Variability of Technical Action Coordination Structure in Boxing at Fatigue

2021 ◽  
pp. 35-44
Author(s):  
Sergey A. Moiseev ◽  
◽  
Aleksandr M. Pukhov ◽  
Ekaterina A. Mikhaylova ◽  
Asiat T. Gafarova ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Task Performance ◽  
Motor Task ◽  
The Body ◽  
Electromyographic Activity ◽  
Joint Movement ◽  
Movement Amplitude ◽  
Hip Joints ◽  
Amplitude Variability ◽  
Motor Load

One of the directions of research into movement variability studies it at changing external or internal conditions during motor task performance. The results of such investigations are ambivalent even when analysing movements with similar kinematic structure. The aim of the research was to study the variability of skeletal muscle bioelectric activity and space-time characteristics of various punches in boxing at fatigue. Six highly skilled boxers of different weight classes were involved. We analysed parameters of variation of muscle electromyographic activity, distance and speed of the anthropometric points of body segments, as well as joint movement amplitude under regular conditions and after an aerobic motor load. We found low amplitude variability in most of the skeletal muscles under study, both in regular conditions and after a motor load. At fatigue, amplitude variability of almost all muscles decreased. Under regular conditions, the movement amplitude of the shoulder, elbow and hip joints on the bodyʼs right side was more varied than that in the joints on the left. After a motor load, changes in the variability of joint movement amplitude during the performance of different punches were dissimilar. The most variable were changes in the angles of the right side of the body, especially the elbow and hip joints, when performing a direct punch. The least changes under the load were observed in the movement amplitude of the elbow and hip joints on the left side. Thus, variability changes in kinematic parameters caused by skeletal muscle activity are a mechanism for maintaining stability of motor task performance. Presumably, the central neural control of complex coordination movements in boxers when performing punches is carried out through the formation of kinematic and muscle synergies. More research is needed to clarify the mechanism of formation and functioning of kinematic synergies and their variability.

Three forms of the scratch reflex in the spinal turtle: movement analyses

1985 ◽  
Vol 53 (6) ◽  
pp. 1501-1516 ◽  
Author(s):  
L. I. Mortin ◽  
J. Keifer ◽  
P. S. Stein
Keyword(s):  
Receptive Field ◽  
Knee Joint ◽  
Transition Zone ◽  
Tactile Stimulation ◽  
Motor Task ◽  
Knee Extension ◽  
The Body ◽  
Joint Movement ◽  
Flexion Extension ◽  
A Site

The scratch reflex is a motor task exhibited by the hindlimb of a turtle after complete transection of the spinal cord just posterior to the forelimb enlargement. The scratch is elicited by applying gentle tactile stimulation to a site innervated by spinal segments caudal to the level of the transection. During the scratch response, the ipsilateral hindlimb reaches toward and rubs against the stimulated site. Each scratch response consists of either a single rub or a rhythmic series of rubs. There are three types or “forms” of the scratch reflex in the spinal turtle: rostral scratch (previously termed the scratch reflex in Refs. 5, 43, 45), pocket scratch, and caudal scratch. We have characterized each scratch form according to which portion of the hindlimb is used to rub against the stimulated site. During a rostral scratch, the dorsum of the foot and/or toes is used to rub against the stimulated site. During a pocket scratch, the side of the thigh, knee, and/or calf is used to rub. During a caudal scratch, the heel or side of the foot is used to rub. Each scratch form has a distinct receptive field on the turtle shell and skin. A rhythmic scratch response to maintained tactile stimulation consists of as many as 10-25 cycles. We have divided each cycle of movement into a prerub, rub, and postrub phase. Extension of the knee joint occurs during the rub phase of each scratch cycle for all scratch forms. The timing of the extension phase of the knee joint movement within the protraction-retraction (flexion-extension) cycle of the hip joint is different for each form of the scratch. During a rostral scratch, extension of the knee joint occurs when the hip is protracted. During a pocket scratch, knee extension occurs when the hip is retracting. During a caudal scratch, knee extension occurs when the hip is retracted. The spinal turtle therefore shifts the timing of movements of a distal joint (knee) with respect to the timing of movements of a proximal joint (hip) to obtain appropriate scratching movements to different regions of the body. A narrow transition zone exists between the receptive field for one form of the scratch and the nearby receptive field for another form of the scratch. There is a rostral-pocket transition zone and caudal-pocket transition zone in the spinal turtle.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of Concurrent Manual Task Performance on Connected Speech Acoustics in Individuals With Parkinson Disease

2019 ◽  
Vol 62 (7) ◽  
pp. 2099-2117 ◽  
Author(s):  
Jason A. Whitfield ◽  
Zoe Kriegel ◽  
Adam M. Fullenkamp ◽  
Daryush D. Mehta
Keyword(s):  
Task Performance ◽  
Speech Production ◽  
Dual Task ◽  
Motor Task ◽  
Task Condition ◽  
Connected Speech ◽  
Speech Acoustics ◽  
Single Task ◽  
Manual Task ◽  
Task Conditions

Purpose Prior investigations suggest that simultaneous performance of more than 1 motor-oriented task may exacerbate speech motor deficits in individuals with Parkinson disease (PD). The purpose of the current investigation was to examine the extent to which performing a low-demand manual task affected the connected speech in individuals with and without PD. Method Individuals with PD and neurologically healthy controls performed speech tasks (reading and extemporaneous speech tasks) and an oscillatory manual task (a counterclockwise circle-drawing task) in isolation (single-task condition) and concurrently (dual-task condition). Results Relative to speech task performance, no changes in speech acoustics were observed for either group when the low-demand motor task was performed with the concurrent reading tasks. Speakers with PD exhibited a significant decrease in pause duration between the single-task (speech only) and dual-task conditions for the extemporaneous speech task, whereas control participants did not exhibit changes in any speech production variable between the single- and dual-task conditions. Conclusions Overall, there were little to no changes in speech production when a low-demand oscillatory motor task was performed with concurrent reading. For the extemporaneous task, however, individuals with PD exhibited significant changes when the speech and manual tasks were performed concurrently, a pattern that was not observed for control speakers. Supplemental Material https://doi.org/10.23641/asha.8637008

scholarly journals Is Skeletal Muscle Dysfunction a Limiting Factor of Exercise Functional Capacity in Patients with Sickle Cell Disease?

2021 ◽  
Vol 10 (11) ◽  
pp. 2250
Author(s):  
Etienne Gouraud ◽  
Philippe Connes ◽  
Alexandra Gauthier-Vasserot ◽  
Camille Faes ◽  
Salima Merazga ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sickle Cell Disease ◽  
Muscle Fatigue ◽  
Sickle Cell ◽  
Functional Capacity ◽  
Muscle Dysfunction ◽  
Electromyographic Activity ◽  
Cell Disease ◽  
Step Frequency ◽  
Hemoglobin C

Patients with sickle cell disease (SCD) have reduced functional capacity due to anemia and cardio–respiratory abnormalities. Recent studies also suggest the presence of muscle dysfunction. However, the interaction between exercise capacity and muscle function is currently unknown in SCD. The aim of this study was to explore how muscle dysfunction may explain the reduced functional capacity. Nineteen African healthy subjects (AA), and 24 sickle cell anemia (SS) and 18 sickle cell hemoglobin C (SC) patients were recruited. Maximal isometric torque (Tmax) was measured before and after a self-paced 6-min walk test (6-MWT). Electromyographic activity of the Vastus Lateralis was recorded. The 6-MWT distance was reduced in SS (p < 0.05) and SC (p < 0.01) patients compared to AA subjects. However, Tmax and root mean square value were not modified by the 6-MWT, showing no skeletal muscle fatigue in all groups. In a multiple linear regression model, genotype, step frequency and hematocrit were independent predictors of the 6-MWT distance in SCD patients. Our results suggest that the 6-MWT performance might be primarily explained by anemia and the self-paced step frequency in SCD patients attempting to limit metabolic cost and fatigue, which could explain the absence of muscle fatigue.

scholarly journals Mitochondrial Dysfunction Is a Common Denominator Linking Skeletal Muscle Wasting Due to Disease, Aging, and Prolonged Inactivity

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 588
Author(s):  
Hayden W. Hyatt ◽  
Scott K. Powers
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Dysfunction ◽  
Chronic Diseases ◽  
Muscle Mass ◽  
Cancer Chemotherapy ◽  
Muscle Wasting ◽  
The Body ◽  
Common Denominator ◽  
Skeletal Muscle Wasting ◽  
Vital Functions

Skeletal muscle is the most abundant tissue in the body and is required for numerous vital functions, including breathing and locomotion. Notably, deterioration of skeletal muscle mass is also highly correlated to mortality in patients suffering from chronic diseases (e.g., cancer). Numerous conditions can promote skeletal muscle wasting, including several chronic diseases, cancer chemotherapy, aging, and prolonged inactivity. Although the mechanisms responsible for this loss of muscle mass is multifactorial, mitochondrial dysfunction is predicted to be a major contributor to muscle wasting in various conditions. This systematic review will highlight the biochemical pathways that have been shown to link mitochondrial dysfunction to skeletal muscle wasting. Importantly, we will discuss the experimental evidence that connects mitochondrial dysfunction to muscle wasting in specific diseases (i.e., cancer and sepsis), aging, cancer chemotherapy, and prolonged muscle inactivity (e.g., limb immobilization). Finally, in hopes of stimulating future research, we conclude with a discussion of important future directions for research in the field of muscle wasting.

scholarly journals Skeletal Muscle Metabolism: Origin or Prognostic Factor for Amyotrophic Lateral Sclerosis (ALS) Development?

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1449
Author(s):  
Cyril Quessada ◽  
Alexandra Bouscary ◽  
Frédérique René ◽  
Cristiana Valle ◽  
Alberto Ferri ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Muscle Metabolism ◽  
The Body ◽  
Energy Deficit ◽  
Acid Oxidation ◽  
Progression Of Disease ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive and selective loss of motor neurons, amyotrophy and skeletal muscle paralysis usually leading to death due to respiratory failure. While generally considered an intrinsic motor neuron disease, data obtained in recent years, including our own, suggest that motor neuron protection is not sufficient to counter the disease. The dismantling of the neuromuscular junction is closely linked to chronic energy deficit found throughout the body. Metabolic (hypermetabolism and dyslipidemia) and mitochondrial alterations described in patients and murine models of ALS are associated with the development and progression of disease pathology and they appear long before motor neurons die. It is clear that these metabolic changes participate in the pathology of the disease. In this review, we summarize these changes seen throughout the course of the disease, and the subsequent impact of glucose–fatty acid oxidation imbalance on disease progression. We also highlight studies that show that correcting this loss of metabolic flexibility should now be considered a major goal for the treatment of ALS.

Operator orientation and compatibility in visual-motor task performance

Ergonomics ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 387-399 ◽  
Author(s):  
CHARLES J. WORRINGHAM ◽  
DENNIS B. BERINGER
Keyword(s):  
Task Performance ◽  
Motor Task ◽  
Visual Motor

scholarly journals Biochemical approaches for nutritional support of skeletal muscle protein metabolism during sepsis

2004 ◽  
Vol 17 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Thomas C. Vary ◽  
Christopher J. Lynch
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Metabolic Response ◽  
Muscle Protein ◽  
The Body ◽  
Integrated Analysis ◽  
Skeletal Muscle Protein ◽  
Catabolic State ◽  
N Metabolism ◽  
Induced Defects

Sepsis initiates a unique series of modifications in the homeostasis of N metabolism and profoundly alters the integration of inter-organ cooperatively in the overall N and energy economy of the host. The net effect of these alterations is an overall N catabolic state, which seriously compromises recovery and is semi-refractory to treatment with current therapies. These alterations lead to a functional redistribution of N (amino acids and proteins) and substrate metabolism among injured tissues and major body organs. The redistribution of amino acids and proteins results in a quantitative reordering of the usual pathways of C and N flow within and among regions of the body with a resultant depletion of the required substrates and cofactors in important organs. The metabolic response to sepsis is a highly integrated, complex series of reactions. To understand the regulation of the response to sepsis, a comprehensive, integrated analysis of the fundamental physiological relationships of key metabolic pathways and mechanisms in sepsis is essential. The catabolism of skeletal muscles, which is manifested by an increase in protein degradation and a decrease in synthesis, persists despite state-of-the-art nutritional care. Much effort has focused on the modulation of the overall amount of nutrients given to septic patients in a hope to improve efficiencies in utilisation and N economies, rather than the support of specific end-organ targets. The present review examines current understanding of the processes affected by sepsis and testable means to circumvent the sepsis-induced defects in protein synthesis in skeletal muscle through increasing provision of amino acids (leucine, glutamine, or arginine) that in turn act as nutrient signals to regulate a number of cellular processes.

Change in skeletal muscle index and its prognostic significance in conversion therapy for initially unresectable colorectal cancer.

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 56-56
Author(s):  
Hiroaki Nozawa ◽  
Shigenobu Emoto ◽  
Koji Murono ◽  
Yasutaka Shuno ◽  
Soichiro Ishihara
Keyword(s):  
Colorectal Cancer ◽  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscles ◽  
Systemic Chemotherapy ◽  
Stage Iv ◽  
The Body ◽  
Pharmacological Intervention ◽  
Conversion Therapy ◽  
Skeletal Muscle Index

56 Background: Systemic chemotherapy can cause loss of skeletal muscle mass in colorectal cancer (CRC) patients in the neoadjuvant and palliative settings. However, it is largely unknown how the body composition is changed by chemotherapy rendering unresectable CRC to resectable disease or how it affects the prognosis. This study aimed at elucidating the effects of systemic chemotherapy on skeletal muscles and survival in stage IV CRC patients who underwent conversion therapy. Methods: We reviewed 98 stage IV CRC patients who received systemic chemotherapy in our hospital. According to the treatment setting, patients were divided into the ‘Conversion’, ‘Neoadjuvant chemotherapy (NAC)’, and ‘Palliation’ groups. The cross-sectional area of skeletal muscles at the third lumbar level and changes in the skeletal muscle index (SMI), defined as the area divided by height squared, during chemotherapy were compared among patient groups. The effects of these parameters on prognosis were analyzed in the Conversion group. Results: The mean SMI increased by 8.0% during chemotherapy in the Conversion group (n = 38), whereas it decreased by 6.2% in the NAC group (n = 18) and 3.7% in the Palliation group (n = 42, p < 0.0001). Moreover, patients with increased SMI during chemotherapy had a better overall survival (OS) than those whose SMI decreased in the Conversion group (p = 0.021). The increase in SMI was an independent predictor of favorable OS on multivariate analysis (hazard ratio: 0.26). Conclusions: Stage IV CRC patients who underwent conversion to resection often had an increased SMI. As such an increase in SMI further conveys a survival benefit in conversion therapy, it may be important to make efforts to preserve muscle mass by meticulous approaches, such as nutritional support, muscle exercise programs, and pharmacological intervention even during chemotherapy in patients with metastatic CRC.

Retention of Hindlimb Stepping Ability in Adult Spinal Cats After the Cessation of Step Training

1999 ◽  
Vol 81 (1) ◽  
pp. 85-94 ◽  
Author(s):  
R. D. De Leon ◽  
J. A. Hodgson ◽  
R. R. Roy ◽  
V. R. Edgerton
Keyword(s):  
Weight Bearing ◽  
Activity Patterns ◽  
Motor Task ◽  
Full Weight Bearing ◽  
Electromyographic Activity ◽  
Locomotor Training ◽  
Neural Pathways ◽  
Step Cycle ◽  
Rapid Learning ◽  
Hindlimb Muscle

de Leon, R. D., J. A. Hodgson, R. R. Roy, and V. R. Edgerton. Retention of hindlimb stepping ability in adult spinal cats after the cessation of step training. J. Neurophysiol. 81: 85–94, 1999. Adult spinal cats were trained to perform bipedal hindlimb locomotion on a treadmill for 6–12 wk. After each animal acquired the ability to step, locomotor training was withheld, and stepping was reexamined 6 and 12 wk after training ended. The performance characteristics, hindlimb muscle electromyographic activity patterns, and kinematic characteristics of the step cycle that were acquired with training were largely maintained when training was withheld for 6 wk. However, after 12 wk without training, locomotor performance declined, i.e., stumbling was more frequent, and the ability to consistently execute full weight-bearing steps at any treadmill speed decreased. In addition, the height that the paw was lifted during the swing phase decreased, and a smaller range of extension in the hindlimbs occurred during the E3 phase of stance. When three of the spinal cats underwent 1 wk of retraining, stepping ability was regained more rapidly than when trained initially. The finding that stepping ability in trained adult spinal cats can persist for 6 wk without training provides further evidence that training-induced enhancement of stepping is learned in the spinal cats and that a memory of the enhanced stepping is stored in the spinal networks. However, it appears that the spinal cord can forget how to consistently execute stepping if that task is not practiced for 12 wk. The more rapid learning that occurred with retraining is also consistent with a learning phenomenon. These results in conjunction with our earlier findings suggest that the efficacy of the neural pathways that execute a motor task is highly dependent on the periodic activation of those pathways in a sequence compatible with that motor task.

Stretch of Quadriceps Inhibits the Soleus H Reflex During Locomotion in Decerebrate Cats

1997 ◽  
Vol 78 (6) ◽  
pp. 2975-2984 ◽  
Author(s):  
John E. Misiaszek ◽  
Keir G. Pearson
Keyword(s):  
Stretch Reflex ◽  
Stance Phase ◽  
Background Level ◽  
Afferent Input ◽  
H Reflex ◽  
The Body ◽  
Afferent Feedback ◽  
Electromyographic Activity ◽  
Locomotor Rhythm ◽  
Decerebrate Cats

Misiaszek, John E. and Keir G. Pearson. Stretch of quadriceps inhibits the soleus H reflex during locomotion in decerebrate cats. J. Neurophysiol. 78: 2975–2984, 1997. Previously, it has been demonstrated that afferent signals from the quadriceps muscles can suppress H reflexes in humans during passive movements of the leg. To establish whether afferent input from quadriceps contributes to the modulation of the soleus H reflex during locomotion, the soleus H reflex was conditioned with stretches of the quadriceps muscle during bouts of spontaneous treadmill locomotion in decerebrate cats. We hypothesized that 1) in the absence of locomotion such conditioning would lead to suppression of the soleus H reflex and 2) this would be retained during periods of locomotor activity. In the absence of locomotion, slow sinusoidal stretches (0.2 Hz, 8 mm) of quadriceps cyclically modulated the amplitude of the soleus H reflex. The H reflex amplitude was least during the lengthening of the quadriceps and greatest as quadriceps shortened. Further, low-amplitude vibrations (48–78 μm) applied to the patellar tendon suppressed the reflex, indicating that the muscle spindle primaries were the receptor eliciting the effect. During bouts of locomotion, ramp stretches of quadriceps were applied during the extensor phase of the locomotor rhythm. Soleus H reflexes sampled at two points during the stance phase were reduced compared with phase-matched controls. The background level of the soleus electromyographic activity was not influenced by the applied stretches to quadriceps, either during locomotion or in the absence of locomotion. This indicates that the excitability of the soleus motoneuron pool was not influenced by the stretching of quadriceps, and that the inhibition of the soleus H reflex is due to presynaptic inhibition. We conclude that group Ia afferent feedback from quadriceps contributes to the regulation of the soleus H reflex during the stance phase of locomotion in decerebrate cats. This afferent mediated source of regulation of the H reflex, or monosynaptic stretch reflex, would allow for rapid alterations in reflex gain according to the dynamic needs of the animal. During early stance, this source of regulation might suppress the soleus stretch reflex to allow adequate yielding at the ankle and facilitate the movement of the body over the foot.

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