How effective are ‘Sliders’ and ‘Tensioners’ in the management of Lumbar Radicular Pain and Radiculopathy?

Blog by Claire Powell MSc Musculoskeletal Physiotherapy student

Illustrations by Laura Jazwinski

Low back pain with leg symptoms is a presentation that I commonly see in my workplace. In a recent clinical case discussion with a colleague, we considered sliders and tensioners as an intervention for painful lumbar radiculopathy and they stated, “There isn’t evidence for using sliders or tensioners”. This led me to review my understanding of the topic. I was first introduced to the concept as an undergraduate and incorporated them into practice following multiple training sessions on junior rotations. Looking back over these lectures, there were no references, so it is difficult to evidence where my early ‘knowledge’ came from. There have been many studies on the topic since then, so I will use this blog to critically evaluate the current literature and how it can be applied to practice.

Radicular Pain and Radiculopathy

Radicular pain and Radiculopathy are separate conditions (See Table 1) but often occur together and radiculopathy can occur as a continuation of radicular pain (Lin et al, 2014).

Neural-Mobilisations (NM)

For the majority of people with lumbar radicular pain or radiculopathy, conservative treatment is the initial approach (Chou et al, 2007; Tulder et al, 2010). The NICE guidelines for conservative management of low back pain and ‘sciatica’ recommend considering exercise and manual therapy. NM can be both an exercise and a form of manual therapy.

Types of NM:

1) Interface techniques: Influence structures close to nerve or areas it passes through. E.g. joint mobilisations

2) Neuro-dynamic mobilisations (NDM): Sliders and Tensioners; a combination of movements to move nerve. In lower back/leg related conditions, often completed using Slump or SLR.

Within this blog, I am focusing on efficacy of Neuro-dynamic mobilisations (NDM). These are one of the most common interventions given by physiotherapists in the management of radiculopathy (Schmid et al, 2013). Is this common clinical practice supported by research?

Systematic reviews by Neto et al (2017) and Basson et al (2017) both supported the use of NDM. Neto et al (2017) completed a meta-analysis looking at lower quadrant NDM in healthy people as well as those with low back pain (LBP), +/- leg pain. They included studies comparing sliders and tensioners of the lower limb to other interventions and found large positive effects on pain and disability in people with LBP +/- leg pain. Although the studies included had limitations (non-blinding characteristics and baseline differences between groups) their quality was assessed within the review using the PEDRO scale and the majority rated high quality.  While results for NDM were positive, the multiple conditions within each study make it difficult to use the findings in clinic for radicular pain and radiculopathy. They included just 5 studies on people with LBP +/- leg pain, with 3 in the meta-analysis for pain and 5 for disability. This small number of trials could mean that studies with larger samples could influence the analysis of combined effects and make it difficult to confidently use the review to support clinical practice.

The largest systematic review on the topic of NM was completed by Basson et al (2017) and strongly recommended the use of NDM for ‘Nerve related LBP’ (N-LBP). They evaluated the effect of NM on a variety of neuro-musculoskeletal conditions (carpal tunnel syndrome, cubital tarsal tunnel syndrome and nerve related back and neck pain). They reviewed 40 studies with 11 on N-LBP. Quantitative data was pooled using the MAStARI and meta-analysis was not completed if the chi-square test had a P value of less than .1. This left 5 studies for meta-analysis of self-reported outcomes (Oswestry Disability Questionnaire and VAS/NPRS) with the remaining presented in descriptive form. Meta-analysis revealed that Slump and SLR mobilisation had a significant effect on both pain and disability when compared to exercises or to exercise and lumbar mobilisation.

Systematic reviews are considered the gold standard when it comes to reviewing evidence, however I feel that Basson et al (2017)’s recommendations need to be taken with caution due to the quality of studies included. Each trials risk of bias was assessed using GRADE guidelines, which take into account randomisation, blinding of outcomes, incomplete data, selective reporting and other biases. The majority of trials had a high risk of bias, including those in the meta-analysis (Jain et al, 2012; Dwornik et al, 2009; Kaur and Sharma, 2011). There were also methodological limitations of studies such as, inappropriate use of outcome measures and use of multiple T-tests (Patel, 2014; Cleland et al, 2006; Nagrale et al, 2012).

A difficulty with using the Basson et al (2017) recommendations in clinical practice is that the definition of ‘Nerve related LBP’ was not clarified. They grouped studies with different participant presentations and multifactorial conditions (Boduck, 2009). One study in the meta- analysis included pain in the back, legs and ‘paraesthesia’ along the sciatic nerve, but excluded those with loss of nerve function (Kaur and Sharma, 2011). Others, studied people with LBP only (Mehta et al, 2014 and Patel, 2014).  Despite the broad use of N-LBP, the majority of the studies did have similar inclusion criteria (Ali et al, 2015; Cleland et al, 2006; Nagrale et al, 2012; Jain et al 2012). These included people with leg and LBP, but all actively excluded people with lumbar radiculopathy, neurological signs and SLR < 45°. So, although they report positivity for NDM in people with back and leg pain, the meta-analysis does not include people with radiculopathy and likely also excluded radicular pain. In using SLR of <45 degrees, it is not clear if they used any differentiation techniques to bias neural tissue. This makes it difficult to apply the recommendations clinically and in specific conditions. The authors of these studies noted that this exclusion was due to the idea that participants who lacked nerve root involvement had a less severe condition and so were more likely to respond to NM. It appears to be based on a loose classification system suggested in a case series by George (2002) and fear that NDM may adversely affect symptoms in those with nerve root involvement (Cleland et al, 2006). So is this true, and do people with radiculopathy respond less well?

There is evidence from Schafer et al (2011) that people without neurological deficit but with nerve mechano-sensitivity do respond better to NM than those with somatic pain, signs of central sensitisation or neurological deficit. They classified people with leg and LBP into four groups; Neuropathic Sensitization (NS), Denervation (D), Peripheral Nerve Sensitization (PNS), Musculoskeletal (M). All participants received lateral flexion of the lumbar spine and a ‘slider’ technique.  The highest proportion of clinically important change (56%) was in the PNS group, with little improvement in the ‘Denervation’ group (12%). The sample sizes were small, with the smallest in the PNS group (9) and this could affect the ability to detect significant baseline differences. There was no control group, so the increased response to treatment by the PNS group could be down to greater natural recovery.

The question of whether recovery is more likely in those without neurological signs is debatable.  Some prognostic studies into back and leg pain have reported that neurological deficits are associated with poorer improvement (Grotle et al, 2005; Haugen et al, 2012). Whilst others found prognosis was similar at 12 months in those with radiculopathy, radicular or non-specific spinal related leg pain (Konstantinou et al, 2018). In contrast to suggestions that neurological deficits are associated with lack of improvement, they found initial myotomal weakness to be linked with improvement at 12 months. This may have been as their subjects were recruited acutely from primary care whereas Grotle et al (2005) and Haugen et al (2012) recruited at a more chronic stage. The most common cause of acute nerve root compression is disc prolapse, which often improves spontaneously (Takada et al, 2001). Differences in improvement between acute and chronic presentation were found in Konstantinou et al (2018), as longer leg pain duration was one of the main factors negatively associated with improvement in people with ‘sciatica’. So, perhaps duration of symptoms has more of a relationship with recovery chances than neurological signs. Schafer et al (2011) had investigated people with a minimum of 6 weeks of symptoms but it isn’t clear if participants in each sub-category had differing chronicity.

Schafer et al (2011) put the lack of improvement in their denervation group down to suspected mechanical compression of nerve root. They suggest that excursion of irritated nerve tissue in NDM could lead to further hypoxia and damage and that tensile stress would have a detrimental effect. This explanation for their findings seems simplistic considering the multiple mechanisms involved in radiculopathy (Schmid et al, 2013). NDM has been shown to affect these mechanisms including multiple neurophysiological effects, dispersal of oedema, anti-inflammatory changes within the dorsal root ganglion and on opioid analgesic pathways in the mid-brain (Beltran-Alacreu et al, 2015; Brown et al, 2011; Santos et al, 2011; Santos et al, 2014). Schafer et al (2011)’s assumption of adverse effects wasn’t supported by their study as there was an improvement in 15% of the denervation population, and no adverse effects were noted.

Conclusions by Schafer et al (2011) that NDM could lead to detrimental effects in lumbar radiculopathy and radicular pain is in contrast with studies looking at those conditions. Mahumoud (2015) investigated lumbar radiculopathy using compression grade on MRI, pain and disability as outcome measures. They compared two intervention groups; Group A-received SLR and Slump mobilisation and Group B-3 manipulations of the spine. They found a significant positive effect of both interventions on all outcome measures, with the ‘lumbar manipulation’ intervention more effective. Interestingly, NDM was actually applied in both groups. Group B manipulations were completed in an SLR, therefore applying a ‘tensioner’. As there was no control group, the effect of placebo cannot be ruled out. The diagnosis of radiculopathy was problematic as they used MRI confirming disc herniation and nerve root compression at L5/S1 however using MRI alone to diagnose radiculopathy does not have support from high quality evidence (Tawa et al, 2016). Clinical presentation is required in clinical decision-making and this paper does not define how else they confirmed radiculopathy.  The use of compression on MRI as an outcome is also questionable, as studies have shown that it was not possible to distinguish between positive outcomes or not in people with ‘sciatica’ by using MRI (Barzouhi et al, 2013).

Despite diagnostic limitations in Mahumoud (2015), the improvements in pain and disability reported are in keeping with Ferreira et al (2016), who also included people with radicular pain and radiculopathy. They split 60 people with nerve related leg pain into two groups. The experimental group received sliders and tensioners and both groups received general advice to remain active.  At 4 weeks, the experimental group had a significant reduction in leg and LBP, global perceived effect and improved function. These treatment effects on people with neuropathic features are in contrast with previous opinion regarding which clinical presentations are likely to benefit from NDM (Cleland et al, 2006; Jain et al, 2012; Nagrale et al, 2012).  It challenges suggestions from Schafer et al (2011) that people presenting with nerve root compromise wouldn’t respond well to NDM.  This argument would be strengthened if Ferreira et al (2016) had sub-grouped conditions. The trial was strong in that it was randomised and blinded but a major limitation was differing amounts of interaction time with a therapist between groups.

Summary

Having reviewed this research, I feel better placed to respond to the statement made by my colleague. There is support for the use of NDM in low back and nerve related pain but the conditions this applies to are not clearly defined (Neto et al, 2017 and Basson et al, 2017). There is a small amount of evidence of positive outcomes in radiculopathy and radicular pain but there are methodological limitations to these studies and few of them (Ferreira et al, 2016; Mahumoud, 2015). Although there is a suggestion that people without neurological signs may respond better to NDM (Schafer et al, 2011), the research was inconsistent as to whether neurological features are negatively associated with recovery (Grotle et al, 2005; Haugen et al, 2012; Konstantinou et al, 2018).  Predictions of adverse effects in people with lumbar radicular pain or radiculopathy weren’t supported by the literature. So should I use NDM on these conditions? It is difficult to draw conclusions with so few studies investigating them. I feel that further trials are required, including subgrouping and larger samples in order to be confident of the effectiveness. Part 2 will discuss clinical use further.

Comments

Thank you for reading the blog Steve and for your comments. I should clarify the statement in the summary “the research was inconsistent as to whether neurological features are negatively associated with recovery”. Here, I was referring to the differences between Konstantinou et al (2018) and Grotle et al (2005) and Haugen et al (2012) as to whether people with neurological deficits were generally less likely to recover than others. As you pointed out, they don’t specifically consider NDM intervention so can’t be used an indication of it’s effectiveness. They could though give some suggestions as to whether subgroups used in other studies like Schafer et al (2011), were likely to differ in recovery anyway, regardless of intervention. As you mentioned, Schafer et al (2011) did not use control groups, so I wondered if differences between the groups could be down to natural history or if, regardless of the intervention, people with neurological signs were likely to recover less well than people with PNS.

As you noted, the lack of control groups in Schafer et al (2011) makes conclusions from it limited. However, I feel that their findings are of importance in the overall understanding of NDM intervention, being one of the only studies that did subgroup participants.  It tells us that for some reason the PNS group responded better than the denervation group. It also tells us that that denervation group did experience improvement, although the proportion was small.

Although Grotle et al (2005) and Haugen et al (2012) found that neurological deficits were associated with lack of improvement, they were investigating people in primary care, acutely. Konstantinou et al (2018) studied over a longer period of time and did not find neurological signs to be a predictor of negative outcome, they also found that chronicity of symptoms rather than neurological signs had more of a negative predictive value of recovery. This would suggest that when looking over longer time periods, people with neurological deficit are not less likely to recover and therefore builds a case that Schafer et al (2011)’s differences in improvement between PNS and denervation group could be down to the NDM intervention. These are loose, hypothetical links and without studies investigating with control groups, subgrouping and over longer periods, the current evidence on NDM does not allow strong conclusions on effectiveness or differences between subgroups to be made.

This is a great question Steve as it has been suggested that sliders and tensioners influence nervous tissue differently. Tensioners aim to lengthen the nerve and sliders lengthening of the nerve bed at one end, whilst releasing the other end. It is thought that sliders lead to overall increased excursion of the nerve but less nerve strain (Coppieters et al 2015). It could be hypothesised that due to these different biomechanical effects, they may have different uses clinically. The studies on efficacy presented in the blog varied widely in the types of NDM intervention (see Table 2). For example, the studies within the systematic review and meta-analysis of Basson et al (2017) differed in type, position and dose of the NDM intervention. Within the meta-analysis, which formed a large part of their recommendations,  Jain et al (2012), Cleland et al (2006) and Nagrele et al (2012) all completed tensioners in slump position with similar doses of 5x 30 second holds. Of the other two studies within the meta-analysis, one completed a tensioner in SLR (Kaur and Sharma, 2011) and the other did not describe their techniques (Dwornik et al, 2009). The remaining studies in the Basson et al (2017) review differed in whether they completed tensioners or sliders, in slump or SLR position, actively or passively as well as the doses given. Of the studies looking at people radicular symptoms, Mahumoud (2015) completed passive tensioners (in both groups) and Ferreira et al (2016), completed slider techniques.  None of the studies presented in the blog investigated differences between sliders or tensioners and with such wide variations in type of treatment and dose, it is beyond these particular studies to form conclusions on whether either Tensioner or Slider techniques are more beneficial.

Conclusion

Having completed the review and in the absence of strong evidence on the best type of conservative management for people with these conditions, my opinion is that it is still reasonable to offer NDM as part of a collection of individualised management strategies.  In the next part of the blog, I will consider in more detail the ‘place’ for NDM in practice and as an intervention choice in the management of people with radicular pain and radiculopathy.

References

Ahmed N, Tufel S, Khan M, Khan P (2013). Effectiveness of neural mobilization in the management of sciatica. Journal of Musculoskeletal Research, 16: 1350012. https://doi.org/10.1142/S0218957713500127

Ali M, Rehman S, Ahmad S and Farooq M (2015). Effectiveness of slump neural mobilization techniquefor the management of chronic radicular low back pain. Rawal Medical Journal, (40) pp 4143.

Barzouhi E, Vleggeert-Lankamp C, Lycklama à Nijeholt G, Van der Kallen B, van den Hout W, Jacobs W, Koes B and Peul W (2013). Magnetic Resonance Imaging in Follow-up Assessment of Sciatica New England Medical Journal, 14; 368(11) pp. 999-1007

Basson A, Olivier B, Ellis R, Coppieters M, Stewart A and Mudzi W (2017). The Effectiveness of Neural Mobilization for Neuromusculoskeletal Conditions: A Systematic Review and Meta-analysis. Journal of Orthopaedic & Sports Physical Therapy, 47 (9) pp. 593-691

Beltran-Alacreu H, Jiménez-Sanz L, Fernández Carnero J, La Touche R (2015). Comparison of hypoalgesic effects of neural stretching vs neural gliding: a randomized controlled trial. Journal of Manipulative Physiological Therapies, 38, pp. 644-652.

Bogduk, N (2009). On the definitions and physiology of back pain, referred pain, and radicular pain. PAIN, 147 pp. 17–19

Boote J, Newsome R, Reddington M, Cole A and Dimairo M (2017). Physiotherapy for patients with sciatica awaiting lumbar micro-discectomy surgery: a nested, qualitative study of patients’ views and experiences. Physiotherapy Research International, (22)  https://doi.org/10.1002/pri.1665

Brown C, Gilbert K, Brismee J, Sizer P, James C, Smith M (2011). The effects of neurodynamic mobilization on fluid dispersion within the tib-ial nerve at the ankle: an unembalmed cadaveric study.  Journal of Manual Manipulative Therapy, 19, pp. 26-34.

Cassell (2010). The person in medicine. International Journal of Integrated Care, 10(5): DOI: http://doi.org/10.5334/ijic.489

Chou R, Qaseem A, Snow V, Casey D, Cross JT Jr, Shekelle P and Owens DK (2007). Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Annals of Internal Medicine,  147(7) pp. 478-91.

Cleland J, Childs J, Palmer J and Eberhart S (2006). Slump stretching in the management of nonradicular low back pain: a pilot clinical trial. Manual Therapy, 11 pp. 279-286.

Coppieters M, Andersen L, Johansen R, Giskegjerde P, Hovik M, Vestre S, Nee R (2015). Excursion of the sciatic nerve during nerve mobilization exercises: an in vivo cross-sectional study using dynamic ultrasound imaging. Journal of orthopaedic and sports therapy(45) 10 pp731-737

Department of Health (2014). Departmental Improvement Plan, pp 1-38

Dwornik M, Kujawa J, Białoszewski D, Slupik A, Kiebzak W (2009). Electromyographic and clinical evaluation of the efficacy of neuromobilization in patients with low back pain. Ortopedia Traumatologia Rehabilitacja  (11) pp. 164-176.

Ferreira G, Stieven F, Arujo F, Wiebusch M, Rosa C, Plentz R, Silva M (2016). Neurodynamic treatment did not improve pain and disability at two weeks in patients with chronic nerve-related pain: a randomised trial. Journal of Physiotherapy, (62) pp. 197-202

George SZ (2002). Characteristics of patients with lower extremity symptoms treated with slump stretching: a case series.  Journal of Orthopaedic and Sports Physical Therapy, 32 pp 391–8.

Goldsmith R, Williams N, Wood F (2019) Understanding sciatica: illness and treatment beliefs in a lumbar radicular pain population. A qualitative interview study. BJGP Open, DOI:10.3399/ bjgpopen19X101654

Grotle M, Brox J, Veierød M, Glomsrød B, Lønn B and Vøllestad N (2005). Clinical course and prognostic factors in acute low back pain: patients consulting primary care for the first time. Spine, (30)pp. 976-982

Haugen A, Brox J, Grovle L, Keller A, Natvig B and Soldal D (2012).Prognostic factors for non-success in patients with sciatica and disc herniation. BMC Musculoskelet Disord, (13), p. 183

(IASP) International Association for the Study of Pain (1994). Classification of Chronic Pain, Second Edition (Revised). Task Force on Taxonomy of the International Association for the Study of Pain. Retrieved from https://www.iasp-pain.org/PublicationsNews/Content.aspx?ItemNumber=1673

Jain R, Hameed UA and Tuteja R (2012). Effectiveness of slump stretching in comparison to conventional physiotherapy in treatment of subacute non-radicular low back pain.  Indian Journal of Physiotherapy and Occupational Therapy, 6 pp. 123-126

Kaur G and Sharma S (2011). Effect of passive straight leg raise sciatic nerve mobilization on low back pain of neurogenic origin. Indian Journal of Physiotherapy and Occupational Therapy, 5 pp. 179-184.

Konstantinou K, Dunn K, Ogollah R, Lewis M, Van der Windt D and Hay E (2018).Prognosis of sciatica and back-related leg pain in primary care: the ATLAS cohort. Spine Journal, (18) pp. 1030–1040.

Lewis R, Williams N, Matar H, Din N, Fitzsimmons D, Phillips C, Jones M, Sutton A, Burton K, Nafees S, Hendry, Rickard I, Chakraverty R, Wilkinson C (2011). The Clinical effectiveness and cost effectiveness of management strategies for sciatica: systematic review and economic model. Health Technology Assessment, 15 (39) pp. 1–578.

Lin J, Chiang Y, Chen C (2014). Lumbar radiculopathy and its neurobiological basis. World Journal of Anesthesiology , July 27; 3(2) pp. 162-173.

Mahmoud WS (2015). Effect of neural mobilization versus spinal manipulation in patients with radicular chronic low back pain. European  Journal Scientific Research, 131 pp. 122-132.

Mehta A, Mhatre B, Mote N (2014).Effects of Maitland’s joint mobilization versus Shacklock’s neurody-namic mobilization techniques in low back pain. Indian Journal of Physiotherapy and Occupational Therapy, 14 (8) pp.248-255.

Nagrale AV, Patil SP, Gandhi RA, Learman K (2012). Effect of slump stretching versus lumbar mobilization with exercise in subjects with non-radicular low back pain: a randomized clinical trial. Journal Manual Manipulative Therapy, 20 pp. 35-42

Neto T , Freitas S, Marques M, Gomes L, Andrade R, Oliveira R (2017). Effects of lower body quadrant neural mobilization in healthy and low back pain populations: A systematic review and metaanalysis. Musculoskeletal Science and Practice, 27, pp. 14-22

National Institute for Health and Care Excellence (2016). Low back pain and sciatica in over 16s: assessment and management. (NICE guideline No. 59) Retrieved from  https://www.nice.org.uk/guidance/ng59

Ong  B, Konstantinou K, Corbett M and Hay E (2011). Patients’ own accounts of sciatica: a qualitative study. Spine ,36, pp. 1251–1256.

Patel G (2014).To compare the effectiveness of Mulligan bent leg raising and slump stretching in patient with low back pain. Indian Journal of Physiotherapy and Occupational Therapy, 14(8) pp. 2428.

Rezk-Allah S, Shehata L, Gharib N (2011). Slump stretching versus Straight leg raising in the management of lumbar disc herniation. Egyptian Journal of Neurology, Psychiatry and Neurosurgery, (48) 4 pp 345-349

Ryan C, Roberts R (2019). ‘Life on hold’: The lived experience of radicular symptoms. A qualitative, interpretative inquiry. Musculoskeletal Science and Practice, (39) pp 51-57

Santos F, Silva Jand Giardini A (2012). Neural mobilization reverses behavioural and cellular changes that characterize neuropathic pain in rats. Molecular Pain, 8, (57)

Santos F, Grecco L and Pereira M (2014). The neural mobilization technique modulates the expression of endogenous opioids in the periaqueductal gray and improves muscle strength and mobility in rats with neuropathic pain. Behavioural and Brain Functions, 10: 19

Schäfer A, Hall T, Müller G and Briffa K (2011). Outcomes differ between subgroups of patients with low back and leg pain following neural manual therapy: a prospective cohort study. European Spine Journal, 20 pp. 482-490.

Schmid A, Nee R and Coppieters M ( 2013). Reappraising entrapment neuropathies-Mechanisms, diagnosis and management. Manual Therapy, 18, pp. 449-457

Takada, Eiichi, Takahashi, Masaya, Shimada, Kimio (2001). Natural history of lumbar disc hernia with radicular leg pain: Spontaneous MRI changes of the herniated mass and correlation with clinical outcome.  Journal of Orthopaedic Surgery (9)pp, 1

Tawa N , Rhoda A and  DienerI (2016). Accuracy of magnetic resonance imaging in detecting lumbosacral nerve root compromise: a systematic literature review. BMC Musculoskeletal Disorders, 17(1) pp. 386.

Tulder M, Peul  W and Koes, B (2010). Sciatica. what the rheumatologist needs to know. Nature Reviews Rheumatology, 6, pp 139–145  Verbeek J, Sengers M, Riemens L and Haafkens J (2004). Patient Expectations of Treatment for Back Pain: A Systematic Review of Qualitative and Quantitative Studies. Spine 29 (20) pp. 2309-2318

Vroomen P, de Krom M, Slofstra, Patty D, Knottnerus J (2000). Conservative treatment of sciatica: a systematic review. Journal of Spinal Disorders , 6, pp 463-469

Images 

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