Pharmacologically Induced Accommodation Palsy and the Bioelectrical Activity of the Muscular System: A Preliminary Investigation

The aim of this study was to pharmacologically induce accommodative paralysis and evaluate its effects on the bioelectrical activity of the muscular system. The study included two participant groups: those with myopia and those with normal vision (emmetropes). Electromyographic assessments were performed using the Noraxon Ultium DTS 8-K MR 3 myo Muscle Master Edition system. The muscles analyzed in this study were the temporalis, masseter, sternocleidomastoid, trapezius, abdominal muscles, biceps brachii, and the external oblique muscles of the abdomen. It is important to acknowledge that, based on the current findings, it cannot be definitively stated that the observed effects have clinical significance, and additional studies are encouraged.

Functional role of lacunar and muscular systems in the externa of Peltogasterella gracilis (Cirripedia: Rhizocephala)

One of the most conspicuous traits of parasitic organisms is a well-developed reproductive system. In Rhizocephala ("Crustacea": Cirripedia) it is believed to be nested in the externa-a "reproductive part" located outside of the host. However, it is not clear how nutrients are transported to the externa. Several authors described a system of lacunae in the externa, and muscular contractions probably enable transport through these cavities. The aim of our study was to visualize (using microcomputed tomography and confocal laser scanning microscopy) and describe lacunar and muscular systems in the externa of Peltogasterella gracilis (fam. Peltogasterellidae). The lacunar system consists of "ventral" lacuna and several protrusions. The "ventral" lacuna is probably responsible for visceral mass nutrition, and mantle protrusions are associated with the mantle nutrition. The gross organization of the muscular system mostly corresponds to previous descriptions in other rhizocephalan species. Nonetheless, we observed several features of the externa morphology that had not been described before such as a muscular thickening in the proximal externa's part and a stalk plug disk. The muscular thickening might play a role of a propulsatory organ, helping to transport liquid through the lacunar system. The plug disk might fill the hole in the host's cuticle after the old externa drop off. The results allow us to make first assumptions on transport mechanisms in Rhizocephala.

Exploring the impact of body mass change on fatigue and activity of the muscular system during daily routine

BACKGROUND

Correct body weight is one of the factors that allows you to maintain a properly functioning body. Abnormal body weight can cause muscle tissue remodelling, affecting activity and muscle fatigue. Changes in the muscular system can cause occurrence of functional limitations.

OBJECTIVE

To determine the effect of weight change on fatigue and activity of the muscular system during daily activities.

METHODS

The evaluation of musculoskeletal functioning was based on the results of computer simulations conducted in the AnyBody Modeling System. The following activities were analysed: standing, sitting down and getting up from a chair, holding and lifting an object, and walking. The simulations of the activities were carried out using averaged kinematic data, and by changing body mass in the range of 50 kg to 100 kg by increments of 2 kg, to map different nutritional status from excessive thinness to extreme obesity. Identification of loads in the musculoskeletal system was based on solving an inverse dynamics problem and then the estimation of muscle force values using static optimization. The simulation results allowed to determine the value of muscle fatigue and the level of muscle activity.

RESULTS

For activities (i.e., standing, walking, sitting down and getting up from a chair) it was observed that the value of muscle fatigue increases with increasing body mass. However, for activities that cause more load on the musculoskeletal system, i.e. lifting and holding an object, the highest value of muscle fatigue was observed in underweight individuals.

CONCLUSION

The change in body weight alters the functioning of the muscular system and thus the ability to perform activities. It was shown that in case of underweight, overweight or obese people, abnormal body weight can be the reason for occurrence of difficulties in performing the activities of lifting and holding a 20 kg object, as well as walking.

Skeletal muscle coverage in undergraduate courses: a comparison of stand-alone human anatomy and anatomy and physiology (A&P) courses

Anecdotal data suggest great variation in breadth and depth of skeletal muscle coverage between undergraduate human anatomy (HA) and anatomy and physiology (A&P) courses. This manuscript is the second in a series (Reynolds A, Goodwin M, O'Loughlin VD. Adv Physiol Educ 46: 309-318, 2022. doi:https://doi.org/10.1152/advan.00084.2021) that methodically assesses skeletal muscle content coverage across undergraduate HA and A&P courses. The authors developed an online skeletal muscle coverage survey and collected 342 responses worldwide, 156 from instructors of HA courses and 186 from A&P course instructors. Demographic results showed that HA courses are primarily taught at 4-year baccalaureate institutions, have relatively larger class sizes, and are more likely to use human (vs. animal) prosections or dissections. In contrast, A&P courses are primarily taught at community colleges, have relatively smaller class sizes, and are more likely to use animal (vs. human) dissections. HA courses tend to require their students to learn all skeletal muscle aspects (i.e., identification, action, attachments, innervation), whereas A&P courses tend to focus on muscle identification or action only. The proportions of courses that require identification of large, superficial skeletal muscles are similar between the two course types. However, HA courses are more likely to require their students to identify deeper and smaller muscles, including more distal appendicular muscles and pelvic muscles. These differences likely are due, in part, to the more anatomical focus of HA courses and the slightly different student populations between these courses. These findings provide much-needed information about muscular system coverage between HA and A&P courses and may guide instructor discussions about curricula.

General trends in skeletal muscle coverage in undergraduate human anatomy and anatomy and physiology courses

There is a widely variable breadth of coverage of skeletal muscle content across both undergraduate human anatomy and undergraduate anatomy and physiology (A&P) courses. In response to the need for a more global understanding of the content taught in undergraduate anatomy courses, we developed an online survey (administered through Qualtrics) where both human anatomy and A&P faculty could report skeletal muscle coverage in their courses. The survey also collected comparative demographic institutional data such as the type of institution (community college vs. 4 year), course format, and geographic location of the undergraduate institution. Skeletal muscles surveyed included those listed and described in a typical undergraduate human anatomy text (McKinley MP, O'Loughlin VD, Pennefather O. Human Anatomy (5th ed.), 2017, p. 960). The data indicated some interesting instructional trends regarding muscular system coverage. First, both the "identification" and "action" of specific muscles are taught at a higher frequency than the teaching of either "attachments or innervation." Innervation of specific skeletal muscles is the least taught concept. In each body region, certain muscles were taught with higher frequency than others. This research shows there is a global trend in teaching identification of specific skeletal muscles within each body region and often this is accompanied by teaching actions of said muscles. These general instructional trends may increase our understanding of the anatomical and physiological education our undergraduate students are receiving and will lead to further critical conversations about content development and curriculum.

Nervous and Muscular Adverse Events after COVID-19 Vaccination: A Systematic Review and Meta-Analysis of Clinical Trials

Background: Nervous and muscular adverse events (NMAEs) have garnered considerable attention after the vaccination against coronavirus disease (COVID-19). However, the incidences of NMAEs remain unclear. We aimed to calculate the pooled event rate of NMAEs after COVID-19 vaccination. Methods: A systematic review and meta-analysis of clinical trials on the incidences of NMAEs after COVID-19 vaccination was conducted. The PubMed, Medline, Embase, Cochrane Library, and Chinese National Knowledge Infrastructure databases were searched from inception to 2 June 2021. Two independent reviewers selected the study and extracted the data. Categorical variables were analyzed using Pearson’s chi-square test. The pooled odds ratio (OR) with the corresponding 95% confidence intervals (CIs) were estimated and generated with random or fixed effects models. The protocol of the present study was registered on PROSPERO (CRD42021240450). Results: In 15 phase 1/2 trials, NMAEs occurred in 29.2% vs. 21.6% (p < 0.001) vaccinated participants and controls. Headache and myalgia accounted for 98.2% and 97.7%, and their incidences were 16.4% vs. 13.9% (OR = 1.97, 95% CI = 1.28–3.06, p = 0.002) and 16.0% vs. 7.9% (OR = 3.31, 95% CI = 2.05–5.35, p < 0.001) in the vaccine and control groups, respectively. Headache and myalgia were more frequent in the newly licensed vaccines (OR = 1.97, 95% CI = 1.28–3.06, p = 0.02 and OR = 3.31, 95% CI = 2.05–5.35, p < 0.001) and younger adults (OR = 1.40, 95% CI = 1.12–1.75, p = 0.003 and OR = 1.54, 95% CI = 1.20–1.96, p < 0.001). In four open-label trials, the incidences of headache, myalgia, and unsolicited NMAEs were 38.7%, 27.4%, and 1.5%. Following vaccination in phase 3 trials, headache and myalgia were still common with a rate of 29.5% and 19.2%, although the unsolicited NMAEs with incidence rates of ≤ 0.7% were not different from the control group in each study. Conclusions: Following the vaccination, NMAEs are common of which headache and myalgia comprised a considerable measure, although life-threatening unsolicited events are rare. NMAEs should be continuously monitored during the ongoing global COVID-19 vaccination program.

The Novel Coronavirus Infection (COVID-19) and Nervous System Involvement: Mechanisms of Neurological Disorders, Clinical Manifestations, and the Organization of Neurological Care

The new coronavirus SARS-CoV-2 and the disease it causes COVID-19 involves not only respiratory system damage, but can also lead to disorders of the central and peripheral nervous system, as well as the muscular system. This article presents published data and our own observations on the course of neurological disorders in COVID-19 patients. There is a relationship between the severity of COVID-19 and the severity and frequency of neurological manifestations. Severe neurological disorders are mostly seen in severe cases of COVID-19 and include acute cerebrovascular accidents (aCVA), acute necrotizing encephalopathy, and Guillain–Barré syndrome. Factors potentially complicating the course of COVID-19 and increasing the development of neurological complications include arterial hypertension, diabetes mellitus, and chronic cardiac and respiratory system diseases. Questions of the possible effects of human coronaviruses on the course of chronic progressive neurological diseases are addressed using multiple sclerosis (MS) as an example. We discuss the management of patients with aCVA and MS depending on the risk of developing coronavirus infection.