performed 60 motor imagery tasks involving wrist dorsiflexion movement. In the motor imagery and repetitive peripheral magnetic stimulation group, we applied repetitive peripheral magnetic stimulation to the extensor carpi radialis longus muscle during motor imagery. We measured the vividness of motor imagery and resting-state electroencephalography before and after the task. Both groups displayed a significant increase in the vividness of motor imagery. The motor imagery and repetitive peripheral magnetic stimulation group exhibited increased β activity in the anterior cingulate cortex by source localization for electroencephalography. Hence, combined motor imagery and repetitive peripheral magnetic stimulation changes the resting-state electroencephalography activity and may promote motor imagery.

Probing cellular health at the muscle level—Multi‐frequency bioimpedance in Parkinson's disease

Bioimpedance (mfBIA) non‐invasively assesses cellular muscle health. Our aim was to explore whether mfBIA captures abnormal cellular muscle health in patients with Parkinson's Disease (PD) and how such changes are modulated with the use of Parkinson's medication. In patients with PD (n = 20) mfBIA measurements were made of biceps brachii, triceps, and extensor carpi radialis longus muscles of the more affected arm whilst at rest, using a mobile mfBIA device (IMPEDIMED, Australia). mfBIA and assessment of motor symptoms were performed in a pragmatic off‐medication state, as well as one and 3 h after oral intake of 200 mg levodopa. Age and sex‐matched healthy subjects (HC; n = 20) served as controls. PD and HC mfBIA parameters were compared by applying an unpaired two‐tailed adjusted t‐test and ANOVA with Tukey's correction for multiple comparisons (p ≤ 0.05). The PD group consisted of 13 men (71 ± 17 years) and 7 women (65 ± 7 years). Independent of medication, internal (Ri) and external resistance (Re) were found to be significantly higher, and membrane capacitance (Mc) significantly lower, in m.biceps brachii in PD subjects compared to HC. Center frequency (fc) was significantly higher in m.biceps brachii of PD subjects in the “medication‐off” state. There was no difference between PD and HC in mfBIA parameters in the measured extensor muscles. The upper limb flexor muscle shows a difference in mfBIA parameters in PD compared to HC. mfBIA may be useful in the diagnosis and assessment of PD patients and is objective, non‐invasive, reliable, and easy to use.