Robert D. Herbert

Effective Exercise for the Prevention of Falls: A Systematic Review and Meta‐Analysis

OBJECTIVES: To determine the effects of exercise on falls prevention in older people and establish whether particular trial characteristics or components of exercise programs are associated with larger reductions in falls.

Acute low back pain: systematic review of its prognosis

Abstract Objectives To describe the course of acute low back pain and sciatica and to identify clinically important prognostic factors for these conditions. Design Systematic review. Data sources Searches of Medline, Embase, Cinahl, and Science Citation Index and iterative searches of bibliographies. Main outcome measures Pain, disability, and return to work. Results 15 studies of variable methodological quality were included. Rapid improvements in pain (mean reduction 58% of initial scores), disability (58%), and return to work (82% of those initially off work) occurred in one month. Further improvement was apparent until about three months. Thereafter levels for pain, disability, and return to work remained almost constant. 73% of patients had at least one recurrence within 12 months. Conclusions People with acute low back pain and associated disability usually improve rapidly within weeks. None the less, pain and disability are typically ongoing, and recurrences are common.

Measurement of muscle contraction with ultrasound imaging.

To investigate the ability of ultrasonography to estimate muscle activity, we measured architectural parameters (pennation angles, fascicle lengths, and muscle thickness) of several human muscles (tibialis anterior, biceps brachii, brachialis, transversus abdominis, obliquus internus abdominis, and obliquus externus abdominis) during isometric contractions of from 0 to 100% maximal voluntary contraction (MVC). Concurrently, electromyographic (EMG) activity was measured with surface (tibialis anterior only) or fine‐wire electrodes. Most architectural parameters changed markedly with contractions up to 30% MVC but changed little at higher levels of contraction. Thus, ultrasound imaging can be used to detect low levels of muscle activity but cannot discriminate between moderate and strong contractions. Ultrasound measures could reliably detect changes in EMG of as little as 4% MVC (biceps muscle thickness), 5% MVC (brachialis muscle thickness), or 9% MVC (tibialis anterior pennation angle). They were generally less sensitive to changes in abdominal muscle activity, but it was possible to reliably detect contractions of 12% MVC in transversus abdominis (muscle length) and 22% MVC in obliquus internus (muscle thickness). Obliquus externus abdominis thickness did not change consistently with muscle contraction, so ultrasound measures of thickness cannot be used to detect activity of this muscle. Ultrasound imaging can thus provide a noninvasive method of detecting isometric muscle contractions of certain individual muscles. Muscle Nerve 27: 682–692, 2003

Evidence for physiotherapy practice: A survey of the Physiotherapy Evidence Database (PEDro)

Evidence-based practice involves the use of evidence from systematic reviews and randomised controlled trials, but the extent of this evidence in physiotherapy has not previously been surveyed. The aim of this survey is to describe the quantity and quality of randomised controlled trials and the quantity of systematic reviews relevant to physiotherapy. The Physiotherapy Evidence Database (PEDro) was searched. The quality of trials was assessed with the PEDro scale. The search identified a total of 2,376 randomised controlled trials and 332 systematic reviews. The first trial was published in 1955 and the first review was published in 1982. Since that time, the number of trials and reviews has grown exponentially. The mean PEDro quality score has increased from 2.8 in trials published between 1955 and 1959 to 5.0 for trials published between 1995 and 1999. There is a substantial body of evidence about the effects of physiotherapy. However, there remains scope for improvements in the quality of the conduct and reporting of clinical trials.

Prognosis in patients with recent onset low back pain in Australian primary care: inception cohort study

Objective To estimate the one year prognosis and identify prognostic factors in cases of recent onset low back pain managed in primary care. Design Cohort study with one year follow-up. Setting Primary care clinics in Sydney, Australia. Participants An inception cohort of 973 consecutive primary care patients (mean age 43.3, 54.8% men) with non-specific low back pain of less than two weeks’ duration recruited from the clinics of 170 general practitioners, physiotherapists, and chiropractors. Main outcome measures Participants completed a baseline questionnaire and were contacted six weeks, three months, and 12 months after the initial consultation. Recovery was assessed in terms of return to work, return to function, and resolution of pain. The association between potential prognostic factors and time to recovery was modelled with Cox regression. Results The follow-up rate over the 12 months was more than 97%. Half of those who reduced their work status at baseline had returned to previous work status within 14 days (95% confidence interval 11 to 17 days) and 83% had returned to previous work status by three months. Disability (median recovery time 31 days, 25 to 37 days) and pain (median 58 days, 52 to 63 days) took much longer to resolve. Only 72% of participants had completely recovered 12 months after the baseline consultation. Older age, compensation cases, higher pain intensity, longer duration of low back pain before consultation, more days of reduced activity because of lower back pain before consultation, feelings of depression, and a perceived risk of persistence were each associated with a longer time to recovery. Conclusions In this cohort of patients with acute low back pain in primary care, prognosis was not as favourable as claimed in clinical practice guidelines. Recovery was slow for most patients. Nearly a third of patients did not recover from the presenting episode within a year.

Comparison of general exercise, motor control exercise and spinal manipulative therapy for chronic low back pain: a randomized trial

Abstract Practice guidelines recommend various types of exercise and manipulative therapy for chronic back pain but there have been few head‐to‐head comparisons of these interventions. We conducted a randomized controlled trial to compare effects of general exercise, motor control exercise and manipulative therapy on function and perceived effect of intervention in patients with chronic back pain. Two hundred and forty adults with non‐specific low back pain ⩾3 months were allocated to groups that received 8 weeks of general exercise, motor control exercise or spinal manipulative therapy. General exercise included strengthening, stretching and aerobic exercises. Motor control exercise involved retraining specific trunk muscles using ultrasound feedback. Spinal manipulative therapy included joint mobilization and manipulation. Primary outcomes were patient‐specific function (PSFS, 3–30) and global perceived effect (GPE, −5 to 5) at 8 weeks. These outcomes were also measured at 6 and 12 months. Follow‐up was 93% at 8 weeks and 88% at 6 and 12 months. The motor control exercise group had slightly better outcomes than the general exercise group at 8 weeks (between‐group difference: PSFS 2.9, 95% CI: 0.9–4.8; GPE 1.7, 95% CI: 0.9–2.4), as did the spinal manipulative therapy group (PSFS 2.3, 95% CI: 0.4–4.2; GPE 1.2, 95% CI: 0.4–2.0). The groups had similar outcomes at 6 and 12 months. Motor control exercise and spinal manipulative therapy produce slightly better short‐term function and perceptions of effect than general exercise, but not better medium or long‐term effects, in patients with chronic non‐specific back pain.

Effects of stretching before and after exercising on muscle soreness and risk of injury: systematic review

Abstract Objective: To determine the effects of stretching before and after exercising on muscle soreness after exercise, risk of injury, and athletic performance. Method: Systematic review. Data sources: Randomised or quasi-randomised studies identified by searching Medline, Embase, CINAHL, SPORTDiscus, and PEDro, and by recursive checking of bibliographies. Main outcome measures: Muscle soreness, incidence of injury, athletic performance. Results: Five studies, all of moderate quality, reported sufficient data on the effects of stretching on muscle soreness to be included in the analysis. Outcomes seemed homogeneous. Stretching produced small and statistically non-significant reductions in muscle soreness. The pooled estimate of reduction in muscle soreness 24 hours after exercising was only 0.9 mm on a 100 mm scale (95% confidence interval −2.6 mm to 4.4 mm). Data from two studies on army recruits in military training show that muscle stretching before exercising does not produce useful reductions in injury risk (pooled hazard ratio 0.95, 0.78 to 1.16). Conclusions: Stretching before or after exercising does not confer protection from muscle soreness. Stretching before exercising does not seem to confer a practically useful reduction in the risk of injury, but the generality of this finding needs testing. Insufficient research has been done with which to determine the effects of stretching on sporting performance.

A randomized trial of preexercise stretching for prevention of lower-limb injury.

PURPOSE This study investigated the effect of muscle stretching during warm-up on the risk of exercise-related injury. METHODS 1538 male army recruits were randomly allocated to stretch or control groups. During the ensuing 12 wk of training, both groups performed active warm-up exercises before physical training sessions. In addition, the stretch group performed one 20-s static stretch under supervision for each of six major leg muscle groups during every warm-up. The control group did not stretch. RESULTS 333 lower-limb injuries were recorded during the training period, including 214 soft-tissue injuries. There were 158 injuries in the stretch group and 175 in the control group. There was no significant effect of preexercise stretching on all-injuries risk (hazard ratio [HR] = 0.95, 95% CI 0.77-1.18), soft-tissue injury risk (HR = 0.83, 95% CI 0.63-1.09), or bone injury risk (HR = 1.22, 95% CI 0.86-1.76). Fitness (20-m progressive shuttle run test score), age, and enlistment date all significantly predicted injury risk (P < 0.01 for each), but height, weight, and body mass index did not. CONCLUSION A typical muscle stretching protocol performed during preexercise warm-ups does not produce clinically meaningful reductions in risk of exercise-related injury in army recruits. Fitness may be an important, modifiable risk factor.

Prognosis for patients with chronic low back pain: inception cohort study

Objectives To describe the course of chronic low back pain in an inception cohort and to identify prognostic markers at the onset of chronicity. Design Inception cohort study with one year follow-up. Setting Primary care clinics in Sydney, Australia. Participants The study sample was a subcohort of an inception cohort of 973 consecutive patients presenting to primary care with acute low back pain (<2 weeks’ duration). 406 participants whose pain persisted for three months formed the inception cohort of patients with chronic low back pain. Main outcome measures Outcomes and putative predictors measured at initial presentation, onset of chronicity (study entry), and follow-up at nine and 12 months. Recovery was determined from measures of pain intensity, disability, and work status. The association between potential prognostic factors and time to recovery was modelled with Cox regression. Results Completeness of follow-up was 97% of total person time for all outcomes. The cumulative probability of being pain-free was 35% at nine months and 42% at 12 months and for complete recovery was 35% at nine months and 41% at 12 months. Of the 259 participants who had not recovered from pain related disability at entry to the chronic study, 47% had recovered by 12 months. Previous sick leave due to low back pain, high disability levels or high pain intensity at onset of chronicity, low levels of education, greater perceived risk of persistent pain, and being born outside Australia were associated with delayed recovery. Conclusion More than one third of patients with recent onset, non-radicular chronic low back pain recover within 12 months. The prognosis is less favourable for those who have taken previous sick leave for low back pain, have high disability levels or high pain intensity at onset of chronic low back pain, have lower education, perceive themselves as having a high risk of persistent pain, and were born outside Australia.

Specific stabilisation exercise for spinal and pelvic pain: a systematic review

The aim of this study was to conduct a systematic review of the efficacy of specific stabilisation exercise for spinal and pelvic pain. Randomised clinical trials evaluating specific stabilisation exercise were identified and retrieved. Outcomes were disability, pain, return to work, number of episodes, global perceived effect, or health-related quality of life. A single trial reported that specific stabilisation exercise was more effective than no treatment but not more effective than spinal manipulative therapy for the management of cervicogenic headache and associated neck pain. Single trials reported that specific stabilisation exercise was effective for pelvic pain and for prevention of recurrence after an acute episode of low back pain but not to reduce pain or disability associated with acute low back pain. Pooled analyses revealed that, for chronic low back pain, specific stabilisation exercise was superior to usual medical care and education but not to manipulative therapy, and no additional effect was found when specific stabilisation exercise was added to a conventional physiotherapy program. A single trial reported that specific stabilisation exercise and a surgical procedure to reduce pain and disability in chronic low back pain were equally effective. The available evidence suggests that specific stabilisation exercise is effective in reducing pain and disability in chronic but not acute low back pain. Single trials indicate that specific stabilisation exercise can be helpful in the treatment of cervicogenic headache and associated neck pain, pelvic pain, and in reducing recurrence after acute low back pain.