Claus Manniche

The course of low back pain from adolescence to adulthood : Eight-year follow-up of 9600 twins

Study Design. Prospective study with 8-year follow-up. Objective. To describe the evolution of low back pain from adolescence into adulthood. Summary of Background Data. High prevalence rates of low back pain among children and adolescents have been demonstrated in several studies, and it has been theorized that low back pain in childhood may have important consequences for future low back pain. It is important to understand the nature of such a link if effective preventive programs are to be established. Methods. Almost 10,000 Danish twins born between 1972 and 1982 were surveyed by means of postal questionnaires in 1994 and again in 2002. The questionnaires dealt with various aspects of general health, including the prevalence of low back pain, classified according to number of days affected (0, 1–7, 8–30, >30). Results. Low back pain in adolescence was found to be a significant risk factor for low back pain in adulthood with odds ratios as high as four. We also demonstrated a dose-response association: the more days with low back pain at baseline, the higher the risk of future low back pain. Twenty-six percent of those with low back pain for more than 30 days during the baseline year also had more than 30 days with low back pain during the follow-up year. This was true for only 9% of the rest of the sample. Conclusions. Our study clearly demonstrates correlations between low back pain in childhood/adolescence and low back pain in adulthood. This should lead to a change in focus from the adult to the young population in relation to research, prevention, and treatment.

Responsiveness and minimal clinically important difference for pain and disability instruments in low back pain patients

BackgroundThe choice of an evaluative instrument has been hampered by the lack of head-to-head comparisons of responsiveness and the minimal clinically important difference (MCID) in subpopulations of low back pain (LBP). The objective of this study was to concurrently compare responsiveness and MCID for commonly used pain scales and functional instruments in four subpopulations of LBP patients.MethodsThe Danish versions of the Oswestry Disability Index (ODI), the 23-item Roland Morris Disability Questionnaire (RMQ), the physical function and bodily pain subscales of the SF36, the Low Back Pain Rating Scale (LBPRS) and a numerical rating scale for pain (0–10) were completed by 191 patients from the primary and secondary sectors of the Danish health care system. Clinical change was estimated using a 7-point transition question and a numeric rating scale for importance. Responsiveness was operationalised using standardardised response mean (SRM), area under the receiver operating characteristic curve (ROC), and cut-point analysis. Subpopulation analyses were carried out on primary and secondary sector patients with LBP only or leg pain +/- LBP.ResultsRMQ was the most responsive instrument in primary and secondary sector patients with LBP only (SRM = 0.5–1.4; ROC = 0.75–0.94) whereas ODI and RMQ showed almost similar responsiveness in primary and secondary sector patients with leg pain (ODI: SRM = 0.4–0.9; ROC = 0.76–0.89; RMQ: SRM = 0.3–0.9; ROC = 0.72–0.88). In improved patients, the RMQ was more responsive in primary and secondary sector patients and LBP only patients (SRM = 1.3–1.7) while the RMQ and ODI were equally responsive in leg pain patients (SRM = 1.3 and 1.2 respectively). All pain measures demonstrated almost equal responsiveness. The MCID increased with increasing baseline score in primary sector and LBP only patients but was only marginally affected by patient entry point and pain location. The MCID of the percentage change score remained constant for the ODI (51%) and RMQ (38%) specifically and differed in the subpopulations.ConclusionRMQ is suitable for measuring change in LBP only patients and both ODI and RMQ are suitable for leg pain patients irrespectively of patient entry point. The MCID is baseline score dependent but only in certain subpopulations. Relative change measured using the ODI and RMQ was not affected by baseline score when patients quantified an important improvement.

Low back pain rating scale : validation of a tool for assessment of low back pain

Low Back Pain Rating scale is an index scale which includes measurements of pain intensity, disability, and physical impairment. The scale was designed to monitor the outcome of clinical trials of low back pain treatment. It has been validated in 58 patients following first-time discectomy. The scale rating can be rapidly carried out and requires no special aids. With slight modification it can be used in office and telephone interviews, as well as postal questionnaires. These modifications only slightly reduce the quantity of information gathered. In the study, a high rater agreement (97.7%) was found without level difference between two observers using the scale. The validation process included: construct validity, criterion-related validity and item bias, relative to Global Assessments pronounced by the patient and an experienced clinician. Low Back Pain Rating scale hs been shown to be valid and reliable in the assessment of low back pain.

Generalized deep-tissue hyperalgesia in patients with chronic low-back pain

Some chronic painful conditions including e.g. fibromyalgia, whiplash associated disorders, endometriosis, and irritable bowel syndrome are associated with generalized musculoskeletal hyperalgesia. The aim of the present study was to determine whether generalized deep‐tissue hyperalgesia could be demonstrated in a group of patients with chronic low‐back pain with intervertebral disc herniation. Twelve patients with MRI confirmed lumbar intervertebral disc herniation and 12 age and sex matched controls were included. Subjects were exposed to quantitative nociceptive stimuli to the infraspinatus and anterior tibialis muscles. Mechanical pressure (thresholds and supra‐threshold) and injection of hypertonic saline (pain intensity, duration, distribution) were used. Pain intensity to experimental stimuli was assessed on a visual analogue scale (VAS). Patients demonstrated significantly higher pain intensity (VAS), duration, and larger areas of pain referral following saline injection in both infraspinatus and tibialis anterior. The patients rated significantly higher pain intensity to supra‐threshold mechanical pressure stimulation in both muscles. In patients, the pressure pain‐threshold was lower in the anterior tibialis muscle compared to controls. In conclusion, generalized deep‐tissue hyperalgesia was demonstrated in chronic low‐back pain patients with radiating pain and MRI confirmed intervertebral disc herniation, suggesting that this central sensitization should also be addressed in the pain management regimes.

The course of low back pain in a general population. results from a 5-year prospective study

OBJECTIVES To investigate the course of low back pain (LBP) in a general population over 5 years. DESIGN Prospective population-based survey by postal questionnaires in 1991, 1992, and 1996. SETTING The municipal of Ebeltoft, Denmark. SUBJECTS Two thousand people aged 30 to 50 years, representative of the Danish population. Main outcome measure Number of days with low back pain during the past year. RESULTS One thousand three hundred seventy were recruited of whom 813 (59%) were followed to 5 years. The responders could be divided into 3 groups with regard to LBP: no pain, short-term pain, and long-lasting/recurring pain. More than one third of people who experienced LBP in the previous year did so for >30 days. Forty percent of people with LBP >30 days at baseline remained in that group 1 and 5 years later, and 9% with LBP >30 days in year 0 were pain free in year 5. People with LBP in year 0 were 4 times more likely to have LBP in year 1, and 2 times more likely to be affected in year 5. CONCLUSIONS Low back pain should not be considered transient and therefore neglected, since the condition rarely seems to be self-limiting but merely presents with periodic attacks and temporary remissions. On the other hand, chronicity as defined solely by the duration of symptoms should not be considered chronic.

Intensive dynamic training for females with chronic neck/shoulder pain. A randomized controlled trial

Objectives: To compare the clinical effectiveness of an intensive three-month training programme with a less intensive programme on females suffering from chronic neck/shoulder pain. Study design: A prospective observer-blinded clinical trial including 12-month pretreatment follow-up. Setting: Patients were referred to the Departments of Rheumatology and Physical Medicine at Hvidovre Hospital by their general practitioners. Training was undertaken at a satellite clinic for physiotherapy of Hvidovre Hospital. Subjects: Female patients aged 18–65 years suffering from chronic neck/shoulder pain for a minimum of six months. Intervention: Patients were examined by a physician in order to exclude serious diseases. They were then randomized to either an intensive neck/shoulder training programme or a programme of lesser intensity but of similar duration. Main outcome measures: Scales measuring pain and activities of daily living (ADL) were used, and strength and endurance measurements of the cervical and shoulder muscles were carried out at baseline and completion of the study. Follow-up measurements were carried out by postal questionnaire at 6 and 12 months after inclusion, and included pain, ADL and treatment satisfaction measurements. Results: Seventy-seven patients were included in the trial, of whom 27 (69%) completed the intensive programme and 25 (61%) the lighter programme. Forty-one (>80%) completed the follow-up questionnaires. The patients in the two groups did not differ with regard to age, pain, ADL scores and physical measurements prior to training. Patients in both groups that completed the trial demonstrated statistically significant improvements in nearly all of the outcome measurements at completion. ADL scores maintained statistical significance at 12 months in both groups, but pain scores were only significantly improved in the intensive group at 12 months follow-up. There was no statistically significant difference between groups regarding pain or ADL, but overall 50% of all patients showed improvement. Conclusions: The type of low-tech dynamic training used in either of our two programmes resulted in both subjective and objective improvements in patients suffering from chronic neck/shoulder pain, but there were no statistically significant differences in outcome between the two approaches. The subjective improvements were maintained throughout the follow-up period.

Intensive dynamic back exercises with or without hyperextension in chronic back pain after surgery for lumbar disc protrusion. A clinical trial.

Sixty-two patients with chronic low back pain occurring 14-60 months after undergoing discectomy for the first time were randomized to two physical treatment groups: 24 sessions of intensive dynamic back exercises with hyperextension or 24 sessions of intensive dynamic back exercises without hyperextension. At the conclusion of therapy and at one-year follow-up, no difference was seen between the randomized groups, with regard to the combined assessments of pain, disability and objective measurements. A difference for back exercises without hyperextension to be superior to the other treatment regimen was statistically significant at the three-month follow-up. In the patients qualitative assessment of treatment outcome there were seen no significant differences between back exercises with or without hyperextension. There was a similar and significant improvement of the isometric endurance of back muscles in both groups, but the flexibility of the spine was significantly improved only in the group using hyperextension exercises. The overall response rate of an earlier published investigation was reproduced. It is concluded that chronic back patients after first time discectomy may benefit from an intensive rehabilitation protocol including intensive exercises. The added use of hyperextension exercises does not confer any independent benefit. Furthermore, the training had to continue for more than 2-3 months before a statistical significant decrease in back pain was reported in the patient pain diary.

Heredity of Low Back Pain in a Young Population: A Classical Twin Study

Important genetic influence on intervertebral disc degeneration has been shown previously. However, the role of the disc in pain production is not clear and the genetic influence on the development of the symptoms of low back pain is largely unknown. Therefore, data on lifetime prevalence of low back pain from the young cohort in The Danish Twin Registry (aged 12-41) were analyzed with respect to heredity. Casewise concordance rates, odds ratios, tetrachoric correlation coefficients and biometric liability models were estimated in relation to gender and age. Finally, age-adjusted heritability of liability estimates were obtained. Both concordance rates and odds ratios show significant genetic influence on the liability to develop low back pain. Also, tetrachoric correlation coefficients show genetic influence, but this is not statistically significant for all age groups. The biometric modeling demonstrates shared environment to be a strong component in the youngest age group (12-15), but not above age 15, and it also demonstrates some non-additive genetic effects in the older age groups. Age-adjusted heritability of liability is estimated to 44% (37-50) for males and 40% (34-46) for females aged 16 to 41. Thus, the various analyses all demonstrate significant genetic influence on the liability to low back pain. The shared environment is an important component until age 15. After age 15, this component is unimportant. As people grow older, the effect of the non-shared environment increases and non-additive genetic effects become more evident, indicating an increasing degree of genetic interaction as age increases.

Prevalence and consequences of musculoskeletal symptoms in symphony orchestra musicians vary by gender: a cross-sectional study

BackgroundMusculoskeletal symptoms are common in the neck, back, and upper limbs amongst musicians. Playing-related musculoskeletal disorders have been found to range from 32% to 87% with a tendency for female musicians to have more problems than males. Studies of musculoskeletal problems in instrumentalists have generally involved pre-professional musicians or populations comprising musicians of different levels. The objective of this study was therefore to investigate the prevalence, duration and consequences of musculoskeletal symptoms in professional symphony orchestra musicians.MethodsA cross-sectional questionnaire study. The study population comprised of 441 musicians from six Danish symphony orchestras; 342 (78%) completed the questionnaire.ResultsDuring the last year 97% of the women and 83% of the men experienced symptoms in at least one of nine anatomic regions (neck, upper and lower back, shoulders, elbows, and hands and wrists). 86% of the women and 67% of the men experienced symptoms for more than seven days, while 63% of the women and 49% of the men had symptoms for more than 30 days. Woodwind players had a lower risk for musculoskeletal symptoms and a lower risk for the consequences. Among consequences were changed way of playing, reported by 73% of the musicians, difficulty in daily activities at home, reported by 55%, and difficulty in sleeping, reported by 49%. Their health behaviour included taking paracetamol as the most used analgesic, while physiotherapists and general practitioners were reported as the most consulted health care professionals concerning musculoskeletal problems.Results regarding symptoms in six anatomic regions were compared to results for a sample of the general Danish workforce. Symptoms were more frequent in musicians and lasted longer than in the general workforce. This applied to both genders.ConclusionsWithin the last year most symphony orchestra musicians experienced musculoskeletal symptoms in the neck, back or upper extremities. The symptoms impacted on their level of function in and outside work and were reflected in their health behaviour. Generally women had a higher risk than men and woodwind players a lower risk than other instrumentalists. Finally, symptoms were more frequent and lasted longer in the musicians than in the general workforce.

Characteristics and natural course of vertebral endplate signal (Modic) changes in the Danish general population

BackgroundVertebral endplate signal changes (VESC) are more common among patients with low back pain (LBP) and/or sciatica than in people who are not seeking care for back pain. The distribution and characteristics of VESC have been described in people from clinical and non-clinical populations. However, while the clinical course of VESC has been studied in patients, the natural course in the general population has not been reported. The objectives of this prospective observational study were to describe: 1) the distribution and characteristics of VESC in the lumbar spine, 2) its association with disc degeneration, and 3) its natural course from 40 to 44 years of age.MethodsThree-hundred-and-forty-four individuals (161 men and 183 women) sampled from the Danish general population had MRI at the age of 40 and again at the age of 44. The following MRI findings were evaluated using standardised evaluation protocols: type, location, and size of VESC, disc signal, and disc height. Characteristics and distribution of VESC were analysed by frequency tables. The association between VESC and disc degeneration was analysed by logistic regression analysis. The change in type and size of VESC was analysed by cross-tabulations of variables obtained at age 40 and 44 and tested using McNemars test of symmetry.ResultsTwo-thirds (67%) of VESC found in this study were located in the lower part of the spine (L4-S1). VESC located at disc levels L1-L3 were generally small and located only in the anterior part of the vertebra, whereas those located at disc levels L4-S1 were more likely to extend further into the vertebra and along the endplate. Moreover, the more the VESC extended into the vertebra, the more likely it was that the adjacent disc was degenerated. The prevalence of endplate levels with VESC increased significantly from 6% to 9% from age 40 to 44. Again, VESC that was only observed in the endplate was more likely to come and go over the four-year period compared with those which extended further into the vertebra, where it generally persisted.ConclusionThe prevalence of VESC increased significantly over the four-year period. Furthermore, the results from this study indicate that the distribution of VESC, its association with disc degeneration and its natural course, is dependent on the size of the signal changes.