Detection of effort maximality in adults performing isokinetic wrist flexion and extension

2021 ◽  
pp. 1-7
Author(s):  
Mercè Torra ◽  
Eduard Pujol ◽  
Anna Maiques ◽  
Salvador Quintana ◽  
Roser Garreta ◽  
...  
Keyword(s):  
High Velocity ◽  
Healthy Male ◽  
Wrist Flexion ◽  
Low Velocity ◽  
Wrist Extensor ◽  
Submaximal Effort ◽  
The Difference ◽  
Muscle Groups ◽  
Maximal Effort ◽  
Flexion And Extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

scholarly journals Importance of the Wrist Extensor Muscle Training: Two Cases of Elbow Flexorplasty following Traumatic Brachial Plexus Injuries

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Shigeki Kubota ◽  
Tadashi Kubo ◽  
Hiromi Kameda ◽  
Yoshiyasu Itoh
Keyword(s):  
Brachial Plexus ◽  
Elbow Flexion ◽  
Wrist Flexion ◽  
Postoperative Rehabilitation ◽  
Wrist Extensor ◽  
Antagonist Muscles ◽  
Extensor Muscles ◽  
Muscle Groups ◽  
Flexion Strength

The modified Steindler procedure—a reconstructive surgery used to restore elbow flexion following upper brachial plexus injuries—involves shifting the origins of the muscle groups responsible for wrist flexion and forearm pronation originating from the medial epicondyle to the proximal direction to be used as flexors of the elbow. In the postoperative rehabilitation, we focused on strengthening not only the transferred muscle but also the wrist extensor muscles as antagonist muscles. After reconstruction surgery for elbow flexion via the modified Steindler procedure for traumatic brachial plexus injury, we performed long-term rehabilitation to strengthen the antagonist muscles. As a result, in two cases, excellent elbow flexion strength and gripping strength were achieved, confirming the importance of the antagonist muscles.

scholarly journals Deformation of the median nerve at different finger postures and wrist angles

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5406 ◽  
Author(s):  
Ping Yeap Loh ◽  
Wen Liang Yeoh ◽  
Hiroki Nakashima ◽  
Satoshi Muraki
Keyword(s):  
Median Nerve ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Healthy Male ◽  
Wrist Flexion ◽  
Cross Sectional ◽  
Finger Posture ◽  
Main Effects ◽  
Flexion And Extension

Background The objective of this study was to evaluate the changes of the median nerve cross-sectional area (MNCSA) and diameters of the median nerve at different finger postures and wrist angles. Methods Twenty-five healthy male participants were recruited in this study. The median nerve at wrist crease was examined at six finger postures, and repeated with the wrist in 30° flexion, neutral (0°), and 30° extension. The six finger postures are relaxed, straight finger, hook, full fist, tabletop, and straight fist. Results The main effects of both finger postures and wrist angles are significant (p < 0.05) on changes of the MNCSA. Different finger tendon gliding postures cause a change in the MNCSA. Furthermore, wrist flexion and extension cause higher deformation of the MNCSA at different finger postures. Discussion The median nerve parameters such as MNCSA and diameter were altered by a change in wrist angle and finger posture. The results may help to understand the direct biomechanical stresses on the median nerve by different wrist-finger activities.

NOTES ON REFRACTION PROSPECTING

Geophysics ◽  
1941 ◽  
Vol 6 (4) ◽  
pp. 378-396 ◽  
Author(s):  
Charles Hewitt Dix
Keyword(s):  
High Velocity ◽  
Linear Increase ◽  
Linear Velocity ◽  
Relative Depth ◽  
Low Velocity ◽  
Velocity Section ◽  
Air Interface ◽  
Machine Calculation ◽  
The Difference ◽  
Refraction Data

This is a series of notes dealing with several aspects of the problem of the interpretation of refraction data. A method of dealing with unreversed refraction lines is outlined. The case of a high velocity section with an overburden having a linear increase of velocity with depth is discussed. We show how the accuracy of the relative depth calculations depends upon the difference between the upper and lower velocities at the interface in question. A method of computing tables for the linear velocity depth case is given which is well adapted to machine calculation. Finally, reflections at the ground‐air interface and the formation of shadows by such obstacles as high or low velocity layers are considered.

scholarly journals The nuclear architecture of NGC 4151: on the path toward a universal outflow mechanism in light of NGC 1068

2020 ◽  
Vol 496 (2) ◽  
pp. 1488-1516
Author(s):  
D May ◽  
J E Steiner ◽  
R B Menezes ◽  
D R A Williams ◽  
J Wang
Keyword(s):  
High Velocity ◽  
Near Infrared ◽  
Nuclear Architecture ◽  
Low Velocity ◽  
Ionized Gas ◽  
Gas Phases ◽  
Ngc 4151 ◽  
Molecular Outflow ◽  
Ngc 1068 ◽  
The Difference

ABSTRACT We report near-infrared integral field spectroscopic observations of the active galactic nucleus NGC 4151 with archive data from the NIFS-Gemini North Telescope. We have selected best-seeing observations (≲0.3 arcsec) that, allied to our methodology of image processing techniques, show structures with spatial resolution comparable to those of the HST. The intricate outflow of NGC 4151 is revisited in light of the results found for NGC 1068, in a previous work, and a very similar dynamic is found: the low-velocity [Fe ii] emission depicts the glowing walls of an hourglass structure, while the high-velocity gas fills its volume. From this finding, we show that the misalignment between the jet and the NLR is not a projection effect, as previously thought. A molecular outflow is detected for the first time in this galaxy and, just like in NGC 1068, the transition between the molecular and the ionized gas phases comes from the fragmentation of molecular cavity walls into bullets of ionized gas exposed to the central source. Furthermore, it is suggestive that the same geometrical dichotomy between the cones seen in NGC 1068 is found here, with one side, where the cavity is disrupted by the AGN, being more extended than the other. Finally, a new spatial correlation between the high-velocity [Fe ii] and the soft X-ray emission of [Ne ix] is found, which is unexpected given the difference between their ionization potentials.

An Isokinetic Study of Submaximal Effort in Elbow Flexion

1997 ◽  
Vol 84 (3_suppl) ◽  
pp. 1431-1438 ◽  
Author(s):  
Zeevi Dvir
Keyword(s):  
Range Of Motion ◽  
Elbow Flexion ◽  
Eccentric Contractions ◽  
Extended Form ◽  
Experimental Conditions ◽  
Healthy Men ◽  
Submaximal Effort ◽  
Highly Effective ◽  
The Difference ◽  
Maximal Effort

The purpose of this study was to examine the efficiency of a protocol, used in previous studies in an extended form, for differentiation of submaximal from maximal effort in elbow flexion. 15 healthy men aged 21 to 55 years took part in two experimental conditions. In the maximal effort condition subjects were instructed to exert maximal concentric and eccentric efforts and in the best reproducible effort condition subjects were asked to exert similar but submaximal concentric and eccentric efforts which they could best reproduce. The amount of effort, represented by the average moment, was measured relative to two ranges of motion, 30° and 60°, at two angular speeds, 20°/sec. and 60°/sec, using 4 intermittent concentric-eccentric contractions. Both the eccentric/concentric strength ratios as well as the difference between these ratios at the high and the low speeds were highly effective in distinguishing maximal from submaximal efforts. Moreover, since the protocol was equally effective irrespective of the range of motion, it may be used to differentiate submaximal from maximal elbow flexion effort in noninjured subjects.

scholarly journals Studying the Depth Structure of the Kyrgyz Tien Shan by Using the Seismic Tomography and Magnetotelluric Sounding Methods

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 122
Author(s):  
Irina Medved ◽  
Elena Bataleva ◽  
Michael Buslov
Keyword(s):  
Seismic Tomography ◽  
High Velocity ◽  
Fault Zones ◽  
Magnetotelluric Sounding ◽  
Tien Shan ◽  
High Resistivity ◽  
Low Velocity ◽  
Low Resistivity ◽  
Velocity Models ◽  
Fluid Saturation

This paper presents new results of detailed seismic tomography (ST) on the deep structure beneath the Middle Tien Shan to a depth of 60 km. For a better understanding of the detected heterogeneities, the obtained velocity models were compared with the results of magnetotelluric sounding (MTS) along the Kekemeren and Naryn profiles, running parallel to the 74 and 76 meridians, respectively. We found that in the study region the velocity characteristics and geoelectric properties correlate with each other. The high-velocity high-resistivity anomalies correspond to the parts of the Tarim and Kazakhstan-Junggar plates submerged under the Tien Shan. We revealed that the structure of the Middle Tien Shan crust is conditioned by the presence of the Central Tien Shan microcontinent. It manifests itself as two anomalies lying one below the other: the lower low-velocity low-resistivity anomaly, and the upper high-velocity high-resistivity anomaly. The fault zones, limiting the Central Tien Shan microcontinent, appear as low-velocity low-resistivity anomalies. The obtained features indicate the fluid saturation of the fault zones. According to the revealed features of the Central Tien Shan geological structure, it is assumed that the lower-crustal low-velocity layer can play a significant role in the delamination of the mantle part of the submerged plates.

Traumatic Brachial Plexus Palsy in Children: Long-Term Outcome and Strategy of Reconstruction

2021 ◽  
Author(s):  
Tarek A. El-Gammal ◽  
Amr El-Sayed ◽  
Mohamed M. Kotb ◽  
Waleed Riad Saleh ◽  
Yasser Farouk Ragheb ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
External Rotation ◽  
Hand Function ◽  
Functional Restoration ◽  
Shoulder Abduction ◽  
Wrist Flexion ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Age At Surgery ◽  
Flexion And Extension

Abstract Background Traumatic brachial plexus injuries in children represent a definite spectrum of injuries between adult and neonatal brachial plexus injuries. Their characteristics have been scarcely reported in the literature. The priority of functional restoration is not clear. Materials and Methods In total, 52 children with surgically treated traumatic brachial plexus injuries, excluding Erb's palsy, were reviewed after a minimum follow-up of 2 years. All children except nine were males, with an average age at surgery of 8 years. Forty-five children had exclusive supraclavicular plexus injuries. Twenty-one of them (46%) had two or more root avulsions. Seven children (13.5%) had infraclavicular plexus injuries. Time from trauma to surgery varied from 1 to 15 months (mean = 4.7 months). Extraplexal neurotization was the most common surgical technique used. Results Shoulder abduction and external rotation were restored to an average of 83 and 26 degrees, respectively. Elbow flexion and extension were restored to grade ≥3 in 96 and 91.5% of cases, respectively. Finger flexion and extension were restored to grade ≥4 in 29 and 32% of cases, respectively. Wrist flexion and extension were restored to grade ≥4 in 21 and 27% of cases, respectively. Results of neurotization were superior to those of neurolysis and nerve grafting. Among the 24 children with insensate hands, 20 (83.3%) recovered S3 sensation, 3 recovered S2, and 1 recovered S1. No case complained of neuropathic pain. Functional recovery correlated negatively but insignificantly with the age at surgery and time from injury to surgery. Conclusion Brachial plexus injuries in children are associated with a high incidence root avulsions and no pain. Neurotization is frequently required and the outcome is not significantly affected by the delay in surgery. In total plexus injuries, some useful hand function can be restored, and management should follow that of obstetric palsy and be focused on innervating the medial cord.

scholarly journals Joint-Specific Play Controller for Upper Extremity Therapy: Feasibility Study in Children With Wrist Impairment

2016 ◽  
Vol 96 (11) ◽  
pp. 1773-1781
Author(s):  
Bethany J. Wilcox ◽  
Megan M. Wilkins ◽  
Benjamin Basseches ◽  
Joel B. Schwartz ◽  
Karen Kerman ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Computer Games ◽  
Average Frequency ◽  
Cross Sectional Study ◽  
Wrist Flexion ◽  
Motor Impairments ◽  
Cross Sectional ◽  
Play Activity ◽  
Play Session ◽  
Flexion And Extension

Abstract Background Challenges with any therapeutic program for children include the level of the child's engagement or adherence. Capitalizing on one of the primary learning avenues of children, play, the approach described in this article is to develop therapeutic toy and game controllers that require specific and repetitive joint movements to trigger toy/game activation. Objective The goal of this study was to evaluate a specially designed wrist flexion and extension play controller in a cohort of children with upper extremity motor impairments (UEMIs). The aim was to understand the relationship among controller play activity, measures of wrist and forearm range of motion (ROM) and spasticity, and ratings of fun and difficulty. Design This was a cross-sectional study of 21 children (12 male, 9 female; 4–12 years of age) with UEMIs. Methods All children participated in a structured in-clinic play session during which measurements of spasticity and ROM were collected. The children were fitted with the controller and played with 2 toys and 2 computer games for 5 minutes each. Wrist flexion and extension motion during play was recorded and analyzed. In addition, children rated the fun and difficulty of play. Results Flexion and extension goal movements were repeatedly achieved by children during the play session at an average frequency of 0.27 Hz. At this frequency, 15 minutes of play per day would result in approximately 1,700 targeted joint motions per week. Play activity was associated with ROM measures, specifically supination, but toy perception ratings of enjoyment and difficulty were not correlated with clinical measures. Limitations The reported results may not be representative of children with more severe UEMIs. Conclusions These outcomes indicate that the therapeutic controllers elicited repetitive goal movements and were adaptable, enjoyable, and challenging for children of varying ages and UEMIs.

Limits to the Control of the Human Thumb and Fingers in Flexion and Extension

2010 ◽  
Vol 103 (1) ◽  
pp. 278-289 ◽  
Author(s):  
W. S. Yu ◽  
H. van Duinen ◽  
S. C. Gandevia
Keyword(s):  
Control System ◽  
Healthy Subjects ◽  
Neural Control ◽  
Force Production ◽  
Total Force ◽  
Neural Drive ◽  
Antagonist Muscles ◽  
Hand Performance ◽  
The Difference ◽  
Flexion And Extension

In humans, hand performance has evolved from a crude multidigit grasp to skilled individuated finger movements. However, control of the fingers is not completely independent. Although musculotendinous factors can limit independent movements, constraints in supraspinal control are more important. Most previous studies examined either flexion or extension of the digits. We studied differences in voluntary force production by the five digits, in both flexion and extension tasks. Eleven healthy subjects were instructed either to maximally flex or extend their digits, in all single- and multidigit combinations. They received visual feedback of total force produced by “instructed” digits and had to ignore “noninstructed” digits. Despite attempts to maximally flex or extend instructed digits, subjects rarely generated their “maximal” force, resulting in a “force deficit,” and produced forces with noninstructed digits (“enslavement”). Subjects performed differently in flexion and extension tasks. Enslavement was greater in extension than in flexion tasks ( P = 0.019), whereas the force deficit in multidigit tasks was smaller in extension ( P = 0.035). The difference between flexion and extension in the relationships between the enslavement and force deficit suggests a difference in balance of spillover of neural drive to agonists acting on neighboring digits and focal neural drive to antagonist muscles. An increase in drive to antagonists would lead to more individualized movements. The pattern of force production matches the daily use of the digits. These results reveal a neural control system that preferentially lifts fingers together by extension but allows an individual digit to flex so that the finger pads can explore and grasp.

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