Muscular Effort Research Articles

Time to target heart rate in dobutamine stress echocardiography is shortened by using dynamic, but not isometric handgrip

Abstract Background Dobutamine stress echocardiography (DSE) is widely used for the detection of obstructive ischaemic heart disease. In our previous study we demonstrated that the magnitude of myocardial injury measured by hsTnT is associated with DSE duration. Shortening of DSE time is therefore desirable. Use of hangrip (HG) during DSE is generally recommended. However, there are no published studies comparing the efect of dynamic and isometric HG on the length of DSE. Purpose To compare the effect of dynamic and static HG on DSE duration. Methods 211 patients undergoing DSE for ischaemia assessment were randomised into no HG (noHG, n=74), isometric HG (isoHG, n=68) and gynamic HG (dynHG, n=69) groups. All patients taking rate limiting medication were instructed to stop it 48 hours prior the test. DSE was performed according to the standard protocol (dobutamine infusion 5, 10, 20, 30, 40 ug/kg/min., increased in 3 min. intervals). HG was applied at the level of 40% maximum isometric muscular effort from the dobutamine dose of 20ug/kg/min. and atropine was administered in 1 min. intervals in 100 ug increments from the dose of 30 ug/kg/min. Patients who did not achieve their target heart rate (HR) or suffered from dobutamine side effects were excluded from the study. Results There were no differences in the groups characteristics (gender p=0.187, known ischaemic heart disease p=0.361, age p=0.128, basal HR p=0.367, target HR p=0.107, achieved HR p=0.257, positive test for ischaemia p=0.583). There was a significant difference in the time to target HR between dynHG and noHG groups (9.97±2.34 vs 11.96±3.02 min., p< 0.001) but not between isoHG and noHG groups (10.76±3.12 vs 11.96±3.02 min., p=0.058). Also, the was a similar difference in the length of dobutamine infusion between dynHG and noHG, but not between isoHG and noHG groups (11.76±2.37 vs 13.78±3.09 min., p< 0.001 and 13.34±4.90 vs 13.78±3.09 min., p=0.308, respectively). No significant correlation was found between the time to target HR and basal (r=0.43) or target HR (r=0.38). Conclusion Dynamic, but not isometric handgrip shortens the length of dobutamine stress echocardiography.

Relative muscular effort in the older adults during the sit-to-stand task: Monitoring neuromuscular reserve and movement limitations

BackgroundDue to lower maximum strength, older adults purportedly need to exert greater muscular effort to stand up from a chair. This study investigated joint-specific muscular effort during a sit-to-stand by calculating relative-muscular-effort and investigating differences between healthy older and young adults. MethodsFifteen older (age: 69.9 ± 3.5 years) and 15 young (age: 22.2 ± 2.6 years) adults performed five self-paced sit-to-stand trials. Kinematic and kinetic data were collected and used to calculate inverse dynamics net joint moment. Peak isometric knee and hip extensor torques were measured and used as inputs to regression models that predicted angle- and velocity-dependent maximum potential net joint moment. Knee and hip relative-muscular-effort were calculated as the net joint moment during the task and their maximum capacity. FindingsKnee and hip extensor relative-muscular-effort did not differ between age groups during momentum-transfer and extension phases of the sit-to-stand. However, peak knee and hip moments during the sit-to-stand, knee and hip maximum potential moments as well as peak knee and hip torques were significantly lower in older adults compared to young adults. InterpretationAlthough there were age-related decreases in muscle strength and joint kinetics during the sit-to-stand task in older adults, the findings that older adults exhibited similar knee and hip relative-muscular-effort to young adults suggests that neither knee nor hip extensors operated close to their maximum capacity during this task. Therefore, neuromuscular reserve in knee and hip strength may not be a critical limiting factor for healthy older adults during the two phases of sit-to-stand.

Human–exoskeleton interaction portrait

Human–robot physical interaction contains crucial information for optimizing user experience, enhancing robot performance, and objectively assessing user adaptation. This study introduces a new method to evaluate human–robot interaction and co-adaptation in lower limb exoskeletons by analyzing muscle activity and interaction torque as a two-dimensional random variable. We introduce the interaction portrait (IP), which visualizes this variable’s distribution in polar coordinates. We applied IP to compare a recently developed hybrid torque controller (HTC) based on kinematic state feedback and a novel adaptive model-based torque controller (AMTC) with online learning, proposed herein, against a time-based controller (TBC) during treadmill walking at varying speeds. Compared to TBC, both HTC and AMTC significantly lower users’ normalized oxygen uptake, suggesting enhanced user-exoskeleton coordination. IP analysis reveals that this improvement stems from two distinct co-adaptation strategies, unidentifiable by traditional muscle activity or interaction torque analyses alone. HTC encourages users to yield control to the exoskeleton, decreasing overall muscular effort but increasing interaction torque, as the exoskeleton compensates for user dynamics. Conversely, AMTC promotes user engagement through increased muscular effort and reduces interaction torques, aligning it more closely with rehabilitation and gait training applications. IP phase evolution provides insight into each user’s interaction strategy formation, showcasing IP analysis’s potential in comparing and designing novel controllers to optimize human–robot interaction in wearable robots.

Development of static balance in professional-applied physical training of cadets with specific learning conditions.

Annotation. Successful professional activity of specialists of the National Police of Ukraine is ensured through the formation of a wide range of professional competencies, which, in particular, provides for the comprehensive development of professionally significant physical qualities during the training of cadets in higher education institutions with specific learning conditions. Taking into account the growing complexity and variety of tasks facing modern police officers, the list of priority physical qualities that a graduate of a higher education institution should have is expanding. The analysis of the content of educational programs in the practical disciplines of higher education institutions shows that they are mainly focused on the development of cadets: strength, flexibility, speed qualities, strength and speed endurance. In the educational process, not enough attention is paid to the development of coordination abilities, which ensure the rational distribution of muscular efforts during physical exercises, the optimal amplitude of movements, the efficiency of motor actions and the economy of energy consumption, and prevent injuries. The authors focus on the fact that modern control tests and standards for assessing physical fitness, used in the system of the Ministry of Internal Affairs of Ukraine, do not make it possible to fully assess the level of development of priority motor qualities of future police officers. It is proposed to use in the educational process of higher education the test for assessing static equilibrium according to the method of E. Y. Bondarevskiy. To develop coordination abilities, it is recommended to use the following exercises: from somat yoga; swimming; Nordic walking; maintaining balance on an unstable platform, with the performance of acyclic motor actions; on a reduced support area; on one leg.

Muscle Property Optimization Based on Motion Intentionality for Motor Skill Augmentation

Understanding motion intentionality is important to augment motor skills. This can be explained by the anatomical structure and innate immune mechanisms of humans. This study aimed to analyze human motion using musculoskeletal information and estimate motion intentionality, motion direction, and muscle properties. The calculation method for the easy-to-move musculoskeletal direction in the task space was reversed to calculate the optimal muscle properties and matching rate for the motion direction. The analysis results of each walking and feint motion showed that the muscles were trained toward reduced muscular effort and improved skills for each motion. In addition, the results of the optimization of the matching rate and muscle properties indicate that the optimized muscle properties can express the motion better than the reference values, and the average matching rate increases by 2.41×10-1, particularly for a feint motion. Therefore, skill acquisition and augmentation were achieved.

Preliminary investigation of a wearable device for evaluating muscular effort and fatigue at workplace

AbstractControls and prevention activities for musculoskeletal disorders are increasingly encouraged in the industrial context. Several ergonomic assessment techniques exist. However, they primarily focus on the biomechanical and postural load requirements of job tasks and rely on self-report and observational methods rather than direct measurements, which are often too intrusive. This study investigates whether a commercially available low-intrusive and low-cost wearable sensor can be utilised to assess muscular effort and fatigue, thereby improving decision-making in work and workstation design. For this purpose, the potential of the Myo™ armband has been explored. The electrical activity of the upper limbs (arm and forearm) was evaluated through 15 physically tasks (manual handling and assembly) conducted in laboratory conditions. Satisfactory results were obtained from the correlation and significance analysis, considering the EMG signal, the Borg scale, and the activity level (e.g., load, distance, n° of repetitions). Further experimentation was conducted to validate the proposed approach in a real production facility.

Deactivation and collective phasic muscular tuning for pointing direction: Insights from machine learning

Arm movements in our daily lives have to be adjusted for several factors in response to the demands of the environment, for example, speed, direction or distance. Previous research has shown that arm movement kinematics is optimally tuned to take advantage of gravity effects and minimize muscle effort in various pointing directions and gravity contexts. Here we build upon these results and focus on muscular adjustments. We used Machine Learning to analyze the ensemble activities of multiple muscles recorded during pointing in various directions. The advantage of such a technique would be the observation of patterns in collective muscular activity that may not be noticed using univariate statistics. By providing an index of multimuscle activity, the Machine Learning (ML) analysis brought to light several features of tuning for pointing direction. In attempting to trace tuning curves, all comparisons were done with respects to pointing in the horizontal, gravity free plane. We demonstrated that tuning for direction does not take place in a uniform fashion but in a modular manner in which some muscle groups play a primary role. The antigravity muscles were more finely tuned to pointing direction than the gravity muscles. Of note, was their tuning during the first half of downward pointing. As the antigravity muscles were deactivated during this phase, it supported the idea that deactivation is not an on-off function but is tuned to pointing direction. Further support for the tuning of the negative portions of the phasic EMG was provided by the observation of progressively improving classification accuracies with increasing angular distance from the horizontal. We also demonstrated that the durations of these negative phases, without information on their amplitudes, is tuned to pointing directions. Overall, these results show that the motor system tunes muscle commands to exploit gravity effects and reduce muscular effort. It quantitatively demonstrates that phasic EMG negativity is an essential feature of muscle control. The ML analysis was done using Linear Discriminant analysis (LDA) and Support Vector Machines (SVM). The two led to the same conclusions concerning the movements being investigated, hence showing that the former, computationally inexpensive technique is a viable tool for regular investigation of motor control.

Human-in-the-Loop Optimization of Knee Exoskeleton Assistance for Minimizing User's Metabolic and Muscular Effort.

Lower limb exoskeletons have the potential to mitigate work-related musculoskeletal disorders; however, they often lack user-oriented control strategies. Human-in-the-loop (HITL) controls adapt an exoskeleton's assistance in real time, to optimize the user-exoskeleton interaction. This study presents a HITL control for a knee exoskeleton using a CMA-ES algorithm to minimize the users' physical effort, a parameter innovatively evaluated using the interaction torque with the exoskeleton (a muscular effort indicator) and metabolic cost. This work innovates by estimating the user's metabolic cost within the HITL control through a machine-learning model. The regression model estimated the metabolic cost, in real time, with a root mean squared error of 0.66 W/kg and mean absolute percentage error of 26% (n = 5), making faster (10 s) and less noisy estimations than a respirometer (K5, Cosmed). The HITL reduced the user's metabolic cost by 7.3% and 5.9% compared to the zero-torque and no-device conditions, respectively, and reduced the interaction torque by 32.3% compared to a zero-torque control (n = 1). The developed HITL control surpassed a non-exoskeleton and zero-torque condition regarding the user's physical effort, even for a task such as slow walking. Furthermore, the user-specific control had a lower metabolic cost than the non-user-specific assistance. This proof-of-concept demonstrated the potential of HITL controls in assisted walking.

Повседневная речь и принцип экономии артикуляционных и мануальных усилий в реальной и виртуальной коммуникации

The article discusses the issues of saving articulatory efforts and related cognitive costs. The research relied on Western studies that link some phonetic changes to the desire of communicants to reduce articulatory efforts in the process of voicing speech segments. This desire is connected with the need to optimize the language system. Communicants try to simplify complex articulations and get rid of sounds that require significant muscular efforts of speech organs, thus changing the language system. The paper introduces examples of how some linguistic units are used in everyday speech and how these units are simplified due to the high frequency of their use. The author comes to the conclusion that frequency generates careless articulation while maintaining effective communication. The reasons for simplified articulation should be sought primarily at the deep level of the generation of primary semantic recording, i.e., in cognition, and not in the muscular work of the speech apparatus. If language is a tool that shapes a product of mental activity, the answers to the questions of language transformations should be sought directly in the cognitive sphere.

Vocal Hygiene Habits in College Students With and Without Self-Reported Symptoms of a Voice Problem

PurposeThe purpose of this study was to determine the prevalence of symptoms of a voice problem in college students and to assess if general health factors and vocal hygiene habits serve as risk factors for symptoms of a voice problem in this population. MethodsParticipants (n = 289) from a university in the United States completed an online survey that included demographic and general health questions, the Screen6 questionnaire, and a list of 23 vocal hygiene habits. Four participants were excluded due to receiving voice therapy and the remaining 285 participants were divided into two groups based on the results of the Screen6 questionnaire: those with two or more symptoms of a voice problem daily or weekly (n = 84) and those with fewer symptoms (n = 201). Results29.5% of the college students in this study experienced two or more symptoms weekly or daily. Throat clearing was the most commonly reported symptom. Risk factors included having a postnasal drip, experiencing severe seasonal allergies, and taking medication for depression or anxiety. The following vocal hygiene habits were reported to occur more frequently in those with symptoms of a voice problem: use your voice until it hurts, use extra muscular effort while talking, use extra respiratory effort while talking, use a pitch that you think is too high, and use a pitch that you think is too low. Non-use behaviors, such as water and caffeine consumption, did not vary significantly between groups. ConclusionsPeople with two or more symptoms of a voice problem daily or weekly report using their voice in a way that may contribute to experiencing these symptoms. Vocal hygiene education for this demographic may be more impactful if it is catered to how the voice is used rather than non-use voice care.

Lightweight active back exosuit reduces muscular effort during an hour-long order picking task

Occupational back exoskeletons and exosuits aim to reduce low back injuries in the workplace. For these technologies to be adopted, it is important that they provide biomechanical benefits to the wearer and do not disrupt job performance. To address this challenge, here we developed a lightweight, soft, active back exosuit that can autonomously control virtual impedance to apply differing assistance during lowering and lifting. In usability tests, participants rated the exosuit as easy to learn and use and reported feeling confident while wearing it. In an experiment involving an hour-long order picking task we demonstrated that the exosuit reduced peak and median muscle activations in the back by 18% and 20%, respectively. Despite the complexity of the movements required, such as walking, bending, and navigating around obstacles while lifting boxes from under a rack, our controller demonstrated impressive robustness with only 14 mistriggers out of 9600 lifts (0.1%). The results of this research suggest that active exosuit technology has the potential to be a highly usable solution to aid warehouse workers in real-world settings.

Evaluation of the lumbar and abdominal muscles behavior in different sagittal plane angles during maximum voluntary isometric extension.

Physical positions and lumbar movements are directly related to lumbar disorders. It is known that the sagittal plane angle affects the person's ability to apply extension torque. However, there is no consensus on whether or not muscle activity and co-contractions change at these angles. This paper aimed to investigate the abdominal and lumbar muscles' behavior at different sagittal plane angles during maximum voluntary isometric extension (MVIE). We have evaluated our findings with the aid of a computational biomechanical model. Fourteen healthy males participated. A total of 16 muscles EMG were recorded during the lumbar MVIE on the Sharif Lumbar Isometric Strength Tester device in 5°, 15°, 30°, and 45° flexion. The torque and muscle activity changes and all co-contraction indexes (CCI) between 120 possible muscle pairs were calculated. Finally, the experimental test conditions were modeled in the AnyBody software, and the MVIE torque, muscle activity, and all CCIs were calculated. Also, muscle torque lever arms were calculated at different angles. Results show that MVIE at four angles is 137.94 ± 36.08, 148.63 ± 47.96, 168.09 ± 50.48, and 171.44 ± 53.95 N · m, respectively. Muscle activity and CCI are similar at all angles. The AnyBody model gives similar findings. Muscles torque lever arms change with angle. In conclusion, to determine the safety mode of lifting in the sagittal plane, it seems that the torque differences are due to changes in the geometrical muscle parameters (including the torque lever arm). Despite the almost constant muscular effort, subjects in the 30°-45° bending positions can apply more MVIE.

ESTIMATING ELECTRICAL ENERGY GENERATION FROM HUMAN MUSCLE EFFORTS

This paper aimed to develop a model to estimate the generation of electrical energy through human muscular effort, using a generator bicycle, connected to the electrical grid. The motivation resulted from the author's experience in distributed electrical energy generation, which identified a difficulty in installing photovoltaic solar generation systems on the top of buildings. As a research methodology, this study used multiple linear regression using time, weight, height, and body mass index (BMI) as independent variables. The model showed promising results, presenting a high adjusted R-squared, respecting the assumptions associated with a linear regression model. The simulations based on the model showed a considerable energy generation potential for Brazil. In conclusion, although the estimated regression model presented a high predictive capability, further studies are recommended before any financial investment.

Effects of ankle exoskeleton assistance and plantar pressure biofeedback on incline walking mechanics and muscle activity in cerebral palsy

Ankle dysfunction affects more than 50 % of people with cerebral palsy, resulting in atypical gait patterns that impede lifelong mobility. Incline walking requires increased lower limb effort and is a promising intervention that targets lower-limb extensor muscles. A concern when prescribing incline walking to people with gait deficits is that this exercise may be too challenging or reinforce unfavorable gait patterns. This study aims to investigate how ankle exoskeleton assistance and plantar pressure biofeedback would affect gait mechanics and muscle activity during incline walking in CP. We recruited twelve children and young adults with CP. Participants walked with ankle assistance alone, biofeedback alone, and the combination while we assessed ankle, knee, and hip mechanics, and plantar flexor and knee extensor activity. Compared to incline walking without assistance or biofeedback, ankle assistance alone reduced the peak biological ankle moment by 12 % (p < 0.001) and peak soleus activity by 8 % (p = 0.013); biofeedback alone increased the biological ankle moment (4 %, p = 0.037) and power (19 %, p = 0.012), and plantar flexor activities by 9 – 27 % (p ≤ 0.026); assistance-plus-biofeedback increased biological ankle and knee power by 34 % and 17 %, respectively (p ≤ 0.05). The results indicate that both ankle exoskeleton assistance and plantar pressure biofeedback can effectively modify lower limb mechanics and muscular effort during incline walking in CP. These techniques may help in establishing personalized gait training interventions by providing the ability to adjust intensity and biomechanical focus over time.

Respiratory and muscular effort during pre-slaughter stress affect Nile tilapia fillet quality.

Nile Tilapia (Oreochromis niloticus) management procedures are directly linked to the final quality of the product. The aim of this study was to evaluate the effect of pre-slaughter density and different stunning methods on biochemical, respiratory and muscle injury parameters associated with quality and sensory characteristics of Nile tilapia fillets. Fish with an average weight of 762±105 g were used, first collected called the control group. The experiment was conducted in a 2 × 2 factorial scheme, with two densities (50 and 300 kg of live weight m-3) and two stunning methods thus totaling four treatments, with 15 repetitions per treatment totaling 75 fish sampled. Blood gas analysis, evaluation of biochemical parameters, analysis of meat quality and sensory analysis were carried out. For blood gas, biochemical and enzymatic parameters, the highest values were obtained for the density of 300 kg m-3 and asphyxia method: partial pressures of CO2; glucose and lactate, the highest values presented were 268.98 and 11.33 mg dL-1 respectively. As well as enzymatic activities, Creatinine kinase (CPK); Creatinine kinase isoenzyme (CKMB) showed higher values (768.93 and 1078.98 mg dL-1 respectively) in the higher density and asphyxia method. Conversely, when evaluating the quality parameters, the highest values were observed for lower density and thermonarcosis. High depuration density (300 kg m-3), combined with the asphyxiation stunning method, promotes changes in respiratory dynamics and provides greater stress, less firm fillet texture and greater weight loss due to cooking, as well as changes in creatine kinase (CK) and its CK-MB isoenzyme, demonstrating greater muscle damage. On the other hand, the density of 50 kg m-3 during pre-slaughter, combined with the method of stunning by thermonarcosis, provide a longer period of permanence in pre rigor mortis, which will result in fillets with a better sensory profile.

Drop Set Continuum Zone Repetition Strategies on the Recovery Week Periodization

Introduction. Short term recovery week high load drop set is optimal condition resistance training periodization enable to maximum strategies of number of repetition. Objective. The study goal was to investigate of perform strength and hypertrophy zone drop set sessions on low and high load frequency muscle fibril effort in recovery week periodization. Materials and Methods. The muay thai athletes; n= (14), age (14.42±1.50), height (166.85±10.75), body mass (61.92±10.73) participated over 3 week and per week 2 days drop set program. High load drop set performed including at 70-90% of 1RM loading range on 3-4 set-ups finish with non-rest interval. Muscular performance efforts of subjects were displayed on selecting multi-parameter maximum absolute and relative strength and repetition maximum protocols: (moderate frequency=70% of 1RM unfatigued muscle contraction and (high frequency= 85% of 1RM muscle fibril composition). Results. In the results, one repetition maximum (1RM) was concluded on seated leg curl (p=0.017; 11.14%), leg extension (p=0.000; 16.28%), however, local muscular endurance on leg press (p=0.024; 23.85%), seated leg curl (p=0.013; 15.35%), addition, muscle fibril composition on leg press, seated leg curl and leg extension has not significant differences. Conclusion. The drop set combination related repetition maximum strategies can be use to longer week maximize muscular performance, Tapering period and enhanced muscular endurance adaptation.

General physical fitness of powerlifters as a basis for effective strength development

The article, based on the analysis and synthesis of data from the source base and practical experience, identifies the main features of the general physical fitness of powerlifting athletes as the basis for effective strength development. The attention is focused on the issues related to the individualization of the training process and the management of the physical condition of athletes, the importance of various forms of manifestation of strength abilities. It is emphasized that the growth of sports achievements i s primarily due to the improvement of the methodology of strength development. It is noted that the level of strength development in powerlifters is one of the most urgent problems of the educational and training process in this sport, and the solution of this problem will significantly increase the effectiveness of sports training in powerlifting.&#x0D; The most important physical quality to develop in the process of general physical training of powerlifters is strength. In general, "strength" is defined as the ability to overcome external resistance or to counteract it with the help of muscle effort. The following specific forms of strength are distinguished by the nature of the effort and the mode of muscle function: fast strength, maximum strength, power endurance, and explosive strength.&#x0D; Muscular effort in the conditions of the training process of powerlifters can manifest itself in different ways: once or repeatedly, in cyclic or variable work with high or low resistance, at high speed or slowly, in a relaxed or tense state of muscles. An important physical quality that needs to be developed in the process of general physical training of powerlifters is endurance. Endurance is usually equated with the powerlifter's ability to perform muscle work (squats with a barbell, bench press, deadlift) for a long time during competitions without signs of significant fatigue.

Effects of Handrail Support usage during CPET on Metabolic Responses in Healthy Participants

Background: Using the support of a handrail during cardiopulmonary exercise testing (CPET) may alter physiologic parameters. The purpose is investigate the effects of handrail usage during the CPET in the metabolic parameters outcomes of young adults. Material and Methods: 39 young adults (age in years, 20.8 ± 2.9) of both sexes, 17 woman and 22 men performed two treadmill CPET on Ellestad protocol, in non-consecutive days. The first (T1) offered access to the support of a handrail; after 7 days, the second (T2) was performed without it. Differences between protocols for metabolic variables were compared using paried the t-test and repeated measures ANOVAS with interaction. Results: Regardless of sex, all participants exhibited superior results of metabolic parameters at T2 in contrast to T1. During T2, there was a major perception of respiratory and muscular effort, as well as a higher respiratory quotient for both sexes. When comparing T1 with T2, the VE/VCO2 slope was also significantly higher for women (29.31 ± 4.7 and 27.27 ± 4.53). For both sexes, when comparing the tests by stages, it was observed in stages 2, 3 and 4 higher values in the metabolic parameters for T2. The percentile difference for both sexes was 17% higher in S3 for women (T1=26.20±4.1 ml.kg-1.min-1;T2 28.79±4.2 ml.kg-1.min-1) and men (T1= 40.07±6.6 ml.kg-1.min-1; T2 45.92±4.8 ml.kg-1.min-1).Conclusion: The holding of the handrail attenuated the participants' cardiorespiratory and metabolic responses by more than 15% during CPET. Material and Methods: 39 young adults (age in years, 20.8 ± 2.9) of both sexes, 17 woman and 22 men performed two treadmill CPET on Ellestad protocol, in non-consecutive days. The first (T1) offered access to the support of a handrail; after 7 days, the second (T2) was performed without it. Differences between protocols for metabolic variables were compared using paried the t-test and repeated measures ANOVAs with interaction. Results: Regardless of sex, all participants exhibited superior results of metabolic parameters at T2 in contrast to T1. During T2, there was a major perception of respiratory and muscular effort, as well as a higher respiratory quotient for both sexes. When comparing T1 with T2, the VE/VCO2 slope was also significantly higher for women (29.31 ± 4.7 and 27.27 ± 4.53). For both sexes, when comparing the tests by stages, it was observed in stages 2, 3 and 4 higher values in the metabolic parameters for T2. VO2 was approximately 17% higher at T2, stage 3, for women and men. Conclusion: The holding of the handrail attenuated the participants' cardiorespiratory and metabolic responses by more than 15% during CPET.

Laparoscopic gastrectomy for gastric cancer: A single cancer center experience.

Laparoscopic gastrectomy (LG) was challenging to most surgeons due to the two-dimensional view, difficult manipulations of the instruments, ergonomic discomfort, and the associated muscular spasm and effort. Technological advances with improved surgical experience, have made LG a more feasible and favorable approach for gastric cancer (GC) patients. LG was performed in 44 patients with GC between July 2015 to June 2022, in the Department of Surgical Oncology, Oncology Center, Mansoura University, Egypt, and we assessed the surgical outcomes of this approach as an initial experience of a single cancer center. Twenty-seven patients underwent laparoscopic distal gastrectomy, and seventeen underwent laparoscopic total gastrectomy. Two cases had combined resection. Operative time was 339.2 ± 76.73 min, while blood loss was 153.86 ± 57.51 mL. The patients were ambulant on postoperative day 0, oral intake was started within three days (range 1-5 days) and the hospital stay was six days (range 3-9 days). LG for GC is a feasible approach for both early and advanced GC patients as it allows for adequate diagnosis of the peritoneal disease, meticulous dissection, and identification of the lymph nodes with minimal blood loss and decrease surgery-related problems and encourage the early patients' discharge from hospital and return to daily life activities.

Ergonomic learning curves on gynecological laparoendoscopic single-site (LESS) surgery

BackgroundFew previous studies have introduced general techniques to overcome the “chopstick effect” in laparoendoscopic single-site surgery (LESS). We aim to investigate and highlight the key ergonomic methodologies for gynaecologic LESS based on the surgeon’s hands-on performance.MethodsThe first author surgeon A reviewed and analyzed the LESS procedures performed by herself and how she taught surgeon B from January 2021 to April 2022. The procedures were classified based on technical difficulty and learning periods, and the hands-on technical skills of LESS module were evaluated.ResultsSurgeon A conducted 580 LESS procedures, which were divided into the novice (n = 48) and intermediate (n = 33) periods, and the remaining cases were included in the routine period. We formed a special ergonomic LESS operating methodology: Maintain good LESS laparoscopic spatial sensation, keep hand-eye coordination, well cooperation between the main surgeon and the assistant; Experienced multiport laparoscopy surgery (MPS) skills, improve basic LESS technique: grasp, lift, transfer, place, blunt separating, coagulation and cutting. Coordination location, orientation, movements, and flexion or extension of shoulders, arms, elbow, wrist and finger joints; Maintain strength, tension and ambidexterity postures with joint and muscular efforts to control instruments. Surgeon B learned the above experiences by performing 39 LESS procedures under the guidance of surgeon A.ConclusionThis educational research sheds light on the common challenges faced in LESS and presents the importance of ergonomic hands-on performance skills in improving surgical outcomes, which could serve as a guide for future training and education in LESS.