Incidence Of Low Back Injuries Research Articles

Incidence of Low Back Injuries Among Iranian Athletes in 12 Disciplines of Olympic Sports

Purpose: The present research aimed to determine the prevalence and incidence rate of low back pain and injury in 12 Olympic sports athletes presenting to the injury surveillance system of the Sports Medicine Federation of Iran. Methods: A retrospective analysis was conducted on the data of athletes from the injury surveillance system of the Sports Medicine Federation of Iran, for three years. Descriptive statistic was used for the study. Results: The incidence rate of 6.7 injuries per 10000 athletes registered was calculated for low back complaints in 12 sports disciplines. Weightlifting, wushu, and judo had the highest, and gymnastic and soccer had the lowest low back injuries incidence. More than one-third of the low back complaints involved the lumbar spine. Also, females were at higher risk of low back pain and injury than males. Of age categories, adults and elderlies had the highest prevalence of low back complaints with more involvement in the lumbar spine. Conclusion: According to the results, wushu, judo, and especially weightlifting should be the priority of prevention. Furthermore, females and elderlies require more focus on preventive measures.

Evaluation of a Harmony Search Algorithm for Manual Lifting Tasks Optimization

This paper presents near optimal solution method to find safe work place design using harmony search algorithm. Revised NIOSH equations are considered to minimize relative estimate of the physical stress associated with a manual-lifting job. The proposed algorithm will assist occupational safety and health practioners in evaluating lifting tasks and reducing the incidence of low back injuries in workers. General Terms Algorithms, Heuristics, Ergonomics, Work Design.

Outcomes of the Introduction of a Standardized Fitness-for-Duty Evaluation of Commercial Truck Drivers on the Incidence of Low Back Injuries and Workers' Compensation Costs

To determine the incidence of low back injuries and associated workers' compensation costs before and after the introduction of a standardized fitness-for-duty evaluation of commercial truck drivers who present for their comprehensive Department of Transportation (DOT) physical examination. Trained physical therapists administered questionnaires and performed functional testing of commercial truck drivers scheduled for their DOT examination. The results were communicated to providers performing DOT examinations. Incidence rates of low back injury and associated workers' compensation costs 3 years before and 3 years after the intervention (1999 to 2006) were determined. There was a 54% reduction in the low back pain incidence rate and an associated 45% reduction in workers' compensation costs from 1999 to 2006. This intervention was associated with a reduced incidence of low back injuries and reduced associated workers' compensation costs in this population.

Injury and lumbar reposition sense in cricket pace bowlers in neutral and pace bowling specific body positions

Background and contextThe cricket pace bowling action consists of a complex sequence of forceful actions, involving practiced, particular movements of the lumbar spine. The nature and repetition of the pace bowling action is known to be associated with a high incidence of low back injuries. PurposeThis study aimed to establish whether lumbar proprioception (as measured by joint position sense) in the neutral lumbar spine position as well as lumbar positions corresponding to those at front foot placement and ball release positions of the cricket pace bowling action were related to previous injury and injury sustained during the cricket season under review. Injuries specifically sustained during the bowling action and those specific to the low back were explicitly investigated. Study settingLongitudinal study with participants tested at the start and monitored over the duration of a cricket season. Participant sampleSeventeen male cricket pace bowlers between the ages of 18 and 26 years participated in this study. Outcome measuresPhysiological outcome measures were used. Lumbar position sense was established using electrogoniometry. MethodsLumbar reposition error was measured in three positions (neutral lumbar spine, front foot placement, and ball release bowling positions). In each position, lumbar orientation was determined in the sagittal (flexion-extension) and coronal (left-right lateral flexion) planes. Wilcoxon matched-pairs ranks and Kruskal-Wallis tests were used to establish the relationship between variables. ResultsReposition error was associated with general injuries sustained in the past and during the cricket season under review, low back injuries, as well as injuries sustained during the bowling action (p<.05). ConclusionLumbar position sense, as a measure of proprioception, was related to injury in general, injuries sustained during the bowling action, and, especially, low back injury sustained in the past. Low back injury prevention methods are particularly needed because of the high load nature of the pace bowling action. If the proprioception of the lumbar spine is improved in pace bowlers, their risk of lumbar injury can potentially be reduced.

Trunk muscle fatigue and its implications in EMG-assisted biomechanical modeling

Muscle fatigue affects the underlying EMG-force relationship on which EMG-assisted biomechanical models rely. The aim of this study was to evaluate the impact of short duration muscle fatigue on the muscle gain value. Participants performed controlled, isometric trunk extension exertions at 10, 20, and 30 degrees of trunk flexion and controlled isokinetic trunk extension exertions at 5 and 15°/sec on five separate days. Fatigue of the lumbar extensors was generated by moderate-intensity, trunk extension exertions. Participants performed controlled test contractions at defined intervals throughout the fatiguing bout and the EMG activities of trunk muscles were collected. These EMG data were employed in a standard EMG-assisted model and fatigue-dependent trends in the gain factor were evaluated. The results of this study show a significant effect of fatigue on the gain factor. Further analysis revealed that by reducing the magnitude of the gain factor in proportion to the drop in median frequency of the EMG signal of the fatigued muscle, a more accurate estimate of muscle force can be calculated. Mean normalized error between predicted internal moments and the measured external moments improved from 17.5 to 9.6% error via the implementation of this modified gain factor. Relevance to industryBiomechanical models are used to quantify low back stress during occupational lifting tasks. Understanding how these models need to be modified under conditions of muscular fatigue will provide more accurate estimates of stress and can help reduce the incidence of low back injury.

Lumbar position sense with extreme lumbar angle

Tasks involving flexed torso postures have a high incidence of low back injuries. Changes in the ability to sense and adequately control low back motion may play a role in these injuries. Previous studies examining position sense errors of the lumbar spine with torso flexion found significant increases in error with flexion. However, there has been little research on the effect of lumbar angle. In this study, the aim of the study was to examine how position sense errors would change with torso flexion as a function of the target lumbar angle. Fifteen healthy volunteers were asked to assume three different lumbar angles (maximum, minimum and mid-range) at three different torso flexion angles. A reposition sense protocol was used to determine a subject’s ability to reproduce the target lumbar angles. Reposition sense error was found to increase 69% with increased torso flexion for mid-range target curvatures. With increasing torso flexion, the increase in reposition sense errors suggests a reduction in sensation and control in the lumbar spine that may increase risk of injury. However, the reposition error was smaller at high torso flexion angles in the extreme target curvatures. Higher sensory feedback at extreme lumbar angles would be important in preventing over-extension or over-flexion. These results suggest that proprioceptive elements in structures engaged at limits (such as the ligaments and facet joints), may provide a role in sensing position at extreme lumbar angles. Sensory elements in the muscles crossing the joint may also provide increased feedback at the edges of the range of motion.

Lower back pain in golfers: a review of the literature

Objective To review the epidemiological literature on low back pain in golfers and to review the golf swing and relate the literature on the mechanics of the swing to the lower back. Methods A computer search was conducted of Index Medicus (1966 to 2004), MANTIS (1880 to present) and CINAHL (1982 to 2004) for literature on the following key words: low back, golf, injury. A manual search for relevant references in review papers on the subject was also conducted. The results were collated and literature fitting the criteria were collected and evaluated for suitability. Results The lower back is a common site of golf-related injury and has resulted in much research being conducted on the forces produced by the ‘modern’ swing in the low back. An analysis of the ‘modern’ swing when compared to the ‘classic’ golf swing, demonstrates lower rotational forces on the low back in the ‘classic’ swing. However, no studies exist to compare the different types of swing. Conclusion The back is an area of the body that undergoes significant movement and muscular activity during the golf swing. It is likely that the significant activity and repetitive nature of the swing are associated with the high rate of injury in golfers. Modification of the golf swing has been hypothesized to reduce the incidence of low back injury in golf. Further research needs to be conducted on the various golf swings to evaluate if different swings change low back injury rates in golfers.

Post‐offer, pre‐placement testing in industry

Pre-placement testing was implemented during World War II. Its current use has been reshaped by economic factors, litigation, legislation, and advances in medicine. In response to a request from a local industry intent upon lowering their work-related injuries, a post-offer screening program was developed and implemented. The aim of this study was to develop a testing protocol for determining physical capacity that could be adapted for a post-offer, pre-placement program. Functional capacity evaluation (FCE) testing was used to determine the physical capacity of 2,482 uninjured, healthy prospective new employees of a large food production plant. A comprehensive medical history and 20 different anthropometric, fitness, strength, and lifting tests were administered to all new hires in the first phase of this study to determine if injury incidence could be estimated through functional screening testing. The second study was designed to determine the effectiveness of the application of a post-offer, pre-placement program in an electrical equipment manufacturing facility. Strength testing alone was of no predictive value for work injury incidence. There was a strong correlation of physical capacity to physical job requirements. If an employee had the physical capability to perform the essential functions of the job, there was a lower injury rate as compared to the employee not demonstrating the physical strength or ability to perform the essential functions of the job. The incidence of low back injuries in those workers with the physical capabilities to perform the required functions of their job was 3%. However, among those workers who did not demonstrate the strength or physical abilities to perform their job, there was a 33% incidence of low back injuries. This study indicates that physical capacity testing that compares lifting ability to job lifting requirements correlates to work injury incidence. The application of appropriate post-offer, pre-placement testing is shown to be a cost-effective method to lower the incidence of work-related injuries.

Physical workload, ergonomic problems, and incidence of low back injury: A 7.5‐year prospective study of San Francisco transit operators

The etiologic role of biomechanical factors for low back injury (LBI) needs to be confirmed in prospective studies that control for psychosocial factors. Complete baseline information on 1,233 vehicle operators was gathered during medical examinations and by questionnaire. First LBI during 7.5 years of follow-up was ascertained from insurance records. Hazard ratios and etiologic fractions were analyzed with Cox regression models stratified by injury severity and controlling for age, sex, height, weight, ethnicity, and biomechanical and psychosocial job factors. Severe LBI was defined as medically diagnosed postlaminectomy syndrome, spinal stenosis, herniated lumbar disc, sciatica, or spinal instability. An exponential dose-response relationship was found between weekly driving hours and incidence of first LBI. Indicators of physical workload were more strongly associated with more severe low back injuries compared to less severe injuries. Rates of severe LBI increased 39% for every 10-hr increase in weekly driving (hazard ratio 1.39, 95% confidence interval 1.15-1.68). Higher risks of severe LBI were also found among operators performing heavy physical labor on cable cars (hazard ratio 2.76, 95% confidence intervals 1.24-6.14) or reporting more ergonomic problems at baseline (HR for upper quartile 1.65 (95% confidence interval 1.08-2.50). Estimates of etiologic fractions suggest that reduction of ergonomic problems to the low level currently experienced by 25% of drivers would result in a 19% reduction of severe LBI among all drivers. A change from full- (more than 30 hr) to part-time driving (20-30 hr) could reduce the number of severe LBI by 59%, although this gain would be reduced to 28% at the company level if injuries expected among additional employees, hired to maintain full service are included. Duration of professional driving and ergonomic problems are independent and preventable risk factors for LBI even after adjustment for psychosocial factors.

Reducing Incidence of Low-Back Injuries Reduces Cost

Reducing Incidence of Low-Back Injuries Reduces Cost

Trunk muscle activation in open stance and square stance tennis forehands.

Electromyography of the trunk muscles were compared between the open and square stance forehand drives of 14 collegiate tennis players. Surface EMG were bilaterally collected from the rectus abdominis (RA), external oblique (EO), and erector spinae (ES) in open and square stance forehand drives. EMG data were transferred by telemetry, 12 bit A/D converted at 1000 Hz, and stored for analysis. Rectified and smoothed EMG data were normalized (NEMG) to maximal isometric voluntary contractions and mean NEMG were calculated during the forward swing and follow through phases of the stroke. A 2 x 2 x 2 x 6 factorial ANOVA (Gender, Stance, Phase, Muscle) with repeated measures on Subject showed significant (p < 0.05) effects of Gender, Muscle, Phase, and several interactions. The nonsignificant differences in muscle activation between stances did not support the belief of tennis experts that open stance forehands require greater trunk activation than square stance forehands. Mean NEMG of the ES were significantly (p < 0.05) larger than EO or RA, which was consistent with observations of tennis-specific strength imbalances and increasing incidence of low back injuries in tennis.

Derivation of Reasonable Lifting Movement from Techniques Utilized in Skilled Weightlifter

The purpose of this study is to derive the reasonable lifting movement from analysis of biomechanical characteristics of the snatch, back lift (BL) and leg lift (LL) in a skilled weightlifter. During the snatch lift, the differences between skilled and unskilled lifter appear in EMG and joint torque patterns. The skilled lifter utilizes the double knee bend technique and motor unit recruitment patterns in agonist and antagonist about joint might be reasonable to lift heavy weight. The present data suggest that skilled weightlifter has acquired the higher neuromuscular performance, which is required the control among the recruited muscles with regard to the tension and the timing of the coactivation and the contraction-relaxation. From comparison of BL and LL, it is suggested that BL has higher EMG activity and produces a much higher shear force about L 5/Sl joint which induces a low back injury. In case of LL, the shear force about L 5-Sl joint depends on the lifting posture. Moreover, it is revealed that the skilled weightlifter might have a lower shear force than unskilled person. From the experimental results, it is shown that the detailed instruction about lifting posture is needed to reduce the incidence of low back injury.

The effect of a back belt on torso motion--survey in an express package delivery company.

According to the Labor Standard Bureau of Japan, accidental back injuries accounted for about 60% of all occupational injuries and diseases in the last decade. The Ministry of Labor issued guidelines to prevent low back injuries in 1994 to address the problem. The use of back belts is recommended for some special working conditions but details on its proper use were not given. This study was planned to evaluate a newly developed back belt and was done at an express package delivery company where the incidence of low back injury was high. The BackTracker was used to evaluate the effect of the back belt on the range and velocity of torso motion. The results indicated that there were no significant differences in the range of motion (ROM) during flexion/extension, lateral bending, and rotation between with and without the belt. The maximum angular velocity (MAV) of flexion decreased significantly (average decrease: 30 +/- 28.3 degrees/sec) when the back belt was worn. The MAV of extension with belt showed a decreasing tendency though not significant. No notable trends were observed in the MAV, during lateral bending and rotation of the subjects while wearing and not wearing the belt. The results also indicated that the back belt affected differently the torso motion of each subject. This study suggested that this back belt could be useful for tasks with high velocity of flexion/extension and that proper instruction on the use of the back belt is needed for each worker.

Relationship of lumbar strength in shipyard workers to workplace injury claims.

Strength testing of lumbar extensors of shipyard workers without back injury claims was accomplished to compare isolated lumbar strength with the severity of their workplace physical demands and the incidence of workplace back injury during a 2-year period. To determine if strength is a predictor of workplace injury and if there is a relationship between the physical demands of the job and strength. The role of preplacement strength testing has not been clarified as a potential means for predicting workplace injury. It has not been clarified whether work activity affects the strength of the worker. One hundred fifty-two shipyard workers were strength tested for isometric lumbar extensor strength. They had been classified as to the severity of their job demands according to the Physical Demand Characteristics. All workers at this industry were likewise classified. Those workers who were tested were followed for 2 years to evaluate for claims of back injury. There was a higher incidence of low back injuries in the heavy and very heavy classification. There was, however, no difference in strength among those workers classified in medium, heavy, and very heavy work. Nine percent of those workers tested had back pains during the following 2 years. All but two had higher-than-average strength. There is no evidence that preplacement back strength testing would predict workplace claims of injury.

Incidence of low back injuries among nursing personnel as a function of patient lifting frequency : Stobbe, T.J., Plummer, R.W., Jensen, R.C., and Attfield, M.D.J Safety Res, 1988, 19.1, 21–28

Incidence of low back injuries among nursing personnel as a function of patient lifting frequency : Stobbe, T.J., Plummer, R.W., Jensen, R.C., and Attfield, M.D.J Safety Res, 1988, 19.1, 21–28

Benefits of a back care and light duty health promotion program in a hospital setting.

Back injuries are a common and expensive problem in industry in terms of both direct and indirect costs. A dramatic increase in the costs of workers' compensation for work-related back injuries occurred from 1981-1985 in a hospital setting. During this five-year period, costs of back injuries rose from $36,384 to $272,751, a 750% increase, and the incidence per thousand employees rose from 21 in 1981 to 33 in 1985. A back care education program was instituted by the Physical Therapy Department and Employee Health Service for all departments within the hospital, with content tailored to individual job requirements. Because employees who have had one back injury are at risk for reinjury, an "at risk" program was also developed. For those injured employees without time off work and without need for medical care, a private session with a physical therapist is required to assess musculoskeletal problems and to review posture and body mechanics directly related to specific job tasks. Those employees unable to work in their usual positions are assigned to temporary modified jobs as part of the Light Duty Program. In 1986, following the institution of these two programs in the hospital, the cost of back injuries dramatically decreased to $72,296, a $200,000 drop, and the incidence per thousand employees fell to fifteen. The efficacy of this health promotion intervention program was confirmed both in the cost benefit to the hospital as well as in reduction in incidence of low back injury.

Subjective and Biomechanical Evaluation of Lifting Tasks

Careful selection and training of workers, and good job design have not substantially reduced the incidence of low back injuries. Therefore, reduction in number and severity of such injuries has become a priority concern of many researchers. The specific question addressed by this research was “Are there any discrepancies between the rankings for the lifting tasks based on the subjective estimates of stress at the lower back and the rankings based on compressive force at L5/S1 predicted by the biomechanical model?” The results showed that some of the tasks evaluated to be less severe biomechanically were evaluated to be severe based on the subjective estimation of stress at the lower back.

Incidence of low back injuries among nursing personnel as a function of patient lifting frequency

Occupational back injuries among nursing personnel are common. Although numerous factors affect risk, a widely recognized (but poorly documented) factor is exposure to patient lifting. Due to a lack of adequate documentation in the research literature, this investigation was undertaken to examine the relationship between the frequency of patient lifting and the frequency of back injuries. A major medical center was used to collect retrospective data on three work groups: (a) licensed practical nurses, (b) nurses' aides, and (c) attendants (orderlies). From these employees, two exposure groups were identified: one group exposed to frequent patient lifting and a control group of nursing personnel who infrequently lift patients. The reported back pain incidents of the two groups were then statistically compared. The statistical procedures used were logistic regression and survival analysis. Both comparisons showed significant differences between exposure groups. From this analysis, it appears that patient lifting frequency is indeed a significant causative factor in the production of low back injuries in nursing personnel.