scholarly journals Saturated Muscle Activation Contributes to Compensatory Reaching Strategies After Stroke

2005 ◽  
Vol 94 (5) ◽  
pp. 2999-3008 ◽  
Author(s):  
Patrick H. McCrea ◽  
Janice J. Eng ◽  
Antony J. Hodgson
Keyword(s):  
Muscle Activation ◽  
Sagittal Plane ◽  
Reaching Movements ◽  
Abduction Angle ◽  
Task Completion ◽  
Shoulder Abduction ◽  
Reaching Task ◽  
Hand Motion ◽  
Control Subjects ◽  
Anterior Deltoid

The control and execution of movement could potentially be altered by the presence of stroke-induced weakness if muscles are incapable of generating sufficient power. The purpose of this study was to identify compensatory strategies during a forward (sagittal) reaching task for 20 persons with chronic stroke and 10 healthy age-matched controls. We hypothesized that the paretic anterior deltoid would be maximally activated (i.e., saturated) during a reaching task and that task completion would require activation of additional muscles, resulting in compensatory movements out of the sagittal plane. For reaching movements by control subjects, joint motion remained largely in the sagittal plane and hand trajectories were smooth and direct. Movement characteristics of the nonparetic arm of stroke subjects were similar to control subjects except for small increases in the abduction angle and the percentage that anterior deltoid was activated. In contrast, reaching movements of the paretic arm of stroke subjects were characterized by increased activation of all muscles, especially the lateral deltoid, in addition to the anterior deltoid, with resulting shoulder abduction power and segmented and indirect hand motion. For the paretic arm of stroke subjects, muscle and kinetic compensations increased with impairment severity and weaker muscles were used at a higher percentage of their available muscle activity. These results suggest that the inability to generate sufficient force with the typical agonists involved during a forward reaching task may necessitate compensatory muscle recruitment strategies to complete the task.

scholarly journals Evaluation of the propulsion technique and motor performance of wheelchair basketball players

2019 ◽  
Vol 33 (2) ◽  
pp. 313-322
Author(s):  
Allan James de Castro Bussmann ◽  
Márcia Greguol ◽  
Emanuel Messias Oliveira de Carvalho ◽  
Felipe Arruda Moura
Keyword(s):  
Sagittal Plane ◽  
Abduction Angle ◽  
Test Time ◽  
Shoulder Abduction ◽  
Left Shoulder ◽  
Speed Test ◽  
Left Elbow ◽  
Maximum Angle ◽  
Significant Difference ◽  
The Right

The objective of this study was to evaluate the propulsion technique of wheelchairs basketball athletes. The group of study was formed for 11 athletes practicing, the modality studied, with an average age of 30.27 ± 6.51 years. The sample was divided in two groups (faster, slowest) according to the performance in the agility and speed tests. To analyze the angular kinematics of the upper limbs, each person performed threeattempts to “round trip” in a distance of 5 meters. The results indicate a strong positive association between the results obtained in the speed and agility tests (r = 0.83; p = 0.002) and negative between speed test time and sports practice time (r = −0.68; p = 0.02). For the analysis of angular behavior significant difference was observed (p = 0.02), only in the variable maximum angle of the left elbow and the faster group presentedthe highest values. The angular behavior analyzes during all the movement, present significant difference at some point of the cycle, for the variables abduction angle on the left shoulder, absolute angle of the right and left forearm, absolute angles of the shoulder in the sagittal plane left and right, maximum angle of the right and left elbow. The results indicate that the athletes present specific characteristics of propulsion, andthat some angular movement characteristics, as a smaller angle of shoulder abduction during early stages of the propulsion, influence the performance in the speed test.

The Effect of Body Roll on Hand Speed and Hand Path in Front Crawl Swimming—A Simulation Study

1997 ◽  
Vol 13 (3) ◽  
pp. 300-315 ◽  
Author(s):  
Carl J. Payton ◽  
James G. Hay ◽  
David R. Mullineaux
Keyword(s):  
Sagittal Plane ◽  
Elbow Flexion ◽  
Shoulder Abduction ◽  
Front Crawl ◽  
Hand Motion ◽  
Hand Path ◽  
Body Roll ◽  
Angular Velocities ◽  
Maximum Body ◽  
Cosine Functions

The aim of this study was to predict the effect of body roll on hand speed and hand path during the pull phase in front crawl swimming. An earlier three-segment model (Hay, Liu, & Andrews, 1993) was developed to enable the hand to move out of the plane through the shoulder parallel to the sagittal plane of the rotating trunk. Elbow flexion, shoulder abduction, and body roll angular velocities were modeled as sine or cosine functions. For a given elbow flexion, an increase in maximum body roll from 45° to 60° produced a marked increase in medial hand motion. For a given body roll, an increase in maximum elbow flexion from 60° to 90° increased medial hand motion and reduced downward hand motion. An increase in body roll increased hand speed in the plane perpendicular to the swimming direction, thus increasing the potential of the hand to develop propulsive lift forces.

scholarly journals A Pilot Study of the Effects of Pulley Location and Design Parameters on Hand Movements during Pulley Threading Operations

2016 ◽  
Vol 60 (1) ◽  
pp. 908-912 ◽  
Author(s):  
Justin M. Haney ◽  
Mary Owczarczak ◽  
Clive D’Souza ◽  
Monica L. H. Jones ◽  
Matthew P. Reed
Keyword(s):  
Completion Time ◽  
Target Location ◽  
Sagittal Plane ◽  
Design Parameters ◽  
Task Completion ◽  
Outer Diameter ◽  
Task Completion Time ◽  
Hand Motion ◽  
Motion Trajectories ◽  
And Task

Three healthy individuals participated in a laboratory experiment that required routing a thin continuous thread through a series of pulleys mounted on a vertical work surface. Task precision demand was manipulated by altering pulley outer diameter (38 mm, 76 mm, and 152 mm) and groove width (3 mm, 6 mm, and 9 mm). The target location of each destination pulley relative to the origin at the mid-sagittal plane was also manipulated. These factors were hypothesized to influence hand motion trajectories, peak speed, and task completion time. Smaller pulley diameters and larger groove widths, representing lower precision demands, were associated with smoother trajectories and a faster task completion time. These preliminary findings suggest a systematic influence of task precision demands on movement kinematics and task performance.

scholarly journals Normal aging affects unconstrained three-dimensional reaching against gravity with reduced vertical precision and increased co-contraction

2020 ◽  
Author(s):  
George F. Wittenberg ◽  
Jing Tian ◽  
Nick Kortzorg ◽  
Lore Wyers ◽  
Florian Van Halewyck ◽  
...  
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Upper Extremity ◽  
Degrees Of Freedom ◽  
Muscle Activation ◽  
Hand Movement ◽  
Three Dimensional ◽  
Reaching Movements ◽  
Shoulder Abduction ◽  
Age Related

AbstractReaching for an object in space forms the basis for many activities of daily living and is important in rehabilitation after stroke and in other neurological and orthopedic conditions. It has been the object of motor control and neuroscience research for over a century, but studies often constrain movement to eliminate the effect of gravity or reduce the degrees of freedom. In some studies, aging has been shown to reduce target accuracy, with a mechanism suggested to be impaired corrective movements. We sought first to explore the changes in control of shoulder and elbow joint movements that occur with aging during performance of reaching movements to different target heights with the normal effects of gravity, unconstrained hand movement, and stable target locations. Three-dimensional kinematic data and electromyography were collected in 14 young (25±6 years) and 10 older adults (68±3 years) during second-long reaches to three targets aligned vertically in front of the participants. Older adults took longer to initiate a movement than the young adults and were more variable and inaccurate in their initial and final movements. Target height had greater effect on trajectory curvature variability in older than young adults, with angle variability relative to target position being greater in older adults around the time of peak speed. There were significant age-related differences in use of the multiple degrees of freedom of the upper extremity, with less variability in shoulder abduction in the older group. Muscle activation patterns were similar, except for a higher biceps-triceps co-contraction and tonic levels of some proximal muscle activation. The path length of movements was not affected by age. These results show an age-related deficit in the motor planning and online correction of reaching movements against a predictable force (i.e., gravity). These results will facilitate interpretation of our forthcoming study of transcranial magnetic stimulation effects on the same task in these two populations, and is relevant to any study that seeks to measure the effect of pathological processes on upper extremity motor performance in the elderly.

scholarly journals Evaluation of the propulsion technique and motor performance of wheelchair basketball players

2019 ◽  
Vol 33 (2) ◽  
pp. 313-322
Author(s):  
Allan James de Castro Bussmann ◽  
Márcia Greguol ◽  
Emanuel Messias Oliveira de Carvalho ◽  
Felipe Arruda Moura
Keyword(s):  
Sagittal Plane ◽  
Abduction Angle ◽  
Test Time ◽  
Shoulder Abduction ◽  
Left Shoulder ◽  
Speed Test ◽  
Left Elbow ◽  
Maximum Angle ◽  
Significant Difference ◽  
The Right

The objective of this study was to evaluate the propulsion technique of wheelchairs basketball athletes. The group of study was formed for 11 athletes practicing, the modality studied, with an average age of 30.27 ± 6.51 years. The sample was divided in two groups (faster, slowest) according to the performance in the agility and speed tests. To analyze the angular kinematics of the upper limbs, each person performed threeattempts to “round trip” in a distance of 5 meters. The results indicate a strong positive association between the results obtained in the speed and agility tests (r = 0.83; p = 0.002) and negative between speed test time and sports practice time (r = −0.68; p = 0.02). For the analysis of angular behavior significant difference was observed (p = 0.02), only in the variable maximum angle of the left elbow and the faster group presentedthe highest values. The angular behavior analyzes during all the movement, present significant difference at some point of the cycle, for the variables abduction angle on the left shoulder, absolute angle of the right and left forearm, absolute angles of the shoulder in the sagittal plane left and right, maximum angle of the right and left elbow. The results indicate that the athletes present specific characteristics of propulsion, andthat some angular movement characteristics, as a smaller angle of shoulder abduction during early stages of the propulsion, influence the performance in the speed test.

scholarly journals A Systematic Review of EMG Applications for the Characterization of Forearm and Hand Muscle Activity during Activities of Daily Living: Results, Challenges, and Open Issues

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3035
Author(s):  
Néstor J. Jarque-Bou ◽  
Joaquín L. Sancho-Bru ◽  
Margarita Vergara
Keyword(s):  
Activities Of Daily Living ◽  
Musculoskeletal System ◽  
Muscle Activity ◽  
Daily Living ◽  
Muscle Activation ◽  
Human Hand ◽  
Hand Motion ◽  
Biomechanical Models ◽  
Rehabilitation Protocols ◽  
Open Issues

The role of the hand is crucial for the performance of activities of daily living, thereby ensuring a full and autonomous life. Its motion is controlled by a complex musculoskeletal system of approximately 38 muscles. Therefore, measuring and interpreting the muscle activation signals that drive hand motion is of great importance in many scientific domains, such as neuroscience, rehabilitation, physiotherapy, robotics, prosthetics, and biomechanics. Electromyography (EMG) can be used to carry out the neuromuscular characterization, but it is cumbersome because of the complexity of the musculoskeletal system of the forearm and hand. This paper reviews the main studies in which EMG has been applied to characterize the muscle activity of the forearm and hand during activities of daily living, with special attention to muscle synergies, which are thought to be used by the nervous system to simplify the control of the numerous muscles by actuating them in task-relevant subgroups. The state of the art of the current results are presented, which may help to guide and foster progress in many scientific domains. Furthermore, the most important challenges and open issues are identified in order to achieve a better understanding of human hand behavior, improve rehabilitation protocols, more intuitive control of prostheses, and more realistic biomechanical models.

Changes in motor cortex activity during reaching movements with similar hand paths but different arm postures

1995 ◽  
Vol 73 (6) ◽  
pp. 2563-2567 ◽  
Author(s):  
S. H. Scott ◽  
J. F. Kalaska
Keyword(s):  
Motor Cortex ◽  
Sagittal Plane ◽  
Single Cells ◽  
Reaching Movements ◽  
Movement Direction ◽  
Tonic Activity ◽  
Population Vector ◽  
Significant Difference ◽  
Direction Of Movement ◽  
Kinematics And Kinetics

1. Neuronal activity was recorded in the motor cortex of a monkey that performed reaching movements with the use of two different arm postures. In the first posture (control), the monkey used its natural arm orientation, approximately in the sagittal plane. In the second posture (abducted), the monkey had to adduct its elbow nearly to shoulder level to grasp the handle. The path of the hand between targets was similar in both arm postures, but the joint kinematics and kinetics were different. 2. In both postures, the activity of single cells was often broadly tuned with movement direction and static arm posture over the targets. In a large proportion of cells, either the level of tonic activity, the directional tuning, or both, varied between the two postures during the movement and target hold periods. 3. For most directions of movement, there was a statistically significant difference in the direction of the population vector for the two arm postures. Furthermore, whereas the population vector tended to point in the direction of movement for the control posture, there was a poorer correspondence between the direction of movement and the population vector for the abducted posture. These observed changes are inconsistent with the notion that the motor cortex encodes purely hand trajectory in space.

Relationship Between Deltoid and Rotator Cuff Muscles During Dynamic Shoulder Abduction: A Biomechanical Study of Rotator Cuff Tear Progression

2018 ◽  
Vol 46 (8) ◽  
pp. 1919-1926 ◽  
Author(s):  
Felix Dyrna ◽  
Neil S. Kumar ◽  
Elifho Obopilwe ◽  
Bastian Scheiderer ◽  
Brendan Comer ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Dynamic Testing ◽  
Correlation Coefficients ◽  
Biomechanical Study ◽  
Rotator Cuff Tears ◽  
Shoulder Abduction ◽  
Mean Values ◽  
Critical Shoulder Angle ◽  
Anterior Deltoid ◽  
Shoulder Angle

Background: Previous biomechanical studies regarding deltoid function during glenohumeral abduction have primarily used static testing protocols. Hypotheses: (1) Deltoid forces required for scapular plane abduction increase as simulated rotator cuff tears become larger, and (2) maximal abduction decreases despite increased deltoid forces. Study Design: Controlled laboratory study. Methods: Twelve fresh-frozen cadaveric shoulders with a mean age of 67 years (range, 64-74 years) were used. The supraspinatus and anterior, middle, and posterior deltoid tendons were attached to individual shoulder simulator actuators. Deltoid forces and maximum abduction were recorded for the following tear patterns: intact, isolated subscapularis (SSC), isolated supraspinatus (SSP), anterosuperior (SSP + SSC), posterosuperior (infraspinatus [ISP] + SSP), and massive (SSC + SSP + ISP). Optical triads tracked 3-dimensional motion during dynamic testing. Fluoroscopy and computed tomography were used to measure critical shoulder angle, acromial index, and superior humeral head migration with massive tears. Mean values for maximum glenohumeral abduction and deltoid forces were determined. Linear mixed-effects regression examined changes in motion and forces over time. Pearson product-moment correlation coefficients ( r) among deltoid forces, critical shoulder angles, and acromial indices were calculated. Results: Shoulders with an intact cuff required 193.8 N (95% CI, 125.5 to 262.1) total deltoid force to achieve 79.8° (95% CI, 66.4° to 93.2°) of maximum glenohumeral abduction. Compared with native shoulders, abduction decreased after simulated SSP (–27.2%; 95% CI, –43.3% to –11.1%, P = .04), anterosuperior (–51.5%; 95% CI, –70.2% to –32.8%, P < .01), and massive (–48.4%; 95% CI, –65.2% to –31.5%, P < .01) cuff tears. Increased total deltoid forces were required for simulated anterosuperior (+108.1%; 95% CI, 68.7% to 147.5%, P < .01) and massive (+57.2%; 95% CI, 19.6% to 94.7%, P = .05) cuff tears. Anterior deltoid forces were significantly greater in anterosuperior ( P < .01) and massive ( P = .03) tears. Middle deltoid forces were greater with anterosuperior tears ( P = .03). Posterior deltoid forces were greater with anterosuperior ( P = .02) and posterosuperior ( P = .04) tears. Anterior deltoid force was negatively correlated ( r = −0.89, P = .01) with critical shoulder angle (34.3°; 95% CI, 32.0° to 36.6°). Deltoid forces had no statistical correlation with acromial index (0.55; 95% CI, 0.48 to 0.61). Superior migration was 8.3 mm (95% CI, 5.5 to 11.1 mm) during testing of massive rotator cuff tears. Conclusion: Shoulders with rotator cuff tears require considerable compensatory deltoid function to prevent abduction motion loss. Anterosuperior tears resulted in the largest motion loss despite the greatest increase in deltoid force. Clinical Relevance: Rotator cuff tears place more strain on the deltoid to prevent abduction motion loss. Fatigue or injury to the deltoid may result in a precipitous decline in abduction, regardless of tear size.

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