Side Bridge Research Articles

Effects of Core Strength Training Using Stable and Unstable Surfaces on Physical Fitness and Functional Performance in Professional Female Futsal Players.

The aim of this study was to assess the effect of core strength training performed on a stable surface (CTS) compared with core strength training performed on an unstable surface (CTU) on physical fitness (jump performance, sprint, and repeated sprint ability (RSA)) and quality of movement (Fundamental Movement Screen) in professional female futsal players. Fourteen professional female futsal players (mean age: 23.7 ± 5.1 years, age range: 18-28 years) were randomly assigned to a CTS (n = 7) or a CTU (n = 7) group. The intervention program was carried out 3 times a week over 6 weeks. Players of both groups performed the same four core-strengthening exercises. The only difference between the two interventions was that the CTU group performed all exercises (i.e., shoulder bridge, side bridge, prone plank, and crunch) on an unstable surface (Togu® Dyn-Air). Within-group analysis showed significant improvements (p < 0.001) in 10 m sprint performance from the pre- to post-test in the CTS (+4.37%) and CTU (+5.00%) groups. Players in both the CTS (+10.39%) and CTU (+11.10%) group also showed significant enhancement in the Functional Movement Screen total score, from the pre-test to post-test. In addition, a significant time effect was also observed for the CTU group in the relative score of the RSA test decreasing from the pre- to post-test (-30.85%). In the between-groups analysis, there were no significant differences between the core strength training groups (CTS vs CTU) in any variable. To conclude, sprint and Functional Movement Screen performance improved following CTS and CTU when conducted in combination with regular futsal training. In addition, CTU had limited benefit in RSA compared to CTS.

Fat-Free Mass and the Balance Error Scoring System Predict an Appropriate Maximal Load in the Unilateral Farmer's Walk.

This study quantified and compared unilateral farmer’s walk (UFW) performance in recreationally active males and females, and determined if additional variables allowed for the prediction of a maximal safe load. Anthropometric (height, body weight (BW), body mass index, body fat percentage, fat-free mass (FFM), and fat mass), muscular endurance (maximal duration side bridge), and balance (Balance Error Scoring System (BESS)) tests were completed. Participants performed a series of 20 s UFW trials (non-dominant side) at a cadence of 66 beats/min. The initial load was 10% of BW and increased by 10% per trial until deviations in spinal alignment or compromised gait patterns were noted, and the series was terminated. The highest load carried before technical failure was recorded. Descriptive and comparative statistics and a stepwise linear regression analysis were utilized to determine relationships between UFW performance and anthropometric, muscular endurance, and balance tests. Males (N = 25) were significantly taller (177.3 ± 6.7 vs. 164.7 ± 7.2 cm, p < 0.05), heavier (81.7 ± 7.0 vs. 62.0 ± 9.4 kg, p < 0.05), and leaner (14.4 ± 4.4 vs. 22.4 ± 4.8%, p < 0.05) than females (N = 26). Further, males had a higher amount of FFM (p < 0.05) than females. The males (52.2 ± 9.0, 64% BW) carried a higher average UFW load than the females (32.5 ± 7.1 kg, 53% BW, p < 0.05). FFM was strongly predictive of UFW load (load = −9.88876 + 0.88679 × (FFM); r2 = 0.774, p < 0.0001). The addition of the BESS test further increased the accuracy of the prediction equation (r2 = 0.800, p < 0.0001). There are differences in UFW performance ability between males and females. As our method does not account for all potential confounding variables, the use of these equations should be combined with technique analysis and participant feedback to ensure an appropriate workload.

Structural Features and Pyrolysis Behaviors of Extracts from Microwave-Assisted Extraction of a Low-Rank Coal with Different Solvents

Microwave-assisted extraction (MAE) of a low-rank Naomaohu (NMH) coal was conducted with two solvents, cyclohexanone (CYC) and tetrahydrofuran (THF), to obtain extracts (ECYC and ETHF) and residues (RCYC and RTHF). The parent coal, extract, and residue were characterized by ultimate analysis, TG, FTIR, GPC, 1H NMR, and solid-state 13C NMR. The results showed that MAE process is more efficient than Soxhlet extraction. The solvent CYC exhibits a higher total extract yield of 8.3 wt % than THF, being 4.7 wt %, during MAE and more efficiency in extracting organic components of NMH coal, especially condensed arenes and macromolecular compounds. The average molecular weight of ECYC is higher than that of average aromatic cluster of NMH coal. Online pyrolysis–vacuum ultraviolet photoionization mass spectrometry was taken to determine the initial pyrolysis products of parent coal, RCYC, and ECYC. The distribution of initial pyrolysis products suggested that NMH coal and ECYC possess similar basic arene structures and ECYC is rich in macromolecular clusters with lots of side chains and bridge bonds. The chemical structure of ECYC could reflect the macromolecular network structure of NMH coal to some extent. This could be an effective method to understand the organic structure of coal.

Eight-Week Battle Rope Training Improves Multiple Physical Fitness Dimensions and Shooting Accuracy in Collegiate Basketball Players.

Chen, WH, Wu, HJ, Lo, SL, Chen, H, Yang, WW, Huang, CF, and Liu, C. Eight-week battle rope training improves multiple physical fitness dimensions and shooting accuracy in collegiate basketball players. J Strength Cond Res 32(10): 2715-2724, 2018-Basketball players must possess optimally developed physical fitness in multiple dimensions and shooting accuracy. This study investigated whether battle rope (BR) training enhances multiple physical fitness dimensions, including aerobic capacity (AC), upper-body anaerobic power (AnP), upper-body and lower-body power, agility, and core muscle endurance, and shooting accuracy in basketball players and compared its effects with those of regular training (shuttle run [SR]). Thirty male collegiate basketball players were randomly assigned to the BR or SR groups (n = 15 per group). Both groups received 8-week interval training for 3 sessions per week; the protocol consisted of the same number of sets, exercise time, and rest interval time. The BR group exhibited significant improvements in AC (Progressive Aerobic Cardiovascular Endurance Run laps: 17.6%), upper-body AnP (mean power: 7.3%), upper-body power (basketball chest pass speed: 4.8%), lower-body power (jump height: 2.6%), core muscle endurance (flexion: 37.0%, extension: 22.8%, and right side bridge: 23.0%), and shooting accuracy (free throw: 14.0% and dynamic shooting: 36.2%). However, the SR group exhibited improvements in only AC (12.0%) and upper-body power (3.8%) (p < 0.05). The BR group demonstrated larger pre-post improvements in upper-body AnP (fatigue index) and dynamic shooting accuracy than the SR group did (p < 0.05). The BR group showed higher post-training performance in upper-body AnP (mean power and fatigue index) than the SR group did (p < 0.05). Thus, BR training effectively improves multiple physical fitness dimensions and shooting accuracy in collegiate basketball players.

Trunk muscle endurance in Chinese adults.

Previous studies in non-Chinese populations have found a relationship between performance on isometric trunk muscle endurance tests and low back pain (LBP). However, the relationship between trunk muscle endurance and LBP in Chinese populations has received little attention and age-referenced data have not been reported. Evaluate the relationship between age-referenced isometric trunk muscle endurance values and LBP in a Chinese cohort. One hundred and eighty-eight participants (20-59-years) performed four timed-endurance tests (Biering-Sørensen, plank, left/right side bridge) in random order. Participants with a history of LBP completed an Oswestry Disability Index (ODI) and pain scale. Holding-times for the four tests were summed and receiver operating characteristic (ROC) curve analysis was performed to differentiate participants with and without LBP. Data were grouped by age. Analysis revealed similar endurance values to those reported in non-Chinese populations, except longer holding times were recorded in the 50-59yr Chinese cohort. Pain scores were positively correlated with ODI scores. ROC curve analysis showed that the area under the curve was 0.723 and optimal cut-off was 288 sec (sensitivity and specificity both 0.75). This study is the first to describe trunk muscle endurance reference data in Chinese people. Individuals with a summed endurance time of < 288 seconds appear more likely to suffer LBP.

Peptides as Bio-Inspired Electronic Materials: An Electrochemical and First-Principles Perspective.

Molecular electronics is at the forefront of interdisciplinary research, offering a significant extension of the capabilities of conventional silicon-based technology as well as providing a possible stand-alone alternative. Bio-inspired molecular electronics is a particularly intriguing paradigm, as charge transfer in proteins/peptides, for example, plays a critical role in the energy storage and conversion processes for all living organisms. However, the structure and conformation of even the simplest protein is extremely complex, and therefore, synthetic model peptides comprising well-defined geometry and predetermined functionality are ideal platforms to mimic nature for the elucidation of fundamental biological processes while also enhancing the design and development of single-peptide electronic components. In this Account, we first present intramolecular electron transfer within two synthetic peptides, one with a well-defined helical conformation and the other with a random geometry, using electrochemical techniques and computational simulations. This study reveals two definitive electron transfer pathways (mechanisms), the natures of which are dependent on secondary structure. Following on from this, electron transfer within a series of well-defined helical peptides, constrained by either Huisgen cycloaddition, ring-closing metathesis, or a lactam bridge, was determined. The electrochemical results indicate that each constrained peptide, in contrast to a linear counterpart, exhibits a remarkable shift of the formal potential to the positive (>460 mV) and a significant reduction of the electron transfer rate constant (up to 15-fold), which represent two distinct electronic "on/off" states. High-level calculations demonstrate that the additional backbone rigidity provided by the side-bridge constraints leads to an increased reorganization energy barrier, which impedes the vibrational fluctuations necessary for efficient intramolecular electron transfer through the peptide backbone. Further calculations reveal a clear mechanistic transition from hopping to superexchange (tunneling) stemming from side-bridge gating. We then extended our research to fine-tuning of the electronic properties of peptides through both structural and chemical manipulation, to reveal an interplay between electron-rich side chains and backbone rigidity on electron transfer. Further to this, we explored the possibility that the side-bridge constraints present in our synthetic peptides provide an additional electronic transport pathway, which led to the discovery of two distinct forms of quantum interferometer. The effects of destructive quantum interference appear essentially through both the backbone and an alternative tunneling pathway provided by the side bridge in the constrained β-strand peptide, as evidenced by a correlation between electrochemical measurements and conductance simulations for both linear and constrained β-strand peptides. In contrast, an interplay between quantum interference effects and vibrational fluctuations is revealed in the linear and constrained 310-helical peptides. Collectively, these exciting findings augment our fundamental knowledge of charge transfer dynamics and kinetics in peptides and also open up new avenues to design and develop functional bio-inspired electronic devices, such as on/off switches and quantum interferometers, for practical applications in molecular electronics.

Relationship between core stability and dynamic balance in women with postmenopausal osteoporosis.

The aim of this study was to investigate the relationship between core stability and dynamic balance in women with postmenopausal osteoporosis. A total of 100 females (mean age 59.9±7.5 years; range, 42 to 73 years) with postmenopausal osteoporosis between January 2016 and June 2016 were included in this study. All patients were evaluated for dynamic balance with the Star Excursion Balance Test (SEBT) and for core stability with trunk flexion, extension, and Side Bridge Test (SBT). There was a significant correlation between age and the reach directions of anterior (A), posteromedial (PM), and posterolateral (PL) of the right limb (p<0.001, p=0.009, p=0.012) and the reach directions of A and PM of the left limb (p<0.001, p=0.004). There was no correlation between the lumbar spine, femoral neck, and total hip Bone Mineral Density (BMD) and the reach directions of SEBT (p>0.05). There was a significant correlation between the trunk flexion test results and the reach directions of A, PM, and PL of the right limb (p=0.005, p=0.001, p=0.002), (r=0.277, r=0.333, r=0.308) and the reach directions of A, PM, and PL of the left limb (p=0.008, p=0.016, p=0.005), (r=0.265, r=0.239, r=0.276). There was a significant correlation between the SBT results and the reach directions of A, PM, and PL of the right limb (p<0.001, p<0.001, p=0.005), (r=0.423, r=0.366, r=0.281) and the reach directions of A, PM, and PL of the left limb (p<0.001, p<0.001, p=0.001), (r=0.418, r=0.356, r=0.316). There was a significant correlation between the trunk extension test results and the reach directions of A, PM, and PL of the right limb (p<0.001, p<0.001, p=0.006), (r=0.383, r=0.471, r=0.276) and the reach directions of A, PM, and PL of the left limb (p<0.001, p<0.001, p=0.003) (r=0.407, r=0.401, r=0.297). Our study results showed that age and core stability were associated with dynamic balance in women with postmenopausal osteoporosis.

Correlation between peak expiratory flow and abdominal muscle activity while holding maximum expiration and side bridge exercise in elderly women

Expiratory flow plays an important role in minimizing the risk of infection by expelling foreign substances and excessive mucus from the lungs. Expiratory flow results primarily from the activities of the abdominal muscles. However, data regarding the association of the abdominal muscle activity during expiratory effort and abdominal exercise with expiratory flow rate are limited. This study aimed to assess the correlation between expiratory flow and abdominal muscle activity while holding maximum expiration and side bridge exercise in elderly women. Rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscle activities were measured using electromyography in 14 elderly women (82.8 ± 6.7 years), who could independently walk, performing two tasks: holding breath after maximum expiration in the crook-lying position (maximum expiration) and holding side bridge on knees without breathing indication (side bridge). Peak expiratory flow (PEF) was obtained using a peak flow meter with the subject in the sitting position. Correlations between PEF and the abdominal muscle activity were determined using Spearman rank correlation coefficient. The Ethics Committee of the Kawasaki University of Medical Welfare approved the protocol for this study. Written informed consent was obtained from each subject before participation in the study. The correlation coefficients between PEF and the RA, EO, and IO activities while holding maximum expiration were 0.407 ( P = 0.149), −0.345 ( P = 0.227), and 0.732 ( P = 0.003), respectively. The correlation coefficients between PEF and the RA, EO, and IO activity while holding side bridge exercise were −0.297 ( P = 0.303), −0.552 ( P = 0.041), and 0.147 ( P = 0.615), respectively. Our results showed that higher IO activity while holding maximum expiration or lower EO activity while holding side bridge exercise was related to higher PEF. Thus, maximum expiration and abdominal exercise might be effective in the improvement or prevention of the decrease of expiratory flow.

The relationship between core endurance and upper extremity performance in sedentary collegiate males

Core muscles contribute to general spine stabilization when the trunk is exposed to flexion and extension moments. It is thought that movements begin from the center of the body (called the “powerhouse” or “core”) and flow outward to the extremities, and a strong core strengthens the whole body. Few studies have examined the relationship between core endurance and upper extremity performance and most of the studies have been done in athletes. Thus, the purpose of this study was to investigate relationships between core endurance, and upper extremity performance in sedentary collegiate males. Sedentary collegiate males who had not suffered any orthopedic injury in the past year were enrolled the study. Core endurance (CE) was evaluated using Trunk Extensor Test, Bilateral Side Bridge Tests, and The Core Muscle Strength and Stability test. The results of the core endurance tests were compared with several upper extremity performance measurements: The Upper Quarter Y Balance Test (bilaterally in medial, inferolateral, and superolateral directions-UQYBT), Close Kinetic Chain Upper Extremity Stability Test (CKCUES test), medicine ball throws test (forward, reverse, right, and left in static and dynamic positions), hand grip strength, and Nelson hand reaction test. Eighty-three males were assessed during the study. Their mean age was 22.07 ± 1.89 year (range: 18–25) and mean body mass index was 23.77 ± 3.26 kg/m 2 (range: 17.67–36.11). We observed low correlations between the CE tests and UQYBT ( r range = 0.220 − 0.393, P < 0.05) but no correlations between the CE and hand grip strength and Nelson hand reaction test. CKCUES and medicine ball throws test (nondominant side in dynamic position) correlated with side bridge test, r = 0.279 and r = 0.240, respectively ( P < 0.05). The results of this study imply that the core endurance is related to the upper extremity performance in closed kinetic chain but not with open kinetic chain functions, where only distal extremity performance is present.

The relationship between transversus abdominis muscle thickness with static and dynamic balance in healthy adults

Current evidence suggests that enhanced core stability increase lower extremity function and promote postural stability. Thus, the purpose of this study was to investigate relationships between ulrasonographic thickness of transversus abdominis muscle (TrA), which is one of the core muscle, and static and dynamic balance and core endurance in healthy collegiate males. Healthy collegiate males who had not suffered any orthopedic injury in the past year were enrolled the study. The thickness of TrA was measured at rest and during contraction on both dominant and nondominant side using ultrasound. Also percentage of change in TrA thickness was calculated as [(thickness(contraction) − thickness(rest))/thickness(rest)] × 100. The static and dynamic balance parameters were evaluated with a balance system (Korebalance Mobile System). Core endurance (CE) was also assessed using trunk extensor test, bilateral side bridge tests and the core muscle strength and stability test. Sixty males were assessed during the study. Their mean age was 22.20 ± 1.77 years and mean body mass index was 23.53 ± 2.93 kg/m 2 . Dominant side TrA muscle thickness at rest was correlated with dynamic balance ( r = −0.319, P = 0.013) whereas no correlation for dominant side TrA muscle thickness at contraction. Nondominant side TrA muscle thickness at rest was correlated with core endurance ( r = 0.350, P = 0.006) wheras no correlation for nondominant side TrA muscle thickness at contraction. Percentage of change in dominant side TrA thickness was correlated with dynamic balance ( r = 0.464, P = 0.000). Percentage of change in nondominant side TrA thickness was correlated with core endurance ( r = −0.361, P = 0.005). According to our results, muscle thickness of TrA is associated with postural balance and core endurance. Training to increase the muscle mass of the TrA would be useful to improve balance parameters. Further prospective studies are warranted to investigate the effects of the training of TrA and core endurance on postural balance and athletic performance.

Are the alterations in body posture related to decreased trunk muscle endurance in healthy young adults?

Trunk muscle endurance exercises are commonly used for correcting the postural alterations. However, there is no study investigating the relationship between postural alignment and trunk muscle endurance in healthy young adults. The aim of this study was to examine whether the three-dimensional (3D) body posture is related to trunk muscle endurance in healthy young adults. Forty-two healthy young adults enrolled in this study. For 3D evaluation of the body posture, an internet-based postural assessment system was used. Alterations in posture (head, ribcage, and pelvis) were evaluated by using the Posture Index which represents the total score of postural displacements. The higher Posture Index scores indicate more severe displacements in the posture. Trunk muscle endurance measurements included side bridge, trunk flexors and trunk extensors endurance tests. Spearman's rho was used to evaluate the associations between measured parameters. The median age of the participants were 22 (IQR: 21.0-23.0) years. The only significant correlation was detected between the side bridge endurance test and the total Posture Index score (rho =⁣-0.402, p= 0.008). These results indicated that the alterations of the body posture was significantly related to lower lateral trunk muscle endurance scores. These findings support the importance of trunk muscles, especially lateral trunk musculature to have a better body posture.

Effect of pyridine extraction on the pyrolysis of a perhydrous coal based on in-situ FTIR analysis

Pyridine extraction of coal can separate the small molecules from macromolecule skeleton and subsequently impacts the thermal behavior of coal. A perhydrous bituminous coal with a high content of volatile matters was extracted by pyridine under microwave irradiation with an extraction yield of 24.6% on the dry, ash free basis (daf). The thermal behavior of the raw coal, its extract and residue was investigated by thermogravimetric analysis and in-situ Fourier Transform Infrared Spectroscopy (FTIR) based on the evolution of weight loss and functional groups, respectively. Though pyridine extraction had only slight effect on TG curve of the perhydrous coal, it greatly influenced the evolution of functional groups during pyrolysis. Aromatic CH and CO was the most susceptible to pyridine extraction because the absence of extractable moieties reduced the production of radicals and the reactions between small molecules and macromolecules during pyrolysis. The interactions between extractable small molecules and non-extractable macromolecules could retard the decomposition of aromatic CC and hydroxyls. The evolution of aliphatic groups and CO was slightly impacted due to the occurrence of the abundant aliphatic side groups and bridge bonds in macromolecule structures.

Trunk Side Strain Has a High Incidence in First-Class Cricket Fast Bowlers in Australia and England.

To investigate the past incidence of side strain injury and its associated factors in first-class cricket fast bowlers in Australia and England. Retrospective case series. Professional cricket. Cricket fast bowlers who were professionally contracted full time at first-class level in Australia and England in 2011. All bowlers were male and aged 18 or older. A bowler was defined as a fast bowler if the wicketkeeper would take their stance back from the stumps. There were 207 participants. Not applicable. The association between bowling arm, player height, active trunk lateral flexion range of motion, side bridge endurance, volume of first-class cricket played, and the history of injury was determined. Over half of the bowlers had sustained at least 1 side strain in their career. Seventy-seven percent of primary injuries occurred in bowlers aged 24 or under. A higher proportion of injured bowlers had reached first-class volume in their career. Recurrence occurred in 30% of bowlers, with over 30% of these bowlers sustaining at least 1 further recurrence. Nearly half of all recurrences occurred within 2 years with a further quarter in the next year. The injury was not associated with any measured factors. Side strain is a common injury among first-class cricket fast bowlers, especially at younger ages. It was associated with the volume of first-class cricket played. Recurrence was common and occurred most frequently in the first 2 years after primary injury.

Muscle activation and local muscular fatigue during a 12-minute rotational bridge

Due to anecdotal reports of back pain during a 12-minute rotational bridge test by uniformed services, the level of fatigue leading to possible back pain and or injury was investigated. We hypothesised a high level of fatigue due to diminishing core muscle activation. Nineteen highly trained uniformed service members were measured by surface electromyography of the rectus abdominis, external oblique, internal oblique, lumbar erector spinae, thoracic erector spinae and latissimus dorsi. Average rectified electromyography amplitude (AEMG) and median power frequency were analysed to determine activation and fatigue. All AEMG were normalised and expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Significant increases in AEMG were observed over the test duration for the rectus abdominis (+19.5%MVIC), external oblique (+18.0%MVIC) and internal oblique (+23.2%MVIC) during the prone position; and for the external oblique (+21.8%MVIC) when bracing on the measurement side (all, p < 0.05). No significant changes in median power frequency were observed (all, p > 0.05). Combining prone and side bridge positions is a reasonable measure of anterior, posterior and lateral trunk musculature. Muscular fatigue remained low throughout making this a safe assessment in trained individuals.

Right versus left side bridge static endurance ability among healthy collegiate students at Taibah University.

Spinal muscles endurance is fundamental for providing adequate trunk stability. The purpose of this study was to compare the side bridge static endurance ability of the right versus left side. Forty right hand dominant students, aged between 18 and 25 years, were recruited from Taibah University. Every participant had to lie down on his side and bear trunk weight on the arm with shoulder abducted to 90∘ and elbow flexed to 90∘. Every participant had to lift off his trunk of the supporting surface, keeping the trunk straight in neutral position, breathing normally and holding on that position as long as tolerated. A paired sample t test was calculated. The mean score, in seconds, for right side bridge was 41.6 (SD = 30.08), and for left side bridge was 38.00 (SD = 26.93). No significant difference was found between right and left side bridge endurance ability [t (39) = 1.67, p> 0.05]. Pearson correlation showed high positive correlation [r (38) = 0.89, p< 0.001]. Among healthy participants, clinicians should expect very close endurance profile for the musculature of the two sides of trunk. Clinicians should equally train both sides of trunk muscles stabilizers in order to enhance tolerance.

Comparing lumbopelvic stabilization exercises and yoga on functional stability and low back pain in young, non-elite, female gymnasts

AbstractBackground: It is beneficial for gymnasts to train key lumbopelvic musculature to decrease or prevent low back injury. This study compares lumbopelvic exercises and yoga on lumbar muscle endurance, lumbopelvic stabilization, abdominal strength and balance in adolescent female gymnasts and the effect on low back pain. Material/Methods: 13 participants were randomly allocated to a lumbo-pelvic or yoga group intervention and performed specific exercises for 6 weeks. Biering-Sorensen Test, Lumbopelvic Control Test, Side Bridge Test, and Star Excursion Balance Test were conducted on the participants before and after the 6-week intervention and low back pain logbooks were completed. Results: The Biering-Sorensen Test was significantly greater results for the lumbopelvic group compared to the yoga group. Both groups had significant changes over time with the Lumbopelvic Control Test but no group difference. Both groups had significant improvement with the Side Bridge with the yoga group benefitting more on the left. Out of the six fully completed logbooks, the yoga group showed less occurrence of low back pain compared to the lumbopelvic group. Conclusions: Yoga and lumbopelvic stabilization exercises are equally effective in developing lumbar muscle endurance, lateral stability and front-on stability for young non-elite gymnasts. This is important as they are under-represented in research but overrepresented in participation. This study sets the basis for further research on the incidence of low back pain in young gymnasts and the effects of age-appropriate exercises as a preventative matter.

Vpliv kratkotrajnega programa stabilizacijske vadbe na zmogljivost mišic trupa pri košarkaricah

Background: Several studies showed that the addition of trunk muscle or core stability exercises in the sport training programs is an effective prevention of spinal and other musculoskeletal injuries.Methods: Twelve female basketball players performed supervised five-week exercise program focused on strengthening the trunk muscles. The program was performed three times per week during pre-season. Sorensen test, Fitnessgram Dynamic Curl-Up test, Prone Plank test and Side Bridge test were used to evaluate trunk muscles performance prior to and immediately after the exercise program completion and again after a three-month follow up period.Results: The results of Sorensen test and Prone Plank test significantly improved immediately after the program, but values returned to baseline at follow-up. In contrast, the results of Fitnessgram Dynamic Curl-Up test and Side Bridge test improved significantly with exercise program and remained significantly higher also at follow-up.Conclusions: Exercise program with emphasis on strengthening the trunk and core muscles can improve muscle performance, however, the results deteriorate shortly after program termination. In order to achieve long-term results, trunk and core muscle exercises have to be performed on regular basis, hence they must be incorporated into general strengthening programs of basketball players.

In Situ Analysis of Catalytic Effect of Calcium Nitrate on Shenmu Coal Pyrolysis with Pyrolysis Vacuum Ultraviolet Photoionization Mass Spectrometry

To investigate the effect of calcium mineral on the product distribution of low-rank coal pyrolysis, a Chinese subbituminous coal (Shenmu coal), and samples with 5% and 10% added calcium content, were selected to study with a homemade pyrolysis vacuum ultraviolet photoionization mass spectrometry (py-VUV-PIMS) system. In this system, secondary reactions of the pyrolysis products were generally inhibited because of in situ sampling, soft ionization, and high vacuum environment, which allowed direct detection of the initial pyrolytic products. Most evolved compounds during temperature-programmed heating from 30 to 650 °C were ionized by a VUV lamp (10.6 eV). The main products include five categories: alkenes, dienes, aromatics, phenols, and dihydroxy aromatics, which were formed via homolytic scission of weak bonds in side chains and bridges between aromatic nuclei in coal structure. The calcium mineral additives can dramatically affect pyrolytic product distribution, especially oxygen-containing compounds....

Deep Trunk Muscle Fatigue Analysis during Side Bridge Endurance Test in Nonspecific Low Back Pain

Deep Trunk Muscle Fatigue Analysis during Side Bridge Endurance Test in Nonspecific Low Back Pain

Investigation of the relationship between infrared structure and pyrolysis reactivity of coals with different ranks

The chemical structures of six coal samples with different ranks were semi-quantitatively characterized by a series of original infrared structural parameters, and the pyrolysis reactivity of the samples were quantitatively characterized by a comprehensive devolatilization index. A correlation was established between the infrared structural parameters and pyrolysis reactivity. The results show that the infrared structural parameter method presented in this paper can reveal the distribution characteristic of chemical bonds in coal effectively. The total content of oxygen-containing functional groups, CH groups and the inorganic mineral can be satisfactorily characterized by infrared structural parameter, Ia3, Ib4 and Id3 respectively. The length of aliphatic side chains or bridge bonds undergoes a Stable-Increased-Decreased process. Good positive correlation was established between the comprehensive infrared structural parameter S and the pyrolysis reactivity, which was proved effective to predict the pyrolysis reactivity of coal over various ranks.