scholarly journals Analýza balancování stoje na rukou

2013 ◽  
Vol 7 (1) ◽  
pp. 51-62
Author(s):  
Petr Hedbávný ◽  
Dušan Hupka ◽  
Jana Sklenaříková

The research was focused on analyzing balancing in handstand, as one of the fundamental physical structure sports gymnastics. With this research dealt many authors, but without application in practice.Its specificity is determined from the mechanical point of gravity height, the size of the support surface and the overall equilibrium position in which maintain stability. The aim of the project was to optimize the training of standing on their hands, depending on the strategy of maintaining a balance in this unstable static physical structure. For a comprehensive analysis of handstands is utilized synchronized 3D kinematic analysis, stabilomathric measuring and EMG, which we were reveal the inner essence of outer performance of technique. It was a case study and the tested person was a gymnast of student category and we focused on changes in the angle of the hip joint ("shoulder - hip - knee") and shoulder joint ("wrist - shoulder - hip") in connection with the muscle activity observed muscles and muscle groups. Now the application of this knowledge in practice, we can optimize the training, which in some cases lengthy.

2002 ◽  
Vol 16 (2) ◽  
pp. 92-96
Author(s):  
Tiina Ritvanen ◽  
Reijo Koskelo ◽  
Osmo H„nninen

Abstract This study follows muscle activity in three different learning sessions (computer, language laboratory, and normal classroom) while students were studying foreign languages. Myoelectric activity was measured in 21 high school students (10 girls, 11 boys, age range 17-20 years) by surface electromyography (sEMG) from the upper trapezius and frontalis muscles during three 45-min sessions. Root mean square (RMS) average from both investigated muscles was calculated. The EMG activity was highest in both muscle groups in the computer-aided session and lowest in the language laboratory. The girls had higher EMG activity in both investigated muscle groups in all three learning situations. The measured blood pressure was highest at the beginning of the sessions, decreased within 10 min, but increased again toward the end of the sessions. Our results indicate that the use of a computer as a teaching-aid evokes more constant muscle activity than the traditional learning situations. Since muscle tension can have adverse health consequences, more research is needed to determine optimal classroom conditions, especially when technical aids are used in teaching.


2021 ◽  
pp. 1-13
Author(s):  
Xiaoyan Wang ◽  
Jianbin Sun ◽  
Qingsong Zhao ◽  
Yaqian You ◽  
Jiang Jiang

It is difficult for many classic classification methods to consider expert experience and classify small-sample datasets well. The evidential reasoning rule (ER rule) classifier can solve these problems. The ER rule has strong processing and comprehensive analysis abilities for diversified mixed information and can solve problems with expert experience effectively. Moreover, the initial parameters of the classifier constructed based on the ER rule can be set according to empirical knowledge instead of being trained by a large number of samples, which can help the classifier classify small-sample datasets well. However, the initial parameters of the ER rule classifier need to be optimized, and choosing the best optimization algorithm is still a challenge. Considering these problems, the ER rule classifier with an optimization operator recommendation is proposed in this paper. First, the initial ER rule classifier is constructed based on training samples and expert experience. Second, the adjustable parameters are optimized, in which the optimization operator recommendation strategy is applied to select the best algorithm by partial samples, and then experiments with full samples are carried out. Finally, a case study on a turbofan engine degradation simulation dataset is carried out, and the results indicate that the ER rule classifier has a higher classification accuracy than other classic classifiers, which demonstrates the capability and effectiveness of the proposed ER rule classifier with an optimization operator recommendation.


Author(s):  
Ken Chen ◽  
Rebecca Widmayer ◽  
Karen B. Chen

Virtual reality (VR) is commonplace for training, yet simulated physical activities in VR do not require trainees to engage and contract the muscle groups normally engaged in physical lifting. This paper presents a muscle activity-driven interface to elicit the sensation of forceful, physical exertions when lifting virtual objects. Users contracted and attained predefined muscle activity levels that were calibrated to user-specific muscle activity when lifting the physical counterpart. The overarching goal is to engage the appropriate muscles, and thereby encourage and elicit behaviors normally seen in the physical environment. Activities of 12 key muscles were monitored using electromyography (EMG) sensors while they performed a three-part patient lifting task in a Cave Automatic Virtual Environment. Participants reported higher task mental loads and less physical loads for the virtual lift than the physical lift. Findings suggest the potential to elicit sensation of forceful exertion via EMG feedback but needed fine-tuning to offset perceived workload.


2021 ◽  
Vol 4 (2) ◽  
pp. 32
Author(s):  
Heather A. Feldner ◽  
Christina Papazian ◽  
Keshia M. Peters ◽  
Claire J. Creutzfeldt ◽  
Katherine M. Steele

Arm recovery varies greatly among stroke survivors. Wearable surface electromyography (sEMG) sensors have been used to track recovery in research; however, sEMG is rarely used within acute and subacute clinical settings. The purpose of this case study was to describe the use of wireless sEMG sensors to examine changes in muscle activity during acute and subacute phases of stroke recovery, and understand the participant’s perceptions of sEMG monitoring. Beginning three days post-stroke, one stroke survivor wore five wireless sEMG sensors on his involved arm for three to four hours, every one to three days. Muscle activity was tracked during routine care in the acute setting through discharge from inpatient rehabilitation. Three- and eight-month follow-up sessions were completed in the community. Activity logs were completed each session, and a semi-structured interview occurred at the final session. The longitudinal monitoring of muscle and movement recovery in the clinic and community was feasible using sEMG sensors. The participant and medical team felt monitoring was unobtrusive, interesting, and motivating for recovery, but desired greater in-session feedback to inform rehabilitation. While barriers in equipment and signal quality still exist, capitalizing on wearable sensing technology in the clinic holds promise for enabling personalized stroke recovery.


Nature ◽  
1938 ◽  
Vol 142 (3594) ◽  
pp. 537-537
Author(s):  
ROLLO APPLEYARD

2017 ◽  
Vol 35 (4) ◽  
pp. 348-363 ◽  
Author(s):  
Rand H.M. Agha ◽  
John M. Kamara

Purpose The purpose of this paper is to investigate the adaptations that have been made to traditional courtyard houses (TCHs) in Baghdad, Iraq. The aim is to develop an understanding of various factors in the adaptation of these buildings to suit contemporary lifestyles, which will contribute to the wider field of building adaptability. Design/methodology/approach Empirical evidence was collected through case studies of 12 TCHs in the Al-Kadhimiya area of Baghdad, which involved a physical survey of buildings and semi-structured interviews with 24 occupants. Findings Case study analysis show that building adaptability involves both a change to physical spaces and also to lifestyles; with the latter being more likely when there are limitations in how much change can be made to the physical structure. Research limitations/implications The focus of this research is mainly on users’ adaptation of spaces and therefore does not consider the full range of stakeholders involved in the adaptation process. The findings also only apply to the cases considered and may not be applicable to other house types or locations. Originality/value Studies on building adaptability mostly focus on the ease of change to the building fabric, although the role of users is acknowledged. This study provides insights into the complexity and variety of changes that users can make, which are influenced by lifestyles and driven by the need for comfort. These insights are represented in an adaptation model, which can serve as a basis for further research.


Author(s):  
Haerim Bak ◽  
Clive D’Souza ◽  
Gwanseob Shin

Physical demands of household carpet vacuuming and associated risks for musculoskeletal problems have received little attention although the level of muscle exertions is often assumed to be similar to that of occupational vacuuming. The aim of this study was to quantitatively assess the level of muscle activities of the upper extremity during carpeted floor vacuuming with household upright vacuum cleaners. Eighteen participants conducted four different carpet vacuuming tasks with two different cleaner models. Electromyography data from seven upper extremity muscles were collected. Median muscle activity ranged from 4.5% to 47.5% of the maximum voluntary contraction capacity for female participants and from 2.7% to 23.6% for male participants. Normalized muscle activity levels were significantly higher in women compared to men across tasks and muscle groups. Study results suggest that home vacuuming with upright vacuum cleaners is physically intensive work, especially for female users who are less physically capable.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. i41-i45
Author(s):  
Jacek Mazek ◽  
Maciej Gnatowski ◽  
Antonio Porthos Salas ◽  
Marcin Domżalski ◽  
Rafał Wójcicki ◽  
...  

Abstract The aim of this case study is to present arthroscopic treatment of recurrent hip instability after acute post-traumatic posterior hip dislocation with a fracture of the posterior acetabular wall. A male patient aged 35 suffered a dislocation of the right hip joint with a fracture of the posterior acetabular wall due to an accident. The fracture was stabilized during emergency surgery with a locking compression plate, and the patient was released home in a hip brace. Multiple dislocations of the hip joint followed with the implant being confirmed as stable. Decision was made to qualify the patient for a right hip arthroscopy. During the surgery, ligamentum teres was reconstructed using gracilis and semitendinous muscle grafts, followed by the labrum and joint capsule repair, where the surgery that stabilized the acetabular wall fracture had damaged them. There were no complications following the procedure. Short-term follow-up of 3 months demonstrates the patient has a stable hip, reduced pain and has returned to pre-injury activities.


Sign in / Sign up

Export Citation Format

Share Document