NEUROMOTOR COORDINATION OF MULTISEGMENTAL MUSCLE DURING A CHANGE IN MOVEMENT DIRECTION

2006 ◽  
Vol 10 (02) ◽  
pp. 63-74 ◽  
Author(s):  
J. M. M. Brown ◽  
J. Wickham
Keyword(s):  
Shoulder Joint ◽  
Motor Task ◽  
Deltoid Muscle ◽  
Movement Direction ◽  
Shoulder Abduction ◽  
Prime Mover ◽  
Joint Rotation ◽  
Functional Roles ◽  
Inter Trial Interval ◽  
The Right

The aim of this investigation was to determine how the CNS controlled seven segments of the human deltoid muscle during a change in the direction of shoulder joint motion. Specifically, we wished to determine how the prime mover, synergist and antagonist muscle segments of this muscle were manipulated to assume new functional roles as the direction of shoulder motion was rapidly changed from shoulder abduction to shoulder adduction. Seven bipolar surface electrodes (7 mm inter-electrode distance) were placed over the seven segments (D1–D7) of the right deltoid, in seven young (19–24yrs) male subjects, to detect changes in muscle segment activation as the subjects transitioned from a rapid shoulder-abduction to a rapid-adduction force impulse (MT = 1000 ms). For each subject, fifteen trials were recorded at an inter-trial interval of 30 seconds. Comparisons of muscle segment timing and intensity of activation were made across 6 equal time intervals between just before the peak of the abduction force impulse and the subsequent peak of the adduction force impulse. The results of this study have shown that segments of the deltoid were activated during both the shoulder abduction and shoulder adduction motor task. In addition, the pattern of muscle segment activation (timing and intensity), during the transition from shoulder abduction to shoulder adduction, was dependent upon the muscle's moment arm and line of pull in relation to the axis of shoulder joint rotation. Three distinct patterns of neuromotor activation were noted within the segments of the deltoid muscle. During abduction the agonist prime mover and synergist segments (D1–D5) were totally deactivated (< 10% MVC) as they became antagonist segments during adduction. The antagonist segment (D7), during abduction, was deactivated and then reactivated as it became a synergist segment during adduction. Finally segment D6 was shown to have a nearly continuous period of activation. The study has shown that during a transition to a new movement direction, a muscle segment's line of pull and future function in the next phase of the movement appears to determine its period and intensity of activation.

scholarly journals Latissimus dorsi tendon transposition combined with shoulder joint proximal capsule plasty with peroneal longus tendon autograft in the treatment of patients with massive rotator cuff ruptures and proximal dislocation of the humerus head (clinical case)

2021 ◽  
Vol 6 (5) ◽  
pp. 178-183
Author(s):  
D. V. Menshova ◽  
N. S. Ponomarenko ◽  
I. A. Kuklin
Keyword(s):  
Rotator Cuff ◽  
Humeral Head ◽  
Shoulder Joint ◽  
Latissimus Dorsi ◽  
Clinical Case ◽  
Deltoid Muscle ◽  
X Rays ◽  
Longus Tendon ◽  
Surgical Methods ◽  
The Right

The frequency of rotator cuff injuries in people over 45 years of age is 25.6–50 %, and  40  % of these injuries are massive. Shoulder rotator cuff injury causes disorders in biomechanics of the shoulder joint such as anterior-superior dislocation of the humeral head. Injury of the deltoid muscle combined with a massive rupture of the rotator cuff causes proximal dislocation of the humeral head during any active movement. In  the  treatment of these cases, surgical methods of treatment are used, such as transposition of the latissimus dorsi muscle, proximal capsule plasty, and reverse shoulder arthroplasty. We present a successful clinical case of treatment of a patient with chronic massive injury of the right shoulder joint rotator cuff tendons in combination with the injury of shoulder joint proximal capsule, dislocation of the right humerus head, and hypotrophy of the anterior portion of the deltoid muscle. We performed transposition of the latissimus dorsi tendon in combination with shoulder joint proximal capsule plasty with an autograft of the peroneal longus tendon. The check-up X-rays show that the dislocation of the right shoulder joint was eliminated. In the early postoperative period, the patient started physiotherapy exercises of the operated limb using abduction pillow. By the 7th day after surgery, the abduction of the operated limb reached 70°. The described surgical technique allows to restore congruence in the shoulder joint and the function of the injured limb in severe multiple injuries of the shoulder joint structures. 

scholarly journals A Comparison Study on the Electrical Activity of Arm Abduction Muscles During Shoulder Abduction and Scaption Between Shooting Disciplines

2020 ◽  
Vol 5 (4) ◽  
pp. 250-261
Author(s):  
Safoura Heshmati ◽  
◽  
Hassan Daneshmandi ◽  
Seyyed Hossein Hosseini ◽  
◽  
...  
Keyword(s):  
Electrical Activity ◽  
Surface Electromyography ◽  
Shoulder Joint ◽  
Tensile Force ◽  
Deltoid Muscle ◽  
Shoulder Abduction ◽  
Comparison Study ◽  
Significance Level ◽  
Anterior Deltoid ◽  
Air Rifle

Objective: Considering the positions that the shooter chooses during shooting in different disciplines, it seems that the activity of deltoid and supraspinatus muscles which are common muscles during movement, varies in different disciplines. Therefore, the purpose of the present study was to evaluate and compare the electrical activity of deltoid and supraspinatus muscles between three shooting disciplines. Methods: 24 shooters (8 archers, 8 air pistol shooters, and 8 air rifle shooters) participated in the study. They performed shoulder abduction and scaption at 60 and 90 degrees. The electrical activity of deltoid and supraspinatus muscles was then recorded using surface electromyography. The data were analyzed by using ANOVA and Tukey’s test at the significance level of P<0.05. Results: The activity of anterior deltoid muscle at 60 and 90 degrees of abduction and the activity of middle deltoid and supraspinatus muscles only at 90 degree of abduction was significantly higher in the archery group than in the air pistol group (P<0.05). Conclusion: The higher electrical activity of deltoid and supraspinatus muscles in archery sport may be related to the tensile force of the bow and the greater arm angle at the shoulder joint during this type of shooting compared to air pistol and air rifle shooting.

Human Cerebral Potentials During Motor Training Under Different Forms of Sensory Feedback

1999 ◽  
Vol 13 (4) ◽  
pp. 234-244
Author(s):  
Uwe Niederberger ◽  
Wolf-Dieter Gerber
Keyword(s):  
Healthy Subjects ◽  
Sensory Feedback ◽  
Motor Task ◽  
Tactile Feedback ◽  
Proprioceptive Feedback ◽  
Motor Training ◽  
Feedback Group ◽  
Emg Feedback ◽  
The Right ◽  
Training Success

Abstract In two experiments with four and two groups of healthy subjects, a novel motor task, the voluntary abduction of the right big toe, was trained. This task cannot usually be performed without training and is therefore ideal for the study of elementary motor learning. A systematic variation of proprioceptive, tactile, visual, and EMG feedback was used. In addition to peripheral measurements such as the voluntary range of motion and EMG output during training, a three-channel EEG was recorded over Cz, C3, and C4. The movement-related brain potential during distinct periods of the training was analyzed as a central nervous parameter of the ongoing learning process. In experiment I, we randomized four groups of 12 subjects each (group P: proprioceptive feedback; group PT: proprioceptive and tactile feedback; group PTV: proprioceptive, tactile, and visual feedback; group PTEMG: proprioceptive, tactile, and EMG feedback). Best training results were reported from the PTEMG and PTV groups. The movement-preceding cortical activity, in the form of the amplitude of the readiness potential at the time of EMG onset, was greatest in these two groups. Results of experiment II revealed a similar effect, with a greater training success and a higher electrocortical activation under additional EMG feedback compared to proprioceptive feedback alone. Sensory EMG feedback as evaluated by peripheral and central nervous measurements appears to be useful in motor training and neuromuscular re-education.

scholarly journals Transcriptomic uniqueness and commonality of the ion channels and transporters in the four heart chambers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sanda Iacobas ◽  
Bogdan Amuzescu ◽  
Dumitru A. Iacobas
Keyword(s):  
Ion Channels ◽  
Cycle Phase ◽  
Functional Roles ◽  
Expression Control ◽  
Gene Expression Control ◽  
Left And Right ◽  
The Right ◽  
Phase Out ◽  
Right Atria ◽  
Agilent Microarrays

AbstractMyocardium transcriptomes of left and right atria and ventricles from four adult male C57Bl/6j mice were profiled with Agilent microarrays to identify the differences responsible for the distinct functional roles of the four heart chambers. Female mice were not investigated owing to their transcriptome dependence on the estrous cycle phase. Out of the quantified 16,886 unigenes, 15.76% on the left side and 16.5% on the right side exhibited differential expression between the atrium and the ventricle, while 5.8% of genes were differently expressed between the two atria and only 1.2% between the two ventricles. The study revealed also chamber differences in gene expression control and coordination. We analyzed ion channels and transporters, and genes within the cardiac muscle contraction, oxidative phosphorylation, glycolysis/gluconeogenesis, calcium and adrenergic signaling pathways. Interestingly, while expression of Ank2 oscillates in phase with all 27 quantified binding partners in the left ventricle, the percentage of in-phase oscillating partners of Ank2 is 15% and 37% in the left and right atria and 74% in the right ventricle. The analysis indicated high interventricular synchrony of the ion channels expressions and the substantially lower synchrony between the two atria and between the atrium and the ventricle from the same side.

Identify Finger Rotation Angles With ArUco Markers and Action Cameras

2021 ◽  
Author(s):  
Tianyun Yuan ◽  
Yu (Wolf) Song ◽  
Gerald A. Kraan ◽  
Richard H. M. Goossens
Keyword(s):  
Dynamic Time Warping ◽  
Tracking System ◽  
Low Cost ◽  
Finger Joint ◽  
Hand Tracking ◽  
Human Hand ◽  
Time Warping ◽  
Joint Rotation ◽  
Dynamic Time ◽  
The Right

Abstract Measuring the motion of human hand joints is a challenging task due to the high number of DOFs. In this study, we proposed a low-cost hand tracking system built on action cameras and ArUco markers to measure finger joint rotation angles. The lens distortion of each camera was corrected first via intra-calibration and the videos of different cameras were aligned to the reference camera using a dynamic time warping based method. Two methods were proposed and implemented for extracting the rotation angles of finger joints: one is based on the 3D positions of the markers via inter-calibration between cameras, named pos-based method; the other one is based on the relative marker orientation information from individual cameras, named rot-based method. An experiment was conducted to evaluate the effectiveness of the proposed system. The right hand of a volunteer was included in this practical study, where the movement of the fingers was recorded and the finger rotation angles were calculated with the two proposed methods, respectively. The results indicated that although using the rot-based method may collect less data than using the pos-based method, it was more stable and reliable. Therefore, the rot-based method is recommended for measuring finger joint rotation in practical setups.

Brodie’s Abscess of the Proximal Humerus Metaphysis: A Case Report

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Nilesh Vishwakarma ◽  
Shaival Chauhan ◽  
Shrey S Binyala ◽  
Sanjeev K Singh
Keyword(s):  
Case Report ◽  
Shoulder Joint ◽  
Proximal Part ◽  
Focal Lesion ◽  
Posterior View ◽  
Brodie’S Abscess ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Pyogenic Osteomyelitis ◽  
Metaphyseal Region

Introduction:Primary subacute pyogenic osteomyelitis, or Brodie’s abscess was initially documented by Sir Benjamin Brodie in 1832. We present a case report with a 6-months follow-up period, demonstrating the successful diagnosis and surgical treatment of a focal lesion of the proximal metaphysis of the right humerus in a 21-years-old female. The pathology of hematologic osteomyelitis and its role in the development of a subacute abscess along with a review of literature and an in detail description of the pathogenesis of Brodie’s abscess is discussed and submitted. Case Report:A 21- years -old healthy female with a history of fall sustaining injury to the right shoulder one 1 year back followed by which she presented to the outpatient clinic with a swelling over her right shoulder. The patient was managed conservatively with analgesics and was relieved of pain over a course of one 1 week of medications, the patient now presents with pain and swelling in the right shoulder joint on and off since the episode of fall one 1 year back, which had increased over a period of past one 1 week. A week before the most recent presentation she started experiencing some discomfort and pain in her right shoulder. No recent trauma was reported. A mild swelling appeared over the proximal part of the humerus. There were no constitutional symptoms of fever or any illness reported. On examination, there was noted a painful restriction of ROM at the right shoulder joint with no rotator cuff injury. Laboratory investigations were suggestive of raised inflammatory markers. Radiograph of the right shoulder taken in the true antero-posterior view with the shoulder in the neutral rotation was suggestive of an oval lucency with surrounding sclerosis in the proximal metaphyseal region of the humerus. Magnetic resonance imaging MRI of the right shoulder joint showed features consistent with Brodie’s abscess in the proximal metaphyseal region of the humerus. Surgical debridement of the abscess w

scholarly journals Motor learning and transfer: from feedback to feedforward control

2019 ◽  
Author(s):  
Rodrigo S. Maeda ◽  
Paul L. Gribble ◽  
J. Andrew Pruszynski
Keyword(s):  
Motor Learning ◽  
Muscle Activity ◽  
Shoulder Joint ◽  
Stretch Reflex ◽  
Feedforward Control ◽  
Motor Task ◽  
Joint Torques ◽  
Motor Commands ◽  
Shoulder Muscle ◽  
Long Latency

AbstractPrevious work has demonstrated that when learning a new motor task, the nervous system modifies feedforward (ie. voluntary) motor commands and that such learning transfers to fast feedback (ie. reflex) responses evoked by mechanical perturbations. Here we show the inverse, that learning new feedback responses transfers to feedforward motor commands. Sixty human participants (34 females) used a robotic exoskeleton and either 1) received short duration mechanical perturbations (20 ms) that created pure elbow rotation or 2) generated self-initiated pure elbow rotations. They did so with the shoulder joint free to rotate (normal arm dynamics) or locked (altered arm dynamics) by the robotic manipulandum. With the shoulder unlocked, the perturbation evoked clear shoulder muscle activity in the long-latency stretch reflex epoch (50-100ms post-perturbation), as required for countering the imposed joint torques, but little muscle activity thereafter in the so-called voluntary response. After locking the shoulder joint, which alters the required joint torques to counter pure elbow rotation, we found a reliable reduction in the long-latency stretch reflex over many trials. This reduction transferred to feedforward control as we observed 1) a reduction in shoulder muscle activity during self-initiated pure elbow rotation trials and 2) kinematic errors (ie. aftereffects) in the direction predicted when failing to compensate for normal arm dynamics, even though participants never practiced self-initiated movements with the shoulder locked. Taken together, our work shows that transfer between feedforward and feedback control is bidirectional, furthering the notion that these processes share common neural circuits that underlie motor learning and transfer.

scholarly journals Neuronal Substrates Underlying Performance Variability in Well-Trained Skillful Motor Task in Humans

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Nobuaki Mizuguchi ◽  
Shintaro Uehara ◽  
Satoshi Hirose ◽  
Shinji Yamamoto ◽  
Eiichi Naito
Keyword(s):  
Task Performance ◽  
Motor Skill ◽  
Brain Activity ◽  
Motor Task ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Cerebellar Hemisphere ◽  
Intensive Training ◽  
Performance Variability ◽  
The Right

Motor performance fluctuates trial by trial even in a well-trained motor skill. Here we show neural substrates underlying such behavioral fluctuation in humans. We first scanned brain activity with functional magnetic resonance imaging while healthy participants repeatedly performed a 10 s skillful sequential finger-tapping task. Before starting the experiment, the participants had completed intensive training. We evaluated task performance per trial (number of correct sequences in 10 s) and depicted brain regions where the activity changes in association with the fluctuation of the task performance across trials. We found that the activity in a broader range of frontoparietocerebellar network, including the bilateral dorsolateral prefrontal cortex (DLPFC), anterior cingulate and anterior insular cortices, and left cerebellar hemisphere, was negatively correlated with the task performance. We further showed in another transcranial direct current stimulation (tDCS) experiment that task performance deteriorated, when we applied anodal tDCS to the right DLPFC. These results indicate that fluctuation of brain activity in the nonmotor frontoparietocerebellar network may underlie trial-by-trial performance variability even in a well-trained motor skill, and its neuromodulation with tDCS may affect the task performance.

639 Maximizing Safe Positioning of Upper Extremities after Axillary Burn Injuries to Prevent Contractures and Maintain Function

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S175-S176
Author(s):  
Connie Greiser ◽  
David Lorello ◽  
Dan Lyons ◽  
Karen J Richey ◽  
Derek Murray ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Elbow Flexion ◽  
Primary Objective ◽  
Burn Injuries ◽  
Shoulder Abduction ◽  
Shoulder Injury ◽  
Shoulder Range Of Motion ◽  
History Of ◽  
The Right ◽  
Shoulder Range

Abstract Introduction Burns crossing over a joint can result in a contracture of that joint. Axillary burns and subsequent contractures are common and may impact negatively on burn survivor rehabilitation. Positioning of burned extremities at the most lengthened position is ideal for maintenance of function and contracture prevention, 90 degrees of abduction is the most accepted position for axillary burn injuries. However, many activities of daily living require shoulder range of motion (ROM) greater than 90 degrees. The primary objective of this study was to describe and examine the incidence of paresthesia, pain, and intolerance in healthy subjects when the shoulder was placed in a position of 90 degrees or greater of shoulder abduction. Methods The subject’s nondominant upper extremity (NDE) was randomly placed in a series three of positions, including: (1) 90 degrees shoulder abduction, 30 degrees horizontal adduction with elbow extension, forearm neutral; (2) 130 degrees shoulder abduction, 30 degrees horizontal adduction, 30 degrees elbow flexion, forearm neutral; (3) 150 degrees shoulder abduction, 30 degrees horizontal adduction, 30 degrees elbow flexion, forearm neutral. Each position was maintained for a maximum of 2 hours. Subjects experiencing subjective symptoms including paresthesia lasting longer than 1 minute, pain rated greater than 3/10, and/or intolerance 2/5 was removed from the position. All subjects received at least 30 minutes of rest between positions. Results A total of 25 subjects were enrolled, mean age was 25.8 years, the majority were female (60%) and 20% had a history of NDE shoulder injury. The right arm was the dominant extremity (DE) in 88% of subjects. There were no significant differences in ROM between the DE and NDE extremity with the exception of external shoulder rotation, 94.96⁰ vs 84.8⁰ (p=.0142). Average total splint time was 136 minutes with a range of 40 – 360 minutes. Only 1 subject successfully completed all 3 splinting periods. There were 75 individual splinting events over the 3 splinting periods, and 90% of the time the splinting was stopped early. The most common reason for stopping early was paresthesia (88%) followed by pain (7%). Conclusions The positions selected represent the routine and usual care at our burn center. Patients are routinely positioned from hours to days depending on patient need. This study demonstrated that healthy subjects were unable to tolerate positioning for even two hours.

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