scholarly journals A Comparison Study of Posture and Fatigue of Neck According to Monitor Types (Moving and Fixed Monitor) by Using Flexion Relaxation Phenomenon (FRP) and Craniovertebral Angle (CVA)

Author(s):  
Kyeong-Hee Choi ◽  
Min-Uk Cho ◽  
Chae-Won Park ◽  
Seoung-Yeon Kim ◽  
Min-Jung Kim ◽  
...  

This study quantified the neck posture and fatigue using the flexion relaxation phenomenon (FRP) and craniovertebral angle (CVA); further, it compared the difference between the level of fatigue and neck posture induced by two types of monitors (regular fixed monitor and moving monitor). Twenty-three male participants were classified into two groups—the low-flexion relaxation ratio (FRR) group and the normal-FRR group, depending on the FRR value. All participants performed a document task for 50 min using both types of monitors. It was found that the FRR values significantly decreased after the documentation task. The CVA analysis showed that the moving monitor’s frequency of forward head posture (FHP) was lower than that for the fixed monitor. Overall, the moving monitor worked better than the fixed monitor; this can be interpreted as proof that such monitors can reduce neck fatigue.

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 810
Author(s):  
I. Concepción Aranda-Valera ◽  
Juan Luis Garrido-Castro ◽  
Alfonso Martínez-Galisteo ◽  
José Peña-Amaro ◽  
Cristina González-Navas ◽  
...  

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease characterized by the presence of inflammatory back pain. In patients with chronic low back pain, the lumbar flexion relaxation phenomenon measured by surface electromyography (sEMG) differs from that in healthy individuals. However, sEMG activity in axSpA patients has not been studied. The purpose of this study was to analyze the flexion relaxation phenomenon in axSpA patients. A study evaluating 39 axSpA patients and 35 healthy controls was conducted. sEMG activity at the erector spinae muscles was measured during lumbar full flexion movements. sEMG activity was compared between axSpA patients and the controls, as well as between active (BASDAI ≥ 4) and non-active (BASDAI < 4) patients. The reliability (using intraclass correlation coefficients (ICC)), criterion validity and discriminant validity using the area Under the curve (AUC) for the inverse flexion/relaxation ratio (1/FRR) were evaluated. Significant differences (p < 0.05) were observed between axSpA patients and the control group in lumbar electric activity, especially during flexion, relaxation, and extension and in FRR and 1/FRR (0.66 ± 0.39 vs. 0.25 ± 0.19, respectively). In addition, significant differences were found between active and non-active but also between non-active and healthy subjects. The sEMG showed good reliability (ICC > 0.8 for 1/FRR) and criterion validity. ROC analysis showed good discriminant validity for axSpA patients (AUC = 0.835) vs. the control group using 1/FRR. An abnormal flexion/relaxation phenomenon exists in axSpA patients compared with controls. sEMG could be an additional objective tool in the evaluation of patient function and disease activity status.


Work ◽  
2021 ◽  
pp. 1-7
Author(s):  
Samira Molaeifar ◽  
Farzaneh Yazdani ◽  
Amin Kordi Yoosefinejad ◽  
Mohammad Taghi Karimi

BACKGROUND: Forward head posture (FHP) is the most common malposition in the head and neck area. With the growing use of digital devices, the prevalence of FHP may be expected to increase dramatically. Thus far, FHP has been evaluated only in the sagittal plane. OBJECTIVE: The objective of this study was to measure angles and indices from anatomical landmarks in the frontal plane and determine the possible correlations between these variables and craniovertebral angle (CVA) as an index of FHP in the sagittal plane. METHODS: Fifty eight healthy individuals (29 men, 29 women) between 18 and 40 years old participated in this cross-sectional study. Participants were evaluated with an 8-camera motion analysis system. After markers were placed on predetermined landmarks, the participants were asked to maintain their head and neck in the neutral position for 5 seconds. Then participants induced FHP by flexing and lowering their head. The correlation between CVA and a set of angles and indices was calculated at the moment of FHP induction. RESULTS: A moderate correlation was observed between 3-D CVA and the angle formed between the sternum and both tragi for the whole sample and separately in both sexes. A moderate negative correlation was observed between 3-D CVA and height, weight, and BMI in women. A moderate negative correlation was observed between 3-D CVA and height, weight, BMI, and hours on digital devices in men. CONCLUSIONS: Changes in CVA in the sagittal plane can be predicted from changes in the angle formed between the midpoint of the sternum and the left and right tragi in the frontal plane.


Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2046
Author(s):  
Michele Paoletti ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Paola Pierleoni

The myoelectric activity of the back muscles can be studied to evaluate the flexion-relaxation phenomenon and find differences between electromyography patterns on different subjects. In this paper, we propose an algorithm able to provide a myoelectric silence evaluation based on the data acquired from a wireless body sensor network consisting of surface electromyography sensors in association with a wearable inertial measurement unit. From the study group was chosen a gold standard subject, a healthy control with the best regular patterns, as a reference to find a first validity range. Through the subsequent iterations, the range was modified to include the other healthy subjects who showed muscle relaxation according to the previous ranges. Through this likelihood analysis, we want to compare patterns on different channels, identified by the electromyography root mean squared values, to study and find with iterations a validity range for the myoelectric activity silence identification and classification. The proposed algorithm was tested by processing the data collected in an acquisition campaign conducted to evaluate the flexion-relaxation phenomenon on the back muscles of subjects with and without lower back pain. The results show that the submitted method is significant for the clinical assessment of electromyography activity patterns to evaluate which are the subjects that have patterns near or far from the gold standard. This analysis is useful both for prevention and for assessing the progress of subjects with low back pain undergoing physiotherapy.


2021 ◽  
Author(s):  
Marzyeh Ramezani ◽  
Amin Kordi Yoosefinejad ◽  
Alireza Motealleh ◽  
Mohsen Ghofrani-Jahromi

Abstract Background: Trunk flexion is a common exercise during daily activities. Flexion relaxation phenomenon (FRP) occurs during forward bending in which there is a sudden silence of erector spinae (ES) muscles. The pattern of forward bending differs in yoga practitioners. This learned pattern probably predisposes yogis to injuries.The hypothesis of this study was that FRP differs in yogis in comparison to non-yogis individuals.Methods: This observational cross-sectional study was performed on 60 women assigned into yogis and non-athlete groups. Each participant was asked to bend forward and then return to the initial position. ES activity was recorded at L3 level, 4 cm from mid line during the trial. Trunk inclination and lumbar flexion angles were calculated at FRP onset and cessation moments. Results: The FRP phenomenon occurred in 80% of yoga practitioners in comparison to 96.7% in the control group. Trunk inclination angle was significantly greater at FRP initiation in yogis compared to control group. Lumbar flexion angle was not different between the groups. Conclusions: It is concluded that the altered pattern of forward bending observed in yogis may change patterns of ES muscles activity if it becomes part of a person's daily lifestyle which might predispose these muscles to fatigue and subsequent injuries.


Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1044 ◽  
Author(s):  
Michele Paoletti ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Massimo Vallasciani ◽  
Paola Pierleoni

An accurate clinical assessment of the flexion-relaxation phenomenon on back muscles requires objective tools for the analysis of surface electromyography signals correlated with the real movement performed by the subject during the flexion-relaxation test. This paper deepens the evaluation of the flexion-relaxation phenomenon using a wireless body sensor network consisting of sEMG sensors in association with a wearable device that integrates accelerometer, gyroscope, and magnetometer. The raw data collected from the sensors during the flexion relaxation test are processed by an algorithm able to identify the phases of which the test is composed, provide an evaluation of the myoelectric activity and automatically detect the phenomenon presence/absence. The developed algorithm was used to process the data collected in an acquisition campaign conducted to evaluate the flexion-relaxation phenomenon on back muscles of subjects with and without Low Back Pain. The results have shown that the proposed method is significant for myoelectric silence detection and for clinical assessment of electromyography activity patterns.


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