High Density Surface Electromyography Activity of the Lumbar Erector Spinae Muscles and Comfort/Discomfort Assessment in Piano Players: Comparison of Two Chairs

Introduction: At a professional level, pianists have a high prevalence of playing-related musculoskeletal disorders. This exploratory crossover study was carried out to assess and compare quantitatively [using high density surface electromyography (HDsEMG)], and qualitatively (using musculoskeletal questionnaires) the activity of the lumbar erector spinae muscles (ESM) and the comfort/discomfort in 16 pianists sitting on a standard piano stool (SS) and on an alternative chair (A-chair) with lumbar support and a trunk-thigh angle between 105° and 135°.Materials and Methods: The subjects played for 55 min and HDsEMG was recorded for 20 s every 5 min. For the quantitative assessment of the muscle activity, the spatial mean of the root mean square (RMSROA) and the centroid of the region of activity (ROA) of the ESM were compared between the two chairs. For the qualitative assessment, musculoskeletal questionnaire-based scales were used: General Comfort Rating (GCR); Helander and Zhang’s comfort (HZc) and discomfort (HZd); and Body Part Discomfort (BPD).Results: When using the A-chair, 14 out of 16 pianists (87.5%) showed a significantly lower RMSROA on the left and right side (p < 0.05). The mixed effects model revealed that both chairs (F = 28.21, p < 0.001) and sides (F = 204.01, p < 0.001) contributed to the mean RMSROA variation by subject (Z = 2.64, p = 0.004). GCR comfort indicated that participants found the A-Chair to be “quite comfortable,” and the SS to be “uncomfortable.” GCR discomfort indicated that the SS caused more numbness than the A-Chair (p = 0.05) and indicated the A-Chair to cause more feeling of cramps (p = 0.034). No difference was found on HZc (p = 0.091) or HZd (p = 0.31) between chairs. Female participants (n = 9) reported greater comfort when using the A-Chair than the SS (F = 7.09, p = 0.01) with respect to males. No differences between chairs were indicated by the BPD assessment.Conclusion: It is concluded that using a chair with lumbar support, such as the A-chair, will provide greater comfort, less exertion of the ESM and less discomfort than the standard piano stool.

Effectiveness of lumbar support with built-in massager system on spinal angle profiles among high-powered traffic police motorcycle riders: A randomised controlled trial

Traffic police riders are exposed to prolonged static postures causing significant angular deviation of the musculoskeletal, including the lumbar angle (L1-L5). This postural alteration contributes to awkward posture, musculoskeletal disorders and spinal injury, especially in the lower back area, as it is one of the most severe modern diseases nowadays. Thus, the study aimed to evaluate the effect of lumbar support with a built-in massager system on spinal angle profiles among traffic police riders. A randomised controlled trial (pre-testpost-test control design) was used to assess spinal angle pattern while riding the high-powered motorcycle for 20 minutes. Twenty-four traffic police riders were randomly selected to participate and 12 riders were assigned to the control group and 12 riders to the experimental group. The pre-test and post-test were conducted at a one-week interval. Each participant was required to wear a TruPosture Smart Shirt (to monitor spinal posture). The TruPosture Apps recorded the spinal angle pattern. The data indicated that the police riders using motorcycle seat with lumbar support and built-in massager system showed a huge improvement in maintaining posture which only involves slight spinal angle deviation changes from the spinal reference angle throughout the 20 minutes ride. The data collected then were analysed using the Mann-Whitney test and Wilcoxon signed-ranked test to verify a statistically significant difference between and within the control and experimental groups. There were significant differences in all sensors between the control group and experimental groups (p<0.05) and within the experimental group. According to the findings, it can be said that the ergonomic intervention prototype (lumbar support with built-in massager system) successfully helps to maintain and improve the natural curve of the spinal posture. This indirectly would reduce the risk of developing musculoskeletal disorders and spinal injury among traffic police riders.

Moving Toward Individual-Specific Automotive Seat Design: How Individual Characteristics and Time Alter the Selected Lumbar Support Prominence

Objective To explore how individual characteristics influence selected lumbar support prominence (LSP), seated lumbar flexion, seatback average pressure, contact area, and center of pressure (CoP) location before and after 1 hr of driving. Background An LSP can alter posture and may reduce low back pain during prolonged driving. Although LSP preference varies across individuals and may change over time, few investigations have explored the time-varying response to individually selected adjustable seat parameters. Method Forty individuals selected LSP settings in an automotive seat through a series of systematic adjustment trials. The average LSP setting was fixed for a 1-hr driving simulation, followed by one final adjustment trial. Regressions were performed between individual characteristics and selected LSP, lumbar posture, and measures of seatback pressure from the initial adjustment trials. ANOVAs were performed to determine the effect of time and sex on these dependent variables. Discomfort was also monitored throughout the protocol. Results Individual’s standing lumbar lordosis, selected LSP, and height and mass were significant predictors for seated lumbar flexion, seatback average pressure, and contact area, respectively. Discomfort levels remained low; however, following the driving protocol, individuals altered their posture to decrease lumbar flexion and increase seatback average pressure without significant adjustments to the LSP. Conclusion These findings highlight individual characteristics to consider in automotive seat design and that the method for determining LSP settings may facilitate appropriate LSP selection. Application A systematic method to determine LSP settings may reduce discomfort and automate seat adjustments, such that only short-term postural adjustments may be required.

Excavator driver seat occupational comfort assessment with Lumbar Support Cushion

The operators of excavators often suffer from dreadful Whole-Body Vibration. Besides, the operators are subject to postural instability which is considered to be a serious occupational health hazard. The main objective of this study is to investigate the role of Lumbar Support Cushion in mitigation of Whole-Body Vibration and postural instability under three different operating conditions such as Front-Manipulator Motion, Swing Motion and Propel-Drive Motion. The obtained Vibration Dose Value reveals a significant difference between the operation cycle ( p < 0.001). Moreover, across the operation cycle with Lumbar Support Cushion a significant decrease in Vibration Dose Value (8) is observed on the operator seat-pan and backrest ( p < 0.05). Further, the effect of Whole-Body Vibration on physiological stress factors, a significant decrease in systolic blood pressure by 1.26%, pulse rate by 2.75% and Rate Pressure Product by 4%, is observed with the use of Lumbar Support Cushion ( p < 0.05) during the operation. The Lumbar Support Cushion helps in promoting a symmetric seating posture, and using Lumbar Support Cushion could help the excavator operator to increase in productivity during shift hour.

Influence of seat lumbar support adjustment on muscle fatigue under whole body vibration: An in vivo experimental study

BACKGROUND: In order to alleviate muscle fatigue and improve ride comfort, many published studies aimed to improve the seat environment or optimize seating posture. However, the effect of lumbar support on the lumbar muscle of seated subjects under whole body vibration is still unclear. OBJECTIVE: This study aimed to investigate the effect of lumbar support magnitude of the seat on lumbar muscle fatigue relief under whole body vibration. METHODS: Twenty healthy volunteers without low back pain participated in the experiment. By measuring surface electromyographic signals of erector spinae muscles under vibration or non-vibration for 30 minutes, the effect of different lumbar support conditions on muscle fatigue was analyzed. The magnitude of lumbar support d is assigned as d1= 0 mm, d2= 20 mm and d3= 40 mm for no support, small support and large support, respectively. RESULTS: The results showed that lumbar muscle activation levels vary under different support conditions. For the small support case (d2= 20 mm), the muscle activation level under vibration and no-vibration was the minimum, 42.3% and 77.7% of that under no support (d1= 0 mm). For all support conditions, the muscle activation level under vibration is higher than that under no-vibration. CONCLUSIONS: The results indicate that the small support yields the minimum muscle contraction (low muscle contraction intensity) under vibration, which is more helpful for relieving lumbar muscle fatigue than no support or large support cases. Therefore, an appropriate lumbar support of seats is necessary for alleviating lumbar muscle fatigue.

Effectiveness of lumbar support on backache among postoperative patients

The post-operative period is a critical time during hospitalization. Back pain is one of the most common indispositions during the post-operative period. Many causes may be attributed to post-operative Back pain. A few of them maybe ACT during a medical procedure, length of medical procedure, a span of immobilization, and exacerbation of existing ailment. The study aims to assess the effectiveness of lumbar support on Backache among post-operative patients. A quantitative approach with the quasi-experimental design was chosen to evaluate the effectiveness of lumbar support on Backache among the post-operative patients at Saveetha Medical College Hospital. Sixty patients who fulfilled the inclusive criteria were selected by purposive sampling technique. Sociodemographic variables of samples were collected by interviewing them. The Numerical pain Rating Scale assessed the Backache. The study findings revealed were recorded. The present study findings depict that in the pre-test of the experimental group majority of them had severe pain, 68%.In contrast, in the post-test the pain level reduced from moderate to mild due to lumbar support among post-operative patients. In the control group, most of them had severe pain 62%, whereas, in the post-test, 52% had moderate level pain. The mean and standard deviation of the effectiveness of lumbar support on Backache among post-operative patients in the experimental group mean is 3.2. The standard deviation of 3.34 w-0, the mean difference is -2.87 z value is -4.7821. The investigation results delineated that there was an association between the degree of back pain and history of back pain among the experimental and the control group patients with p< 0.05.

The Effect of Lumbar Support on Lower Back Pain in Ojek Online Drivers in Solo Indonesia

Online motorcycle taxi drivers (Ojek Online) work long hours driving motorbikes. the driver experiences low back pain. The use of elastic lumbar support when driving is expected to reduce pain when sitting too long in a two-wheeled vehicle and when lifting weights. Therefore, the authors are interested in conducting research on the effect of use of lumbar support on lower back pain in ojek online drivers.. This type of qualitative research is quasi-experimental with one group pretest-posttest design test approach. This research will be conducted at the online motorcyclist basecamp of Solo, Central Java, Indonesia in February to March 2020. The sample used in this study is 80 people with back discomfort due to pain when sitting while riding a two-wheeled vehicle on a motorcycle taxi driver online that fulfills inclusion and exclusion. The measurement tool used is Visual Analog Scale. Normality test data used Normality test using Kolmogorov-Smirnov. Hypothesis testing in this study uses Wilcoxon on the value of the degree of pain at the beginning and at the end of the study. The results of the study are that there is an influence of the use of lumbar corset on online back pain of motorcycle taxi drivers online. There is a decrease in low back pain to the online motorbike driver after being treated with elastic lumbar support