Exercise treatment effect modifiers in persistent low back pain: an individual participant data meta-analysis of 3514 participants from 27 randomised controlled trials.

BACKGROUND: Low back pain is one of the leading causes of disability worldwide. Exercise therapy is widely recommended to treat persistent non-specific low back pain. While evidence suggests exercise is, on average, moderately effective, there remains uncertainty about which individuals might benefit the most from exercise. METHODS: In parallel with a Cochrane review update, we requested individual participant data (IPD) from high-quality randomised clinical trials of adults with our two primary outcomes of interest, pain and functional limitations, and calculated global recovery. We compiled a master data set including baseline participant characteristics, exercise and comparison characteristics, and outcomes at short-term, moderate-term and long-term follow-up. We conducted descriptive analyses and one-stage IPD meta-analysis using multilevel mixed-effects regression of the overall treatment effect and prespecified potential treatment effect modifiers. RESULTS: We received IPD for 27 trials (3514 participants). For studies included in this analysis, compared with no treatment/usual care, exercise therapy on average reduced pain (mean effect/100 (95% CI) -10.7 (-14.1 to -7.4)), a result compatible with a clinically important 20% smallest worthwhile effect. Exercise therapy reduced functional limitations with a clinically important 23% improvement (mean effect/100 (95% CI) -10.2 (-13.2 to -7.3)) at short-term follow-up. Not having heavy physical demands at work and medication use for low back pain were potential treatment effect modifiers-these were associated with superior exercise outcomes relative to non-exercise comparisons. Lower body mass index was also associated with better outcomes in exercise compared with no treatment/usual care. This study was limited by inconsistent availability and measurement of participant characteristics. CONCLUSIONS: This study provides potentially useful information to help treat patients and design future studies of exercise interventions that are better matched to specific subgroups. PROTOCOL PUBLICATION: https://doi.org/10.1186/2046-4053-1-64.

[Update on Current Care Guideline: Low back pain]. / Alaselkäkipu.

Classification to severe diseases, sciatic symptoms or non-specific back pain is recommended. Radiography in acute or subacute non-specific back pain is not recommended in the primary health care. In specialized care magnetic resonance imaging is the main imaging modality. Importance of patient information is emphasized. In acute non-specific pain avoidance of bed rest, advice and paracetamol are recommended. Indications for an emergency referral should be considered. In disabling pain for 6 weeks, multidisciplinary measures are needed. Pain over 3 months indicates intensive multidisciplinary rehabilitation, and also surgery may be considered.

Effectiveness of a home exercise programme in low back pain: a randomized five-year follow-up study.

BACKGROUND AND PURPOSE: Therapeutic exercise has been shown to be beneficial in decreasing pain and in increasing functioning in patients with chronic low back pain. However, longitudinal follow-up studies are small in number, and often limited in the numbers of subjects due to drop-outs. In addition there is a shortage of real control groups in most cases. The purpose of the present study was to describe long-term changes in intensity of low back pain and in functioning for two study groups five years after undertaking a home exercise programme. METHOD: This was a randomized follow-up study over five years. Fifty-seven subjects were reassessed with questionnaires five years after their initial recruitment for an intervention study. A home exercise group (n = 29), with training once a day, and a control group (n = 28), without exercise, were included in the present study protocol. The primary outcome measurements included a questionnaire on the intensity of low back pain (Borg CR-10 scale) and on functioning (Oswestry Disability Index; ODI). The confounding physical activity was controlled with metabolic unit (MET) values. RESULTS: The CR-10 and ODI scores decreased during the first three months in both study groups. During the follow-ups, the corresponding indicators of the home exercise group remained below baseline values. The CR-10 score was significantly lower in the home exercise group (p = 0.01) during the last five-year follow-up session compared with the control group. Overall physical activity decreased slightly during the five-year follow-up, but there were no differences between the two study groups. CONCLUSIONS: The present randomized study indicates that supervised, controlled home exercises lead to reduced low back pain, and that positive effects were preserved over five years.

Effect of stretching on hamstring muscle compliance.

OBJECTIVE: To evaluate the effects of stretching on hamstring muscle compliance indirectly and directly. METHODS: Twelve healthy men were instructed to perform passive stretching of one leg daily over 4 weeks, while the other leg served as a control. An instrumental straight leg raise was used to measure stretching force and muscle compliance indirectly with surface electromyography to measure muscle activity during stretching. Muscle compliance was measured directly by computerized muscle tonometer. The thickness of the biceps femoris muscle was measured by ultrasound and knee flexion strength by a dynamometer. RESULTS: In the stretched legs the mean increase in straight leg raise was 17 degrees after 4 weeks (p<0.001) and the mean stretching force increased by 19 N (p<0.001). Improved straight leg raise correlated with biceps muscle thickness (r=0.74).The angle at which stretching was first felt increased by 15 degrees in the stretched legs (p<0.001). Controls showed no significant changes in straight leg raise. There was no difference in force between the stretched and control legs in comparison of the same angles. No significant changes were noted in muscle compliance, surface electromyography or isometric maximal knee flexion strength. CONCLUSION: Stretching improved passive straight leg raise with no change in muscle compliance. Muscle viscoelastic properties and strength were preserved despite improved straight leg raise.

Trunk muscle strength in flexion, extension, and axial rotation in patients managed with lumbar disc herniation surgery and in healthy control subjects.

STUDY DESIGN: A cross-sectional study was conducted. OBJECTIVE: To compare maximal flexion, extension, and rotation strength as well as force-time characteristics of trunk muscles in patients who undergo lumbar disc herniation with those in healthy control subjects 2 months after surgery. SUMMARY OF BACKGROUND DATA: Insufficient attention has been paid to muscle strength characteristics after lumbar disc herniation surgery. METHODS: For this study, 30 postoperative patients with lumbar disc herniation and 30 healthy control subjects volunteered to participate. Isometric trunk flexion, extension in the standing position, and seated rotation strength were tested bilaterally in a neutral posture and at 30 degrees axial prerotation. The area under the curve was calculated to analyze explosive force capacity. Dynamic endurance strength was measured by calculating the repetition maximum. Pain during the strength measurements was assessed by a visual analog scale. RESULTS: The healthy control subjects showed 44% and 36% higher isometric trunk flexion (P < 0.001) and extension (P < 0.001) forces, respectively, than the patients. The respective values for the area under the curve were 41% and 37% higher for the trunk flexors (P < 0.001) and extensors (P < 0.001) in the healthy control subjects than in the patients. The differences in trunk rotation force between the groups were statistically significant when the lower body was rotated 30 degrees to the right (P = 0.023) or to the left (P = 0.043) and the upper body was rotated in the opposite direction. Furthermore, in the dynamic endurance strength test, the healthy control subjects performed 70% more repetitions both for trunk flexors and extensors than did the patients. Some of the patients reported mild pain during the strength measurements, but the level of pain did not correlate with the strength values. CONCLUSIONS: The recovery of maximal endurance and explosive type strength characteristics is incomplete in patients with lumbar disc herniation 2 months after surgery. Active strength training is recommended to restore muscle function in these patients.