Ultrastructural design of anuran muscles used for call production in relation to the thermal environment of a species

2001 ◽  
Vol 204 (8) ◽  
pp. 1445-1457 ◽  
Author(s):  
S.J. Ressel

I examined the aerobic trunk muscles, which are used for call production, of male frogs from species that breed in different thermal environments to test the hypothesis that cold-adapted frogs should have fewer capillaries per unit mitochondrial volume in oxidative muscles than warm-adapted frogs because of reduced mitochondrial function at low temperatures. The species of interest were the cold-temperate Pseudacris crucifer and the warm-tropical Hyla microcephala in the family Hylidae, and the cold-temperate Rana sylvatica and the warm-temperate Rana clamitans in the family Ranidae. Trunk-muscle mitochondrial volume, V(V)(mt,f), was proportionally higher in species with higher mean calling rates (number of notes per hour), irrespective of the familial affinity of a species and the thermal environment in which it vocalized. Trunk-muscle capillary length density, J(V)(c,f), was significantly lower in P. crucifer than in H. microcephala because of significantly higher mean fiber area, a-(f). Conversely, trunk-muscle J(V)(c,f) was similar in the two ranid species. Using total capillary length, J(c), and total mitochondrial volume, V(mt,m), as a measure of maximal oxygen supply and demand, respectively, in trunk muscles, J(c)-to-V(mt,m) ratios were significantly lower in cold-adapted P. crucifer (4.3 km cm(−)(3)) and R. sylvatica (4.8 km cm(−)(3)) than in warm-adapted H. microcephala (7.1 km cm(−)(3)) and R. clamitans (6.4 km cm(−)(3)). In contrast, J(c)-to-V(mt,m) ratios in the more anaerobic gastrocnemius muscle of these species was not related to the thermal environment of a species, which may reflect capillaries conforming to microcirculatory functions, e.g. lactate removal, that take precedence over oxygen delivery. Mitochondrial cristae surface area, S(V)(im,mt), in P. crucifer trunk and gastrocnemius muscles (37.7+/−1.6 and 35.9+/−1.5 m(2)cm(−)(3) respectively) was, on average, similar to mammalian values, suggesting equivalent structural capacities of muscle mitochondria in these two taxa. Taken together, the present data suggest that trunk-muscle respiratory design may reflect a capillary supply commensurate with maximal levels of oxygen delivery set by mitochondria operating at different environmental temperatures. P. crucifer and H. microcephala trunk muscles were also characterized by a high lipid content, which contrasted with a near absence of trunk-muscle lipids in R. sylvatica and R. clamitans. The extraordinarily high lipid content of P. crucifer trunk muscles (26 % of muscle volume) may serve as an auxiliary oxygen pathway to mitochondria and thus compensate in part for this tissue's reduced capillary/fiber interface. The effect of potentially high depletion rates of trunk-muscle lipid stores on metabolic rates of male frogs while calling is discussed.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Toru Shirahata ◽  
Hideaki Sato ◽  
Sanehiro Yogi ◽  
Kaiji Inoue ◽  
Mamoru Niitsu ◽  
...  

Abstract Background Physical inactivity due to cachexia and muscle wasting is well recognized as a sign of poor prognosis in chronic obstructive pulmonary disease (COPD). However, there have been no reports on the relationship between trunk muscle measurements and energy expenditure parameters, such as the total energy expenditure (TEE) and physical activity level (PAL), in COPD. In this study, we investigated the associations of computed tomography (CT)-derived muscle area and density measurements with clinical parameters, including TEE and PAL, in patients with or at risk for COPD, and examined whether these muscle measurements serve as an indicator of TEE and PAL. Methods The study population consisted of 36 male patients with (n = 28, stage 1–4) and at risk for (n = 8) COPD aged over 50 years. TEE was measured by the doubly labeled water method, and PAL was calculated as the TEE/basal metabolic rate estimated by the indirect method. The cross-sectional areas and densities of the pectoralis muscles, rectus abdominis muscles, and erector spinae muscles were measured. We evaluated the relationship between these muscle measurements and clinical outcomes, including body composition, lung function, muscle strength, TEE, and PAL. Results All the muscle areas were significantly associated with TEE, severity of emphysema, and body composition indices such as body mass index, fat-free mass, and trunk muscle mass. All trunk muscle densities were correlated with PAL. The product of the rectus abdominis muscle area and density showed the highest association with TEE (r = 0.732) and PAL (r = 0.578). Several trunk muscle measurements showed significant correlations with maximal inspiratory and expiratory pressures, indicating their roles in respiration. Conclusions CT-derived measurements for trunk muscles are helpful in evaluating physical status and function in patients with or at risk for COPD. Particularly, trunk muscle evaluation may be a useful marker reflecting TEE and PAL.


2021 ◽  
pp. 1-10
Author(s):  
Ryo Miyachi ◽  
Nana Koike ◽  
Suzu Kodama ◽  
Junya Miyazaki

BACKGROUND: Although trunk muscles are involved in many important functions, evaluating trunk muscle strength is not an easy task. If trunk muscle mass and thickness could be used as indicators of trunk muscle strength, the burden of measurement would be reduced, but the relationship between trunk muscle strength and trunk muscle mass and thickness has not been clarified. OBJECTIVE: The purpose of this study was to clarify the relationship between trunk muscle strength and trunk muscle mass by bioelectrical impedance analysis and trunk muscle thickness by ultrasound imaging in healthy adults. METHODS: One hundred and twenty-one healthy university students were included in this study. Trunk flexion/extension muscle strength and trunk muscle mass by bioelectrical impedance analysis, and trunk muscle thickness by ultrasound imaging were measured. RESULTS: Both trunk flexion strength and trunk extension strength were significantly correlated with trunk muscle mass and oblique and rectus abdominis muscle thickness. Multiple regression analysis showed that trunk extension muscle strength had an independent relationship with trunk muscle mass. CONCLUSIONS: This study demonstrated that trunk muscle mass or trunk muscle thickness can be used as an alternative means for evaluating trunk muscle strength, making the evaluation of trunk muscles less burdensome.


Author(s):  
María del Mar Moreno-Muñoz ◽  
Fidel Hita-Contreras ◽  
María Dolores Estudillo-Martínez ◽  
Agustín Aibar-Almazán ◽  
Yolanda Castellote-Caballero ◽  
...  

Background: Abdominal Hypopressive Training (AHT) provides postural improvement, and enhances deep trunk muscle activation. However, until recently, there was a lack of scientific literature supporting these statements. The major purpose of this study was to investigate the effect of AHT on posture control and deep trunk muscle function. Methods: 125 female participants aged 18–60 were randomly allocated to the Experimental Group (EG), consisting of two sessions of 30 min per week for 8 weeks of AHT, or the Control Group (CG), who did not receive any treatment. Postural control was measured with a stabilometric platform to assess the static balance and the activation of deep trunk muscles (specifically the Transverse Abdominal muscle (TrA)), which was measured by real-time ultrasound imaging. Results: The groups were homogeneous at baseline. Statistical differences were identified between both groups after intervention in the Surface of the Center of Pressure (CoP) Open-Eyes (S-OE) (p = 0.001, Cohen’s d = 0.60) and the Velocity of CoP under both conditions; Open-Eyes (V-OE) (p = 0.001, Cohen´s d = 0.63) and Close-Eyes (V-CE) (p = 0.016, Cohen´s d = 0.016), with the EG achieving substantial improvements. Likewise, there were statistically significant differences between measurements over time for the EG on S-OE (p < 0.001, Cohen´s d = 0.99); V-OE (p = 0.038, Cohen´s d = 0.27); V-CE (p = 0.006, Cohen´s d = 0.39), anteroposterior movements of CoP with Open-Eyes (RMSY-OE) (p = 0.038, Cohen´s d = 0.60) and activity of TrA under contraction conditions (p < 0.001, Cohen´s d = 0.53). Conclusions: The application of eight weeks of AHT leads to positive outcomes in posture control, as well as an improvement in the deep trunk muscle contraction in the female population.


1987 ◽  
Vol 31 (4) ◽  
pp. 462-466 ◽  
Author(s):  
Sean Gallagher ◽  
Richard L. Unger ◽  
E. William Rossi

The purpose of this study was to examine the lifting capacity of low-seam coal miners in four restricted work postures (roof heights of 36″, 40″, 44″, and 48″), investigate the associated metabolic costs, and to examine electromyographic (EMG) data from eight trunk muscles during the lifting procedure. Subjects were thirteen underground miners accustomed to handling materials in restricted work postures. Each subject performed two twenty-minute periods of asymmetric lifting in each of four postures during the day of testing. The frequency of lifting was 10 lifts per minute. A specially designed lifting box incorporated microswitches in one handle of the box and another in the bottom of the box, in order to examine the trunk muscle function at specific points during the lfting cycle. The data collected will be used by the Bureau of Mines to make recommendations for lifting materials in low-seam coal mines.


2001 ◽  
Vol 90 (5) ◽  
pp. 1919-1926 ◽  
Author(s):  
Shane B. Kanatous ◽  
Robert Elsner ◽  
Odile Mathieu-Costello

The purpose of this study was to examine muscle capillary supply in harbor seals. Locomotory and nonlocomotory muscles of four harbor seals (mass = 17.5–41 kg) were glutaraldehyde-perfusion fixed and samples processed for electron microscopy and analyzed by morphometry. Capillary-to-fiber number and surface ratios were 0.81 ± 0.05 and 0.16 ± 0.01, respectively. Capillary length and surface area per volume of muscle fiber were 1,495 ± 83 mm/mm3 and 22.4 ± 1.6 mm2/mm3, respectively. In the locomotory muscles, we measured capillary length and surface area per volume mitochondria (20.1 ± 1.7 km/ml and 2,531 ± 440 cm2/ml). All these values are 1.5–3 times lower than in muscles with similar or lower volume densities of mitochondria in dogs of comparable size. Compared with terrestrial mammals, the skeletal muscles of harbor seals do not match their increased aerobic enzyme capacities and mitochondrial volume densities with greater muscle capillary supply. They have a smaller capillary-to-fiber interface and capillary supply per fiber mitochondrial volume than terrestrial mammals of comparable size.


Author(s):  
Lina Budrienė ◽  
Romualdas Sinkevičius ◽  
Tomas Aukštikalnis ◽  
Indrė Ščiukaitė

Background. Idiopathic scoliosis (IS) affects 1–3% of children aged 10–16 years (Weinstein et al., 2008). It is important to make comprehensive evaluation and treatment of IS because it provokes health problems and progresses (Negrini et al., 2006). There is a lack of research on muscle impairments, their relations with posture in IS (Parent, Ritchter, 2016). Aim – to assess relations between posture and trunk muscle functions in schoolaged girls with IS. Methods. The study included 20 patients with IS. Anthropometric measurements, measurements of posture (habitual standing posture, posture performing auto-correction and performing Matthias test), functional trunk stability evaluation, trunk muscle static endurance tests were used. Results. After performing auto-correction, thoracic kyphosis signifcantly decreased. Measurements showed decreased static trunk muscle endurance, normal proportions between trunk muscle groups: 75% of subjects have trunk instability. Trunk inclination, left major surface rotation statistically signifcantly changed in functional trunk stability test. Statistical moderate correlations were determined between both side trunk muscle static endurance and: medium surface rotation, major left surface rotation, medium lateral deviation. Also between Cobb angle and static endurance of left side trunk muscles. Changes of major left surface rotation in functional trunk stability test correlated with static endurance ratio of both sides trunk muscles. Statistical strong correlation was determined between major right lateral deviation and both sides muscles static endurance. Conclusions. School-aged girls with IS change kyphosis after auto-correction have low static endurance of trunk muscles and dysfunction of functional stability. Statistically moderate and strong correlations between posture parameters and trunk muscle functions were assessed.Keywords: posture, trunk muscle functions, idiopathic scoliosis, school-aged girls.


2019 ◽  
Vol 13 (2) ◽  
pp. 112 ◽  
Author(s):  
Rifki Wahyu Kurnianto ◽  
Wiratni Budhijanto ◽  
Rochim Bakti Cahyono

Anaerobic digestion has been an attractive field of research in the era of energy crisis. Biogas, which is the product of anaerobic digestion, provides alternative energy, while at the same time it also prevents pollution due to organic waste accumulation. Among various organic wastes, dairy fat waste is a potential substrate for anaerobic digestion. Fat waste has high theoretical biogas potential because of its high lipid content. However, anaerobic digestion of organic waste with high lipid content is quite challenging. The main obstacle in anaerobic digestion of fat waste is its tendency to form insoluble floating layer on top of the liquid phase. This phenomenon hinders the access of hydrolytic bacteria to the substrate. Saponification is one of the methods to increase the solubility of the floating layer and hence to improve the availability of substrate for the bacteria. Saponification changes the lipid content into soap which has both polar and non-polar functional groups and the polar side will increase the solubility of the substrate in water. This study evaluated the effect of different dosage of base added as the reactant during saponification pre-treatment on the productivity of anaerobic digestion of dairy fat waste. The kinetics of the anaerobic digestion process was analyzed by mean of mathematical model. The variations of the alkaline dosages studied for saponification pre-treatment were 0.04 mol base/g sCOD; 0.02 mol base/g sCOD; and no pre-treatment for control reactor. This study proved that saponification increased the solubility of dairy fat waste. This result was confirmed by the hydrolysis constant value (kH) of 0.00782/day for reactor with saponification, which was twenty times of magnitude higher than the kH value of 0.00032/day in the reactor without saponification. However, the exposure to high pH during the saponification pre-treatment might somewhat inhibit indigenous acidogenic bacteria in the waste which results in lower methane yield in the reactors with saponification to be compared to the control reactor. A B S T R A KPeruraian anaerobik merupakan salah satu bidang riset yang sangat menarik perhatian dalam era krisis energi. Biogas tidak hanya menyediakan energi alternatif, tetapi juga dapat mencegah pencemaran akibat limbah organik. Limbah lemak susu adalah substrat yang potensial untuk proses peruraian anaerobik karena memiliki potensi biogas teoritis yang tinggi akibat kandungan lemaknya yang tinggi. Namun, peruraian anaerobik dari limbah organik dengan kandungan lemak yang tinggi memiliki tantangan tersendiri. Hambatan utama dalam peruraian anaerobik dari limbah lemak susu adalah kecenderungan untuk membentuk lapisan padatan yang tidak larut dan mengapung di bagian atas fase cair. Fenomena ini menghambat akses bakteri hidrolisis terhadap substrat. Saponifikasi adalah salah satu cara untuk meningkatkan kelarutan lapisan padatan tersebut, sehingga meningkatkan ketersediaan substrat untuk bakteri. Saponifikasi akan mengubah kandungan lemak menjadi sabun yang memiliki gugus fungsi polar maupun non-polar. Gugus fungsi yang bersifat polar akan meningkatkan kelarutan substrat dalam air. Studi ini mengevaluasi pengaruh dari berbagai dosis larutan basa yang ditambahkan sebagai reaktan selama perlakuan awal saponifikasi terhadap peruraian anaerobik limbah lemak susu. Kinetika proses peruraian anaerobik dianalisis dengan menggunakan model matematika. Variasi dosis yang diamati pengaruhnya untuk perlakuan awal saponifikasi adalah 0,04 mol basa/g sCOD; 0,02 mol basa/g sCOD; dan nol (tanpa perlakuan awal saponifikasi). Dari penelitian ini, terbukti bahwa saponifikasi berhasil meningkatkan kelarutan limbah lemak susu dan juga ditunjukkan oleh nilai konstanta hidrolisis (kH) 0,00782/hari lebih tinggi dua puluh kali lipat dibandingkan dengan nilai kH 0,00032/hari pada reaktor tanpa saponifikasi. Akan tetapi, penelitian ini juga mengindikasikan bahwa bakteri asidogenik bawaan substrat terhambat kinerjanya oleh paparan pH yang tinggi selama perlakuan awal saponifikasi berlangsung sehingga hasil gas metan yang diperoleh lebih rendah daripada reaktor kontrol.


2021 ◽  
Author(s):  
Nika Zolfaghari

The study of seated balance, specifically for the application of wheelchair users, has been an area of interest for quite some time. Unfortunately, most of the available studies to date have focused on upper limb and shoulder muscles, and little has been done analyzing the activity of trunk muscles (abdominal and back). For the purpose of this study, motorized rotational motion in the forward and backward directions at ±45 degrees was simulated, and the corresponding trunk muscle activity of nine healthy subjects was recorded by surface electromyography (EMG) for eight muscles, including an analysis on the effect of holding on to a harness for support, coupled with the presence of a visual input. The collected raw data was filtered, and the produced results illustrated that the muscle activity was greatest in the forward rotational direction, when the subject was holding on to a harness for support, with visuals present.


1992 ◽  
Vol 36 (10) ◽  
pp. 742-746
Author(s):  
Christopher A. Hamrick ◽  
Sean Gallagher

Trunk muscle activity of twelve healthy males with coal mining experience was examined while each subject lifted a box under various conditions. The independent variables were four levels of posture (kneeling, stooped under a 1.2 m roof, stooped under a 1.6 m roof, and standing), height to which the box was lifted (35 cm or 70 cm), and weight of the lifting box (15 kg, 20 kg, or 25 kg). The dependent variables were the peak EMG values recorded during a lift for each of eight trunk muscles (left and right erectores spinae, left and right latissimus dorsi, left and right external oblique, and left and right rectus abdominis). Posture and weight of lift significantly affected peak activity of the left and right erectores spinae, the left and right latissimus dorsi muscles, and the right external oblique muscle. The latissimus dorsi muscle activity was highest in the low stooping posture, and was lowest in the kneeling posture, while erectores spinae activity was highest in the kneeling posture and decreased as the trunk became more flexed. Thus, the muscle activity during lifting tasks is affected by restricting a worker's posture. Consequently, many lifting guidelines and recommendations currently in use may not be directly applicable to work being performed in restricted postures.


Author(s):  
Kazuma Uebayashi ◽  
Yu Okubo ◽  
Takuya Nishikawa ◽  
Taro Morikami ◽  
Jindo Hatanaka

BACKGROUND: Given the characteristics of the superficial trunk muscles that cross the chest and pelvis, their excessive contraction might limit chest mobility. OBJECTIVE: To examine the immediate effects of two types of trunk muscle exercises on chest mobility and trunk muscle activities. METHODS: Fourteen healthy men (age: 21.1 ± 1.0 years, height: 172.7 ± 5.6 cm, weight: 61.0 ± 7.1 kg, body mass index: 20.4 ± 1.7 kg/m2; mean ± SD) randomly performed trunk side flexion and draw-in exercises using a cross-over design. The chest kinematic data and trunk muscle activities were measured before and after each intervention during the following tasks: maximum inspiration/expiration and maximum pelvic anterior/posterior tilt while standing. Two-way repeated measures analysis of variance was used for statistical analysis (P< 0.05). RESULTS: After the side flexion, upper and lower chest mobility significantly decreased, and superficial trunk muscle activity significantly increased during the maximum pelvic anterior tilt (P< 0.05). Additionally, after the draw-in, upper chest mobility significantly increased during the maximum pelvic anterior tilt (P< 0.05). CONCLUSIONS: Increased activity of the superficial abdominal muscles might limit chest mobility during maximum pelvic anterior tilt. Conversely, the facilitation of deep trunk muscles might increase upper chest mobility during the maximum pelvic anterior tilt.


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