|Year : 2023 | Volume
| Issue : 1 | Page : 66-72
Immediate effect of mulligan's spinal mobilization with limb movements on straight leg raise test in patients with lumbar radiculopathy: A randomized controlled trial
Shashwath P Naidu, Soni Srikantaiah, Ruth Boyle
Department of Physiotherapy, Ramaiah Medical College, Bengaluru, Karnataka, India
|Date of Submission||01-Jun-2022|
|Date of Decision||15-Jun-2023|
|Date of Acceptance||17-Jul-2023|
|Date of Web Publication||11-Aug-2023|
Dr. Soni Srikantaiah
Department of Physiotherapy, Ramaiah Medical College, MSRIT Post, Bengaluru - 560 054, Karnataka
Source of Support: None, Conflict of Interest: None
Context: Lumbar radiculopathy is pain which starts from the lumbar spine and radiates to one or both lower limbs. Spinal mobilization with limb movement (SMWLM) has been proposed for the treatment of lumbar radiculopathy by Brian Mulligan. Studies on SMWLM have found it to have positive effect in reducing radicular symptoms, but a comparative study of SMWLM versus sham mobilization is lacking to prove the beneficial effect of SMWLM since sham procedures more clearly differentiate the efficacy of an intervention.
Aims: To compare the immediate effect of SMWLM with sham SMWLM on straight leg raise (SLR) and Visual Analog Scale (VAS) in patients with lumbar radiculopathy.
Settings and Design: Single-blinded randomized controlled trial.
Subjects and Methods: Twenty-eight participants with lumbar radiculopathy (mean age 40.2 ± 12.2 years) were included. The trial group (n = 14) received SMWLM and control group (n = 14) received sham SMWLM. In SMWLM a transverse glide was applied with the therapist thumb just lateral to the involved lumbar spinous process and the hip was taken into flexion. Sham SMWLM was given by placing thumb just lateral to the involved spinous process without applying any glide while the limb was taken into only 10° of hip flexion. The pre- and immediate post-SLR test angle and VAS was compared within each group and postvalues was compared between the two groups.
Statistical Analysis: The data were analyzed with Wilcoxon's signed-rank test and Mann–Whitney U-test.
Results: Post intervention in the experimental group there was a significant increase in SLR test angle (P = 0.001) and reduction in VAS (P = 0.001) while in the control group only VAS decreased (P = 0.034). There was a significant difference between the groups in postintervention SLR test angle (P = 0.038) and VAS (P = 0.018).
Conclusion: Through its biomechanical, neurophysiological effects, and marginal placebo effects, SMWLM can be used as an effective treatment technique for immediate improvement in pain-free SLR range in patients with lumbar radiculopathy.
Keywords: Lumbar radiculopathy, Straight leg raise test, Spinal mobilization with limb movement
|How to cite this article:|
Naidu SP, Srikantaiah S, Boyle R. Immediate effect of mulligan's spinal mobilization with limb movements on straight leg raise test in patients with lumbar radiculopathy: A randomized controlled trial. Indian J Phys Ther Res 2023;5:66-72
|How to cite this URL:|
Naidu SP, Srikantaiah S, Boyle R. Immediate effect of mulligan's spinal mobilization with limb movements on straight leg raise test in patients with lumbar radiculopathy: A randomized controlled trial. Indian J Phys Ther Res [serial online] 2023 [cited 2023 Sep 27];5:66-72. Available from: https://www.ijptr.org/text.asp?2023/5/1/66/383686
| Introduction|| |
Lower back pain can extend from the lower margin of the twelfth ribs to the gluteal fold which may or may not refer to the lower limbs. The pain which originates from the lumbar spine and radiates down to either one or both legs can be described as lumbar radiculopathy. The world wide prevalence of lumbar radiculopathy ranges from 1.2% to 43%. In Indian population, the prevalence of lower back pain is 60%–85%. Men have a higher occurrence of lumbar radiculopathy in their 4th decade of life, while women are more likely in their 5th and 6th decade of life, with an overall incidence of 23.09% in India.,
The common cause of radicular pain is degenerative changes in the lumbar spine, intervertebral disc prolapse (IVDP), and hypertrophy of facet joint. These reduce the neural foramen diameter leading to compressive forces on the nerve root that exits from the dural sac. Clinical features of lumbar radiculopathy include, pain at the lower back and travelling into the involved limb and sometimes accompanied by paresthesia and numbness. In severe cases, the patient may present with motor symptoms like lower limb muscle weakness. The features associated with lumbar radiculopathy result from a combination of pathophysiological changes like ischemia and inflammation, caused by local pressure on the nerve roots along with neurochemical inflammatory factors that are present within the disc material.
According to the National Clinical Guidelines, conservative management should be the first line of management. For management of lumbar radiculopathy Mulligan introduced the technique of spinal mobilization with limb movement (SMWLM) which involves a transverse glide given to the spinous process of the affected lumbar spine while the involved limb is taken into hip flexion with knee in extension. Mulligan mobilization has been explained to work on two mechanisms: Biomechanical correction and neurophysiological processes. The biomechanical method states that joint mobilization can be used for the correction of positional faults. Acute effects of joint mobilization techniques in managing pain may is attributed to neurophysiological processes via the descending pain inhibitory structures that suppress pain sensation.
The straight leg raise (SLR) test is considered beneficial for assessing the extent of symptoms in patients with lumbar radiculopathy. It is the only finding in physical examination that has been reported positive consistently and sensitive for radiculopath, a positive SLR test is a sign of nerve root irritation and possible entrapment. SLR test has a sensitivity of 0.91, specificity of 0.26 and diagnostic odds ratio of 3.74. Reproduction of symptoms between 35° and 70° points towards impingement of the nerve roots that are exiting from the lumbar spine. The SLR test is an important measurement because acute response to a treatment intervention can be assessed. Increasing pain-free SLR range indicates restoration of physiological spinal movements and may reduce the intensity of pain caused by the dysfunction.
A study comparing SMWLMs against Shacklock Neural Tissue Mobilization by Thakur et al. showed that both intervention significantly decreased pain intensity on Visual Analog Scale (VAS) and disability measure on Oswestry Disability Index. The study also found that there was a significant increase in range of motion (ROM) of the spine and SLR range postintervention in both the groups, but the SLR range improved to a greater extent in the group which received SMWLM as intervention. A systematic review by Pourahmadi et al. looked at the effectiveness of Mulligan mobilization in patients with lower back pain included three studies of SMWLM. The study concluded that the current evidence was not sufficient to support the use of Mulligan mobilization on intensity of pain, spinal ROM and extent of disability in patients with low back pain.
Most of the studies have used either conventional pain relief methods or other intervention along with SMWLM and have shown positive changes in patients with lumbar radiculopathy, but it is not clear if these effects are due to actual biomechanical and neurophysiological changes or placebo. To our knowledge no studies have assessed the efficacy of SMWLM alone by comparing SMWLM intervention against sham of SMWLM in patients with lumbar radiculopathy. Sham procedures act as stronger control than using conventional or other treatment methods in proving the efficacy of an intervention. Since many of the passive pain management modalities in physiotherapy seem to work through placebo mechanism, sham procedure will help distinguish the efficacy of SMWLM beyond placebo response.
This study will fill the gaps in the available research by comparing SMWLM against a sham to check of SMWLM is effective in the management of lumbar radiculopathy. Hence the research aimed to compare the immediate effect of SMWLM with sham SMWLM on SLR in patients with lumbar radiculopathy.
| Materials and Methods|| |
The ethical clearance was taken from the Institute Ethics Committee of M S Ramaiah Medical College (MSRMC/EC/AP-15/03-202) and the study was enrolled with the Clinical Trial Registry – India, New Delhi (CTRI/2020/06/026063). Sample size was estimated based on a study by Satpute et al. where the SLR with SMWLM intervention at 2 weeks of treatment was found to be 65° ± 6.5° and in control group it was 55.8° ± 8.4°. Expecting similar result, with 80% power, 95% confidence level and effect size of 1.06, we estimated the total sample size to be 28 (14 in each group).
The participants were recruited from outpatient department of tertiary care hospital in Bengaluru from June 2020 to April 2021. The inclusion criteria was patients with either acute or chronic lumbar radiculopathy with a positive on SLR test angle between 35° and 70°; both male and female in the age group of 20–65 years. Participants with vertebral fractures, spondylolisthesis, spinal surgeries, pain in the lower limbs from sacro-iliac joint dysfunction were excluded from the study. Participants willing to take part in the study were requested to give written informed consent. The selected participants were then randomly allocated into either experimental or control group based on software created randomized table of numbers which was obtained before starting of the trial. [[Flow chart 1]-Consort Diagram]
To measure the SLR test angle, two therapists were present; therapist 1 performed the SLR test procedure and therapist 2 measured the SLR angle. The SLR test angle measurement was taken using digital goniometer (Mediguage Medical Measurement Tools, Columbia, USA). SLR test was performed on the limb with radicular symptom [Figure 1]. Neural involvement confirmation was then done for structural differentiation with dorsiflexion and plantarflexion of the foot. The cutaneous area to which the pain radiated to, was also identified during the SLR test. This was used to identify the level at which the nerve root was getting compressed.
VAS on a 100 mm line with anchor words 0 mm (no pain) to 100 mm (worst pain imaginable) was used to assess pain intensity.
Experimental group – Spinal mobilization with limb movements
Participants in the experimental group received SMWLM [Figure 2]. The involved spine level was identified based on the dermatome the pain radiated to, during the SLR test. The participant was positioned in side lying with limb the pain radiated to on top. Therapist 1 stood at the participant's ventral side and applied transverse glide with the thumb on the involved lumbar spinous process. Therapist 2 then abducted the affected leg by 10° and took the limb gently into hip flexion with knee extended while the glide was sustained continuously by therapist 1. The entire motion during mobilization was maintained pain-free. The procedure was repeated three times as per Mulligans rule of 3, post which the SLR test and VAS was re-measured.
Control group – Sham spinal mobilization with movement
Patients allotted to the control group received sham SMWLM. The patient was asked to lay in side lying with the painful limb on top. Therapist 1 stood at the ventral side of the patient and placed his thumb just lateral to the involved spinous process and reinforced with the other thumb without applying any pressure (glide) to the spinous process. Therapist 2 then abducted the affected leg by 10° and with knee extended took the hip to only 10° flexion. The procedure was repeated three times, post which the SLR test and VAS was remeasured.
Statistical design and data analysis
Statistical software (IBM SPSS Statistics for Windows, Version 16. Armonk, NY: IBM Corp) was used to analyze the data. The Shapiro–Wilk test was conducted to test the normality of the collected data. The pre intervention SLR test angle and post-VAS in the experimental group was not normally distributed hence nonparametric test with median and interquartile range was used for data analysis. Wilcoxon's sign rank test was applied to analyze the data within each group and Mann–Whitney-U two-tailed test was implemented to analyze the data between the two groups. The P value was kept at < 0.05 for significance analysis.
| Results|| |
Twenty-eight participants were selected to assess the immediate effects of SMWLM and to compare the effects SMWLM to sham SMWLM in patients with lumbar radiculopathy. The mean age and symptom duration were similar in both the groups.[Table 1] In the experimental group, 9 of the participant's had L4-L5 level involvement and 5 had L5-S1 involvement, and in the control group, 11 participant's had L4-L5 level involvement and 3 had L5-S1 involvement.
Pre–post-analysis within group
Wilcoxon's sign rank test was applied for the analysis of pre-post-scores difference within each group. In experimental group, there as a statistically significant improvement in the post-SLR test angle (P < 0.05) compared to pre-SLR test immediately with SMWLM [Table 2]. The minimal detectable change with SLR test is 6°, In the present study the increase in SLR test angle with SMWLM was found to be 9.5°, hence showing both a statistical and clinically significant increase [Graph 1]. The pain score on VAS also significantly decreased (P < 0.05) with SMWLM in experimental group [Graph 2]. In the control group pre and postdata analysis shows that there is no significant difference in the post-SLR test angle (P > 0.05) with sham SMWLM compared to per intervention [Graph 1]. But there was a significant reduction (P < 0.05) in VAS [Table 2] and [Graph 2].
Comparison between experimental and control group
Mann–Whitney U-test was implemented to compare the postintervention SLR test angle and VAS between the experimental and control group [Table 3]. The analysis showed there was a significant difference between the two groups in post-SLR test angle values (P < 0.05), the experimental group showing greater improvement postintervention compared to control group [Graph 1]. The pain values on VAS also showed statistical difference between the experimental and control group (P < 0.05) with experimental group showing greater reduction in pain [Graph 2].
| Discussion|| |
Lumbar radiculopathy is a condition physiotherapist's often encounter in the outpatient setup. Manual therapy or joint mobilization helps in reducing pain and improving ROM by correcting the abnormal joint tracking mechanism through small biomechanical changes, it also works through neurophysiological processes in which the descending pain inhibiting structures via the peri-aqueductal grey area get activated resulting in inhibition of pain impulse transmission and producing analgesia., SMWLM technique specifically has shown neurophysiological response such as side-specific changes in the activity of peripheral sympathetic nervous system (SNS), which was assessed by measuring the skin conductance at the time of intervention, it recorded the limb being treated to have double the SNS activity compared to the other limb. Activation of the SNS in the brain leads to reduction in pain by activation of descending inhibition of nociceptive impulse in spinal cord and hence results in an increased pressure pain threshold immediately following mulligan mobilization in the area.,
Research on SMWLM have found it to be effective in management of symptoms in patients with lumbar radiculopathy, but all studies used additional pain management techniques such as electrotherapy, neural mobilization, hot packs and exercises; hence, the actual efficacy of SMWLM in the management is not clear. Our research study was aimed to evaluate the acute effect of SMWLM alone on SLR test angle in people with lumbar radiculopathy and compared the findings with a control group which received sham SMWLM to check the efficacy of SMWLM.
In our study, we detected a significant increase in the SLR test angle (P = 0.001) immediately post-SMWLM intervention in the experimental group. The increase in the SLR test angle immediately post-SLWLM intervention could be due to the glide applied to the spinous process of the involved vertebral segment, which improved the neural foramen diameter and thereby reducing the compressive forces on the nerve root at that level. This allows free movement of the nerve as it passes through the foramen resulting in an immediate increase in the pain-free SLR range.
The limb being taken into the forward motion repeatedly during SMWLM may itself cause neural tissue mobilization because the movement of hip flexion with knee extended may cause the nerves exiting from the lumbar spine and traveling into the lower limb to slide and stretch. The repeated motion of side lying SLR may cause the nerve to slide more freely through the interface resulting in better mobility of the nerve and thereby increase the SLR angle. The limb being taken into the flexion movement during the intervention may also cause the interface around the nerve such as muscles and facia at the lower back and leg to get stretched which may result in an increase in the pain-free ROM.
In the present study we also assessed pain intensity on VAS pre and immediately postintervention. We found considerable decrease in VAS scores immediately postintervention in the SMWLM group (P = 0.001). The reduction in pain may have occurred due direct to the reduction of shear force on the nerve root and through the neurophysiological processes of the SNS excitation and activation of the descending inhibitory pain pathway causing analgesia. This decrease in pain could also be the reason for the increase in SLR test angle.
Evidence also suggest the mechanoreceptors present in the joint get activated during joint mobilization because of the capsular stretch and repeated joint mobilization can decrease firing response in the large fiber mechanoreceptors articular afferents. This neuronal adaptation has been linked to relaxation of stress within the capsule resulting in reduction in pain.
In the control group which received sham SMWLM, the change in SLR test angle postintervention was not found to be significant (P = 0.622). This could be because no spinal mobilization was given to reduce the compressive force on nerve. Furthermore, the limb was taken only to about 10° of hip flexion movement which would not result in an increase in neural mobility or stretch of the interface. Although the SLR test angle did not improve significantly the VAS score showed a significant reduction (P = 0.034), this could have occurred due to activation of cutaneous sensory receptors when the therapist placed his thumb on the back or due to placebo effect.
On comparing the results of SLR test angle between the groups there was a significant difference as the control group which received sham SMWLM did not improve significantly on the SLR test angle postintervention compared to pre intervention while the experimental group which received SMWLM improved significantly. This shows that SMWLM is effective in increasing pain-free SLR range in patients with lumbar radiculopathy when assessed with the SLR test. But since the VAS reduced significantly even in the control group, SMWLM may have a partial placebo mechanism.
Lumbar radiculopathy has a high incidence in India and many of these patients may be unable to come for daily therapy to a physiotherapy clinic for management of the symptoms. Providing immediate relief from the symptoms of lumbar radiculopathy is necessary to reduce the overall frequency of visits to the physiotherapist and also to reduce the economic burden on the patients, this study shows that physiotherapists can used SMWLM as an effective treatment in patients with lumbar radiculopathy for immediate relief from symptoms, allowing patient to do active exercises and continue their day-to-day activities with less pain and restriction. Patients suffering from severe pain may not be unable to do corrective exercises in the initial sessions, they will require immediate passive pain reduction intervention to reduce the pain intensity which will then allow them to do the active exercises.
There were few limitations in the study. Though the sample size was estimated to be 28, with a larger sample response of patients with acute and chronic pain could have been analyzed further. Only the immediate effect of SMWLM on SLR test was assessed in this study and long term effect was not looked into.
We suggest a long term randomized controlled trial to assess the effect of SMWLM on pain, SLR test and functional outcome in people with lumbar radiculopathy.
| Conclusion|| |
The present study indicates SMWLM is an effective intervention in improving the angle of pain-free SLR range in patients with lumbar radiculopathy and SMWLM reduced pain intensity in the patients as seen in the experimental group. The mechanism of SMWLM may be partly placebo because it was found that the pain intensity reduced even in the control group, but the pain-free SLR range did not improve significantly with sham intervention. Since the SLR test angle and VAS both improved significantly in the experimental group, clinicians can use SMWLM for treating people with lumbar radiculopathy.
We wish to express our sincere thanks to Prof. Savith Ravindra, HOD, Department of Physiotherapy, Ramaiah Medical College, for her valuable support and continuous encouragement during the study. We also wish to thank Mr. Shivaraj for helping with statistical analysis during the study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Hoy D, March L, Brooks P, Blyth F, Woolf A, Bain C, et al.
The global burden of low back pain: Estimates from the global burden of disease 2010 study. Ann Rheum Dis 2014;73:968-74.
Tarulli AW, Raynor EM. Lumbosacral radiculopathy. Neurol Clin 2007;25:387-405.
Konstantinou K, Dunn KM. Sciatica: Review of epidemiological studies and prevalence estimates. Spine (Phila Pa 1976) 2008;33:2464-72.
Krismer M, van Tulder M, Low Back Pain Group of the Bone and Joint Health Strategies for Europe Project. Strategies for prevention and management of musculoskeletal conditions. Low back pain (non-specific). Best Pract Res Clin Rheumatol 2007;21:77-91.
Igatpurikar P. Effect of maitland spinal mobilization therapy versus conventional therapy in lumbar spondylosis with radiculopathy. Indian J Physiother Occup Ther Int J 2013;7:177.
Berry JA, Elia C, Saini HS, Miulli DE. A review of lumbar radiculopathy, diagnosis, and treatment. Cureus 2019;11:e5934.
Exelby L. The mulligan concept: Its application in the management of spinal conditions. Man Ther 2002;7:64-70.
Stochkendahl MJ, Kjaer P, Hartvigsen J, Kongsted A, Aaboe J, Andersen M, et al.
National clinical guidelines for non-surgical treatment of patients with recent onset low back pain or lumbar radiculopathy. Eur Spine J 2018;27:60-75.
Mulligan BR. Manual Therapy: NAGS, SNAGS, MWMS, etc., 6th
ed. Wellingthon: Bateson Pubishing Ltd; 2010.
Bialosky JE, Bishop MD, Price DD, Robinson ME, George SZ. The mechanisms of manual therapy in the treatment of musculoskeletal pain: A comprehensive model. Man Ther 2009;14:531-8.
Thakur A, Mahapatra RK, Mahapatra R. Effect of mulligan spinal mobilization with leg movement and shacklock neural tissue mobilization in lumbar radiculopathy: A randomised controlled trial. J Med Thesis 2015;3:27-30.
Camino Willhuber GO, Piuzzi NS. Straight leg raise test. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023.
Devillé WL, van der Windt DA, Dzaferagić A, Bezemer PD, Bouter LM. The test of lasègue: Systematic review of the accuracy in diagnosing herniated discs. Spine (Phila Pa 1976) 2000;25:1140-7.
Magee DJ. Orthopedic Physical Assessment. 4th
ed. 2005: Elsevier Health Sciences, Elsevier; USA.
Hall T, Hardt S, Schäfer A, Wallin L. Mulligan bent leg raise technique – A preliminary randomized trial of immediate effects after a single intervention. Man Ther 2006;11:130-5.
Pourahmadi MR, Mohsenifar H, Dariush M, Aftabi A, Amiri A. Effectiveness of mobilization with movement (Mulligan concept techniques) on low back pain: A systematic review. Clin Rehabil 2018;32:1289-98.
Satpute K, Hall T, Bisen R, Lokhande P. The effect of spinal mobilization with leg movement in patients with lumbar radiculopathy-A double-blind randomized controlled trial. Arch Phys Med Rehabil 2019;100:828-36.
Crichton N. Visual analogue scale (VAS). J Clin Nurs 2001;10:706-6.
Dixon JK, Keating JL. Variability in straight leg raise measurements. Physiotherapy 2000;86:361-70.
Tsirakis V, Perry J. The effects of a modified spinal mobilisation with leg movement (SMWLM) technique on sympathetic outflow to the lower limbs. Man Ther 2015;20:103-8.
Schlereth T, Birklein F. The sympathetic nervous system and pain. Neuromolecular Med 2008;10:141-7.
Voogt L, de Vries J, Meeus M, Struyf F, Meuffels D, Nijs J. Analgesic effects of manual therapy in patients with musculoskeletal pain: A systematic review. Man Ther 2015;20:250-6.
Baeske R. Mobilisation with movement: A step towards understanding the importance of peripheral mechanoreceptors. Phys Ther Rev 2015;20:299-305.
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]