Assessing patient utilities for varying degrees of low back pain

RATIONALE AND OBJECTIVES: We sought to quantify patient preferences for mild, moderate, and severe low back pain via time-tradeoff analysis and utility measurement. MATERIALS AND METHODS: Forty-one patients being treated for low back pain in a tertiary care teaching hospital participated in the study. Patients were asked to decide which of three health states they were currently experiencing as well as which of the three health states was the worst experienced during their lifetime. A time-tradeoff analysis was performed, during which patients were asked the amount of time in each of the health states they would exchange for complete resolution of symptoms. We correlated (1) subjects' current health state with reported utility and (2) degree of previous low back pain with results of time-tradeoff measurements. RESULTS: All patients were willing to trade a greater number of life-years for resolution of symptoms given a more severe perceived health state. Utility decreased as severity of back pain scenarios increased, with an average utility of 0.93 +/- 0.11 for mild, 0.65 +/- 0.21 for moderate, and 0.18 +/- 0.17 for severe pain. No significant difference in time-tradeoff among subjects was identified based upon current health state on the day of interview. A statistically significant difference was seen in patients' willingness to trade time among those who had actually experienced severe pain versus those who had not. Kendall's correlation revealed that subjects who had experienced severe back pain exhibited significantly lower utilities (P < 0.01) compared with subjects who had never experienced severe pain. CONCLUSIONS: As expected, patients with severe low back pain were willing to sacrifice more potential years of life for resolution of symptoms, suggesting time-tradeoff can accurately reflect patient utility. 2. However, we found no correlation between a subject's current health state and reported utility.     

Low back pain and other overuse injuries in a group of Japanese triathletes.

OBJECTIVE: To document the incidence of low back pain and other overuse injuries in a group of triathletes, and to investigate any associations with various physical and triathlon related factors. METHODS: By means of a questionnaire, the physical characteristics, training habits, and the incidences of overuse injuries of 92 Japanese triathletes (70 males, 22 females) were documented. Student's t and chi 2 tests were used to determine the significance of any associations with injury incidence, as well as differences between subjects experiencing or not experiencing low back pain in the previous year. RESULTS: Low back pain was experienced by 32% of subjects in the previous year. The majority (54%) of low back pain episodes lasted under seven days, suggesting mainly soft tissue involvement, and 19% lasted over three months, suggesting involvement of the intervertebral discs. Weekly trunk flexor muscle training frequency was significantly greater (P = 0.035) for the low back pain subjects. Close to significant differences for average weekly cycling time, trunk flexor muscle training time, and low intensity aerobic training, as well near significant associations for weight training and average weekly triathlon training load, were also found. No other factors were significantly associated with low back pain. Low back injuries accounted for 28% of all injuries. Only the knee was a more common single site of injury (33%). CONCLUSIONS: The three most common injuries suffered by the triathletes were of the knee, back and shoulder. The low back pain suffered by many triathletes could be of a potentially serious nature. It is suggested that cycling is a major risk factor for low back pain in triathletes.     

Racquetball: Long on Exercise,Short on Time

In brief: Rifle and pistol shooters often experience low back pain during or after competition. As a first step in determining the extent and possible causes of such pain, a questionnaire and a rapid screening test for posture and flexibility were designed and administered to 80 shooters. It was found that 78% of the shooters had experienced back pain during competition and 63% had experienced pain afterward. Of the 11 posture and flexibility tests, only the results of Ober's test for tightness of the iliotibial band and tensor fascia lata muscle correlated significantly with reported back pain.     

The trunk muscles of elite oarsmen

OBJECTIVES: To investigate the trunk strength of elite rowers and the impact of low back pain on these measures in order to determine if asymmetries or weakness were present. METHODS: Twenty two elite rowers were recruited: 13 reported previous low back pain, five current low back pain, and the remainder had no history of low back pain. All subjects were scanned during simulated rowing in an interventional open magnetic resonance imaging scanner. In each simulated rowing position, axial scans were obtained at the level of the L4-5 and L5-S1 disc interspace to determine the cross sectional area of the posterior trunk muscles. RESULTS: Considerable differences were observed between the three groups of rowers. In contrast with expectations and previous literature, the trunk muscles of rowers with low back pain had significantly larger cross sectional areas (p<0.001). No left/right asymmetries were observed and no differences between oarside and non-oarside in terms of muscle cross sectional area. CONCLUSION: These findings suggest that low back pain in rowers does not arise as a result of muscle weakness.     

Back injuries and pain in adolescents attending a ski high school

This study compared overuse injuries, small abnormalities, and pain alone in different types of skiing and activity levels. Subjects were 45 ski high school athletes aged 15–19 years. We found the back and knees significantly more prone to activity-related injuries and pain than other body regions. Thirty subjects (67%) had low back pain on the first examination, and 17 had pain caused by overuse of the back. This was more frequent among active, young competitive boys in the cross-country skiing group, with mature height less than 99%, than among noncompetitive boys in the same group or among the alpine skiers. Neck pain was reported only by girls. Eight subjects had low back pain related to small abnormalities. The subjects were given counseling about training and physiotherapy. The 1-year follow-up found a significant reduction in back pain due to overuse injuries (from 17 to 3 subjects) and indistinct neck pain (from 10 to 2) but no reduction in pain in those with small abnormalities in the low back. Low back pain was common in young athletes, particularly in cross-country skiers. Excessively rapid progression of training and faulty technique increased back pain complaints from 36% when entering the school to 67% at the first examination. A proper evaluation and treatment of overuse injuries and accurate counseling of training types, volume, and progression reduced the low back pain problems to 29% of subjects 1 year later in spite of a maintained high activity level. A minimum entrance requirement to conditioning seems mandatory for students attending a ski high school.     

腰椎间盘MRI高信号区在诊断椎间盘源性下腰痛中的意义

目的:研究椎间盘源性下腰痛患者腰椎间盘纤维环后方MRI高信号区(HIZ)的临床意义。方法:回顾性分析2003年～2005年行MRI检查的下腰痛患者123例,合并有腰椎间盘突出、椎间盘炎、腰椎结核、滑脱、椎管狭窄等能引起下腰痛疾病的患者排除在本研究之外。对照组60例无典型的下腰部慢性疼痛,或有下腰部疼痛症状但临床检查已明确诊断为其它疾病。卡方检验比较两组HIZ出现率差异是否有显著性意义。结果:实验组出现HIZ患者67例(54%),明显多于对照组(9例,15%),P<0.001。结论:MRI显示的HIZ是椎间盘源性下腰痛的重要征象。     

Muscular performance after a 3 month progressive physical exercise program and 9 month follow-up in subjects with low back pain. A controlled study

The purpose of this study was to assess, in subjects with low back pain, the changes and their permanence in muscular performance after a 3 month progressive physical exercise program. Ninety subjects with chronic low back pain participated in the study. The study design was controlled and it was carried out in three groups: intensive training, home exercise, and control group. Isometric and dynamic muscle strength of the trunk and lower limb were measured, at the beginning of the study and after the 3 months exercise program, and then during each of the follow-up sessions. The Oswestry Index and back pain intensity were also determined. Both exercise groups received benefit from the progressive exercise program. Their muscular performance improved and their back pain intensity decreased significantly. Among the home exercise group, the Oswestry Index also changed positively. The results demonstrate that the home exercise program could be as effective as the intensive training program in increasing muscle strength, as well as decreasing back pain and functional disability among low back pain patients with mild functional limitations.     

Abdominal muscle activation of elite male golfers with chronic low back pain

PURPOSE: The purpose of this study was twofold: 1) to determine whether elite male golfers with chronic low back pain (CLBP) exhibit different abdominal muscle activity patterns during the golf swing than asymptomatic control (AC) golfers and 2) to determine whether elite male golfers with CLBP experience greater fatigue in the abdominal muscles than AC golfers after a typical practice session. METHODS: Surface EMG data were collected bilaterally from the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles. Muscle activity during the golf swing was measured using the root mean square (RMS) of the EMG signal in various phases of the golf swing. Fatigue was assessed using the median frequency (MF) and RMS of the EMG signal during a 10-s submaximal isometric contraction. Low back pain was quantified with the McGill Pain Questionnaire before and after the practice session. RESULTS: No differences in the RMS of abdominal muscle activity were noted during the golf swing between AC and CLBP subjects. However, EO (lead) onset times were significantly delayed with respect to the start of the backswing in CLBP subjects. Low back pain in CLBP golfers increased significantly after the practice session. Abdominal muscle fatigue, as measured with MF or RMS, was not evident after the practice session for either AC or CLBP subjects. CONCLUSION: Abdominal muscle activity and muscle fatigue characteristics were quite similar between AC and CLBP subjects after repetitive golf swings. Despite this, it was clear that repetitive golf swings were aggravating some part of the musculoskeletal system in CLBP subjects, which resulted in increased pain in the low back area.     

Biological risk indicators for recurrent non-specific low back pain in adolescents

Objectives: A matched case-control study was carried out to evaluate biological risk indicators for recurrent non-specific low back pain in adolescents.

Methods: Adolescents with recurrent non-specific low back pain (symptomatic; n = 28; mean (SD) age 14.9 (0.7) years) and matched controls (asymptomatic; n = 28; age 14.9 (0.7) years) with no history of non-specific low back pain participated. Measures of stature, mass, sitting height, sexual maturity (Tanner self assessment), lateral flexion of the spine, lumbar sagittal plane mobility (modified Schöber), hip range of motion (Leighton flexometer), back and hamstring flexibility (sit and reach), and trunk muscle endurance (number of sit ups) were performed using standardised procedures with established reliability. Backward stepwise logistic regression analysis was performed, with the presence/absence of recurrent low back pain as the dependent variable and the biological measures as the independent variables.

Results: Hip range of motion, trunk muscle endurance, lumbar sagittal plane mobility, and lateral flexion of the spine were identified as significant risk indicators of recurrent low back pain (p<0.05). Follow up analysis indicated that symptomatic subjects had significantly reduced lateral flexion of the spine, lumbar sagittal plane mobility, and trunk muscle endurance (p<0.05).

Conclusions: Hip range of motion, abdominal muscle endurance, lumbar flexibility, and lateral flexion of the spine were risk indicators for recurrent non-specific low back pain in a group of adolescents. These risk indicators identify the potential for exercise as a primary or secondary prevention method.

     

训练性下腰痛躯干肌功能变化特点及防治干预

为探讨训练性下腰痛患者躯干肌功能变化 ,分别应用CYBEX 6 0 0 0型等速测试训练系统、彩超、肌电图、立位腰椎侧位X线片测试腰痛组(n=4 0 )和正常组 (n =4 0 )的躯干肌力指标、骶棘肌横截面积、腰背肌肌电指标及腰椎曲度。结果显示 ,在腰痛组与正常组 ,除躯干屈肌PT/BW、ER及骶棘肌横截面积差异无统计学意义 (P >0 0 5 )外 ,其他指标相比差异均有统计学意义(P <0 0 5 )。提示由于缺乏有效的腰背肌锻炼 ,训练性下腰痛患者存在明显的躯干肌肌力失衡 ,其主要由腰背肌肌力下降引起 ;同时腰背肌肌爆发力以及腰背肌静态耐力也明显下降 ,腰椎生理曲度变小 ,但不伴随有明显的椎旁肌萎缩 ;耐力比ER(动态耐力)与下腰痛关系并不密切。同时在此基础上设计了预防训练性下腰痛的现场干预实验 ,结果显示训练性下腰痛发生率明显降低 (锻炼组 8 93% ,对照组 17 0 1% ,P <0 0 1)。提示腰背肌锻炼可降低训练性下腰痛的发生率。     

Inter-joint coordination and the flexion-relaxation phenomenon among adults with low back pain during bending

BackgroundAltered inter-joint coordination and reduced flexion-relaxation at end-range trunk flexion are common in people with low back pain. Inconsistencies in these behaviors, however, make assessment and treatment challenging for this population.Research questionThe study objective was to investigate patterns of regional lumbo-pelvic coordination and flexion-relaxation in adults with and without low back pain, during a bending task.MethodsAdults with low back pain (n = 16) and a healthy group (n = 21) performed three trials of a bending task. Motion capture and surface electromyography systems measured joint kinematics (hip, lower and upper lumbar spine) and muscle activity (erector spinae longissimus, iliocostalis, and multifidus). Continuous relative phase analysis determined inter-joint coordination of the hip/lower lumbar and lower lumbar/upper lumbar joint pairs, during flexion and extension periods. Flexion-relaxation ratios using normalized surface electromyography data determined the extent of flexion-relaxation for each muscle, during each period. For inter-joint coordination, two-way repeated measure mixed ANOVAs calculated the effects of group (healthy/low back pain), period, and their interactions. Separate hierarchical linear models were constructed and tested relationships between flexion-relaxation ratios and our independent variables, group and muscle, while controlling for patient characteristics.ResultsThe low back pain group had more out-of-phase coordination of the hip/lower lumbar joint pair compared to the healthy group (mean difference = 24.7°; 95 % confidence interval = 3.93–45.4), independent of movement period. No significant between group differences in lower lumbar/upper lumbar coordination were observed. The low back pain group demonstrated reduced flexion-relaxation of all muscles during full flexion (21.7 % reduction on average), with multifidus showing the least relaxation.SignificanceRegional differences in the lumbar spine and the possibility of subgroups with distinct movement pattern should be considered when analyzing coordination in people with low back pain. Multifidus showed the largest changes in flexion-relaxation and should be included when measuring this construct.     

中度高原地区坦克乘员腰痛的现患调查

目的：了解中度高原地区坦克乘员腰痛的发病情况、流行病学特点。方法：采用问卷调查、实地考察、物理检查、统计分析等方法，对中度高原地区1041名坦克乘员腰痛情况进行横断面调查。结果：1041名坦克乘员中腰痛患病率45．9％，各工种驾驶员检出率最高（P〈0．05）。腰痛随兵龄增加而明显升高，5年以上驾驶员患病率高达87．5％。经多元回归分析，吸烟、反复高举重物、训练中反复弯腰3种因素与腰痛相关。结论：中度高原地区坦克驾驶员腰痛患病率高，发病率随从业时间而增大。     

训练性下腰痛患者躯干肌生物力学及相关研究

为探讨训练性下腰痛患者的躯干肌力，腰椎曲度及骶棘肌横截面积的变化，应用CYBEX－6000型等速测试训练系统测试腰痛组和正常组各40名的躯干肌力指标，并在立位腰椎侧位X线片上测量腰椎曲度，应用彩超测量骶棘肌横截面积，两组间进行比较。结果显示，躯干屈肌PT／BW腰痛组与正常组无显著性差异，TAE则腰痛组低于正常组（P＜0．05），而躯干伸肌PT／BW和TAE腰痛组均低于正常组（P＜0．05）；腰痛组的F／E大于正常组(P＜0．05），腰椎曲度小于正常组（P＜0．05），骶棘肌横截面积与正常组无显著性差异。提示训练性下腰痛者存在着明显的腰背肌力下降，以及由此所致的躯干肌肌力失衡，腰椎生理曲度变直，但并不伴有明显的椎旁肌萎缩。     

非特异性慢性腰背痛飞行员与无症状飞行员之间腰部竖脊肌表面肌电特征比较（摘要）

目的非特异性慢性腰背痛飞行员与无症状飞行员之间腰部竖脊肌表面肌电特征比较,为飞行员非特异性慢性腰背痛患者的客观诊断提供依据。方法用芬兰MEGA公司ME6000一T8表面肌电仪测量43名非特异性慢性腰背痛飞行员与9名无症状飞行员腰部竖脊肌等长收缩与站立位屈伸运动时表面肌电。     

歼击机飞行员非特异性慢性腰背痛患者腰部竖脊肌表面肌电特征

目的测量分析非特异性慢性腰背痛歼击机飞行员与对照组歼击机飞行员腰部竖脊肌表面肌电（surface electromyography,sEMG）,为歼击机飞行员非特异性慢性腰背痛患者的客观诊断评价提供参考依据。方法芬兰ME6000-T8表面肌电仪测量39名非特异性慢性腰背痛歼击机飞行员（病例组）与12名无症状歼击机飞行员（对照组）腰部竖脊肌俯卧位等长收缩、站立位屈伸运动时的表面肌电。MEGAWIN700046,2．4版软件处理等长收缩时疲劳性肌电信号,获取中位频率下降率（median frequency slope,MFs）、平均功率频率下降率（mean power frequency slope,MPFs）、过零率下降频率（zero crossing rate slope,ZCRs）、平均电压下降率（average electromyography slope,AEMGs）,分析屈伸动作时的肌电信号,得出屈曲伸直动作时的平均肌电电压（averageelectromyography,AEMG）,并由此计算屈曲伸直比（flexion extension ratio,FER）。分析病例组与对照组各指标的差别。结果竖脊肌等长收缩时病例组与对照组疲劳性肌电指标之间无统计学差异。屈伸运动时病例组与对照组AEMG及FER指标有统计学差异（t=1．979～5．387,P％0．05或P％0．01）。结论非特异性慢性腰背痛歼击机飞行员与无症状歼击机飞行员之间的表面肌电指标FER差异显著,屈曲时竖脊肌AEMG增高,伸直时竖脊肌AEMG降低,FER可以作为歼击机飞行员非特异性慢性腰背痛诊断及疗效评价的客观量化参考指标。     

Usefulness of the lumbar support cushion for pilots of military helicopters

The aim of our study was to evaluate the possibility of prevention of local reflex hyperactivity of the paraspinal muscles as the one of causes of low back pain during long-term sitting in forced position. We examined eight pilots, with low back pain during and after flying tasks. In improvised conditions, sitting position was performed in an equal term as the real, with and without lumbar support cushion. The pause between two examinations was 24 to 48 hours. Activity of paraspinal muscles was measured by surface electromyography, just after the ended sitting position. In six out of eight our subjects was decreased EMG activity after using the lumbar cushion, in comparison to values registered after sitting without cushion in comparison to values registered after sitting without cushion. We concluded that reflex hyperactivity of the paraspinal muscle could be prevented with lumbar cushion which, on the other hand can improve working and operative capabilities of the pilots, and simultaneously is rational from economic point of view.     

The psoas sign in normal subjects without bowel preparation: the influence of scoliosis on visualisation

The lumbar spine films of 1494 subjects who were examined for low back pain or prior to job placement were studied to assess psoas muscle visualisation. The study group were almost all aged 18-39 years. None of the subjects had prior bowel preparation for a contrast examination. In the subjects without scoliosis only 36% had well seen psoas shadows on both sides. Taking the psoas shadows separately, 72% of left psoas shadows were well seen, while only 40% were seen on the right side. In the scoliotic group, the psoas shadow was seen bilaterally in 30% of subjects while in another 50% the muscle was seen only on the convex side of the curve. In no case was it seen only on the concave side. The direction of the curve to left or right did not influence visualisation. Thus in 80% of subjects with scoliosis of 5 degrees or more, the psoas was seen on the convex side, while in only 30% was it seen on the concave side.     

Low back pain in elite cross-country skiers

Low back pain is a common complaint among competitive cross-country skiers. Fifty-three top male and 34 female skiers in the age group 16–25 were interviewed with a questionnaire regarding anthropometric parameters, training variables, back pain and other injuries. The frequency of back pain was 64% in the whole group, men affected slightly more often than women. Back pain was defined as previous or present recurrent skiing correlated backache that more or less affected skiing ability. Diagonal skiing style was the most commonly back pain-inducing style, whereas no skier experienced back pain when "skating" only. The low back was the predominant location of pain. Anthropometric and training variables seemed to be of little value in predicting back pain.     

Low back pain in professional golfers: the role of associated hip and low back range-of-motion deficits

BACKGROUND: Low back pain is fairly prevalent among golfers; however, its precise biomechanical mechanism is often debated. HYPOTHESIS: There is a positive correlation between decreased lead hip rotation and lumbar range of motion with a prior history of low back pain in professional golfers. STUDY DESIGN: A cross-sectional study. METHODS: Forty-two consecutive professional male golfers were categorized as group 1 (history of low back pain greater than 2 weeks affecting quality of play within past 1 year) and group 2 (no previous such history). All underwent measurements of hip and lumbar range of motion, FABERE's distance, and finger-to-floor distance. Differences in measurements were analyzed using the Wilcoxon signed rank test. RESULTS: 33% of golfers had previously experienced low back pain. A statistically significant correlation (P <.05) was observed between a history of low back pain with decreased lead hip internal rotation, FABERE's distance, and lumbar extension. No statistically significant difference was noted in nonlead hip range of motion or finger-to-floor distance with history of low back pain. CONCLUSIONS: Range-of-motion deficits in the lead hip rotation and lumbar spine extension correlated with a history of low back pain in golfers.     

The effect of pre-season dance training on physical indices and back pain in elite cross-country skiers: a prospective controlled intervention study

OBJECTIVE: To evaluate the effect of pre-season dance training on back pain, joint mobility, and muscle flexibility, and on speed and agility in elite cross-country skiers. METHODS: 26 skiers participated (mean (SD) age, 19 (3.9) years). An intervention group (n = 16) had 12 weeks of dance training; a control group (n = 10) did not dance; otherwise both groups followed a similar pre-season physical training programme. Joint mobility and muscle flexibility of the spine, hip, and ankle were measured. Two sports related functional tests (slalom and hurdle) were also done. All measurements/tests were carried out before and after the dancing period. RESULTS: Four (of six) subjects from the intervention group who initially complained of ski related back pain did not report back pain after the dance training; the three subjects with back pain from the control group were unchanged. At study onset the intervention group had a slightly impaired range of motion in the spine compared with the control group. After dance training, there was a better relation between kyphosis of the thoracic spine and lordosis of the lumbar spine, and a 7.1 degrees increase in hip flexion with the knee extended (p = 0.02). In the control group hip extension decreased by 0.08 m on average (p = 0.01). No positive effects of dance training on sports related functional tests were observed. CONCLUSIONS: Preseason dance training improved the range of hip motion and joint mobility and the flexibility of the spine. These improvements might explain the reduction in ski related back pain in the intervention group.