Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
David B. Segala ◽  
Deanna H. Gates ◽  
Jonathan B. Dingwell ◽  
David Chelidze
Keyword(s):  
Muscle Fatigue ◽  
Fixed Number ◽  
Orthogonal Decomposition ◽  
Muscle Injuries ◽  
Individual Muscle ◽  
Dimensional Reconstruction ◽  
Order Of Magnitude ◽  
Muscle Groups ◽  
The Right ◽  
Smooth Orthogonal Decomposition

Tracking or predicting physiological fatigue is important for developing more robust training protocols and better energy supplements and/or reducing muscle injuries. Current methodologies are usually impractical and/or invasive and may not be realizable outside of laboratory settings. It was recently demonstrated that smooth orthogonal decomposition (SOD) of phase space warping (PSW) features of motion kinematics can identify fatigue in individual muscle groups. We hypothesize that a nonlinear extension of SOD will identify more optimal fatigue coordinates and provide a lower-dimensional reconstruction of local fatigue dynamics than the linear SOD. Both linear and nonlinear SODs were applied to PSW features estimated from measured kinematics to reconstruct muscle fatigue dynamics in subjects performing a sawing motion. Ten healthy young right-handed subjects pushed a weighted handle back and forth until voluntary exhaustion. Three sets of joint kinematic angles were measured from the right upper extremity in addition to surface electromyography (EMG) recordings. The SOD coordinates of kinematic PSW features were compared against independently measured fatigue markers (i.e., mean and median EMG spectrum frequencies of individual muscle groups). This comparison was based on a least-squares linear fit of a fixed number of the dominant SOD coordinates to the appropriate local fatigue markers. Between subject variability showed that at most four to five nonlinear SOD coordinates were needed to reconstruct fatigue in local muscle groups, while on average 15 coordinates were needed for the linear SOD. Thus, the nonlinear coordinates provided a one-order-of-magnitude improvement over the linear ones.

Linear and Nonlinear Smooth Orthogonal Decomposition to Reconstruct Local Fatigue Dynamics: A Comparison

2010 ◽  
Author(s):  
David B. Segala ◽  
David Chelidze ◽  
Deanna Gates ◽  
Jonathan Dingwell
Keyword(s):  
Time Series ◽  
Muscle Fatigue ◽  
Power Spectra ◽  
Dimensional Subspace ◽  
Orthogonal Decomposition ◽  
Muscle Injuries ◽  
Data Set ◽  
Individual Muscle ◽  
The Individual ◽  
Smooth Orthogonal Decomposition

Identifying physiological fatigue is important for the development of more robust training protocols, better energy supplements, and/or reduction of muscle injuries. Current fatigue measurement technologies are usually invasive and/or impractical, and may not be realizable in out of laboratory settings. A fatigue identification methodology that only uses motion kinematics measurements has a great potential for field applications. Phase space warping (PSW) features of motion kinematic time series analyzed through smooth orthogonal decomposition (SOD) have tracked individual muscle fatigue. In this paper, the performance of a standard SOD analysis is compared to its nonlinear extension using a new experimental data set. Ten healthy right-handed subjects (27 ± 2.8 years; 1.71 ± 0.10 m height; and 69.91 ± 18.26 kg body mass) perform a sawing motion by pushing a weighted handle back and forth until voluntary exhaustion. Three sets of joint kinematic angles are measured from the elbow, wrist and shoulder as well as surface Electromyography (EMG) from ten different muscle groups. A vector-valued feature time series is generated using PSW metrics estimated from movement kinematics. Dominant SOD coordinates of these features are extracted to track the individual muscle fatigue trends as indicated by mean and median frequencies of the corresponding EMG power spectra. Cross subject variability shows that considerably fewer nonlinear SOD coordinates are needed to track EMG-based fatigue markers, and that nonlinear SOD methodology captures fatigue dynamics in a lower-dimensional subspace than its linear counterpart.

scholarly journals Berechnung der Oberfläche von Kernmaterie mit Hilfe spezieller Einteilchen-Wellenfunktionen

1962 ◽  
Vol 17 (8) ◽  
pp. 640-649
Author(s):  
Franz Lanzl
Keyword(s):  
Surface Energy ◽  
Plane Waves ◽  
Yukawa Interaction ◽  
Range Interaction ◽  
Zero Range ◽  
Volume Energy ◽  
Order Of Magnitude ◽  
The Right ◽  
Right Order ◽  
Surface Thickness

Using a YUKAWA interaction between the nucleons the volume energy per particle and the specific surface energy are calculated. These expressions assume a very simple form for a zero range interaction. The space parts of the applied orthogonal single particle wave functions are products of plane waves and a momentum independent function which brings about the decrease in density within the surface layer. First the volume energy per particle as a function of the density in the interior of nuclear matter is minimized. The interaction parameters are so selected that the values of the volume energy per particle and the density at the minimum agree with the experimental data. Then the surface energy as a function of the surface thickness is minimized. The values of the surface energy and the surface thickness in the minimum are compared with the empirical data. They are found to be of the right order of magnitude

scholarly journals Post-anaesthetic myelomalacia in a horse : clinical communication

2005 ◽  
Vol 76 (1) ◽  
Author(s):  
K.E. Joubert ◽  
N. Duncan ◽  
S.E. Murray
Keyword(s):  
Peripheral Nerves ◽  
Voluntary Movement ◽  
Rare Complication ◽  
Neurological Complication ◽  
Pain Response ◽  
Sitting Position ◽  
Axonal Swelling ◽  
Clinical Communication ◽  
Muscle Groups ◽  
The Right

This article describes a rare neurological complication of anaesthesia in a 2 year-old Clydesdale colt undergoing castration. Anaesthesia was induced with glyceryl guaiacol ether and ketamine and maintained with halothane. Following an uneventful anaesthetic of 40 minutes, the horse recovered from anaesthesia in a padded recovery stall. After approximately 70 minutes in the recovery stall, the horse attempted to stand and adopted a dog sitting position. One hundred and fifty minutes later, the horse became distressed and was sedated with xylazine. Clinical examination of the horse did not reveal any evidence of myositis or fractures. A neurological examination revealed an intact anal reflex, deep pain response in the hind legs, tail tone and voluntary movement of the hind legs was possible. The horse deteriorated neurologically over the next 24 hours and was euthanased on humane grounds. The horse was submitted for necropsy. Gross pathology was unremarkable except for a small amount of haemorrhage around the right kidney. Histopathology revealed no abnormalities in any muscle groups or peripheral nerves. Congestion and axonal swelling of the spinal cord was evident from T16 to S1. Ischaemic neurons were evident from L 1 to L 6. The most prominent lesions were at L4 and L5. A diagnosis of myelomalacia was made. This is a rare complication of anaesthesia in horses with 9 case studies appearing in the literature since 1979. This is the 1st case to be reported in South Africa. The speculated pathophysiology and risk factors for this complication are discussed.

Viscerosomatic interaction induced by myocardial ischemia in conscious dogs

2007 ◽  
Vol 103 (2) ◽  
pp. 511-517 ◽  
Author(s):  
Patricia A. Gwirtz ◽  
Jerry Dickey ◽  
David Vick ◽  
Maurice A. Williams ◽  
Brian Foresman
Keyword(s):  
Myocardial Ischemia ◽  
Contractile Function ◽  
Muscle Tone ◽  
Muscle Tension ◽  
Left Ventricular ◽  
Diagnostic Potential ◽  
Myocardial Contractile ◽  
Muscle Groups ◽  
The Right ◽  
Somatic Response

Studies tested the hypothesis that myocardial ischemia induces increased paraspinal muscular tone localized to the T2–T5 region that can be detected by palpatory means. This is consistent with theories of manual medicine suggesting that disturbances in visceral organ physiology can cause increases in skeletal muscle tone in specific muscle groups. Clinical studies in manual and traditional medicine suggest this phenomenon occurs during episodes of myocardial ischemia and may have diagnostic potential. However, there is little direct evidence of a cardiac-somatic mechanism to explain these findings. Chronically instrumented dogs [12 neurally intact and 3 following selective left ventricular (LV) sympathectomy] were examined before, during, and after myocardial ischemia. Circumflex blood flow (CBF), left ventricular contractile function, electromyographic (EMG) analysis, and blinded manual palpatory assessments (MPA) of tissue over the transverse spinal processes at segments T2–T5 and T11–T12 (control) were performed. Myocardial ischemia was associated with a decrease in myocardial contractile function and an increase in heart rate. MPA revealed increases in muscle tension and texture/firmness during ischemia in the T2–T5 segments on the left, but not on the right or in control segments. EMG demonstrated increased amplitude for the T4–T5 segments. After LV sympathectomy, MPA and EMG evidence of increased muscle tone were absent. In conclusion, myocardial ischemia is associated with significant increased paraspinal muscle tone localized to the left side T4–T5 myotomes in neurally intact dogs. LV sympathectomy eliminates the somatic response, suggesting that sympathetic neural traffic between the heart and somatic musculature may function as the mechanism for the interaction.

scholarly journals Muscle strength and inflammatory response to the training load in rowers

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10355
Author(s):  
Tomasz Podgórski ◽  
Alicja Nowak ◽  
Katarzyna Domaszewska ◽  
Jacek Mączyński ◽  
Magdalena Jabłońska ◽  
...  
Keyword(s):  
Muscle Metabolism ◽  
Creatine Kinase Activity ◽  
Lower Limbs ◽  
Total Testosterone ◽  
Blood Biochemical ◽  
Global Force ◽  
Significant Difference ◽  
Muscle Groups ◽  
Torque Values ◽  
The Right

Background Regular exercise leads to changes in muscle metabolism. The consequence of this is the adaptation to higher training loads.The aim of this study was to evaluate biomechanical and biochemical parameters describing the functions of skeletal muscles in periods when changes in training forms were introduced. Methods Seventeen male sweep-oar rowers, members of the Polish national rowing team, participated. The study was carried out at the beginning and at the end of the preparatory period. In the first and second examination measurements of torques of selected muscle groups and blood biochemical analysis were performed. Results There was observed a statistically significant decrease in the relative global force of the right lower limb between both terms of examination. A statistically significant increase in maximum torque was found for torso flexors. In the case of muscles responsible for torso rotation, a statistically significant decrease in the torque values of right torso rotators was observed. A significant difference was found with respect to creatine kinase activity, total testosterone concentration, total testosterone to cortisol ratio and total phenolics concentration (p < 0.05). Conclusion The study shows that the rowers’ training should be more focused on building the strength of lower limbs to prevent the overload of lumbar spine and that the amount of force developed may be significantly affected by the antioxidant potential of rowers.

scholarly journals Determination of Neuromuscular Control of the Upper Limbs in Children - Case Study

2020 ◽  
Vol 11 (4Sup1) ◽  
pp. 46-61
Author(s):  
Carmen-Magdalena Camenidis ◽  
◽  
Irina Băițel ◽  
Amalia Oatu ◽  
Octavian Amzulescu ◽  
...  
Keyword(s):  
Kinematic Chain ◽  
Neuromuscular Control ◽  
Female Gender ◽  
Upper Limbs ◽  
Motor Action ◽  
Muscle Groups ◽  
The Moment ◽  
The Right

The objective of this case study is to observe the existence of an anticipation mechanism at the muscle groups level of the upper limbs. We tried to highlighted this anticipation process by measuring the potential of surface electric for some muscle groups representing the kinematic chain on the right side, involved in the motor action of catching a basketball and a 3kg medicine ball with two hands to the chest. We conducted a case study of a 13-year-old child, female gender. As a measurement method, we used surface electromyography signals of the EMG Trigno Delsys wireless system with 16 electrodes. We determined the moment when the muscles come into action by increasing the potential of surface electric and the moment when the action of catching the ball takes place, using the information provided by the accelerometers incorporated in the sensors of the Delsys equipment used. Therefore, we obtained information about how different muscle groups come into action which helped us to get an idea of how the child's movement is structured. Based on results of accelerations and EMG signals acquired we have formulated conclusions regarding the neuromuscular control of the tested subject. We also planned for the future to test a larger group of participants in the study research of anticipation mechanism in children who do not practice any performance sports.

scholarly journals Design of Inverted Nano-Cone Arrayed SERS Substrate for Rapid Detection of Pathogens

2021 ◽  
Vol 11 (17) ◽  
pp. 8067
Author(s):  
Zixun Jia ◽  
Sarah Asiri ◽  
Asma Elsharif ◽  
Widyan Alamoudi ◽  
Ebtesam Al-Suhaimi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Rapid Detection ◽  
Close Contact ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Label Free ◽  
Surface Enhanced Raman ◽  
Order Of Magnitude ◽  
The Right ◽  
Pathogen Diagnosis

Rapid detection of bacteria is a very critical and important part of infectious disease treatment. Sepsis kills more than 25 percent of its victims, resulting in as many as half of all deaths in hospitals before identifying the pathogen for patients to get the right treatment. Raman spectroscopy is a promising candidate in pathogen diagnosis given its fast and label-free nature, only if the concentration of the pathogen is high enough to provide reasonable sensitivity. This work reports a new design of surface-enhanced Raman spectroscopy (SERS) substrate which will provide high enough sensitivity and fast and close contact of the target structure to the optical hot spots for immunomagnetic capturing-based bacteria-concentrating technique. The substrate uses inverted nanocone structure arrays made of transparent PDMS (Polydimethylsiloxane) to funnel the light from the bottom to the top of the cones where plasmonic gold nanorods are located. A high reflective and low loss layer is deposited on the outer surface of the cone. Given the geometry of cones, photons are multi-reflected by the outer layer and thus the number density of photons at hotspots increases by an order of magnitude, which could be high enough to detect immunomagnetically densified bacteria.

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