ArticlePDF AvailableLiterature Review

Abstract

Many occupations require standing for extended periods of time, resulting in complaints of musculoskeletal fatigue and pain. One intervention method to reduce this problem has been to alter the flooring on which workers stand by using "antifatigue" mats. This article reviews the published research on the influence of flooring on people during long-term standing. Most studies have used subjective ratings of fatigue and discomfort experienced while standing in controlled laboratory settings. Some have included objective measures, such as electromyography, leg volume changes, and postural movements. Studies in the literature report mixed and sometimes conflicting results. There are methodological differences across the studies that could have led to many of the conflicting results, with the foremost variable being duration of testing. Generally, softer floors result in reduced discomfort as compared with a hard floor, particularly for the lower extremities and the lower back. Objective measures have been less conclusive, with no consensus about the influence of flooring on any physiological or biomechanical measures. Investigations of the influence of flooring characteristics on discomfort suggest that elasticity, stiffness, and thickness play roles. Further research is needed on underlying physiological causes of standing discomfort and fatigue as well as the influence of flooring properties on subjective and objective measures.
... Injuries from prolonged exposure to standing or walking at work contribute to $4.2 billion in worker compensation costs in the United States in 2011 (NSC, 2015). These injuries encompass lower extremity and low back pain, degenerative joint damage including osteoarthritis, muscle injury, and circulatory diseases (Cham and Redfern, 2001;Halim and Omar 2011;Halim et al., 2012;Macfarlane et al., 1997;Meijsen and Knibbe, 2007;Na et al., 2011;Redfern and Cham, 2000;Tomei et al., 1999). ...
... The effect of prolonged standing, standing for greater than 20 minutes, has been evaluated using subjective and objective measures of discomfort and fatigue. Consistent reports of increased subjective discomfort over time in the low back, legs and feet have been found during prolonged standing, (Cham and Redfern, 2001;Halim et al., 2012;Hansen et al., 1998;Redfern and Cham, 2000). Objective measures of muscle fatigue and swelling have been used in an attempt to explain this discomfort. ...
... Objective measures of muscle fatigue and swelling have been used in an attempt to explain this discomfort. Unfortunately, the results are inconsistent with some finding changes in muscle fatigue and leg swelling after varying periods of time and others reporting no change (Coenen et al., 2017;Halim et al., 2012;Redfern and Cham, 2000). Halim et al. (2012) found muscle fatigue, measured as median power frequency, in the legs and low back developing after only 20 minutes. ...
Article
Prolonged periods of walking have been associated with musculoskeletal discomfort and injuries. Previous research has shown that muscle fatigue is related to decreases in muscle oxygenation during short term walking. The objective of the proposed research is to determine the impact of prolonged walking with intermittent standing on musculoskeletal discomfort and muscle oxygenation measures in young adults. Nine young adults walked for a period of 2 hours. Ratings of perceived discomfort were recorded using a questionnaire. Muscle oxygenation and hemoglobin levels were collected from the lower back erector spinae and soleus muscles using near infrared spectroscopy (NIRS). Subjective discomfort significantly increased throughout the 2 hours. Prolonged walking generally induced increased oxygenation of the erector spinae and soleus across walking periods, within walking periods and across standing periods. These increases were more pronounced at the beginning of the walking session and continued through the second or third periods. Erector spinae and soleus total hemoglobin increased within walking period one and two. Only the soleus total hemoglobin significantly increased after the first walking and standing periods and during all the transitions from walking to standing. Increased oxygenation and total hemoglobin during prolonged walking with intermittent standing are likely a result of the repeated dynamic contractions and exercise-induced blood volume expansion. Increased discomfort was found; however, this was not explained by detrimental changes in oxygenation or total hemoglobin.
... Les recherches sur l'influence des caractéristiques du revêtement de sol sur l'inconfort en position debout suggèrent que l'élasticité, la rigidité et l'épaisseur jouent un rôle (350). En général, il semble y avoir un effet bénéfique à avoir un sol plus souple par rapport à un sol dur sur la fatigue et l'inconfort subjectifs (350) (360). ...
Thesis
INTRODUCTION : In the military environment, the function of the foot is constrained by the daily wearing of combat boots, a veritable orthopedic brace. A significant segment of the military population reports shoe-related foot disorders and pain, but there is little research evaluating the effects of military footwear on the development of these disorders, both internationally and in the Algerian context. The main objective of this work was to evaluate the effects of regular wearing of Rangers type military footwear on the soldier's foot, by studying the incidence of musculoskeletal and skin disorders affecting the ankle-foot complex during a 12-month follow-up period, and by comparing foot health status before and after wearing military footwear. SUBJECTS AND METHODS : This is a prospective study of the longitudinal type on a population of young male adults following their training in a military school in the south-east of Algeria. These new recruits were observed for a period of twelve months with regular wearing of Rangers type military footwear. This follow-up period extends from T0 to T12 knowing that T0 corresponds to the date of incorporation, and T12 corresponds to twelve months after the start of military training. During this period, we recorded all the cases consulting for a problem of the foot or the ankle, on a register created especially for this purpose. Foot status was analyzed at T0 and at T12 using three evaluation methods : clinical, podoscopic and functional. The footprint taken by the electronic podoscope was analyzed by calculating the Chippaux Smirak Index (CSI) and measuring the Alpha angle (α) of hallux valgus and the Beta angle (ß) of quintus varus of the two feet. To assess the functional impact, we opted for the use of the scale "Lower Extremity Functional Scale" in its Arabic version (LEFS-Ar). Furthermore, a comparative analysis before after wearing the shoe was carried out for the different parameters studied. RESULTS : 426 soldiers are participating in this study, of which 384 have completed all stages of the protocol. In this young adult population (mean age = 19.5 ± 0.89 years), the cumulative incidence of all foot and ankle disorders was estimated at 80.5%. The incidence of musculoskeletal disorders is higher than that of dermatological disorders (64.6% versus 38.5%). The main risk factors retained are footwear mismatch, obesity, lower limb misalignments, lower limb previous injuries, and anatomical shape of the foot. Abstract The comparison of foot statue before and after wearing combat boots (T0/T12) showed a significant upward trend in the prevalence of the majority of foot disorders. This difference concerns the musculoskeletal disorders such as hallux valgus, quintus varus, claw toes and overlapping toes, and the dermatological disorders such as corns, calluses, blisters, wounds, and onychodystrophies. Comparative analysis of the T0/T12 footprint indicates a significant increase in the CSI (p < 0.001), the Alpha angle (α) of hallux valgus on the left foot (p < 0.005), and the Beta angle (ß) quintus varus on both feet (p < 0.001). Regarding the evolution of the functional state from T0 to T12, we observe a very significant regression (p < 0.005) in the LEFS-Ar score. DISCUSSION & CONCLUSION: These results confirm that podiatric disorders remain fairly common among military personnel. Its frequency seems to worsen with the wearing of Rangers type military footwear. These epidemiological data, obtained in a completely original way, can help in the planning of future prevention interventions. Keywords: Military footwear, foot deformities, musculoskeletal disorders, footprint, Chippaux Smirak Index, Lower Extremity Functional Scale, Algeria
... Como forma de amenizar/prevenir as sobrecargas e adoecimento no ambiente de trabalho os tapetes anti-fadigas têm sido utilizados como alternativa para promover a redução do desconforto músculo-esquelético percebido nos membros inferiores (MMII) e parte inferior das costas na postura de pé no trabalho (SPEED; HARRIS; KEEGEL, 2018, p. 3-14). No entanto, embora as medidas subjetivas indiquem que os tapetes proporcionam menor desconforto do que as superfícies duras, ao atentar para as medidas objetivas a literatura existente é inconclusiva sobre a eficácia do uso dos tapetes anti-fadiga e não foi encontrada diferença significativa entre os modelos comercializados que foram analisados, fato esse que pode ser explicado justamente pelos estudos utilizarem apenas a avaliação subjetiva da dor/desconforto e metodologias heterogêneas (WIGGERMAN; KEYSERLING, 2010, p. 785-786;REDFERN;CHAM, 2000, p. 9-11). ...
Article
Full-text available
Resumo Introdução: Na tentativa de minimizar as implicações negativas da permanência na posição de pé no local de trabalho industrial, tapetes anti-fadigas estão sendo utilizados, no entanto a literatura é inconclusiva quanto à eficácia dos tapetes ao utilizar medidas objetivas. Objetivo: Avaliar o uso de tapetes anti-fadiga na redução da dor na região lombar e nos membros inferiores e edema em trabalhadores da linha de produção. Materiais e Métodos: Os participantes passaram pelas etapas de coleta de informações pessoais e de saúde ocupacional; identificar intensidade da dor pela EVA; medição do limiar de dor à pressão pela algometria; medida da circunferência da panturrilha direita; resposta ao questionário de usabilidade dos tapetes. A coleta de dados ocorreu em quatro dias pré e pós jornada de trabalho para analisar as respostas nas diferentes superfícies estudadas. Foi ralizado o teste t de Student e o Teste de Wilcoxon e o nível de significância de 0,05. Resultados: Dentre os 15 participantes diferenças estatisticamente significativas foram encontradas na algometria e na perimetria, o que configura os tapetes antifadiga como eficazes na redução da dor e edema de MMII ao avaliar de forma objetiva. Já na EVA, embora os tapetes não apresentaram diferenças estatisticamente significativas na redução da dor, impossibilitaram o aumento do nível da dor semelhante ao observado nas superfícies rígidas. Os trabalhadores aprovaram o uso dos tapetes antifadiga. Conclusão: Os resultados objetivos e subjetivos foram positivos para o uso dos tapetes antifadiga a fim de evitar as repercussões negativas relacionada a dor e edema oriundas da posição ortostática estática no trabalho. Estudos que avaliem a eficácia dos tapetes a longo prazo e comparem com outras intervenções são necessários.
... Como forma de amenizar/prevenir as sobrecargas e adoecimento no ambiente de trabalho os tapetes anti-fadigas têm sido utilizados como alternativa para promover a redução do desconforto músculo-esquelético percebido nos membros inferiores (MMII) e parte inferior das costas na postura de pé no trabalho (SPEED; HARRIS; KEEGEL, 2018, p. 3-14). No entanto, embora as medidas subjetivas indiquem que os tapetes proporcionam menor desconforto do que as superfícies duras, ao atentar para as medidas objetivas a literatura existente é inconclusiva sobre a eficácia do uso dos tapetes anti-fadiga e não foi encontrada diferença significativa entre os modelos comercializados que foram analisados, fato esse que pode ser explicado justamente pelos estudos utilizarem apenas a avaliação subjetiva da dor/desconforto e metodologias heterogêneas (WIGGERMAN; KEYSERLING, 2010, p. 785-786;REDFERN;CHAM, 2000, p. 9-11). ...
Article
Resumo Introdução: Na tentativa de minimizar as implicações negativas da permanência na posição de pé no local de trabalho industrial, tapetes anti-fadigas estão sendo utilizados, no entanto a literatura é inconclusiva quanto à eficácia dos tapetes ao utilizar medidas objetivas. Objetivo: Avaliar o uso de tapetes anti-fadiga na redução da dor na região lombar e nos membros inferiores e edema em trabalhadores da linha de produção. Materiais e Métodos: Os participantes passaram pelas etapas de coleta de informações pessoais e de saúde ocupacional; identificar intensidade da dor pela EVA; medição do limiar de dor à pressão pela algometria; medida da circunferência da panturrilha direita; resposta ao questionário de usabilidade dos tapetes. A coleta de dados ocorreu em quatro dias pré e pós jornada de trabalho para analisar as respostas nas diferentes superfícies estudadas. Foi ralizado o teste t de Student e o Teste de Wilcoxon e o nível de significância de 0,05. Resultados: Dentre os 15 participantes diferenças estatisticamente significativas foram encontradas na algometria e na perimetria, o que configura os tapetes antifadiga como eficazes na redução da dor e edema de MMII ao avaliar de forma objetiva. Já na EVA, embora os tapetes não apresentaram diferenças estatisticamente significativas na redução da dor, impossibilitaram o aumento do nível da dor semelhante ao observado nas superfícies rígidas. Os trabalhadores aprovaram o uso dos tapetes antifadiga. Conclusão: Os resultados objetivos e subjetivos foram positivos para o uso dos tapetes antifadiga a fim de evitar as repercussões negativas relacionada a dor e edema oriundas da posição ortostática estática no trabalho. Estudos que avaliem a eficácia dos tapetes a longo prazo e comparem com outras intervenções são necessários.
... Workers across a variety of occupations are often required to stand for extended periods, including those in the manufacturing, retail, healthcare, and service industries (Redfern and Cham 2000;Coenen et al. 2017;Bureau of Labor Statistics 2021). According to an occupational requirements survey conducted by the US Department of Labour (Bureau of Labor Statistics 2021), civilian workers, on average, spend 57.3% of the workday standing. ...
Article
This study aimed to determine the effects of inflatable mat design on body discomfort, task performance, and musculoskeletal exposures during standing computer work. Twenty-seven healthy adults completed three 2-hour standing trials on different mediums (concrete floor, foam mat, and inflatable mat) on different days in an experimental laboratory. Both mats were associated with reduced discomfort in all lower-body regions and increased typing performance compared to the concrete floor. Perceived discomfort in lower extremities (except thighs) was further alleviated while standing on the inflatable mat than on the foam mat. Use of the inflatable mat led to increased lower-body muscle activity, a flexed lower back, and a wide range of sagittal knee movements. As standing time increased, body discomfort increased, typing accuracy decreased, and there were increased variations in muscle activity and postural movements in the lower body. The inflatable mat shows potential to improve the ergonomic experience during prolonged standing. Practitioner summary: Incorporating standing postures in office-based workplaces can reduce sitting time and may mitigate the health hazards associated with sedentary behaviour. With adequate weight-shifting movements, using an inflatable mat for standing could be an effective way to lessen discomfort and accumulated musculoskeletal strain due to constrained standing, without jeopardising task productivity. Abbreviations: APDF: amplitude probability distribution function. AVR: average rectified value. CI: confidence interval. CMRR: common mode rejection ratio. COP: center of pressure. CV: coefficient of variation. EA: electrical activity. EMG: electromyography. FL: fibularis longus. GM: gluteus medius. LBP: lower back pain. LES: lumbar erector spinae. MVC: maximum voluntary contraction. PD: pain developer. rANOVA: repeated-measures analysis of variance. SOL: soleus. VAS: visual analog scale. WPM: words per minute
... Several studies have recommended floor mats and shoe insoles to reduce symptoms of discomfort (Cham & Redfern, 2001;King, 2002;Lin et al., 2012b;Speed et al., 2018;Waters & Dick, 2015). However, other studies have found no influence of these two interventions on physiological outcomes including the reduction of leg swelling and muscle fatigue (Brownie & Martin, 2015;Garcia et al., 2016;Redfern & Cham, 2000;Zander et al., 2004). A growing body of literature has proposed to mitigate the negative effects of standing by incorporating seated periods (Karakolis & Callaghan, 2014) and increasing dynamic standing activities such as walking (Balasubramanian et al., 2008;Garcia et al., 2020Garcia et al., , 2020. ...
Article
Full-text available
Objective The goal of this study was to evaluate and compare lower-leg muscle fatigue, edema, and discomfort induced by the prolonged standing of security guards wearing regular socks and those wearing 15–20 or 20–30 mmHg compression stockings as intervention. Background Compression stockings are somewhat used by individuals standing all day at work. However, quantitative evidence showing their potential benefits for lower-leg health issues in healthy individuals during real working conditions is lacking. Method Forty male security employees participated in the study. All were randomly assigned to the control or one of the two intervention groups (I 15–20 or I 20–30 ). Lower-leg muscle twitch force, volume, and discomfort ratings were measured before and after their regular 12-hr standing work shift. Results Significant evidence of lower-leg long-lasting muscle fatigue, edema, and discomfort was observed after standing work for guards wearing regular socks. However, no significant changes were found for guards wearing either compression stockings. Conclusion In healthy individuals, compression stockings seem to attenuate efficiently the tested outcomes in the lower leg resulting from prolonged standing. Application Occupational activities requiring prolonged standing may benefit from 15–20 or 20–30 mmHg compression stockings. As similar benefits were observed for both levels of compression, the lower level may be sufficient.
... Prolonged standing required for certain procedures places pressure on the spine and can create discomfort. Redfern et al. demonstrated that creating a soft interface between the feet and the hard floor results in reduced back and leg pain [27]. The use of cushion support under the feet has also been found to lead to subtle movement that facilitates blood flow to the muscles [28]. ...
Article
Strain and injury related to endoscopy are frequently reported. Recent studies have shown that female gender may be independently associated with musculoskeletal injury (MSI). Incorporation of ergonomic principles into endoscopic practice helps to prevent MSI caused by sustained high force exertion, awkward postures and repetitive motion. The strategies that can be implemented in the endoscopy unit to minimize injury risk and create a safe environment include: ergonomic endoscope instrument redesign, integrating adjustable elements into the endoscopy suite, providing supportive equipment, and implementing an ergonomic checklist and time out into the work flow. Additionally, an ergonomic approach to endoscopy while pregnant can help address new musculoskeletal challenges. This article reviews ergonomic issues arising in endoscopy with a focus on women in the field.
... the low back and lower extremity are strongly associated with prolonged standing exposures common to manufacturing, retail, operative medicine, and hospitality industries (Garcia et al., 2015;Redfern & Cham, 2000). In such contexts, antifatigue flooring is a common engineering control that replaces nondeformable flooring with a compliant flooring surface. ...
Article
This study quantified the effect of compression load and duration on the deflection of five separate anti-fatigue flooring surfaces. Following standardized measurement of A Shore hardness, each sample underwent simulated single-leg stance indentation procedures that differed by compression load (45.3 kg, 90.7 kg, 136.1 kg) and duration (initial = 2.5s, intermediate = 6.25s, final = 12.5s). Vertical deflection was compared across conditions, and the relationship between A Shore hardness and deflection was characterized. When compressed with 45.3 kg, deflection was not influenced by duration, but at 136 kg, deflection differed between durations by up to 15%. The relationship between A Shore hardness and deflection was characterized by a third order polynomial function (R2 > 0.991).
... Though Prado et al. (2011) also identified a small amplitude weight transfer, only PWT with amplitudes greater than 0.5 Â bodyweight are considered in the present analysis. The variety of methods for obtaining and presenting information on bodyweight distribution changes during prolonged standing makes it difficult to compare across studies (Redfern & Cham, 2000), compare between subjects (Prado et al., 2011), and most importantly, contextualize physiologically in terms of injury risk and prevention. ...
Article
Occupational Applications: Prolonged standing, often required in health care, factory, and retail jobs, is associated with adverse health effects. In the present study, we introduce a novel method for analyzing prolonged-standing data, which accounts for time-dependent strain characteristics of both cartilage and muscle tissue to identify two different types of weight distribution change events. Compared to existing methods for analyzing this type of data, our proposed method provides more information about the amplitude and temporal quality of the movements occurring. If a worker were to stand on a surface that measures postural sway during a typical work day, this analysis method could identify the types of movements an individual makes, and help infer sources of discomfort. By understanding the movement strategy utilized, the most appropriate work environment adaptations can be put into place to decrease discomfort. These environmental adaptations may have downstream effects on worker satisfaction and days on disability. Technical Abstract: Background: The typical American worker spends about two-thirds of their work day standing. Prolonged standing has been found to be associated with acute and chronic adverse health outcomes. There is considerable variability among existing methods of analysis for prolonged-standing data, and therefore difficulty interpreting and comparing results across studies. Purpose: The purpose of this study is to develop a bodyweight transfer analysis method that incorporates factors of both time and amplitude of loading. This method was then applied to actual prolonged-standing data, to understand how the results of this method are impacted by time spent standing, and how the results relate to previously-reported methods of analysis for weight shifting data. Methods: Seven subjects (six male, one female) stood with each foot on one of two force plates for six hours with a 5-minute seated rest break between hours. Our new method identified two different types of events: fidgets and weight shifts. Center-of-pressure data were analyzed with the proposed method and three existing methods of analysis. Results: Subjects utilized different quantities of fidgets and weight shifts over the course of the trials. Existing methods of analysis identified a wide range in number of events, with some methods consistently identifying more events than others. These existing methods significantly differed from the proposed method. Fidgets, weight shifts, and fidgets + weight shifts, as identified using the proposed method, had significant interactions with time, while only one of the existing methods showed a significant time interaction. Conclusions: The conclusions drawn from analysis of prolonged center-of-pressure data can differ significantly depending on the method of analysis used. The method proposed here accounts for the different sources of discomfort and the tissue characteristics of these sources. Future work should explore the relationships between physiologic parameters and fidgets and weight shifts, so that appropriate clinical interventions can be identified.
Article
Prolonged standing is an occupational hazard that may evoke many cardiovascular problems. This study investigates the effects of anti-fatigue mats on hemoglobin levels—related to blood pooling—in the lower extremities during prolonged standing. Fifteen subjects (6 M, 9 F; Age = 26 ± 3 years; BMI = 23.2 ± 2.5 kg/m2) stood for one hour on a hard floor and anti-fatigue mat. Oxygenated (HbO), deoxygenated (HbR), and total (HbT) hemoglobin levels were measured for the soleus muscle using near infrared spectroscopy. A mixed-effects model was performed indicating that time, flooring, and their interaction effect were significantly associated with levels of HbO (time, p<0.0001; floor, p=0.0056; interaction, p=0.0033), HbR (time, p<0.0001), and HbT (time, p<0.0001; floor, p=0.0060; interaction, p=0.0062). Results indicate that hemoglobin levels change with time, and flooring has an effect. Blood pooling seems to be the mechanism. Anti-fatigue mats may have a positive effect on cardiovascular outcomes.
Article
Full-text available
This study investigated effects of flooring on perceived tiredness, fatigue, and discomfort for workers required to stand while performing their jobs. Eight flooring conditions of varying thickness and stiffness (including one shoe insert) were evaluated by workers who answered a questionnaire. Questions were asked regarding whole-body tiredness. leg fatigue. and discomfort. Flooring had a significant effect on workers' perception. In general softer materials caused less perceived tiredness; however, one extremely soft floor resulted in higher ratings of tiredness. Similar results were found for material thickness. The shoe insert condition showed low tiredness ratings as compared with most floors, including one made of the same material. The discomfort ratings indicated that harder flooring materials caused greater discomfort. Discomfort of the lower extremities tended to decrease as distance from the floor increased. Low back discomfort was found for hard flooring surfaces.
Article
Full-text available
An investigation to identify the relation between torques at hip, knee and ankle, posture holding time, and perceived discomfort was carried out. Subjects held four different extents of straight-legged forward bend as long as they could whilst reporting perceived overall and body-part discomforts at regular intervals.The results indicated that changes in postures correlated significantly with changes in holding time and in discomfort. Averaged results showed that discomfort levels in the body segment immediately superior to the joints studied were significantly related to torque at the joint. The relation was strongest for the ankle joint, where the location of the muscles producing the resisting torque could be associated most clearly with the body segment concerned.
Article
( This reprinted article originally appeared in the Journal of Experimental Psychology, 1935, Vol 18, 643–662. The following abstract of the original article appeared in PA, Vol 10:1863.) In this study pairs of conflicting stimuli, both being inherent aspects of the same symbols, were presented simultaneously (a name of one color printed in the ink of another color—a word stimulus and a color stimulus). The difference in time for reading the words printed in colors and the same words printed in black is the measure of the interference of color stimuli on reading words. The difference in the time for naming the colors in which the words are printed and the same colors printed in squares is the measure of the interference of conflicting word stimuli on naming colors. The interference of conflicting color stimuli on the time for reading 100 words (each word naming a color unlike the ink-color of its print) caused an increase of 2.3 sec or 5.6% over the normal time for reading the same words printed in black. This increase is not reliable, but the interference of conflicting word stimuli on the time for naming 100 colors (each color being the print of a word which names another color) caused an increase of 47.0 sec or 74.3% of the normal time for naming colors printed in squares.… (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Prolonged standing is common in many industrial workplaces. It is also quite common for workers to complain of discomfort in the back and legs as a result of prolonged standing. Mats are often provided for the worker to relieve this fatigue. However, there is no quantitative evidence that these mats relieve leg and back fatigue. Five subjects were asked to stand on a concrete surface and two mat surfaces for prolonged periods of time. Spectral electromyographic analyses indicated that mats reduced localized muscle fatigue in the erector spinae muscle only. Furthermore, this fatigue reduction occurred only with the more compressible of the two mats tested. These results imply that localized muscular fatigue in the leg may not be relieved with ‘anti-fatigue’ mats, and some of these mats only benefit the back.
Article
A methodological study was conducted to provide a multivariate evaluation of the foot/floor interface in constrained standing. Measures of body movement (from force platform and video recording), leg muscle EMGs, reported exertion/discomfort and task performance were taken during a two-hour task. Factor Analysis showed four major factors named Body Movement, Muscle Contraction, Perceived Fatigue and Task Errors. Most measures showed strong effects of time on task (Period Effect), indicating cumulative fatigue. Hard-soled shoes where marginally worse than soft soled shoes on a number of measures. Mat thickness had little effect. To test the methodology a commercial mat was evaluated in a separate experiment. Strong period effects were again obtained, but again the mat had little effect on any measures. Implications for a measurement methodology are discussed
Article
The Victorian Branch of the Shop Distributive and Allied Employees Association became concerned in 1985 by the large number of cases of musculo-skeletal symptoms being reported by members working in food and grocery supermarkets. With the support of the Victorian Occupational Health and Safety Commission a survey was carried out which was aimed at determining the prevalence of such symptoms, and identifying associated factors. A questionnaire designed to establish the presence of musculo-skeletal symptoms was administered to all employees of seven supermarkets ranging in size from 15 to 171 employees, with a response rate of 73%. The staff of supermarkets were predominantly young, female and transient. One-third reported regular symptoms in some part of their body. Prevalence rates were calculated for body area and department. The checkout department had the highest rates for almost all body areas. The lower back, lower limbs and feet were the body areas with the highest rates. Postures and activities of a sample of job categories in each department were sampled at 10 s intervals for periods of 30 min for a total of 1000 observations for each department. A positive and significant correlation was found between proportion of time spent standing and symptoms in the lower limb and foot, especially in the checkout department where 90% of the time was spent standing in one place. It was concluded that there was an excess of symptoms appearing in checkout operators, and therefore, the operating methods of the checkout department warrant revision.
Article
Low back pain is generally believed to be common among hospital employees. This cross-sectional, retrospective study was carried out to determine the annual incidence of low back pain ascribable to occupational injuries in hospital employees and to evaluate factors influencing the prognosis of these injuries. In 1989, 70 employees working at the Grenoble Teaching Hospital (GTH) reported an occupational injury responsible for low back pain. Each of these employees filled out an epidemiological questionnaire during a routine evaluation by a rheumatologist. Overall annual incidence of occupational injuries with subsequent low back pain was 1.9% among GTH employees. Higher incidences were seen among employees whose occupations involved patient transfer, as well as among nursing assistants. Activities associated with an increased risk of low back pain included handling of patients or objects and work requiring prolonged periods in uncomfortable positions or in the standing position. A previous history of low back disease and a longer period of time in the current work were also associated with an increased risk of low back pain. Characteristic clinical profiles of patients with low back pain subsequent to occupational injury were determined by occupation and type of hospital department. The analysis of long-duration absence from work and long-term consequences on career confirmed the significant adverse socioeconomic impact of these injuries.
Article
The purpose of this study was to determine whether or not surgical floor mats affect low back and leg muscle activity during prolonged standing. The EMG activity was measured continuously using surface electrodes on the paraspinal muscles of the low back and on the anterior tibialis muscles; the subjects were normal and stood on two different surfaces. Six male subjects were each instructed to stand for two hours on a specially designed surgical floor mat and then, on a separate day, to stand for two hours on a linoleum-covered concrete surface. Six other subjects carried out the same procedure, but stood on the linoleum first. There was no difference in EMG activity obtained from the anterior tibialis muscles and paraspinal muscles of the low back when the subjects stood on the surgical mat, as compared with the linoleum-covered concrete.