The influence of a seated break on prolonged standing induced low back pain development

With the recent attention to ‘sitting disease’, health practitioners and scientists are promoting standing in the workplace to decrease sedentary time, despite a high prevalence of low back pain (LBP) development during prolonged standing. The purpose of this study was to assess how a seated break inserted between bouts of prolonged standing would influence LBP development, posture and movement. A total of 20 participants stood for 45 minutes, sat for 15 minutes and repeated this sequence while lumbar and thoracic angles were measured, and LBP visual analogue scale reports were taken. Of the sample, 55% participants reported LBP in standing. A stand to sit ratio of 3:1 did not provide lasting recovery of LBP from standing and pain developers utilised a limited range of their lumbar spine angle and increased thoracic extension, resulting in static postures that caused tissue aggravation that was not resolved after 15 minutes of sitting. Prolonged standing in the workplace has the potential to result in LBP for some workers and alternate ways to reduce sedentary time should be investigated.     

Repeatability of stature measurements in individuals with and without chronic low-back pain

Measurements of reduction in stature have been used to compare spinal loading in chronic low-back pain (CLBP) and asymptomatic populations. Whether there are any differences in the repeatability of stature measurements, between those with and without CLBP, is not known. This investigation aimed to determine the repeatability of stature measurements in those with (n = 12) and without (n = 12) CLBP, and to establish if the ability to produce repeatable measurements is retained after a specific timeframe. Stature measurements were taken on two separate sessions that were 2 weeks apart, using a stadiometer accurate to 0.01 mm. All participants attained a mean SD of < or = 0.5 mm by the third measurement set taken on the first session of testing and no significant difference in mean SD was found between those with (0.37 mm) and without (0.40 mm) CLBP (p > 0.05). Intraclass correlation coefficients (ICC) demonstrated good levels of repeatability for all stature measurements obtained from the participants and the values for Standard error of the measurement (SEM) improved as the mean SD decreased with each measurement set. Investigators should have confidence in the ability of those with and without CLBP to produce equally repeatable stature measurements with appropriate prior practice. The second session of testing demonstrated that both groups had retained the ability to achieve the desired level of repeatability (SD < or = 0.5 mm) 2 weeks later without further practice.     

The immediate effect of the abdominal drawing-in maneuver technique on stature change in seated sedentary workers with chronic low back pain

Abstract

Many studies have measured stature change arising from loads imposed on the spine during sitting. To improve stature recovery, it is important to stabilise the lumbar spine and compensate forces from the upper body. The abdominal drawing-in maneuver (ADIM) technique has been found to mainly activate deep trunk muscles. The purpose of this study was to determine whether activation of deep trunk muscles by the ADIM technique could immediately improve stature recovery during prolonged sitting. Twenty-four patients with chronic low back pain (CLBP) were randomly allocated into different orders of experimental conditions: control (sitting without ADIM technique) and intervention conditions (sitting with ADIM technique). The latter condition required participants to complete ADIM technique for 1?min and repeat it three times throughout 41?min prolonged sitting time. Stature recovery was improved by 3.292?mm in the intervention condition compared with control condition (p-value = 0.001). Our finding demonstrated that ADIM technique improved stature recovery.

Practitioner Summary: Prolonged sitting seemingly harms sedentary workers’ health, particularly affecting the lower back. Activation of deep trunk muscles using abdominal drawing-in maneuver technique can promote spinal recovery. Clinicians can teach abdominal drawing-in maneuver technique to activate deep trunk muscles in chronic low back pain, thereby promoting self-management of seated stature recovery.

Abbrevations: ADIM: abdominal drawing-in maneuver; RA: rectus abdominis; ICLT: iliocostalis lumborum pars thoracis; LM: lumbar multifidus; TrA: transversus abdominis; IO: internal oblique; CLBP: chronic low back pain; LBP: low back pain; RMDQ: Roland Morris disability questionnaire; NRS: numerical rating scale.     

Estimating physical working capacity and training changes in the elderly at the fatigue threshold (PWCft)

The test for estimating physical working capacity at the fatigue threshold (PWCft), previously validated for young men, was evaluated for use with elderly men and women. A sample of 27 volunteer subjects (67.6 +/- 5.6 years, 11 male, 16 female) was divided into three matched groups: (1) controls (n = 10), (2) low intensity (70% PWCft) training group (n = 10) and (3) high intensity (85% PWCft) training group (n = 7). The subjects were tested for PWCft before and after 10 weeks of exercise training on cycle ergometers (30 min/day, 3 days/week). Controls did not exercise but met once a week for a health lecture. No significant pre-test to post-test change was noted in the mean PWCft of the control group (78.8-78.5 W); low intensity training resulted in 29.8% improvement in PWCft (81.0 to 105.0 W); and the high intensity group realized an improvement of 38.4% (83.6-115.7 W). One-way ANOVA indicated that the gains made by each of the groups were significantly different (p less than 0.01). Post hoc analysis revealed that the gains made by each exercise training group were significantly greater than controls (p less than 0.05) with no significant difference between high and low intensity groups. Reproducibility of the PWCft was excellent (R = 0.976). Since RPE averaged 14.2 at PWCft and 64% of subjects provided useful data, this test appears to be useful for evaluating the fitness of the elderly.     

Preparation of dynamic posture and occurrence of low back pain.

Improper posture is considered as one of the causes for low back pain. This study focused attention on low back pain that occurs when people adopt a dynamic posture. Low back pain in attendants was investigated as a typical example of low back pain in a dynamic posture. When multi-dimensional quantification III was applied to the results of the investigation, low back pain was found to occur in six postural patterns: bending knee posture, the posture of lifting and holding a light object, the posture of tilting the trunk, working posture to push a cart, the posture of turning or lifting a cart, and the posture of stretching. This survey found that low back pain frequently occurred when an unexpected load was imposed on the lumbar region and experiments were conducted to simulate the unexpected loading of this region. The experimental results showed that lumbar muscular activity was not fast enough to cope with the load and resulted in an increased swaying of the trunk. This swaying was considered to induce a load on the lumbar region. It is concluded that low back pain can be prevented if an appropriate preparatory set is taken.     

Preparation of dynamic posture and occurrence of low back pain

Abstract

Improper posture is considered as one of the causes for low back pain. This study focused attention on low back pain that occurs when people adopt a dynamic posture. Low back pain in attendants was investigated as a typical example of low back pain in a dynamic posture. When multi-dimensional quantification III was applied to the results of the investigation, low back pain was found to occur in six postural patterns: bending knee posture, the posture of lifting and holding a light object, the posture of tilting the trunk, working posture to push a cart, the posture of turning or lifting a cart, and the posture of stretching. This survey found that low back pain frequently occurred when an unexpected load was imposed on the lumbar region and experiments were conducted to simulate the unexpected loading of this region. The experimental results showed that lumbar muscular activity was not fast enough to cope with the load and resulted in an increased swaying of the trunk. This swaying was considered to induce a load on the lumbar region. It is concluded that low back pain can be prevented if an appropriate preparatory set is taken.     

Ergonomie guidelines for the prevention of low back pain at the workplace

The aim of this paper is to discuss the usefulness of common ergonomie guidelines for preventing low back pain at the workplace. Sixteen recent ergonomie, biomechanical and epidemiological books were reviewed to obtain common ergonomie guidelines for both static and dynamic work (e.g., sitting, lifting), and to obtain an overview of commonly-observed individual and work-related risk factors of low back pain. The results show that the aspects of work for which ergonomie guidelines are presented generally correspond to work-related risk factors as shown by epidemiological studies. However, in quantitative terms the guidelines show a great variety, possibly due to differences in criteria. In certain cases, it is not clear whether or not the guidelines are based on back load or back pain data, due to lack of references. It appears that many guidelines are based upon a combination of back load criteria and other criteria, although it is unknown how these criteria are combined. Hence, many guidelines do not apply specifically to low back pain.

With certain exceptions, most guidelines do not take into account individual factors, although epidemiological studies indicate that several factors such as age, strength, fitness, psychosocial factors, and history of back pain should be considered. However, because of the qualitative character of most current epidemiological studies, results cannot be readily implemented into quantitative ergonomie guidelines.

The above general results are discussed with examples. It is concluded that there is a great need for ergonomie guidelines that apply specifically to low back pain, and for quantitative epidemiological data on which these guidelines may be based.     

The influence of occupation on lumbar sagittal motion and posture

The aim of this study was to determine whether sheep shearers have clinically hypothesized adaptive postural and sagittal mobility parameters of the lumbar spine and pelvis. Sixty-four shearers and 64 non-shearers, matched by age and anthropometry and surveyed for present and previous low back pain, participated in a study to determine the effects of occupation on sagittal spinal motion and posture. Lumbar and hip mobility measurements were made with a geometric CAD analysis of lateral photographs using surface reflective markers. Sagittal range of motion demonstrated similar ranges of lumbar flexion between the two groups; however, there was a marked gain in hip flexion in the shearers as well as a marked loss of lumbar extension. The shearers also demonstrated a more lordotic lower lumbar curvature compensated by a flatter (less kyphotic) mid to lower thoracic region. Shearers appear to lose lumbar extension, gain hip flexion and develop an adaptive normal stance. This adaptation appears to be independent of previous or current back pain. Conversely, lumbar extension loss in non-shearers correlates with previous back injury. A stepwise linear regression of all participants indicated that the occupation is the predominant influence on motion and posture followed by age. The implications are one of structural adaptation in this occupational group that does not appear to be correlated with back pain.     

The influence of occupation on lumbar sagittal motion and posture

The aim of this study was to determine whether sheep shearers have clinically hypothesized adaptive postural and sagittal mobility parameters of the lumbar spine and pelvis. Sixty-four shearers and 64 non-shearers, matched by age and anthropometry and surveyed for present and previous low back pain, participated in a study to determine the effects of occupation on sagittal spinal motion and posture. Lumbar and hip mobility measurements were made with a geometric CAD analysis of lateral photographs using surface reflective markers. Sagittal range of motion demonstrated similar ranges of lumbar flexion between the two groups; however, there was a marked gain in hip flexion in the shearers as well as a marked loss of lumbar extension. The shearers also demonstrated a more lordotic lower lumbar curvature compensated by a flatter (less kyphotic) mid to lower thoracic region. Shearers appear to lose lumbar extension, gain hip flexion and develop an adaptive normal stance. This adaptation appears to be independent of previous or current back pain. Conversely, lumbar extension loss in non-shearers correlates with previous back injury. A stepwise linear regression of all participants indicated that the occupation is the predominant influence on motion and posture followed by age. The implications are one of structural adaptation in this occupational group that does not appear to be correlated with back pain.     

Effects of seated lumbar extension postures on spinal height and lumbar range of motion during prolonged sitting

Prolonged sitting during sedentary work has been reported as a potential risk factor for low back pain. Furthermore, prolonged sitting can result in both reduced spinal height (SH) and lumbar range of motion (LROM). This study compared the effects of no intervention (control) with two recovery postures on SH and LROM (flexion and extension) during prolonged sitting. Twenty-four participants were randomly assigned to three interventions for three consecutive days. The interventions comprised two seated lumbar extension recovery postures (unsupported sustained and supported dynamic lumbar extension postures) and a control. Both interventions facilitated a relatively short recovery period for both SH and LROM. Supported dynamic lumbar extension conditions significantly helped SH recovery, as compared with control condition, after the first recovery posture intervention, and both postures have potential to maintain LROM. However, both postures failed to induce SH recovery over an extended time.     

Massed versus distributed wordprocessor training

Two groups of subjects were trained on 12 basic word processing (WP) functions. One group was trained in a 'massed' 60-minute session and the other on a 'distributed' schedule of 60 min in two sessions separated by a ten-minute break. Subjects were tested on speed and accuracy immediately after training, and one week later to measure retention. It was found that the distributed training group performed significantly faster and more accurately than the massed group. This result was obtained at the end of the training period and also on the retention test. The results strongly indicate that a session of 60 min is too long for efficient WP training.     

Effects of intermittent hypoxic training on aerobic and anaerobic performance

The aim of the present study was to determine whether short-term intermittent hypoxic training would enhance sea level aerobic and anaerobic performance over and above that occurring with equivalent sea level training. Over a 4-week period, two groups of eight moderately trained team sports players performed 30 min of cycling exercise three times per week. One group trained in normobaric hypoxia at a simulated altitude of 2750 m (F(I)O2= 0.15), the other group trained in a laboratory under sea level conditions. Each training session consisted of ten 1-min bouts at 80% maximum workload maintained for 2 min (Wmax) during the incremental exercise test at sea level separated by 2-min active recovery at 50% Wmax. Training intensities were increased by 5% after six training sessions and by a further 5% (of original Wmax) after nine sessions. Pre-training assessments of VO(2max), power output at onset of 4 mM blood lactate accumulation (OBLA), Wmax and Wingate anaerobic performance were performed on a cycle ergometer at sea level and repeated 4-7 d following the training intervention. Following training there were significant increases (p < 0.01) in VO(2max) (7.2 vs. 8.0%), Wmax (15.5 vs. 17.8%), OBLA (11.1 vs. 11.9%), mean power (8.0 vs. 6.5%) and peak power (2.9 vs. 9.3%) in both the hypoxic and normoxic groups respectively. There were no significant differences between the increases in any of the above-mentioned performance parameters in either training environment (p > 0.05). In addition, neither haemoglobin concentration nor haematocrit were significantly changed in either group (p > 0.05). It is concluded that acute exposure of moderately trained subjects to normobaric hypoxia during a short-term training programme consisting of moderate- to high-intensity intermittent exercise has no enhanced effect on the degree of improvement in either aerobic or anaerobic performance. These data suggest that if there are any advantages to training in hypoxia for sea level performance, they would not arise from the short-term protocol employed in the present study.     

Back pain in the nursing profession II. The effectiveness of training

Abstract

The role of training in techniques of patient handling with respect to control of the back pain problem within the nursing profession has been examined. An evaluation of some of the methods commonly taught and the ability and time required to acquire such skills have been investigated. In relation to the use of four existing techniques carried out by eight student nurses on a 53 kg subject, it has been shown that the shoulder (Australian) lift produces least stress, as assessed through intraabdominal pressure (IAP). Subjective measures of comfort have shown that the nurses found the shoulder and orthodox lifts more comfortable. No differences were found between techniques for the ‘patient’ comfort ratings. A pilot investigation of training for eight handling procedures has suggested that little improvement, as assessed by IAP, has occurred throughout the trial or at a follow-up session. In many instances a decrement of performance has been observed. Further epidemiology has been presented which shows no relationship between the time spent training in such techniques and subsequent point prevalence of back pain. The current emphasis on training has been questioned and the need for controlled prospective trials is stressed. An approach requiring the development of intrinsically safe systems of work, with particular emphasis on the contribution of ergonomics, has been advanced.     

Impact of observers' experience and training on reliability of observations for a manual handling task

Observation reliability (agreement percentage and kappa coefficients) for six experienced ergonomists and six untrained participants was computed. Participants were first tested after a training session and 1 week later after an additional practice session. Two formats were used: free practice and directed exercise. Reliability was tested for 17 variables and 20 sequences using photographic and video supports. The participants were asked to indicate whether they were confident about their answer, to rate this confidence on a scale of 1 to 10, and when the confidence rating was below 8, to provide a reason for this. Experience and additional practices had no clear impact on reliability, which was excellent overall. The main reason given was that the event to be observed took place at the borderline between two classes. The observers' rating on the scale appeared to be tied to the subsequent reliability computed. The use of a confidence scale appeared to be a useful tool for forecasting observation problems.     

Research to reality: a critical review of the validity of various criteria for the prevention of occupationally induced low back pain disability

Criteria have been suggested to reduce the incidence, or severity of low back pain disability. Five underlying theories for such criteria have been identified in the literature, and a critical review of the validity of these criteria has been carried out. Despite attributions elsewhere, peer-reviewed validation of the various criteria range from modest to nil. The need for a validation criterion for use in workplace design in order to reduce low back pain disability, or severity, is identified and the need for an international protocol to allow cross-study validation of present and future criteria is suggested.     

Impact of observers' experience and training on reliability of observations for a manual handling task

Observation reliability (agreement percentage and kappa coefficients) for six experienced ergonomists and six untrained participants was computed. Participants were first tested after a training session and 1 week later after an additional practice session. Two formats were used: free practice and directed exercise. Reliability was tested for 17 variables and 20 sequences using photographic and video supports. The participants were asked to indicate whether they were confident about their answer, to rate this confidence on a scale of 1 to 10, and when the confidence rating was below 8, to provide a reason for this. Experience and additional practices had no clear impact on reliability, which was excellent overall. The main reason given was that the event to be observed took place at the borderline between two classes. The observers' rating on the scale appeared to be tied to the subsequent reliability computed. The use of a confidence scale appeared to be a useful tool for forecasting observation problems.     

Recurrent non-specific low-back pain in adolescents: the role of exercise

This study evaluated the efficacy of an exercise programme as an intervention for recurrent non-specific low-back pain (NLSBP) in adolescents. A randomized controlled trial was conducted with an experimental group (n = 27, age 14.6 years) who participated in an 8-week exercise programme and a matched control group (n = 27, age 14.6 years) who continued normal daily activities. All participants suffered from recurrent NSLBP. Pre and post intervention measures of NSLBP status (pain severity and consequences) and daily inactivity (time spent sitting, PC time, TV time) were reported in one week diaries. Two-way mixed ANOVA (independent variables: pre/post and experimental/control) was conducted for each dependent variable, significance was set at P < 0.05. Significant interaction effects were identified for the severity of pain, number of occasions missing sport due to NSLBP and amount of sport participated in. In each case the experimental group benefited from the exercise programme. In contrast, no significant interaction effects were observed for physical inactivity, both groups spent a similar amount of time sitting, watching TV and using a PC pre- and post- intervention. It was concluded that an exercise programme acted as an effective short-term treatment strategy for NSLBP in adolescents. Further evaluation is required to assess the long-term effectiveness.     

The effect of feedback training on lumbosacral compression during simulated occupational lifting

This study measured the effect of a feedback training program on lumbar compression during simulated occupational lifting. Two distinct types of feedback were compared: real-time electromyographic feedback, vs. an acceleration index delivered verbally post-lift. Kinematic data were collected from 28 subjects during symmetrical sagittal plane lifts. Following a baseline session, two feedback training sessions were provided, with a 1-week interval between each session. A control group followed the same protocols, but without receiving feedback training. A post-training session, using protocols identical to the baseline session, was used to assess pre-to-post changes in the dependent variable: peak lumbosacral compression computed using a dynamic linked-segment model. All three groups showed reductions in peak compression from pre-to-post: on average the control group improved by 11.2%, the EMG group by 16.7%, and the acceleration group by 25.3%. The results revealed an interaction between the improvement and the group (p=0.023), and a difference between the improvement in the control group and that in the verbal acceleration feedback group (p<0.01). These reductions in lumbosacral compression persisted after a 7-day interval without feedback training, suggesting that this approach could provide sustained risk-reduction during manual materials handling.     

The effect of feedback training on lumbosacral compression during simulated occupational lifting

This study measured the effect of a feedback training program on lumbar compression during simulated occupational lifting. Two distinct types of feedback were compared: real-time electromyographic feedback, vs. an acceleration index delivered verbally post-lift. Kinematic data were collected from 28 subjects during symmetrical sagittal plane lifts. Following a baseline session, two feedback training sessions were provided, with a 1-week interval between each session. A control group followed the same protocols, but without receiving feedback training. A post-training session, using protocols identical to the baseline session, was used to assess pre-to-post changes in the dependent variable: peak lumbosacral compression computed using a dynamic linked-segment model. All three groups showed reductions in peak compression from pre-to-post: on average the control group improved by 11.2%, the EMG group by 16.7%, and the acceleration group by 25.3%. The results revealed an interaction between the improvement and the group (p?=?0.023), and a difference between the improvement in the control group and that in the verbal acceleration feedback group (p?<?0.01). These reductions in lumbosacral compression persisted after a 7-day interval without feedback training, suggesting that this approach could provide sustained risk-reduction during manual materials handling.