Abstract: Since 1997, there has been increasing research focusing on muscledysmorphia, a condition underpinned by people’s beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the con- dition beyond knowledge about their characteristics. Much of the existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples), which are largely confined to Western (North American, British, and Australian) males. Although much research has been undertaken since the term “muscledysmorphia” entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent to which the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base than currently exists. Future work will help clinicians assist a group of people whose quality of life and health are placed at risk by their muscular preoccupation. Keywords: psychopathology, mental health, body image, self-perceptions
Conclusions: Muscledysmorphia is an emerging phenom- enon in society. Pressure on males to appear more muscular and lean has prompted a trend in the area of psychobehavioral disorders often likened to anorexia and bulimia nervosa. Ath- letes are particularly susceptible to developing body image dis- orders because of the pressures surrounding sport perfor- mance and societal trends promoting muscularity and leanness. Health care professionals need to become more familiar with the common signs and symptoms of muscledysmorphia, as well as the treatment and referral options, in order to assist in providing appropriate care. In the future, authors should contin- ue to properly measure and document the incidence of muscledysmorphia in athletic populations, both during and after partic- ipation.
Background: Muscledysmorphia (MD) is a relatively young diagnosis referring to the desire for a high degree in lean muscle mass, while simultaneously believing that one is insufficiently muscular, mostly found in men. It goes along with a risk for social withdrawal to maintain rigid exercise and dietary regimen. The aim of the current study was thus, to explore differences in men with and without a risk for muscledysmorphia regarding their desire for social interaction. Furthermore, we investigated potential effects of individual social comparison tendencies (the tendency to compare oneself with persons who are perceived to be superior or inferior to oneself on a certain dimension) and of one ’ s own body schema on the desire for social interaction.
Before the educational intervention, a 300 word description of MuscleDysmorphia, only 27.9% of participants claimed to be familiar with the term ‘MuscleDysmorphia’. 48.8% of participants were not familiar with the term, and 23.3% were unsure. After the brief educational intervention, 91.5% of participants stated they understood the term ‘MuscleDysmorphia’. Only 1.2% reported they did not understand, and 7.3% of participants were unsure. The difference in self-reported awareness of MD improved by over 63% post-intervention. The impact of the educational intervention is statistically significant for a difference in the number of subjects who answered that they understood the concept of MD, with p< 0.001 as determined by McNemar’s test (α<0.05), statistical significance p<0.05).
Muscledysmorphia was first described in 1993 by Pope and coll.  as an obsessive-compulsive disorder, characterized by the obsession of body appearance, the fear of not being sufficiently muscled, and the compul- sion to excessive physical exercise . Such individuals show changes in feeding behavior, such as radical diets and dietary supplements, abuse of anabolic substances, and impairment or distress in social and physical do- mains , and in social and occupational functioning [16,17]. According to the DSM-5, the specification “with muscledysmorphia” has been added to body dysmorphic disorder, suggesting that this is an important distinction to be done as regards this disorder. Muscledysmorphia is more frequently diagnosed in male young adults [14,18], and bodybuilders represent a high-risk group . The prevalence of muscledysmorphia in the general popula- tion is still unknown since only few small studies are avail- able . We wonder if students from schools oriented to fitness and body care show an increased prevalence of the traits of this disorder.
When comparing the BMI of the classi- fied normal weight and overweight participants according to MD symptomatology scores and WTD, statistical significant differences (p<.01) in DFS (M = 1.6, SD = 0.7, d=.4), AI (M = 0.8, SD = 0.5, d=.3), FI (M = 1.4, SD = 0.6, d=.4) and WTD (M = 2.1, SD = 0.7, d=.7) were detected (Figure 2). The normal weight participants scored significantly higher on DFS compared to the overweight partici- pants, but the difference is considered small (d=.4, p<.01), and should therefore be interpreted care- fully. However, the results suggest that overweight participants have a large body mass at current, hence they may not want to increase their body mass any further compared to that of normal weight participants who possess a high drive for increasing their body mass. Hildebrandt et al. (2006) reported higher DFS (M = 11.31, SD = 4.80) among muscle concerned weightlifters with a mean normal weight BMI compared to lower DFS (M = 5.50, SD = 4.82) in fat concerned weightlifters with a mean over- weight BMI. On the contrary, Hildebrandt et al. (2006) reported even higher DFS (M = 14.87, SD = 4.12) in dysmorphic weightlifters with a mean over- weight BMI, but were lower than the DFS scores (M = 16.09, SD = 4.02) detected in the normal weight participants in the present study, providing support for that DFS may be higher in normal weight indi- viduals training at the gym.
This research was performed to determine the effects of MET on the flexibility of hamstring muscle in futsal players. The results of the study revealed that following the intervention of MET in the chronic implication, the subjects displayed a significant improvement (P < .05) in the flexibility of the hamstring muscle. The participant in this study were futsal players. A study done by Ivan (2012) on futsal players states that MET is a non-traumatic manipulative technique which is effective, he said MET inhibits the motor activity through the Golgi tendon organs. The purpose of the relaxation phase immediately after MET is to reduce the tone of the muscle, which makes the movement towards the new length of the muscle much easier. Islam et al. (2017) stated that the changes inside connective tissues exhibit mechanical properties involving both viscous and elastic components. “Creep” represents the impermanent elongation of connective tissue during stretch by means of an outcome of its viscoelastic properties”. He also stated that everlasting “plastic” changes can happen as a result from micro‑tearing and remodeling of the connective tissue fibers. He concluded that “MET may produce improved muscle length by a mixture of creep and plastic changes in the connective tissues”.
Another important category of bioactive molecules used for skeletal muscle tissue engineering is small mol- ecules; they can be synthesized with controlled physico- chemical properties, excellent permeability, and most importantly, high selectivity and potent bioactivity against target molecules, also with relatively lower manufacturing cost [18, 19]. The emergence of high- throughput screening technologies has enabled the dis- covery of small molecules that control cell behavior while also activating signaling pathways related to skel- etal tissue regeneration [20, 21]. For example, retinoic acid signaling plays an essential role in regulating the differentiation of muscle progenitor cells; selective retin- oic acid receptor-γ (RARγ) agonists have been demon- strated to promote repair of injured skeletal muscle in mouse . Other potential small bioactive molecules for skeletal muscle regeneration include BIO (glycogen synthase-3 kinase inhibitor), SQ22536 (adenylyl cyclase inhibitor), SB203580, (p38-MAPK inhibitor), and lyso- phosphatidic acid (pleiotropic activator of G-protein- coupled receptors) . As more and deeper insights into the regulatory role of small molecules presenting the benefits of delivering small molecules in supporting muscle regeneration become increasingly apparent, it is likely that the delivery of therapeutic small molecules will develop into a more widely used approach in muscle regeneration.
Red or aerobic muscle from the anterior of rainbow trout Oncorhynchus mykiss activates (generates force) more quickly than that from the posterior. TnT is a component of the troponin complex that modulates muscle activation once Ca 2+ is bound. Since trout express at least two forms of TnT in their red muscle (S1 and S2), the differential expression of these two forms was predicted to explain variations in contractile properties. TnT isoforms from trout muscle were identified through hydroxy- apatite chromatography of purified myofibrillar proteins followed by SDS-PAGE. Western blots employing a mammalian anti-troponin T monoclonal antibody were used to identify TnT isoforms. The relative expression of the two isoforms of TnT was then examined at seven longitudinal positions from each of three fish using SDS- PAGE and densitometry on the silver-stained TnT bands. A significant shift in expression was detected from anterior to posterior in all three fish with TnT S1 becoming more dominant in the posterior red muscle. As
Skeletal muscle damaged by injury or by degenerative diseases such as muscular dystrophy is able to regenerate new muscle fibers. Regeneration mainly depends upon satellite cells, myogenic progenitors localized between the basal lamina and the muscle fiber membrane. However, other cell types outside the basal lamina, such as pericytes, also have myogenic potency. Here, we discuss the main properties of satellite cells and other myogenic progenitors as well as recent efforts to obtain myogenic cells from pluripotent stem cells for patient-tailored cell therapy. Clinical trials utilizing these cells to treat
dated non-invasive method . By using that method , MGU, SMGU (lumbar) and SMGU (thigh) can be calculated with one sequential PET scan with only 3 - 5 times of venous blood sampling leading to avoiding arte- rial blood sampling. Moreover, if there were no differ- ence in SMGU value between the lumbar and thigh re- gion, thigh muscle PET imaging can be avoided leading to decrease the PET data sampling time to study heart and skeletal muscle insulin resistance. If there were dif- ferences in the SMGU value and/or the relationship be- tween SMGU and the whole body glucose utilization rate (WBGU) between the lumbar and thigh, measurement of SMGU in both regions would provide additional infor- mation to increase our knowledge of several diseases with insulin resistance. Since PET data acquisition time with 18 F-FDG under insulin clamping might be reduced
It is plausible that a more severe muscle damage protocol may have elicited a shift in the length-torque relationship following exercise. We discussed the absence of a shift in the length-torque curve 2-hr post-initial bout with respect to an earlier study by our group that did identify a shift (line 492-501). We suggested that a shorter duration exercise task or changes in the collection and analysis of the length-tension data could attribute for the lack of an observed shift in the present study. Irrespective of this, the exercise protocol employed here was sufficient for muscles to protect themselves against further delayed-onset muscle soreness and force decrements from a repeated bout of exercise. Thus large changes in the
Although it has been estabhshed that muscle gene expression is activity dependent and high expression of IGF-1 mRNA in skeletal muscle is related to overload or stretch, very little is known about the relationship between IGF-1 and skeletal muscle gene expression. An observation about effects o f growth hormone treatments on the proportion o f the type 1 and type 2 fibre in skeletal muscle o f hyp ophysectomized rats demonstrated that growth hormone treatment, presumably acting through increased e?q)ression of IGF-1, ehcited an increase in the relative proportion o f type 1 fibres (Ayling et al, 1989), A collaborative study was formed with a group (Wahib et al) using the IGF-1 probes designed as described in chapter 2. The subsequent results which involved in situ hybridization studies upon muscles sections fiom growth hormone deficient human patients demonstrated that 70% IGF-1 mRNA is distributed in type 1 fibres. Together these observations indicate that IGF-1 may be related to the expression of specific myosin genes. These also indirectly supported the observation as described in chapter 3 that suggested IGF-1 may play a role in fibre type in transition. Further investigation is needed to address the exact relationship between IGF-1 and muscle gene expression and to determine if there are IGF-1 response elements in the 5' or 3' flanking sequences of different MyHC isoform genes.
In conclusion, rattling in rattlesnakes is accomplished by the high-frequency contraction of three pairs of muscles. Each muscle contracts with each tail movement cycle but the muscles on the left and right sides of the animal are out of phase; hence, the contraction of the three muscles on one side acts to restore the tail position for contraction of the muscles on the other side. While the oxygen uptake of this group of muscles is high, the cost per contraction is low and constant, irrespective of temperature and rattling frequency. Although the muscles have no unique structures, the proportions of structures present seem to be suited for rapid activation and relaxation as well as for a high rate of ATP production, but less so for high force production. The maximum synthetic capacity of the mitochondria, when expressed per unit area of inner mitochondrial membrane, is identical to that of other vertebrate skeletal muscle mitochondria. The one unique feature of these muscles may be that each of the six shaker muscles seems to be composed of a single motor unit; however, we suspect this may be a property common to all noise-making muscles.
In aging, oxidative stress is associated with muscle protein loss or skeletal muscle atrophy . Dietary supplementation with exogenous antioxidants such as Vitamins C and E and herbal medicines may exert health-promoting effects and may help to prevent muscle aging . Jakyakgamcho-tang (JGT) consists of a 2:1 (w/w) mixture of Paeonia lactiflora and Glycyrrhiza uralensis roots and is used both clinically and pharmacologically in the treatment of muscle and acute abdominal pain and backache [16, 17]. Here, we analyzed the relative compositions and antioxidant efficacies of a water extract and a 30% (w/v) ethanol extract of JGT. We also assessed whether JGT prevented oxidative stress-induced death and ROS generation in skeletal muscle cells.
The operation of moving patients is performed by two people in cooperation. One is responsible for carrying the lower side of body and the other is in charge of the upper side. The upper side of body accounts for 70% of whole body weight, as a result, the subject in charge of the upper body uses the muscle suit. In this experiment, the height of bed is set to 750 mm, which is an average value of beds using in the actual home-visit bathing service. The distance between bed and bath is set to 900 mm. Furthermore, the height of bath is set to 500 mm as the bath used is the standard type of everyday bathing service. The weight of the user of bathing service is set to 60 kg. Subjects perform the operation carrying the patient from bed to bath, up and down, in 12.5 seconds, similarly, from bath to bed in 12.5 seconds as well. The total 25 seconds operation is considered as one cycle, sub- jects perform 5 cycles of operation in a row as the prior in- vestigation suggests after 5 times the fatigue reaches the peak value. We then compare blood oxygenation in case of using muscle suit and not using muscle suit.
The muscles at the hip are larger, stronger, more fatigue resistant, have shorter levers and short tendons compared to those at the ankle. Doherty et al. (2015) observed significant increases in hip muscle activity during drop landings in participants tested within two weeks of sustaining a lateral ankle sprain compared to healthy controls. They suggested that the body unloaded the lateral ankle by exhibiting a modified centrally mediated motor response to compensate for deficits within the kinetic chain. This is the manifestation of the cerebellum and motor control centre, which crave stability, adapting to the situation to provide stability. When the distal ankle joint is injured (Doherty et al., 2015) or in the current study, possibly fatigued, the human body off-loads the ankle and provides stability and control using the proximal hip joint musculature. In this way, the dynamic defence mechanism still occurs within a duration to still be effective (no change in peroneus longus reaction time or peak amplitude), but with a contribution to the overall response from the hip musculature (reduction in average peroneus longus amplitude).
Strength/Duration Curves. Strength / duration (S/D) curves for cardiac muscle cells (filled circles) and smooth muscle cells (unfilled circles) (5-cell chains) when R gj was ∞ (0 channels) (A) or when R gj was 10 MΩ(1000 channels) (B). The S / D curves are rectangular hyperbolas. The time (pulse duration) it takes for a current intensity of twice the rheobasic intensity to pro- duce the all-or-none repolarization is the chronaxie (σ) The rheobase is the asymptote of the data points extrapolated back to the ordinate, as shown. The chronaxie was about 1.0 ms, in both panels A and B. But the absolute current intensity required was about 8–10-fold greater in panel B compared to panel A. The membrane time constant (τ m ) is related to the chronaxie (σ)
The characteristics presented in the article were determined on a laboratory stand for testing pneumatic muscles. This stand was designed and made by the author of this article. It is adapted to conduct studies on an individual muscle or pairs of muscles operating antagonistically. The stand makes it possible to determine static and dynamic characteristics of pneumatic muscles. The scheme and actual view of the stand was shown in fig. 1. The stand includes the supporting structure, linear guides that adjust the stand to the length of the tested muscle and bearing block with gear belt drive, turning the plane motion of the muscle on the rotary motion. An important element of the stand is the AC MT-C06401C2NT3D servomotor from Servotronix with the CDHD-0032AAP1 servo controller and a precise planetary gear [11–14]. It is used to load the axis of a gear belt drive with a known torque, and thereby to load the muscle with the force of known value. The chosen servomotor has the capability of producing a continuous torque with the value of 26 Nm, and an instantaneous torque with the value of up to 78 Nm. This translates into a continuous loading force of the muscle with the value of up to 812 N, or an instantaneous torque with the value of up to 2436 N. In addition, the stand was equipped with a strain gauge with a measuring range of ±1000 N with an analogue voltage output. The change in internal pressure is achieved by means of a piezoelectric proportional pressure valve Hoerbiger Tecno Plus with an analogue voltage input. It allows to change the pressure in range of 0–10 bars. The measurement of the muscle length is implemented as a measurement of the angle of rotation of the gear belt drive by means of an optical absolute encoder Posital/Fraba OCD-S101G-1416-S060-CAW with a resolution of 16bit with the SSI digital output. The control of stand components and data acquisition is performed by means of an electronic circuit with the STM32F407VGT6 microcontroller equipped with circuits of 16 analogue inputs and 16 analogue outputs with a resolution of 16 bit each, and an interface supporting up to 6 sensors with the SSI output [15–18].