scholarly journals Early Shortening of Wrist Flexor Muscles Coincides With Poor Recovery After Stroke

2018 ◽  
Vol 32 (6-7) ◽  
pp. 645-654 ◽  
Author(s):  
Karin L. de Gooijer-van de Groep ◽  
Jurriaan H. de Groot ◽  
Hanneke van der Krogt ◽  
Erwin de Vlugt ◽  
J. Hans Arendzen ◽  
...  
Keyword(s):  
Time Course ◽  
Robot Manipulator ◽  
Wrist Joint ◽  
Joint Stiffness ◽  
Peripheral Tissue ◽  
Tissue Stiffness ◽  
Wrist Flexion ◽  
Poor Recovery ◽  
Flexor Muscles ◽  
Slack Length

Background. The mechanism and time course of increased wrist joint stiffness poststroke and clinically observed wrist flexion deformity is still not well understood. The components contributing to increased joint stiffness are of neural reflexive and peripheral tissue origin and quantified by reflexive torque and muscle slack length and stiffness coefficient parameters. Objective. To investigate the time course of the components contributing to wrist joint stiffness during the first 26 weeks poststroke in a group of patients, stratified by prognosis and functional recovery of the upper extremity. Methods. A total of 36 stroke patients were measured on 8 occasions within the first 26 weeks poststroke using ramp-and-hold rotations applied to the wrist joint by a robot manipulator. Neural reflexive and peripheral tissue components were estimated using an electromyography-driven antagonistic wrist model. Outcome was compared between groups cross-sectionally at 26 weeks poststroke and development over time was analyzed longitudinally. Results. At 26 weeks poststroke, patients with poor recovery (Action Research Arm Test [ARAT] ≤9 points) showed a higher predicted reflexive torque of the flexors ( P < .001) and reduced predicted slack length ( P < .001) indicating shortened muscles contributing to higher peripheral tissue stiffness ( P < .001), compared with patients with good recovery (ARAT ≥10 points). Significant differences in peripheral tissue stiffness between groups could be identified around weeks 4 and 5; for neural reflexive stiffness, this was the case around week 12. Conclusions. We found onset of peripheral tissue stiffness to precede neural reflexive stiffness. Temporal identification of components contributing to joint stiffness after stroke may prompt longitudinal interventional studies to further evaluate and eventually prevent these phenomena.

scholarly journals Improvement of Heavy Load Robot Positioning Accuracy by Combining a Model-Based Identification for Geometric Parameters and an Optimized Neural Network for the Compensation of Nongeometric Errors

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yuxiang Wang ◽  
Zhangwei Chen ◽  
Hongfei Zu ◽  
Xiang Zhang ◽  
Chentao Mao ◽  
...  
Keyword(s):  
Neural Network ◽  
Manufacturing Systems ◽  
Robot Manipulator ◽  
Joint Stiffness ◽  
Calibration Method ◽  
Geometric Parameters ◽  
Heavy Load ◽  
Positioning Accuracy ◽  
Robot Positioning ◽  
Residual Errors

The positioning accuracy of a robot is of great significance in advanced robotic manufacturing systems. This paper proposes a novel calibration method for improving robot positioning accuracy. First of all, geometric parameters are identified on the basis of the product of exponentials (POE) formula. The errors of the reduction ratio and the coupling ratio are identified at the same time. Then, joint stiffness identification is carried out by adding a load to the end-effector. Finally, residual errors caused by nongeometric parameters are compensated by a multilayer perceptron neural network (MLPNN) based on beetle swarm optimization algorithm. The calibration is implemented on a SIASUN SR210D robot manipulator. Results show that the proposed method possesses better performance in terms of faster convergence and higher precision.

Estimation of tissue stiffness, reflex activity, optimal muscle length and slack length in stroke patients using an electromyography driven antagonistic wrist model

2016 ◽  
Vol 35 ◽  
pp. 93-101 ◽  
Author(s):  
Karin L. de Gooijer-van de Groep ◽  
Erwin de Vlugt ◽  
Hanneke J. van der Krogt ◽  
Áróra Helgadóttir ◽  
J. Hans Arendzen ◽  
...  
Keyword(s):  
Muscle Length ◽  
Reflex Activity ◽  
Tissue Stiffness ◽  
Stroke Patients ◽  
Slack Length

scholarly journals The surface electromyography analysis of the non-plegic upper limb of hemiplegic subjects

2010 ◽  
Vol 68 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Heloyse U Kuriki ◽  
Raquel N. de Azevedo ◽  
Augusto C. de Carvalho ◽  
Fábio Mícolis de Azevedo ◽  
Rúben F Negrão-Filho ◽  
...  
Keyword(s):  
Control Group ◽  
Electromyographic Activity ◽  
Healthy Individuals ◽  
Wrist Flexion ◽  
Functional Changes ◽  
Normal Individuals ◽  
Flexor Muscles ◽  
Stroke Group ◽  
Dominant Member ◽  
Flexion And Extension

Many authors have studied physical and functional changes in individuals post-stroke, but there are few studies that assess changes in the non-plegic side of hemiplegic subjects. This study aimed to compare the electromyographic activity in the forearm muscles of spastic patients and clinically healthy individuals, to determine if there is difference between the non-plegic side of hemiplegics and the dominant member of normal individuals. 22 hemiplegic subjects and 15 clinically healthy subjects were submitted to electromyography of the flexor and extensor carpi ulnaris muscles during wrist flexion and extension. The flexor muscles activation of stroke group (average 464.6 u.n) was significantly higher than the same muscles in control group (mean: 106.3 u.n.) during the wrist flexion, what shows that the non affected side does not present activation in the standart of normality found in the control group.

scholarly journals Myoelectric Control Techniques for a Rehabilitation Robot

2011 ◽  
Vol 8 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Alan Smith ◽  
Edward E. Brown
Keyword(s):  
Healthy Subjects ◽  
Sagittal Plane ◽  
Robot Manipulator ◽  
Wrist Joint ◽  
Elbow Flexion ◽  
Myoelectric Control ◽  
Average Error ◽  
Rehabilitation Robot ◽  
Control Scheme ◽  
Central Cord Syndrome

This work examines two different types of myoelectric control schemes for the purpose of rehabilitation robot applications. The first is a commonly used technique based on a Gaussian classifier. It is implemented in real time for healthy subjects in addition to a subject with Central Cord Syndrome (CCS). The myoelectric control scheme is used to control three degrees of freedom (DOF) on a robot manipulator which corresponded to the robot's elbow joint, wrist joint, and gripper. The classes of motion controlled include elbow flexion and extension, wrist pronation and supination, hand grasping and releasing, and rest. Healthy subjects were able to achieve 90% accuracy. Single DOF controllers were first tested on the subject with CCS and he achieved 100%, 96%, and 85% accuracy for the elbow, gripper, and wrist controllers respectively. Secondly, he was able to control the three DOF controller at 68% accuracy. The potential applications for this scheme are rehabilitation and teleoperation. To overcome limitations in the pattern recognition based scheme, a second myoelectric control scheme is also presented which is trained using electromyographic (EMG) data derived from natural reaching motions in the sagittal plane. This second scheme is based on a time delayed neural network (TDNN) which has the ability to control multiple DOF at once. The controller tracked a subject's elbow and shoulder joints in the sagittal plane. Results showed an average error of 19° for the two joints. This myoelectric control scheme has the potential of being used in the development of exoskeleton and orthotic rehabilitation applications.

Nonlinear viscosity of human wrist

1984 ◽  
Vol 52 (3) ◽  
pp. 553-569 ◽  
Author(s):  
C. C. Gielen ◽  
J. C. Houk
Keyword(s):  
Constant Velocity ◽  
Time Course ◽  
Fractional Power ◽  
Comparison Method ◽  
Mean Value ◽  
Emg Activity ◽  
Triggered Reactions ◽  
Nonlinear Viscosity ◽  
Flexor Muscles ◽  
Reflex Arc

Nonlinear viscous properties of stretch and unloading reflexes in the human wrist were examined using constant-velocity ramp stretches and releases in the range between 5 and 500 mm/s. Subjects were asked to oppose an initial flexor preload and were instructed not to intervene voluntarily when the changes in position were applied. Electromyographic (EMG) activity and net force exerted by the wrist were measured. Although subjects were instructed not to intervene to the applied stretches, even well-practiced subjects sometimes showed unintended triggered reactions, which character could be assisting or resisting. A trial comparison method was used to detect and eliminate responses contaminated by unintended reactions. Ramp stretches further loaded the preloaded flexor muscles. Responses of EMG and force increased steeply initially but after about 1-cm displacement, the slope of these responses decreased to a lower value and remained constant during the remainder of the 5-cm ramp. For higher stretch velocities, the magnitudes and slopes of the responses of EMG and force increased but less than proportionally with ramp velocity. Except for the initial transient, EMG in the loaded flexor muscles and force responses could be described by a product relationship between a linear position-related term and a low fractional power of velocity, after a correction was made for delays in the reflex arc. Mean value of the exponent in the power function of velocity was 0.3 for EMG and 0.17 for force. For higher preloads, incremental responses of force to constant-velocity stretches, plotted as a function of wrist position, shifted to higher values and the slope of increase of force with position became somewhat steeper. This upward shift of the force trace reflects a change of apparent threshold of the stretch reflex. Ramp releases shortened and unloaded the preloaded flexor muscles and stretched the initially inactive extensor muscles. Flexor EMG activity declined progressively with a time course that was independent of velocity. Extensor EMG response depended on preload. At high preloads, there was no activity except for some bursting at the highest velocities. At low preloads, EMG activity was initially absent but started part way through the ramp. The increase of activity was somewhat greater for higher ramp velocities. Force responses to shortening ramps depended on preload. At high preloads, force responses superimposed at all of the low velocities but fell to slightly lower forces at the higher velocities. At low preloads, force traces again superimposed for low velocities and at high velocities only during the initial part of the response.(ABSTRACT TRUNCATED AT 400 WORDS)

Three-dimensional kinematics of the lunate, hamate, capitate and triquetrum with type 1 or 2 lunate morphology

2017 ◽  
Vol 43 (4) ◽  
pp. 380-386 ◽  
Author(s):  
Shingo Abe ◽  
Hisao Moritomo ◽  
Kunihiro Oka ◽  
Kazuomi Sugamoto ◽  
Kenji Kasubuchi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Wrist Joint ◽  
Three Dimensional ◽  
Wrist Flexion ◽  
Ulnar Deviation ◽  
Dart Throwing ◽  
Carpal Kinematics ◽  
Throwing Motion

The purpose of this study was to investigate the differences in three-dimensional carpal kinematics between type 1 and 2 lunates. We studied 15 instances of wrist flexion to extension (nine type 1, six type 2), 13 of radial to ulnar deviation (seven type 1, six type 2), and 12 of dart-throwing motion (six each of type 1 and 2) in 25 normal participants based on imaging with computerized tomography. Mean proximal translation of the distal articular midpoint of the triquetrum relative to type 2 lunates during wrist radioulnar deviation was 2.9 mm (standard deviation (SD) 0.7), which was significantly greater than for type 1 lunates, 1.6 mm (SD 0.6). The hamate contacted the lunate in ulnar deviation and ulnar flexion of wrists with type 2 lunates but not with type 1. We conclude that the four-corner kinematics of the wrist joint are different between type 1 and 2 lunates.

Activity of precentral neurons during torque-triggered hand movements in awake primates

1979 ◽  
Vol 57 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Y. C. Wong ◽  
H. C. Kwan ◽  
J. T. Murphy
Keyword(s):  
Wrist Joint ◽  
Wrist Flexion ◽  
Somatosensory Stimulation ◽  
Sensory Stimuli ◽  
Neuronal Populations ◽  
Supportive Role ◽  
Flexion Extension ◽  
Cortical Responses ◽  
Early Portion ◽  
Temporally Correlated

In monkeys performing a handle-repositioning task involving primarily wrist flexion–extension (F–E) movements after a torque perturbation was delivered to the handle, single units were recorded extracellularly in the contralateral precentral cortex. Precentral neurons were identified by passive somatosensory stimulation, and were classified into five somatotopically organized populations. Based on electromyographic recordings, it was observed that flexors and extensors about the wrist joint were specifically involved in the repositioning of the handle, while many other muscles which act at the wrist and other forelimb joints were involved in the task in a supportive role. In precentral cortex, all neuronal responses observed were temporally correlated to both the sensory stimuli and the motor responses. Visual stimuli, presented simultaneously with torque perturbations, did not affect the early portion of cortical responses to such torque perturbations. In each of the five somatotopically organized neuronal populations, task-related neurons as well as task-unrelated ones were observed. A significantly larger proportion of wrist (F–E) neurons was related to the task, as compared with the other, nonwrist (F–E) populations. The above findings were discussed in the context of a hypothesis for the function of precentral cortex during voluntary limb movement in awake primates. This hypothesis incorporates a relationship between activities of populations of precentral neurons, defined with respect to their responses to peripheral events at or about single joints, and movements about the same joint.

Effects of Upper Limb Muscle Vibration on Human Voluntary Wrist Flexion-Extension Movements

1994 ◽  
Vol 78 (1) ◽  
pp. 43-47 ◽  
Author(s):  
T. Kasai ◽  
M. Kawanishi ◽  
S. Yahagi
Keyword(s):  
Upper Limb ◽  
Limb Muscle ◽  
Wrist Flexion ◽  
Flexor Muscle ◽  
Simultaneous Application ◽  
Eyes Closed ◽  
Wrist Flexor ◽  
Flexion Extension ◽  
Flexor Muscles ◽  
Elbow Extensor

The effect of upper limb muscle tendon vibration during alternating step flexion-extension movements about the wrist was studied in 6 normal humans. A vibrator was mounted over either the wrist flexor muscle or the elbow flexor and extensor muscles. Vibration was applied either to a single muscle or simultaneously to both muscles during wrist flexion-extension movements. After a period of practice, subjects learned the required movements and were able to make them with their eyes closed. Simultaneous application of subthreshold vibration to the wrist flexor and the elbow extensor or flexor muscles during extension movements produced an undershooting of the required end-movement position. The observed results indicated the pattern of transjoint projections from elbow extensor and flexor muscles to motoneurons supplying wrist extensor and flexor muscles. It is also suggested that those transjoint projections play an important role in coordinated movement of wrist and elbow joints.

scholarly journals Carpal Tunnel Syndrome and its relation to dentist

2015 ◽  
Vol 27 (3) ◽  
Author(s):  
Nyoman Ayu Anggayanti ◽  
I Putu Gde Adiatmika
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Musculoskeletal Disorders ◽  
Carpal Tunnel ◽  
Wrist Joint ◽  
Compressive Force ◽  
Incidence Rates ◽  
Wrist Flexion ◽  
Entrapment Neuropathies ◽  
Compressive Neuropathy ◽  
Tunnel Syndrome

Introduction: Carpal Tunnel Syndrome (CTS) is a compressive neuropathy, caused by mechanical distortion produced by a compressive force of the median nerve at the level of the wrist. Primary sign is pain in the wrist, tingling sensation, pain or numbness in thumb, index finger, middle finger, and radial side of the ring finger, also there is a reduction of the grip strength and function of the affected hand. This sign tend to be worse at night and clumsiness during the activities that requiring wrist flexion. This syndrome is well-known and frequent accounts for 90% of all entrapment neuropathies. Incidence rates up to 276:100.000 per year. More common in females than in males, its occurrence is commonly bilaterally with a peak age range of 40 to 60 years. This is the productive age, which is often reported that the Carpal Tunnel Syndrome are work-related musculoskeletal disorders caused by strain and repeated movements. Disscussion: Dentist are high risks to go through musculoskeletal disorders covering wrist joint. The condition may happen because of the dentist position while handling patients is not in ergonomic position. These include repetitive prolonged hand activities, forceful static posture of wrist, vibration, and localized mechanical stress. To reduce the symptoms of musculoskeletal disorders since the beginning, has developed an integrated concept of teamwork in a modern dental practice. This concept is known as the four-handed dentistry which consists of dentists and assistants with their respective skills. Conclusion: The four-handed treatment techniques has been developed that is now largely acceptable. The concept of four-handed dentistry is expected to prevent the movement that makes the muscles tense, especially in the area around the wrist. And may ultimately reduce the incidence of Carpal Tunnel Syndrome

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