Spinal shrinkage during work in a sitting posture compared to work in a standing posture

1997 ◽  
Vol 12 (7-8) ◽  
pp. 409-418 ◽  
Author(s):  
G Leivseth ◽  
B Drerup
Author(s):  
Howraa Nash ◽  
Gourav Kumar Nayak ◽  
Jashwant Thota ◽  
Mohammed Alsowaidi ◽  
Hashem Alsowaidi ◽  
...  

A user’s posture at a computer workstation, especially wrist posture, is determined by the keyboard angle. Most commercially available computer keyboards have a built-in positive slope that requires the user to extend their wrist approximately 20° when typing. The purpose of this study is to find the negative keyboard angles that minimize wrist extension for both sitting and standing workstations. In this study, we compared upper limb working postures, including those of the wrist, elbow and shoulder, at 5 different keyboard angles between −16° and +6° in sitting and standing postures. Based on our results, we can conclude that the optimal range of keyboard slope is from −4° to −12° in sitting posture and −8° to −12° in the standing posture in terms of minimum wrist extension, typing performance, and user preference. We also propose a universal keyboard support design as an attachment to currently available keyboards.


Author(s):  
Ulf Landström ◽  
Ronnie Lundström

The experiments were conducted to evaluate the subjective experience associated with sinusoidal whole body vibration. Exposures were carried out in vertical (z) direction with the subject placed in upright sitting and standing positions. According to the present results, the vibration perception level is approximately the same for both postures, about 80–90 dB, (re 1 μm/s2 (r.m.s)) when comparing frequencies below 100 Hz. The threshold values were found to be influenced by the body weight, heavy people being more sensitive to whole body vibration in sitting posture, light people being more sensitive to vibrations in standing posture. Furthermore, the present study clearly shows the existence of temporary threshold shifts (TTS) in perception of whole body vibration after 5 minutes of vibration fatigue. If measured c. 30 seconds after the end of the exposure the temporary threshold shifts were in the magnitude of 10 dB.


Author(s):  
Daichi Yokoyama ◽  
Nobuhiko Hama ◽  
Noboru Nakamichi ◽  
Keiya Sugihara ◽  
Keita Watanabe ◽  
...  

Work ◽  
2020 ◽  
Vol 67 (4) ◽  
pp. 837-846
Author(s):  
Zahra Vahedi ◽  
Adel Mazloumi ◽  
Ali Sharifnezhad ◽  
Zeinab Kazemi ◽  
Ehsan Garosi

BACKGROUND: Smartphones (SPs) are widely used by people of all age groups and genders. Users spend many hours per day on the SPs for different purposes, which imposes significant stress on their musculoskeletal system. OBJECTIVES: This study explored head forward flexion, lateral bending angle, and viewing distance while working with a SP in sitting/standing postures and one-handed/two-handed grips. The users’ performance as well as pain development were also investigated. METHODS: Participants answered a questionnaire on pain experience before and after SP usage. Neck kinematics of 20 SP users were monitored by a motion analysis system while doing three tasks (typing, video watching, and reading) in sitting and standing postures. Performance was evaluated by number of typed words, amount of errors in typing, and total read words. RESULTS: The results indicated a significant increase in pain complaints in neck and upper limbs after test completion. Working with SPs in sitting and standing postures were, respectively, associated with greater head forward flexion for watching and viewing distance for two-handed typing tasks. Higher left lateral bending values were measured for one-handed watching and reading tasks in standing posture. The performance measures were superior for two-handed grips in all conditions. CONCLUSIONS: Overall, using SPs in sitting posture creates greater head forward flexion and lower lateral bending angles in all tasks and grip types. The findings of this study can be used to provide recommendations for SP users.


Author(s):  
Keiya Sugihara ◽  
Kenta Amahaya ◽  
Keita Watanabe ◽  
Noboru Nakamichi ◽  
Toshiya Yamada

2019 ◽  
Vol 14 ◽  
pp. 155892501986847 ◽  
Author(s):  
Rafiu King Raji ◽  
Xuhong Miao ◽  
Ailan Wan ◽  
Li Niu ◽  
Yutian Li ◽  
...  

Recognizing alterations in respiration patterns is an essential early sign not only for disease diagnoses but also for determining psychosomatic condition of the individual. The desire for measuring these parameters outside the hospital setting has led to a great interest in embedding this functionality in everyday wearable materials. This study presents an assessment of respiration patterns using a knitted piezoresistive smart chest band. A total of 20 users—Asians and Africans from 8 countries—were tested 14 times over a 67-day period. Experiments were conducted with users being under several varied test conditions including standing and sitting posture, varying physical activities, and different times in the day. Results show a successful application of the band with result patterns being in congruence with studies conducted using other related respiratory measurement technologies and instruments. Sedentary standing posture presented less signal noise compared to physical activity tests. Individuality and the repeatability of results over time suggest feasibility of the use of breath patterns as a biometric feature. Influences of ethnicity, gender, and body mass index on respiration patterns have also been discussed.


2019 ◽  
pp. 1-5

Abstract Background: There is no effective therapy for many neurological disorders associated with significant neurological damage such as kernicterus. Patients with Kernicterus (Chronic bilirubin encephalopathy) which is a neurological dysfunction resulting from exposure of the brain to severe hyperbilirubinemia mostly during the neonatal period continue to experience significant disability. There is no known therapeutic intervention that can obviously improve this condition. The aim of this paper is to describe a novel therapeutic approach which in two months produced marked improvement of the neurological dysfunction caused by kernicterus. Patients and methods: A girl with kernicterus were not speaking and not saying any word. She was lacking the balance (co-ordination) without obvious muscle weakness. She was unable to maintain the sitting posture on a chair for few minutes. She was unable to maintain straight standing posture when supported on chair at all. She had difficulty in holding things. The girl was treated with a novel therapeutic approach including two courses of intramuscular cerebrolysin and intramuscular citicoline. Results: After treatment the first month of treatment, speech development was initiated and she was saying few words. She was able to sit normally on the chair and maintaining the sitting posture indefinitely. She was able to maintain more straight stable standing posture without holding a chair and with the ability to hold things at the same time indicting improved coordination. She also developed improved ability to hold small things like a pen. After the second month of treatment, the girl was able to stand alone and was making few steps slowly holding furniture. After treatment the second course of treatment, the girl was able to stand alone and walk rapidly holding furniture. Treatment was not associated with any side effects. Conclusion: The novel use of intramuscular cerebrolysin and citicoline in a patient with kernicterus was safe and effective.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5124
Author(s):  
Andreja Rudolf ◽  
Zoran Stjepanovič ◽  
Andrej Cupar

This study deals with the development of a kinematic 3D human-body model with an improved armature in the pelvic region, intended for a sitting posture (SIT), using Blender software. It is based on the scanned female body in a standing posture (STA) and SIT. Real and virtual measures of females’ lower-body circumferences for both postures were examined. Virtual prototyping of trousers was performed to investigate their fit and comfort on the scanned and kinematic 3D body models and to make comparison with real trousers. With the switch from STA to SIT, real and virtual lower-body circumferences increase and are reflected in the fit and comfort of virtual and real trousers. In SIT, the increased circumferences are attributed to the redistribution of body muscles and adipose tissue around the joints, as well as changes in joints’ shapes in body flexion regions, which are not uniformly represented on the kinematic sitting 3D body model, despite improved armature in the pelvic region. The study shows that average increases in waist, hip, thigh, and knee circumferences should be included in the process of basic clothing-pattern designs for SIT as minimal ease allowances, as should, in the future, armature designs that consider muscle and adipose tissues, to achieve realistic volumes for kinematic 3D body models in SIT.


2019 ◽  
Vol 9 (4) ◽  
pp. 718
Author(s):  
Chi-Heng Lu ◽  
Chiu-Ching Tuan ◽  
Yi-Chao Wu ◽  
Chi-Chuan Wu ◽  
Mei-Chuan Chen ◽  
...  

In order to ameliorate the anterior knee pain or peripheral pain around the tibia caused by patellar lateral subluxation, we evaluated the kick training effects of standing or sitting postures in strengthening the vastus medialis obliquus (VMO) on the quadriceps femoris muscle. A total of 83 subjects (45 male; 38 female) in both sitting and standing positions performed 10° to 90° leg lift and kick training. Among the male group, the effect of the sitting posture was better than that of the standing posture, 74.31% of the former achieved the training goal. In the female group, the effect of a standing posture was better than that of a sitting posture, for which only 37.71% of the latter achieved the training purpose. However, a ratio of 84.34% in the female group showed that the strength of VMO on the quadriceps femoris muscle generated by leg kicking was greater than the strength generated by walking. While it was impossible to immediately achieve a greater effect of VMO on the quadriceps femoris muscle than vastus lateralis on the quadriceps femoris muscle, leg kicking did achieve the objective of enhancing the strength of VMO on the quadriceps femoris muscle.


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