Elbow Flexion Movements Research Articles

EMG model calibration and trajectory tracking of rehabilitation exoskeleton by asynchronous tele-training

ABSTRACT This study presents a novel kinematic tracking model, designed for a networked exoskeleton system that is asynchronously taught by a remote therapist. The therapist’s rehabilitation exercises are quantitatively assessed using a monocular vision system. The resultant metrics are then transmitted asynchronously over the network to patients equipped with exoskeletons. The exoskeleton utilises these metrics as reference paths for exercises, complemented by electromyography (EMG) feedback. This work introduces a calibration approach aimed at estimating angular positions by utilising EMG observations. The calibration model establishes real-time correlations between polynomial reference positions. We further explore redundant kinematics, incorporating an EMG observer for linear, time-variant rehabilitation tracking control. Our methodology is validated using vision-based metric data and experimental EMG measurements including shoulder flexion, elbow flexion, and rowing-like movements. Computer simulations demonstrate the system’s ability to reliably, robustly, and effectively follow desired trajectories. This research offers a promising approach for remote personalized rehabilitation.

Assessment of joint position sense in active and passive modes with various elbow flexion angles and movement speeds using an isokinetic dynamometer

BackgroundJoint position sense is the ability to detect body segment position in space and is commonly used to represent proprioceptive performance. The isokinetic dynamometer is frequently used to evaluate elbow joint position sense during active and passive reproduction tasks with various testing protocols. However, few studies have reported the performance of joint position sense under different testing conditions. ObjectiveTo compare elbow joint position sense between active and passive reproduction tasks under different matching speeds and reference targets. DesignA cross-sectional study. MethodsTwenty participants without a history of upper-extremity surgery or neuromuscular diseases that affect the joint position sense of the elbow. Active and passive ipsilateral matching tasks were performed at four movement speeds (0.5°/s, 1°/s, 2°/s, and 4°/s) and three reference targets (elbow flexion at 0°–15°, 45°–60°, and 75°–90°), using an isokinetic dynamometer. The absolute and variable errors of each condition were calculated for comparison. ResultsIn active matching task with elbow flexion of 0°–15°, the absolute error at 0.5°/s was significantly larger than that at 2°/s and 4°/s, while the variable error at 1°/s was significantly larger than that at 2°/s. However, no differences were found at elbow flexion angles of 45°–60° and 75°–90°. Larger absolute errors were found at 4°/s with three testing angles in passive matching task. ConclusionsThis study compared the joint position sense errors under various testing conditions in the active and passive reproduction tasks. The movement speeds and target position effects should be considered during evaluation.

Contralateral cervical 7 as a potential donor in nerve transfer of adult brachial plexus injury especially in root avulsion case: A case report

Introduction: Contralateral cervical 7 (CC7) nerve transfer can be used in the absence of neurotizer in the BPI total root avulsion case. CC7 nerve transfer was introduced by Gu et al. in 1986, and aimed to restore motor and sensory function in the hand. The purpose of this paper is to report BPI patients with nearly total root avulsion using CC7 nerve transfer to the median nerve. Case Presentation: A man suffered a motorcycle accident in March 2010. There was a complete loss of motor and sensory in the right upper limb. From the examination, it was obtained that the cervical root avulsion of C5-6, C7 postganglionic rupture and cervical root avulsion of C8-T1. In April of 2010 has been done root neurotization C4 to C5, C3 root neurotization was to the suprascapular nerve, neurotization of the phrenic nerve to C6, neurotization C7 to C6 with graft, and neurotization CC7 to median nerve with vascularized pedicle ulnar graft. An evaluation was made at the donor and recipient sites. From the first admission he had total motoric loss to the last evaluation for 5 years post operation of motoric in the recipient site showed range of motion (ROM) of elbow flexion recovered to M4 with ROM 135o, shoulder abduction reached M3 30 o, finger flexion recovered to M2, and hand sensation came up to S1. There was no morbidity on the donor site from the first evaluation. Conclusion: Therefore, CC7 can be a potential donor in nerve transfer of adult BPI root avulsion cases without causing morbidity in the donor site.

The use of the Classic and Modified Transfer of the Lower Trapezius Muscle (Elhassan Transfer) as a Primary or Secondary Method for Surgical Reconstruction of the Abduction and External Rotation of the Shoulder in Brachial Plexus Injury

Background. Brachial plexus injury (BPI) leads to severe dysfunction of the upper extremity (UE). Elbow flexion and multiaxial movements in glenohumeral joint (MGHJ) are prioritized in reconstruction strategy. Time-dependent (< 6 months) nerve transfers (NT) allow effective restoring of MGHJ. Late (> 6 months) reconstruction of MGHJ remains completely dependent on transfers of the functional tendon-muscle complexes.
 Objective: to compare the outcomes of the classic Elhassan (c) and modified (m) transfer of the lower trapezius muscle (LTT) on recovery of monoaxial MGHJ.
 Materials and Methods. Patient (P.) #3 with M4+ recovery of the deltoid muscle (DM) after NT and P. #4 without spontaneous recovery (SR) of DM – forward flexion (FF) was 170° and 0°, respectively, received cLTT. Patient #1 with M4+ recovery of DM after NT and P. #2 with M4+ SR of DM (FF was 160° and 50°, respectively), received mLTT – distal fixation point has been changed from the tendon of the infraspinatus to the tendon of supraspinatus muscle.
 Results. Shoulder abduction (ABD) has been restored to 50° in P. #1 and P. #2, while the recovery of the external rotation (ER) has not been achieved – upper arm remained internally rotated (IR). ABD has been restored to 40° and 80° in P. #3 and P. #4; simultaneously +15° and +70° of ER has been restored.
 Conclusions. The use of mLTT leads to more effective recovery of monoaxial MGHJ – ABD – 50° vs. 40° after cLTT. The use of cLTT leads to more effective recovery of another monoaxial MGHJ – ER – +15° and +70° vs. IR after mLTT; LTT should only be considered as a complementary surgical procedure, which utilization should cohere with a patient’s requirements to the MGHJ.

Range of motion required for Auslan: a biomechanical analysis.

Auslan is used by the Australian deaf community and relies heavily on hand, wrist, and elbow movement. Upper limb injury or dysfunction may require surgical intervention to alleviate pain and provide a stable skeleton for function, leading to partial or complete reduction in motion. The aim of this study was to assess the wrist, forearm, and elbow motion required to communicate via Auslan, to tailor optimal interventions in this population. A biomechanical analysis was conducted on two native Auslan communicators, who signed 28 pre-selected and common Auslan words and phrases. Sagittal plane wrist and elbow motion was found to be of greater importance than axial plane forearm rotation. Relative elbow flexion and generous wrist motion was common for many of the words and phrases, while end-range elbow extension was not recorded. The maintenance of wrist and elbow motion should be prioritized when selecting surgical interventions for patients who communicate using Auslan.

Accuracy study of the Oculus Touch v2 versus inertial sensor for a single-axis rotation simulating the elbow’s range of motion

Virtual reality (VR) has emerged as a valid addition to conventional therapy in rehabilitation and sports medicine. This has enabled the development of novel and affordable rehabilitation strategies. However, before VR devices can be used in these situations, they must accurately capture the range of motion of the body-segment where they are mounted. This study aims to state the accuracy of the Oculus Touch v2 controller when used to measure the elbow’s motion in the sagittal plane. The controller is benchmarked against an inertial sensor (ENLAZA^{mathrm{TM}}), which has already been validated as a reliable measurement device. We have developed a virtual environment that matches both the Oculus Touch v2 and the inertial sensor orientations using a digital goniometer. We have also collected the orientation measurements given by each system for a set of 17 static angles that cover the full range of normal elbow flexion and hyperextension motion, in 10° intervals from − 10° (hyperextension) to 150° (flexion). We have applied the intra-rater reliability test to assess the level of agreement between the measurements of these devices, obtaining a value of 0.999, with a 95% confidence interval ranged from 0.996 to 1.000. By analyzing the angle measurement outcomes, we have found that the accuracy degrades at flexion values between 70° and 110°, peaking at 90°. The accuracy of Oculus Touch v2 when used to capture the elbow’s flexion motion is good enough for the development of VR rehabilitation applications based on it. However, the flaws in the accuracy that have been revealed in this experimental study must be considered when designing such applications.

Electromyographic and Systemic Physiological Thresholds in Single-Joint Elbow Flexion Movements.

Reported relationships between electromyographic (EMG) thresholds and systemic thresholds based on lactate, ventilation, or heart rate are contradictory. This might be related to the complexity of the investigated whole-body movements involving many muscles with different activation patterns. Therefore, the aim of the study was to investigate these relationships during an incremental single-joint exercise. Eighteen male subjects (29.7 [4.4]y) performed single-arm elbow flexions on a biceps curl machine with loads increasing every minute until exhaustion. EMG signals of the main elbow flexors (short and long head of the biceps brachii, flexor carpi radialis, and brachioradialis) as well as gas exchange variables, blood lactate concentration, and heart rate were measured, and 2 turn points based on a 3-phase model of metabolism were determined for each variable. The first and second turn points for EMG were determined at 32.0% to 33.1% and 64.4% to 66.5% of maximal achieved performance (maximum weight), respectively. Systemic turn points were determined at 33.3% to 34.4% and 65.9% to 66.7% of maximum weight and were not significantly different from EMG turn points. Furthermore, systemic and EMG turn points showed a strong or very strong relationship at the first (ρ = .54-.93, P < .05) and second turn point (ρ = .76-.93, P < .01). A close relationship between EMG and systemic turn points could be confirmed for the applied movement of a small muscle group. The determination of local single muscle thresholds using EMG provides additional muscle-specific information about performance-limiting properties of muscles involved in endurance-type incremental exercise.

Virtual Rehabilitation of Elbow Flexion Following Nerve Transfer Reconstruction for Brachial Plexus Injuries Using the Single-Joint Hybrid Assisted Limb

PurposeThe upper limb single-joint hybrid assistive limb (HAL), a wearable robot that can support elbow flexion and extension motions, was originally used to rehabilitate patients with stroke. We report the preliminary outcomes of serial HAL use for rehabilitation following nerve transfer (NT) for elbow flexion reconstruction in brachial plexus injuries.MethodsHybrid assistive limb training consisted of virtual and power training courses. Virtual training was started before HAL picked up motor unit potentials (MUPs) from the target muscle through electrodes attached to the skin overlying the original donor muscles. Power training was started after the maturation of MUPs, the stage where the MUPs were strong to be recognized to arise from the target muscles. Hybrid assistive limb assist at this stage was carried out by decreasing the settings in an inversely proportionate manner to the increase in target muscle strength. Fourteen patients underwent HAL training following NT. Eight patients had the intercostal nerve to musculocutaneous nerve (ICN-MCN) transfer, and their postoperative functional outcomes and rehabilitation performance were compared to 50 patients with ICN-MCN transfer who underwent conventional postoperative rehabilitation with electromyographic biofeedback (EMG-BF) techniques.ResultsComparison of the long-term results following ICN-MCN transfer between EMG-BF and HAL groups showed similar follow-up times, elbow flexion range of motion, or power of elbow flexion assessed using the British Medical Council grade, and quantitative measurement using Kin-Com dynamometer. However, the number of rehabilitation sessions was significantly fewer in the HAL than EMG-BF group.ConclusionHAL training accelerated patients’ learning to convert the original muscle function into elbow flexion following NT by replicating elbow flexion during the pre-MUP detection stage and shortening the rehabilitation time.Type of study/level of evidenceTherapeutic IV.

Feasibility and Challenges of Performing Magnetoencephalography Experiments in Children With Arthrogryposis Multiplex Congenita.

Arthrogryposis multiplex congenita (AMC) has recently drawn substantial attention from researchers and clinicians. New effective surgical and physiotherapeutic methods have been developed to improve the quality of life of patients with AMC. While it is clear that all these interventions should strongly rely on the plastic reorganization of the central nervous system, almost no studies have investigated this topic. The present study demonstrates the feasibility of using magnetoencephalography (MEG) to investigate brain activity in young AMC patients. We also outlined the general challenges and limitations of electrophysiological investigations on patients with arthrogryposis. We conducted MEG recordings using a 306-channel Elekta Neuromag VectorView system during a cued motor task performance in four patients with arthrogryposis, five normally developed children, and five control adults. Following the voice command of the experimenter, each subject was asked to bring their hand toward their mouth to imitate the self-feeding process. Two patients had latissimus dorsi transferred to the biceps brachii position, one patient had a pectoralis major transferred to the biceps brachii position, and one patient had no elbow flexion restoration surgery before the MEG investigation. Three patients who had undergone autotransplantation prior to the MEG investigation demonstrated activation in the sensorimotor area contralateral to the elbow flexion movement similar to the healthy controls. One patient who was recorded before the surgery demonstrated subjectively weak distributed bilateral activation during both left and right elbow flexion. Visual inspection of MEG data suggested that neural activity associated with motor performance was less pronounced and more widely distributed across the cortical areas of patients than of healthy control subjects. In general, our results could serve as a proof of principle in terms of the application of MEG in studies on cortical activity in patients with AMC. Reported trends might be consistent with the idea that prolonged motor deficits are associated with more difficult neuronal recruitment and the spatial heterogeneity of neuronal sources, most likely reflecting compensatory neuronal mechanisms. On the practical side, MEG could be a valuable technique for investigating the neurodynamics of patients with AMC as a function of postoperative abilitation.

Restoration of Elbow Flexion for Upper Trunk Brachial Plexus Injuries: Evaluation of Nerve Transfers and Modified Steindler Flexorplasty

Introduction. In patients with delayed presentation between 6 to 12 months, surgical treatment guidelines are not well defined in brachial plexus injury. Still, several authors have agreed that functional outcomes in patients treated within six months from the date of injury have the best results. Nerve transfers are still considered one of the treatment options in the said subset of patients even after six months. In contrast, a primary Steindler flexorplasty, or proximal advancement of the flexor-pronator group, is an ideal technique for elbow flexion with an elapsed time from injury &gt;6 to 9 months.&#x0D; Objective. The purpose of this investigation was to compare the clinical outcome s of nerve transfers versus modified Steindler flexorplasty for the restoration of elbow flexion in upper type brachial plexus injuries (BPI).&#x0D; Methods. A retrospective review of 28 patients who underwent nerve transfers (NT) and 12 patients who underwent modified Steindler flexorplasty (MSF) was done to determine the outcome of treatments. The manual muscle testing using the Medical Research Council scaling system, Visual Analog Scale for pain, active range of motion, and Disabilities of the Arm, Shoulder and Hand form scores were taken as dependent variables.&#x0D; Results. The NT group had a median age of 27.5 years, with 26 men, a median surgical delay of 5.6 months, and a median follow-up of 33 months. Twenty out of 28 patients (71%) had ≥M3 with a median range of 117.6° elbow flexion motion. Median postoperative DASH (n=16) and VAS scores were 29.2 and 3, respectively. For the MSF patients, the median age was 27 years, including ten men, the median surgical delay was 12 months, and the median follow-up was 18.4 months. All the 12 patients had ≥M3, with a median range of motion of 106°. The median postoperative DASH score (n=5) and VAS score were 28.3 and 0, respectively. In the NT group, 73.3% (11/15) achieved ≥M3 elbow flexion if the operation was done in &lt;6 months.&#x0D; Conclusion. Nerve transfers and the modified Steindler procedure are still excellent options for successful elbow flexion reanimation in patients with brachial plexus injuries. Our results also showed that those with surgical delays of less than six months had the highest rate of achieving ≥M3 elbow flexion strength in the nerve transfer group.

The influence of accuracy constraints on bimanual and unimanual sequence learning

An experiment was designed to determine whether accuracy constraints can influence how unimanual and bimanual motor sequences are produced and learned. The accuracy requirements of the task were manipulated using principles derived from Fitts’ Law to create relatively low (ID = 3) and high (ID = 5) accuracy demands. Right-limb dominant participants (N = 28, age = 21.9 yrs; 15 females and 13 males) were required to produce unimanual left, unimanual right or bimanual movement sequences using elbow extension and flexion movements to hit a series of illuminated targets. The targets were illuminated in a repeating sequence of 16 elements. Participants performed 20 practice trials. Thirty minutes following the practice trials participants performed a retention test. Element duration (time interval between target hits) and segment harmonicity (hesitations/adjustments in movement pattern) were calculated. The results indicate longer element duration and lower harmonicity values (more adjustments) when the task required higher accuracy demands (ID = 5) compared to low accuracy demands (ID = 3). Element duration was shorter and harmonicity was higher at ID = 5 for both unimanual groups than the bimanual group. However, element duration was shorter and harmonicity was higher at ID = 3 for the bimanual group than for both unimanual groups. These results indicate that the accuracy demands of the task can influence both performance and learning of motor sequences and suggest differences between unimanual and bimanual motor sequence learning. It appears there is a bimanual advantage for tasks with lower accuracy demands whereas performance is more accurate with unimanual performance, regardless of limb, with higher accuracy demands. These results are consistent with recent research indicating that accuracy requirements change the control processes for bimanual performance differently than for unimanual tasks.

Short-term effectiveness of free radial head reconstruction of coronoid process combined with artificial radial head replacement in treatment of complex terrible triad of elbow

To investigate the short-term effectiveness of free radial head reconstruction of coronoid process, artificial radial head replacement, and ulna olecranon internal fixation in the treatment of the complex terrible triad of the elbow. Retrospective analysis was made on the clinical data of 12 patients with complex terrible triad of the elbow treated with free radial head reconstruction of coronoid process, artificial radial head replacement, and ulna olecranon internal fixation between April 2011 and April 2018. There were 8 males and 4 females with an average age of 44.5 years (range, 26-62 years). The causes of injury included 5 cases of traffic accident, 7 cases of falling from hight. The Regan-Morrey classification of ulnar coronoid process fractures was type Ⅲ; Mason classification of radial head fractures was type Ⅲ in 7 cases and type Ⅳ in 5 cases. The time from injury to operation was 5-14 days, with an average of 6.0 days. The operation time, intraoperative blood loss, and complications were recorded. After operation, X-ray film of elbow joint was reexamined, fracture healing condition was observed, and fracture healing time was recorded. The flexion, extension, and rotation of the elbow joints on the healthy and affected sides were recorded and measured. The elbow function was evaluated according to Mayo elbow function score. The operation time was 90-140 minutes (mean, 110 minutes); the intraoperative blood loss was 100-300 mL (mean, 150 mL). None of the patients had vascular injury during the operation. One patient developed numbness in the ulnar nerve innervation area and recovered completely after symptomatic treatment for 1 week. All the 12 patients were followed up 12-22 months, with an average of 16 months. At last follow-up, the fracture healed completely, 1 patient developed ectopic ossification of elbow joint, and 2 patients developed traumatic arthritis of elbow joint. No internal fixation-related complications occurred. There was no significant difference in the range of motion of elbow flexion, extension, pronation, and supination between the affected and healthy sides ( P>0.05). The median Mayo elbow function score was 96, and the interquartile range was (94, 97), and the excellent and good rate was 91.7%. For patients with complex terrible triad of the elbow with ulna coronoid process fractures of Regan-Morrey type Ⅲ and radial head fractures of Mason type Ⅲ, Ⅳ combined with ulna olecranon fractures, the free radial head reconstruction, artificial radial head replacement, and ulna olecranon internal fixation, through active rehabilitation function exercise after operation, can achieve more satisfactory short-term effectiveness.

Perbandingan Gerak Elbow Extension dan Elbow Flexion Terhadap Akurasi Forehand Tenis Lapangan

Some of the beginner athletes in UKM of court tennis in UPGRIS conduct swing on the forehand striking in a slightly different way. Some when swinging with fully straight arms, some are slightly bent. The aim of the study is to investigate the differences between elbow extension and elbow flexion toward the accuracy level of forehand striking of court tennist. This research method uses comparative design. The sample of this study is the tennis players of the students in Universitas PGRI Semarang, the total are 7 people. The Hewiit Tennis Achievement Test is used for forehand striking instruments and dartfish software to find out the differences between the elbow movements and the analysis. Independent t-test is used to find out the differences of the striking accuracy result. The results show the significant differencs between elbow extension and elbow flexion with an average score of 22 and 63, with the significance value of a difference of 0.001. The conclusion of this research is that the elbow flexion movement in forwardswing step is better than elbow extension movement.

Kinematics and workspace analysis of a robotic device for performing rehabilitation therapy of upper limb in stroke-affected patients

Exoskeleton robots generally have multi-functions and one such function is doing rehabilitation therapy in upper limb and lower limb in stroke-affected patients. A novel hybrid (serial-parallel) robot manipulator was proposed in this paper for rehabilitation of upper limb and its kinematics are studied systematically. This robot manipulator intends to perform wrist flexion, wrist extension, wrist radial deviation, wrist ulnar deviation, elbow flexion, elbow extension, elbow pronation and elbow supination motions. The contemporary mechanical designs especially the kinematic structure of upper limb exoskeleton robots have a unique feature that is, almost all of them use serial manipulators, and few others used parallel manipulators. The kinematic structure of the proposed robot is that of a hybrid manipulator (two parallel manipulators connected in series) which has 4-degrees-of-freedom. It is composed of an upper 3SPS-type parallel manipulator and 2SPR-type parallel manipulator connected in series. The Jacobian and Hessian Matrix method was used to derive the manipulator kinematic formula for solving the displacement, velocity and acceleration. A 3D model of the robotic arm was constructed and analyzed by simulation. The positioning workspace of manipulator was constructed and analyzed. The 3SPS-type parallel manipulator has good kinematic characteristics while performing wrist motions. The 2SPR-type parallel manipulator produced singular configuration, while performing the desired rehabilitation elbow motions, it was found to not be suitable for usage in performing rehabilitation therapy in stroke-affected patients.

The role of biceps loading and muscle activation on radial head stability in anterior Monteggia injuries: An in vitro biomechanical study

IntroductionLittle evidence-based information is available to direct the optimal rehabilitation of patients with anterior Monteggia injuries. Purpose of the StudyThe aims of this biomechanical investigation were to (1) quantify the effect of biceps loading and (2) to compare the effect of simulated active and passive elbow flexion on radial head stability in anterior Monteggia injuries. Study DesignIn vitro biomechanical study. MethodsSix cadaveric arms were mounted in an elbow motion simulator. The effect of biceps loading, simulated active and passive elbow flexion motions was examined with application of 0N, 20N, 40N, 60N, 80N, and 100N of load. Simulated active and passive elbow flexion motions were then performed with the forearm supinated. Radial head translation relative to the capitellum was measured using an optical tracking system. After testing the intact elbows, the proximal ulna was osteotomized and realigned using a custom jig to simulate an anatomical reduction. We then sequentially sectioned the anterior radiocapitellar joint capsule, annular ligament, quadrate ligament, and the proximal and middle interosseous membrane to simulate soft tissue injuries commonly associated with anterior Monteggia fractures. ResultsGreater magnitudes of biceps loading significantly increased anterior radial head translation. However, there was no significant difference in radial head translation between simulated active and passive elbow flexion except in the final stage of soft tissue sectioning. There was a significant increase in anterior radial head translation with progressive injury states with both isometric biceps loading and simulated active and passive motion. ConclusionsOur results demonstrate that anatomic reduction of the ulna may not be sufficient to restore radial head alignment in anterior Monteggia injuries with a greater magnitude of soft tissue injury. In cases with significant soft tissue injury, the elbow should be immobilized in a flexed and supinated position to allow relaxation of the biceps and avoid movement of the elbow in the early postoperative period.

Elbow motion patterns during daily activity

This invivo kinematic study was developed to ascertain (1) elbow posture and motion during daily activities and (2) to compare motions of the dominant and nondominant elbows. Forty-six subjects wore a custom instrumented shirt to continuously measure elbow posture and motion for the waking hours of 1 day. The 3D orientations of each of the forearm and humerus sensors enabled calculation of elbow flexion-extension and pronation-supination angles. The elbow flexion-extension postures that were most common ranged from 60°-100° for both the dominant and nondominant extremities averaging 44% ± 4% and 35% ± 4% of the day, respectively. When elbow flexion motions were calculated, there were a large number of motions over a wide distribution of flexion angles, with the dominant side exhibiting significantly more motions per hour than the nondominant side. Both flexion-extension and pronation-supination motions occur more commonly in the dominant arm, and the dominant arm is more commonly in pronation. These data providea baseline for assessing treatment outcomes, ergonomic studies, and elbow arthroplasty wear testing.

The Clinical Function Comparison of Post Operative Nerve Grafting and Nerve Transfer in Patients with Brachial Plexus Injury

Background: Brachial plexus injury is most commonly caused by motorcycle accidents and leads to a deficit of motor strength, pain and disability of the upper limb. The main purpose of reconstructive action of brachial plexus injury is to restore the function of the shoulder and elbow. Aim: This study aimed to compare the clinical function of post-operative nerve grafting with nerve transfer in patients with brachial plexus injury. Methods: This study enrolled a sample of patients who had surgery and evaluated the range of active movement of shoulder abduction and elbow flexion; motor strength using the scale of the British Medical Research Council (BMRC); neuropathic pain using Visual Analog Scale (VAS); and upper extremity disability using the Quick Disability of the Arm, Shoulder, and Hand (Quick DASH) questionnaire. Results: 30 patients were divided into groups of nerve grafting and nerve transfer with each group consisting of 15 patients. 13 patients (87%) of each group had motor strength of functional shoulder abduction (&gt;M3) (p = 0.874). 13 patients (87%) had better functional elbow flexion motor strength (&gt;M3) in the nerve transfer group than 11 patients (73%) of the nerve grafting group (p = 0.036). Conclusion: The postoperative nerve transfered clinical function showed a better elbow flexion function with a lower severity of upper limb disability.

Intermuscular coupling based on wavelet packet-cross frequency coherence

Human motion control system has a high degree of nonlinear characteristics. Through quantitative evaluation of the nonlinear coupling strength between surface electromyogram (sEMG) signals, we can get the functional state of the muscles related to the movement, and then explore the mechanism of human motion control. In this paper, wavelet packet decomposition and n: m coherence analysis are combined to construct an intermuscular cross-frequency coupling analysis model based on wavelet packet- n: m coherence. In the elbow flexion and extension state with 30% maximum voluntary contraction force (MVC), sEMG signals of 20 healthy adults were collected. Firstly, the subband components were obtained based on wavelet packet decomposition, and then the n: m coherence of subband signals was calculated to analyze the coupling characteristics between muscles. The results show that the linear coupling strength (frequency ratio 1:1) of the cooperative and antagonistic pairs is higher than that of the nonlinear coupling (frequency ratio 1:2, 2:1 and 1:3, 3:1) under the elbow flexion motion of 30% MVC; the coupling strength decreases with the increase of frequency ratio for the intermuscular nonlinear coupling, and there is no significant difference between the frequency ratio n: m and m: n. The intermuscular coupling in beta and gamma bands is mainly reflected in the linear coupling (1:1), nonlinear coupling of low frequency ratio (1:2, 2:1) between synergetic pair and the linear coupling between antagonistic pairs. The results show that the wavelet packet- n: m coherence method can qualitatively describe the nonlinear coupling strength between muscles, which provides a theoretical reference for further revealing the mechanism of human motion control and the rehabilitation evaluation of patients with motor dysfunction.

Outcome of buttress plate fixation of coronoid process fracture via a modified anteromedial approach

Fractures of Coronoid process of ulna are rare and difficult injury to treat with pain and instability to elbow. The aim is to study outcomes of buttress plate fixation of coronoid via modified anteromedial approach. We evaluated 15 patients from august 2017 to September 2019 with 9 (60%) of type II & 6(40%) of type III Regan-Morrey fractures. At final follow up all patient were have solid osseous union with mean elbow flexion & extension movement was 0 to129 degrees,4 patients have extension lag of 5 degrees,12 patients had full flexion of elbow while 3 patients have flexion upto 120 degrees. Mean supination movement was 79 degrees & mean pronation movement was 80 degrees. The mean MEPS score was 95 with 12 (80%) excellent and 3 (20%) good results. Coronoid factors can be treated with modified anteromedial approach and Buttress plating with excellent outcomes.

Microcontroller-based assistive device for training weak biceps brachii muscle

A person with a certain degree of biceps brachii muscle weakness will not able to move the lower hand. The muscle needs contraction and relaxation practice regularly to avoid the condition getting worse. An electromyography-based assistive device has been developed. It uses biopotential signals from biceps brachii muscle when contracted and relaxed to control the elbow flexion and extension movement of the weak hand. The device uses a Muscle Sensor V3 module to sense the muscle biopotential signals, and also an Arduino Nano 3.0 microcontroller module and a servo motor to control the elbow movement. The elbow movement is limited to 90° to its maximum degree of movement at 170°. It is the range of elbow movement that used in a method to work out the biceps brachii muscle. The starting process needs to adjust elbow position manually using potentiometer to 90° angles. This device can work properly when stimulated by the biceps brachii muscle biopotential signals and produce as low as 0,0977V at the input of the internal ADC of Arduino Uno 3.0 when the muscle contracted and lower than that voltage when it relaxed. The device consumes low power to operate at 0.374watts.