Lumbar Range of Motion and Flexion Relaxation Phenomenon Onset During Static Trunk Bending Postures

2018 ◽  
Vol 62 (1) ◽  
pp. 915-919
Author(s):  
Faisal M Alessa ◽  
Xiaopeng Ning
Keyword(s):  
Range Of Motion ◽  
Load Sharing ◽  
Relaxation Phenomenon ◽  
Trunk Flexion ◽  
Trunk Posture ◽  
Flexion Relaxation Phenomenon ◽  
Almost All ◽  
Lumbar Range Of Motion ◽  
Flexion Relaxation ◽  
Different Levels

The purpose of the current study was to assess the changes in lumbar tissue load sharing mechanism and lumbar range of motion at different trunk flexion postures. Eight participants performed the tasks of changing lumbar posture from extended to flexed posture while maintaining fixed trunk postures (30°, 60°, or 90°). Results of the present study showed that FRP onset was observed in almost all the trials at two conditions of trunk posture (i.e. 60° and 90°). The results also showed that lumbar range of motion changed significantly between the different levels of trunk posture. Findings of the current study could help for better understanding of the dynamics of lumbar active and passive tissue loading during static trunk flexion.

scholarly journals Comparison of Flexion Relaxation Phenomenon Between Female Yogis and Matched Non- Athlete Group

2021 ◽  
Author(s):  
Marzyeh Ramezani ◽  
Amin Kordi Yoosefinejad ◽  
Alireza Motealleh ◽  
Mohsen Ghofrani-Jahromi
Keyword(s):  
Erector Spinae ◽  
Relaxation Phenomenon ◽  
Control Group ◽  
Trunk Flexion ◽  
Lumbar Flexion ◽  
Trunk Inclination ◽  
Forward Bending ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation ◽  
Yoga Practitioners

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.

scholarly journals Changing the pattern of the back-muscle flexion–relaxation phenomenon through flexibility training in relatively inflexible young men

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259619
Author(s):  
Yi-Lang Chen ◽  
Wei-Cheng Lin ◽  
Ying-Hua Liao ◽  
Yi Chen ◽  
Pei-Yu Kang
Keyword(s):  
Pelvic Tilt ◽  
Young Men ◽  
Erector Spinae ◽  
Relaxation Phenomenon ◽  
Trunk Flexion ◽  
Back Muscle ◽  
Study Results ◽  
Flexion Relaxation Phenomenon ◽  
Flexibility Training ◽  
Flexion Relaxation

Although several studies have investigated the back-muscle flexion–relaxation phenomenon (FRP), the effect of individual flexibility on the FRP has been discussed infrequently, with very limited data on the influence of flexibility training on the FRP. This study thus examined the effect of flexibility training on the change of back-muscle FRP pattern in relatively inflexible young men. We collected and analyzed the valid data from 20 male participants (10 each with high and low flexibility included in the control and trained groups, respectively) when flexing their trunks at seven trunk flexion positions (0°–90°, in increments of 15°); their erector spinae and hamstring activation, pelvic tilt, and lumbosacral angle were then recorded. After 7 weeks of flexibility training for the low-flexibility group, no difference in flexibility was discovered between this group and the control (originally high-flexibility) group. The trunk flexion experiment was then repeated. The results showed that before the training stage, the low-flexibility group had lower erector spinae and higher hamstring activation, a larger pelvic tilt, and a smaller lumbosacral angle. By contrast, after training, the erector spinae and hamstring activation, pelvic tilt, and lumbosacral angle were significantly changed, and no intergroup differences were observed in FRP patterns. The study results suggest that flexibility training changes lumbopelvic movement and thereby reduces the degree of the back-muscle FRP when trunk flexion is performed.

scholarly journals High-Density Electromyography Provides New Insights into the Flexion Relaxation Phenomenon in Individuals with Low Back Pain

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Carlos Murillo ◽  
Eduardo Martinez-Valdes ◽  
Nicola R. Heneghan ◽  
Bernard Liew ◽  
Alison Rushton ◽  
...  
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
High Density ◽  
Mean Difference ◽  
Relaxation Phenomenon ◽  
Low Back ◽  
Trunk Flexion ◽  
Paraspinal Muscles ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation

Abstract Recent research using high-density electromyography (HDEMG) has provided a more precise understanding of the behaviour of the paraspinal muscles in people with low back pain (LBP); but so far, HDEMG has not been used to investigate the flexion relaxation phenomenon (FRP). To evaluate this, HDEMG signals were detected with grids of electrodes (13 × 5) placed bilaterally over the lumbar paraspinal muscles in individuals with and without LBP as they performed repetitions of full trunk flexion. The root mean square of the HDEMG signals was computed to generate the average normalized amplitude; and the spatial FRP onset was determined and expressed as percentage of trunk flexion. Smoothing spline analysis of variance models and the contrast cycle difference approach using the Bayesian interpretation were used to determine statistical inference. All pain-free controls and 64.3% of the individuals with LBP exhibited the FRP. Individuals with LBP and the FRP exhibited a delay of its onset compared to pain-free controls (significant mean difference of 13.3% of trunk flexion).  They also showed reduced normalized amplitude compared to those without the FRP, but still greater than pain-free controls (significant mean difference of 27.4% and 11.6% respectively). This study provides novel insights into changes in lumbar muscle behavior in individuals with LBP.

scholarly journals Patients with Axial Spondyloarthritis Show an Altered Flexion/Relaxation Phenomenon

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 ◽  
...  
Keyword(s):  
Back Pain ◽  
Discriminant Validity ◽  
Axial Spondyloarthritis ◽  
Criterion Validity ◽  
Erector Spinae ◽  
Relaxation Phenomenon ◽  
Control Group ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation ◽  
Semg Activity

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.

scholarly journals Electromyography Pattern Likelihood Analysis for Flexion-Relaxation Phenomenon Evaluation

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2046
Author(s):  
Michele Paoletti ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Paola Pierleoni
Keyword(s):  
Back Pain ◽  
Gold Standard ◽  
Relaxation Phenomenon ◽  
Measurement Unit ◽  
Myoelectric Activity ◽  
Back Muscles ◽  
Likelihood Analysis ◽  
Validity Range ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation

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.

scholarly journals A Wireless Body Sensor Network for Clinical Assessment of the Flexion-Relaxation Phenomenon

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1044 ◽  
Author(s):  
Michele Paoletti ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Massimo Vallasciani ◽  
Paola Pierleoni
Keyword(s):  
Sensor Network ◽  
Clinical Assessment ◽  
Activity Patterns ◽  
Relaxation Test ◽  
Relaxation Phenomenon ◽  
Myoelectric Activity ◽  
Back Muscles ◽  
Body Sensor Network ◽  
Flexion Relaxation Phenomenon ◽  
Flexion Relaxation

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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