Neuromuscular Reaction Research Articles

Comparison of hip abductor and adductor muscle performance between healthy and osteitis pubis professional footballers.

The study aimed to compare the concentric and eccentric muscle performance of the hip abductor and adductor muscles at a high angular velocity in football players with osteitis pubis and healthy players. A total number of 32 male football players with osteitis pubis and 20 healthy footballers were tested using an isokinetic dynamometer at a speed of 180°/s. Hip abductor and adductor peak torque/body weight, time to peak torque, acceleration, and deceleration times produced during concentric and eccentric muscle contraction modes were measured using a Biodex dynamometer. Football players with osteitis pubis demonstrated a significantly higher time to peak torque, acceleration, and deceleration times (p < 0.05); however, when compared to healthy athletes, there was no significant change in muscle strength. The present study showed that football players with osteitis pubis had a reduction in neuromuscular reaction. Therefore, the reaction time of these muscles is critical, and the reduction could result in magnified stresses and/or poorly distributed loads across the musculotendinous structure of the anterior pelvis, which presumably could lead to the development of osteitis pubis. Incorporate findings of the current study in clinical practice could afford critical information when evaluating the hip muscles in football players with osteitis pubis, for pre-screening, enhancing the rehabilitation programs, and guiding the decision of returning to sports after injury.

Effects of Dynamic Stretching on Neuromuscular Reaction Time of Young Female Athletes

"Introduction. Reaction time is the ability to perform a single (non repeated) movement in the shortest time and it is a crucial skill in sports. It has been shown that using different warm-up strategies can improve performance output. Recently it has been discovered that static stretching may temporarily decrease the muscle’s ability to perform. Objectives. The aim of this paper was to determine if the neuromuscular reaction time during jumping is influenced by dynamic stretching. Materials and Methods. The participants in this study were young female basketball players (N = 22), ages from 16 to 18 years old that underwent two measurements using the MGM-15 carpet in two situations: without doing dynamic stretching and after doing dynamic stretching. Results. There was a significant statistical difference in the scores between the control and after dynamic stretching measurements. This means that the dynamic stretching had an influence over the reaction time. Conclusion. The results of the present research demonstrated that local neuromuscular reaction time increased significantly after dynamic stretching compared to the baseline condition. Keywords: dynamic stretching, reaction time, female, athletes, neuromuscular "

Integrating cardiopulmonary exercise testing and 6-min walk test for predicting postoperative cardiopulmonary complications in patients undergoing lung cancer surgery: A narrative review

Cardiopulmonary exercise testing (CPET) is an effective method for the assessment of cardiopulmonary and neuromuscular reaction to physical stress. It offers an independent assessment of cardiopulmonary fitness and functional capacity in patients undergoing lung cancer surgery. The 6-min walk test (6MWT) can be used for the assessment of functional capacity when CPET is unavailable. Through this review, we aim to emphasize the importance of utilizing both CPET and 6MWT in the assessment of cardiorespiratory fitness/functional capacity in patients with lung cancer undergoing major thoracic oncological resections. We searched the PubMed electronic database using the MeSH system for articles reporting the use of CPET and 6MWT in cardiopulmonary fitness/functional capacity evaluation during cancer treatment. The full-text articles were assessed, and significant evidence was extracted. Only the articles written in the English language were selected. Using a combination of CPET and 6MWT for the assessment of cardiopulmonary fitness/functional capacity in patients with lung cancer undergoing complex oncological resections, could give a definite prediction of the possibility of postoperative cardiopulmonary complications in these patients.

Effects of regular Tai Chi practice and jogging on neuromuscular reaction during lateral postural control in older people

ABSTRACTThis study examined the effects of regular Tai Chi practice and jogging on the neuromuscular activity of the trunk, hip, and ankle joint muscles of older people during lateral postural perturbation. A total of 42 older people participated in the study and formed the Tai Chi, jogging, and sedentary control groups. Electromyography signals were collected from the peroneus longus, anterior tibialis, gluteus medius, and erector spinae during unpredictable mediolateral perturbation. The Tai Chi group exhibited significantly faster latencies of the tibialis anterior and erector spinae than the control group. The jogging group showed a significantly shorter neuromuscular reaction time of the erector spinae than the control group. No significant difference was observed between the Tai Chi and jogging groups. Long-term regular Tai Chi practice enhanced the neuromuscular reaction of the erector spinae and tibialis anterior to lateral perturbation and will help timely posture correction when lateral postural distributions occur.

Effect of 1-year regular Tai Chi on neuromuscular reaction in elderly women: a randomized controlled study

This study assessed the effect of 1-year regular Tai Chi (TC) on neuromuscular reaction in elderly women. A total of 41 elderly women (55 years–68 years) completed the study. The TC group (n = 21) performed the 24-form TC, while the control group (C, n = 20) was instructed to read newspapers or watch television when the TC group practised. Electromyogram measurements were conducted before and after intervention. After a year-long intervention, the post-test results of between-group neuromuscular reaction time showed significant differences in the rectus femoris (t = 3.607, p = 0.001), semitendinosus (t = 2.678, p = 0.011), anterior tibialis (t = 3.455, p = 0.001), and gastrocnemius muscles (t = 4.061, p = 0.000). Within-group results showed that the TC group had significantly shorter neuromuscular reaction time compared to its baseline value in the rectus femoris (t = 3.066, p = 0.006), semitendinosus (t = 2.485, p = 0.022), anterior tibialis (t = 2.311, p = 0.032), and gastrocnemius muscles (t = 2.462, p = 0.023). Results suggested that year-long regular TC can improve neuromuscular reaction function in elderly women.

Adiposity is associated with improved neuromuscular reaction time

Many studies have focused on the detrimental effects of malnourishment to the performance of the brain and peripheral nerves. Undernourished children and adults have been studied extensively to establish these consequences. Little attention has been given to the body habitus that affects optimum neurological performance and the implications for individuals on the spectral extremes of the healthy weight range. This paper examines the association between markers of adiposity and neurological performance, inclusive of all body types. The data were obtained from Cape Coloured youths (5–20 years) in South Africa from the rural district of Klein Karoo and the urban population of Cape Town. In all, the sums of skin-folds were measured for almost 4000 students. The neuromuscular reaction time was also calculated using a ruler drop test. This measure may serve as a gross marker of peripheral and central neurological performance as both are needed to execute the reflex command. There was a direct correlation between adiposity and neuromuscular reaction time. Whilst controlling for age, increasing fatness was associated with a decrease in neuromuscular reaction time amongst both sexes. This relationship remained statistically significant, even when removing the thinnest 40% of participants, eliminating the scope of influence exerted by malnourishment on the correlation. The trend appears to be more prominent amongst boys. These findings indicate that body lipid reserves are integral to the development of the nervous system even amongst children within the healthy weight ranges. Our hypothesis is that the myelination of the nerves, both centrally through oligodendrocytes and peripherally by Schwann cells, is integral to this process as they are predominantly lipid. Amongst thin but not clinically undernourished individuals, the somatic lipid reserves are modest. These fats may be minimally sequestered away for the development of myelin nerve sheath at the expense of saltatory conduction. This may account for the slowed neuromuscular reaction time demonstrated.

Unloading reaction during sudden ankle inversion in healthy adults

The purpose of this research study was to determine the dynamics of early human response from sudden ankle inversion (30° tilt). Changes in vertical ground reaction forces (GRFs) following trapdoor release in a group of healthy subjects were compared to those from the similar experiments using a chair with two U shaped steel legs and matched weights of the human subjects. The experiments with the chair were further repeated with additional foam paddings at their bases to introduce visco-elastic properties to legs of the chair. Following the trapdoor release a decrease in the vertical ground reaction force under the inverting leg and subsequent increase in the supporting leg were observed in both human and chair experiments. The short onset of changes in vertical GRFs in our experiments indicate that the dynamic features of early response following trapdoor release are primarily due to mechanical events and may not be significantly affected by the neuromuscular reaction of human subjects.

Relative age effect and selection of young basketball players

Purpose of the present study was to examine whether influence of relative age effect (RAE) exists or not in the selected 13 year old basketball players. Subjects were 20 basketball players (HT=177.35cm±6.73, BW=61.42kg±8.98, average age 13 years and 7 months ±.28, average experience in basketball training 4 years and 6 months ±1.15). Sample was divided in two groups: 11 players born in first half of the year and 9 players born in the second half of the year. One-way ANOVA was used in order to analyze the differences between the two groups of players in set of anthropometric variables (body height, arm span, standing reach height, body weight and percentage of body fat), motor variables (velocity of neuromuscular reaction time, vertical jump, 5 meters sprint, 10 meters sprint, 20 meters sprint, T-test, Zig-zag test, ball throw from sitting position, Sit-ups for 30 seconds and standing forward bend) and one functional variable (20-M shuttle run test). Subjects do not differ in applied set of parameters, except in on variable (sit-ups for 30 seconds, p=.040). It was concluded that RAE does not exist in this sample of examinees.

Insufficient recovery of neuromuscular activity around the knee after experimental anterior cruciate ligament reconstruction

Background Operative and nonoperative treatment of anterior cruciate ligament (ACL) injuries is often associated with a lack of proprioception and persistent muscle weakness of unknown origin.Methods This long-term study in the cat experimentally compares both neural and muscular activity in the articular nerves of the knee (PAN and MAN), quadriceps and hamstrings, in the chronic unstable knee, and in the reconstructed knee. We also investigated changes in neuromuscular response due to the mechanical competence of the graft, comparing stable and unstable reconstructed knees.Results We found increased periarticular muscle activity during anterior tibial translation in chronically unstable knees. Both reconstructed and non-reconstructed knees lost fast reactive activity in the articular nerves. When stability was recovered after reconstruction, the knees showed a more adjusted—although incomplete—muscular reaction.Interpretation ACL-injured knees in the cat, with or without reconstruction, show definite abnormalities in neuromuscular reaction in the long term. Regaining stability with a competent graft in the reconstructed knee is crucial for reduction of this anomalous reaction.

Possible Factors Related to Functional Ankle Instability

Case control study. To classify individuals with functional ankle instability (FAI) into deficit and non-deficit categories based on the evaluation of the most common factors that have been proposed to be related to FAI. Recent studies have suggested that FAI may be secondary to a combination of factors including ankle proprioceptive deficit, muscular weakness, impaired balance, delayed neuromuscular reaction time, and joint laxity. However, only a few authors have investigated the prevalence and association among these factors in a single group of individuals. The above 5 factors were tested bilaterally in 21 individuals with FAI and in 16 healthy control subjects. Data were analyzed for (1) within- and between-group comparison, (2) classification of subjects with FAI into deficit and no-deficit categories, and (3) magnitude of association between factors in the subjects with FAI using Pearson bivariate correlation. Balance control and evertors' strength were significantly less on the affected side in comparison to the unaffected side in subjects with FAI. The evertors' strength was also significantly different between the side difference of the FAI group and the side difference of the control group. Passive ankle stiffness was significantly correlated to balance control, ankle proprioception, and evertor peak torque. Individuals with FAI demonstrated a large variation in the deficit categories ranging from multiple deficits to no noticeable deficits. Mechanical alterations in the ankle joint may influence several aspects of the ankle's functional ability. Alterations in the afferent processes, represented in this study by ankle proprioception, may effect the evertors' strength or vice versa. More importantly, individuals with FAI might exhibit high variability in ankle deficits.

Effect of regular Tai Chi and jogging exercise on neuromuscular reaction in older people

to investigate the effects of regular Tai Chi (TC) or jogging exercise on neuromuscular reaction in older people. cross-sectional study. university biomechanics laboratory. 21 long-term elderly TC practitioners were compared with 18 regular elderly joggers and 22 sedentary counterparts. electromyography (EMG) was used to detect the neuromuscular reaction of the leg muscles to an unexpected ankle inversion perturbation. The latency of the muscles, which was defined as the time that the moment of perturbation began to the onset of the EMG response, was evaluated. a one-way ANOVA revealed that there were significant differences in the latency of the rectus femoris (R) and anterior tibialis (T) muscles between the three groups, but that there were no differences in the latency of the semitendinosus (S) and gastrocnemius (G) muscles. Further tests indicated that the R and T muscles in the TC and jogging groups were activated significantly faster than those in the control group. No significant difference was found for the muscle onset latencies between the TC and jogging groups. maintaining information processing speed during ageing is important, because of the role that it plays in many everyday events. The R and T muscles in the regular TC and jogging groups showed faster responses to unexpected ankle inversion perturbations, which is helpful for the timely correction of postural disturbances, than those in the sedentary control group.

Growth of specific muscle strength between 6 and 18 years in contrasting socioeconomic conditions

The influence of sex, age, and socioeconomic conditions on specific grip strength of 6-18-year-old individuals was studied among 1,704 males and 1,956 females belonging to the so-called "Cape Coloured" community in the western part of South Africa. Half of the participants of both sexes came from communities in the Greater Cape Town area where living conditions are comparable to those of middle-class First World communities (high SES). The other half came from the poorest rural communities of Klein Karoo (low SES). Arm circumferences, triceps skinfold thickness, and grip strength of the right and of the left hand were greater in individuals from high SES at all ages. Females within each SES group had skinfolds thicker than males, especially at older ages, and were weaker. Specific grip strength (SS), estimated as grip strength per unit area of cross section of the fat-free arm, increased with age in each group, was greater in males, and was significantly lower in low SES groups, than in the high SES ones, especially during and after puberty. It seems that SES difference in SS will persist into adulthood. Sexual differences in SS can be attributed to hormonal differences; while the SS increase with age and the difference between SES groups find no clear explanation in current theories of muscle growth and development. Since the speed of neuromuscular reaction observed in our participants is slower among low SES individuals, it seems that the difference in neuromuscular control of strength may be responsible for our findings. Differences in muscle metabolism and hormonal regulation must also be considered.

The small child: anthropometric and physical performance characteristics of short-for-age children growing in good and in poor socio-economic conditions.

To ascertain whether individuals whose short stature is caused by poor living conditions differ in their other biological characteristics from those individuals who grow short, supposedly due to their genetic endowment, under favourable environmental conditions. From the growth survey of nearly 4000 children of the 'Cape Coloured' community aged 6-18 y half of whom lived in the middle-class suburbs of Cape Town [high socio-economic status (SES)], the other half who lived in poor rural settlements (low SES), boys and girls of similarly short stature were selected. Average body height by sex and age in each selected sample was close to the 5th percentile of height distribution among all high SES individuals surveyed. Cape Town and neighbouring rural settlements in South Africa. Four thousand children of the Cape Coloured community aged 6-18 y. Among these were 109 high SES boys, 123 high SES girls, 302 low SES boys and 344 low SES girls selected for short stature study. Anthropometric measurements in public schools with appropriate permissions. Both short stature males and females from the low SES group tended to be significantly (P < 0.05) different from the high SES group of comparable stature in having lower body weights, shorter limbs, longer trunks, narrower shoulders, hips and chests, thinner skinfolds, smaller arm circumferences, and were very notably weaker and had poorer neuromuscular reaction times. Biepicondylar widths and pulse rates were little different between groups. Genetically short children do differ in various anthropometric and functional traits from those who are small from environmental causes.

Jeckel, N., Rakosi, T., and Joos, U. The neuromuscular reaction to continuous dynamic jaw extension in cases with restricted mouth opening. J. Craniomaxillofac. Surg. 15

Jeckel, N., Rakosi, T., and Joos, U. The neuromuscular reaction to continuous dynamic jaw extension in cases with restricted mouth opening. J. Craniomaxillofac. Surg. 15

The neuromuscular reaction to continuous dynamic jaw extension in cases with restricted mouth opening

20 patients with severe trismus resulting from either trauma or infection have been treated using the method of "continuous dynamic jaw extension". The clinical results and the electromyographic tests show that almost complete rehabilitation of mandibular movement is possible. The treatment is most effective during the healing phase of the abscess and as an early treatment for the traumatised patient. Extension exercises should not be undertaken during the exudative phase of abscess formation. The reaction ability of the masticatory musculature obtained from the electromyographic investigations is defined in the "reactive myotonus-index". Thus the jaw extension appliance used is helpful both in the diagnosis and treatment of severe trismus.

Neuromuscular reaction to paired stimuli.

A modification of the twin pulse method is described, by which the nerve tested is stimulated at one proximal site percutaneously and the neuromuscular response to it is derived from a dependent muscle. An electronic subtraction procedure provides separation of the conditioned muscle action potential for measurement by means of a microcomputer. Several parameters were determined in the conditioned action potential and compared to the same criteria in an unconditioned single action potential. Changes of the conditioned action potential were measured at fixed stimulus intervals between 2 and 6 msec. Preliminary normal ranges interindividually and intraindividually were established. Their dependency on skin surface temperature was determined. In polyradiculoneuropathy, the data for motor nerve conduction velocity were characteristically pathologic, and neuromuscular reaction to paired stimuli data deviated minimally from normal. In vincristine neuropathy, motor nerve conduction velocity was normal, but neuromuscular reaction to paired stimuli data fell outside the normal range early in the clinical course. Since polyradiculoneuropathy is a primary demyelinating and remyelinating process and vincristine neuropathy is an example of axonal degeneration, neuromuscular reaction to paired stimuli can facilitate the differential diagnosis in polyneuropathy. Furthermore, this method seems apt to quantify axonal degeneration. In a mixed form of polyneuropathy, peroneal muscular atrophy, motor nerve conduction velocity, as well as neuromuscular reaction to paired stimuli, were abnormal, the latter resulting in abnormally high relative amplitudes. In muscle disorders such as Duchenne muscular dystrophy, neuromuscular reaction to paired stimuli data was abnormal, contrasting experiments using double stimulation of the diseased muscle itself.

ELECTROPHYSIOLOGIC ASSESSMENT OF PERIPHERAL NEUROPATHY in CHILDREN WITH CHRONIC RENAL FAILURE (CRF)

Peripheral nerve function is frequently altered in CRF although clinical manifestations in children are rare. For assessment of uremic neuropathy the measurement of motor nerve conduction velocity (MNCV) has widely been used. In an earlier study we failed to find a correlation between MNCV and severity of CRF. In the present study a more sensitive neurographic parameter has been applied: the relative refractory period as estimated by neuromuscular reaction to paired stimuli (NMRPS). This method was tested in 24 children with CRF on conservative treatment(CT), 11 pts immediately before and after a haemodialysis(HD) session and 13 pts after transplantation(TP). In CT a correlation was found between some parameters of NMRPS and serum creatinine(SCR). The changes of NMRPS correlated even better with those of SCR during a HD session. After TP a significant improvement of MNCV was observed whereas NMRPS was unchanged. These data suggest that 1) NMRPS is a sensitive parameter of uremic neuropathy which might be used to control adequacy of therapy, 2) short term improvement of neuroaxonal function occurs by HD, 3) long-term improvement of myelin sheeth function is induced after TP.

Honey-bee abdomen assays of hemolymph from stressed and externally poisoned American cockroaches

Blood from cockroaches stressed by having their mouthparts sealed or by being dehydrated by contact with silica aerogel, administered into the opened wounds of freshly excised honey bee abdomens, produced neuromuscular reaction that was monitored and recorded as characteristic myograms. When blood became too viscous or unobtainable during the terminal stages of stress, coxal muscle was substituted. Abdomens used for assay were also used for toxicological studies, comparing their survival time with untreated abdomens. Intact and decapitated cockroaches were equally desiccated by contact with silica aerogel to determine if presence or absence of the coordinating center had any bearing on stress. Fragments of coxal muscle from the intact cockroaches deactivated 10 bee abdomens in 15 hr while coxal muscle from the decapitated cockroaches deactivated only one out of 10 abdomens. Blood from cockroaches poisoned by oral administrations of boric acid solution was readily available, clear, and free-flowing, and produced myograms showing periods of lethargy followed by deep convulsions. Portions of these myograms resembled symptoms of lethargy and convulsions produced by boric acid solution when it was administered directly into the bee abdomens.

Some bio-sociological aspects of the mathematical theory of communication

In the first part of the paper a general discussion of the transmission of information through neural chains is given in terms of the Shannon-Weaver theory. It is pointed out that with the all-or-none law a single chain of neurons connected in series transmits one bit of information per signal. A set ofN independent parallel chains transmitsN bits per signal. If, however, the chains are interconnected, the amount of information is reduced. At the same time, however, the degree of coordination of the final neuromuscular reaction is increased. A relation between the maximum possible speed of a reaction and its degree of coordination is derived, and possible applications to spoken language are suggested. A general quantitative discussion of the relation between amount of information and amount of knowledge which an individual may obtain when confronted with the external world is made and a possible connection with new trends in logical thinking is pointed out.

Studies in Endothelial Permeability. II

Abstract The fact that anaphylactic shock in the dog is associated with phenomena largely neuroendothelial in character as contrasted to the neuromuscular reaction that predominates in the guinea pig has led to an extensive study of these alterations in the vascular relations. It has been found that the effect on the lymph flow is quite similar to that when lymphagogues of 1st class are injected, i.e., an increased flow of lymph that is more concentrated in solids. This has been ascribed to the increased intraportal pressure. This increase in intraportal pressure has been assumed by some to be due to factors in which the liver is not directly participating, by others, such as Mautner and Pick (1) and Simmonds (2), actual vasoconstriction in the liver is held to be causative. Jaffe (3) has demonstrated smooth muscle fibers about the smaller veins in the liver and states that they are seen most easily when the liver is engorged and the capillary spaces distended.