Spinal manipulation for acute low back pain: what the evidence shows

Acute low back pain refers to pain in the lower back that has lasted for less than six weeks [1]. This type of pain often improves on its own over time [3]. This article focuses specifically on spinal manipulative therapy (SMT) for acute low back pain. We publish a separate piece about spinal manipulation for CHRONIC low back pain.

Spinal manipulative therapy is a common, hands-on treatment for low back pain [1]. It includes both manipulation and mobilization techniques applied to the spine [1]. These therapies are performed by various regulated health professionals, such as chiropractors, manual therapists, and osteopaths [1].

In Canada, health professions are regulated under provincial legislation, such as Alberta's Health Professions Act (HPA) [5]. This regulation aims to protect the public by ensuring health professionals meet certain standards of practice and ethical conduct [5]. Regulatory colleges, which are legal entities delegated powers for self-governance, establish and enforce these standards [5]. For example, if you are looking for chiropractors in Calgary, you can check their registration with their respective regulatory college [5]. These colleges also handle complaints about regulated health professionals [5].

What is spinal manipulative therapy (SMT)?

Spinal manipulative therapy (SMT) is a hands-on approach used to treat conditions affecting the spine [1]. It involves specific techniques to move spinal joints beyond their usual range of motion, often with a rapid, controlled thrust (manipulation), or within their usual range of motion (mobilization) [1]. The goal is to address pain, stiffness, and improve function in the spine [1].

Evidence from the Cochrane Review (2012)

A comprehensive review published in the Cochrane Database of Systematic Reviews in 2012 examined the effects of SMT for acute low back pain [1]. Acute low back pain was defined as pain lasting less than six weeks [1].

The review included 20 randomized controlled trials (RCTs) involving a total of 2674 participants [1]. Twelve of these trials had not been included in the previous version of the review [1]. The studies varied in size, with participant numbers ranging from 36 to 323 [1]. The quality of the evidence was assessed using the GRADE system, and at most, three RCTs could be identified for any single comparison, outcome, and time interval, suggesting that the data might not be robust [1].

The main findings of this Cochrane review were:

• SMT versus inert interventions, sham SMT, or as an additional therapy: There was low to very low quality evidence suggesting that SMT was no more effective than inert interventions (like a placebo), sham SMT (a simulated treatment), or when it was added to another treatment [1].
• SMT versus other recommended therapies: Evidence quality varied from very low to moderate, but generally suggested no difference in effect when SMT was compared to other common treatments for acute low back pain [1].
• Specific short-term effects:
  • One trial, providing low-quality evidence, showed a significant and moderately clinically relevant short-term effect of SMT on pain relief when compared to inert interventions [1].
  • Another instance of low-quality evidence demonstrated a significant short-term and moderately clinically relevant effect of SMT on functional status when it was added to another intervention [1].
• SMT techniques: Side-lying and supine thrust SMT techniques showed a significant short-term difference compared to non-thrust SMT techniques for pain, functional status, and recovery [1].

The authors concluded that, for people with acute low back pain, SMT is generally no more effective than inert interventions, sham SMT, or when added to another treatment [1]. It also appeared to be no better than other recommended therapies [1].

The review highlighted limitations due to the small number of studies available for each comparison, outcome, and time interval [1]. This means that future research could significantly change these estimates [1]. The authors suggested that decisions to refer patients for SMT should consider factors such as costs, the preferences of both patients and providers, and the relative safety of SMT compared to other treatment options [1].

Evidence from the JAMA Meta-analysis (2017)

A 2017 meta-analysis published in JAMA (Journal of the American Medical Association) also investigated the effectiveness and harms of SMT for acute low back pain, defined as pain lasting up to six weeks [2]. This review systematically searched for studies published between January 2011 and February 2017 [2].

The meta-analysis identified 26 eligible randomized clinical trials (RCTs) [2]. The key findings regarding the effectiveness of SMT were:

• Pain improvement: Fifteen RCTs, involving 1711 patients, provided moderate-quality evidence that SMT was associated with statistically significant improvements in pain [2]. The pooled mean improvement on a 100-mm visual analog pain scale was -9.95 (with a 95% confidence interval of -15.6 to -4.3) [2].
• Function improvement: Twelve RCTs, involving 1381 patients, produced moderate-quality evidence that SMT was associated with statistically significant improvements in function [2]. The pooled mean effect size for function was -0.39 (with a 95% confidence interval of -0.71 to -0.07) [2].

The researchers noted that there was significant variation (heterogeneity) in the results across the studies [2]. This variation was not explained by factors such as the type of clinician performing SMT, the specific manipulation technique used, the quality of the study, or whether SMT was provided alone or as part of a broader package of therapies [2].

Safety and Harms of Spinal Manipulative Therapy

When considering any treatment, understanding potential harms is important. Both the Cochrane review and the JAMA meta-analysis addressed safety:

• The Cochrane review suggested that the relative safety of SMT compared to other options should be a factor in decision-making, but did not detail specific harms [1].
• The JAMA meta-analysis reported that no serious adverse events were observed in any of the randomized clinical trials included in their review [2]. However, minor, temporary adverse events were reported [2]. These included increased pain, muscle stiffness, and headache, and they occurred in 50% to 67% of patients in large case series studies of SMT [2].

It is important to note that randomized controlled trials, especially those with smaller sample sizes, may not be able to detect very rare serious adverse events [2]. The information on common, minor harms often comes from larger observational studies or case series [2].

Clinical Practice Guidelines

Several clinical guideline bodies provide recommendations for the management of low back pain, including acute low back pain.

American College of Physicians (ACP) Guideline (2017)

The American College of Physicians (ACP) published a clinical practice guideline in 2017 on noninvasive treatments for low back pain [3]. For patients with acute or subacute low back pain (pain lasting less than 12 weeks), the ACP guideline made a strong recommendation:

• Nonpharmacologic treatment: Given that most patients with acute or subacute low back pain improve over time regardless of treatment, clinicians and patients should consider nonpharmacologic treatments first [3]. These options include superficial heat (moderate-quality evidence), massage, acupuncture, or spinal manipulation (low-quality evidence) [3].
• Pharmacologic treatment: If medication is desired, the guideline suggests nonsteroidal anti-inflammatory drugs (NSAIDs) or skeletal muscle relaxants (moderate-quality evidence) [3].

The ACP guideline emphasizes that the choice of treatment should be a shared decision between the clinician and the patient [3].

National Institute for Health and Care Excellence (NICE) Guideline

In the United Kingdom, the National Institute for Health and Care Excellence (NICE) publishes guidelines for health and social care [4]. NICE guideline NG59, titled "Low back pain and sciatica in over 16s: assessment and management," provides recommendations for managing these conditions [4]. Regulated health professionals are expected to follow standards of practice and guidelines from bodies like NICE.

What this means for you

If you are experiencing acute low back pain (pain lasting less than six weeks), it's important to know that this type of pain often improves on its own [3]. Spinal manipulative therapy (SMT) is one nonpharmacologic option that may be considered [3].

Research suggests that SMT is associated with modest, short-term improvements in both pain and function for acute low back pain [2]. However, some reviews indicate it may not be more effective than other common therapies or even sham treatments [1].

While serious adverse events from SMT are rare in studies, minor and temporary side effects like increased pain, muscle stiffness, or headache are common [2].

When deciding on a treatment approach for acute low back pain, it is recommended to discuss all options with a regulated health professional [3]. They can help you understand the potential benefits and risks of SMT and other treatments, considering your individual situation, preferences, and the costs involved [1]. A licensed professional can assess whether SMT fits your needs and help you choose a treatment plan that aligns with current clinical guidelines [3, 5].