Effect of Neural Mobilization Exercises in Patients With Low Back-Related Leg Pain With Peripheral Nerve Sensitization: A Prospective, Controlled Trial

Abstract

Objective

The aim of this study was to investigate the short-term effect of slider and tensioner exercises on pain and range of motion (ROM) of straight leg raise (SLR) and slump tests in patients with low back–related leg pain with peripheral nerve sensitization.

Methods

In this prospective, controlled trial, 51 patients with low back–related leg pain with peripheral nerve sensitization were divided into 3 treatment groups: slider (slider neural mobilization exercise + transcutaneous electric nerve stimulation [TENS]), tensioner (tensioner neural mobilization exercise + TENS), and control (only TENS). Each patient received 6 sessions over 2 weeks. The following outcomes were measured at baseline and after the first, third, and sixth sessions: visual analog scale (VAS) for pain and ROM of SLR and slump tests were performed for the symptomatic side.

Results

Compared with controls, patients receiving the slider and tensioner exercises showed a greater decrease in pain at the third and sixth sessions (mean difference: ≥1.54 cm; 95% CI, 0.1-3.9). There was a significant difference in the ROM of the SLR test between the slider and controls at only the sixth session (mean difference: 16.7°; 95% CI, -29.2 to -4.3). Patients in the slider and tensioner groups demonstrated greater improvements in the ROM of slump test at all sessions compared with controls (mean difference: ≥12.5°; 95% CI, -32.1 to -6.4). There were no significant differences between the slider and tensioner groups in any outcome at any session.

Conclusion

Patients in both slider and tensioner neural mobilization exercise groups demonstrated improvements in pain and ROM in patients with low back–related leg pain with peripheral nerve sensitization compared to those in the control group.

Introduction

Low back pain (LBP) is a very common symptom worldwide that occurs in all age groups. In 2015, LBP was responsible for 60.1 million disability-adjusted life-years, and represented an increase of 54% since 1990.¹ Low back–related leg pain is present in approximately two-thirds of patients with LBP and is associated with increased pain and poorer function and quality of life.² A systematic review appraised several systems that classified patients with low back–related leg pain. One of the systems that scored higher compared with other systems is the classification system by Schafer and colleagues.³ Their system is a pain mechanism classification system that classifies patients with low back–related leg pain into 4 categories: central sensitization, denervation, peripheral nerve sensitization, and musculoskeletal.⁴ Peripheral nerve sensitization represents a reduced threshold and/or enhanced mechanosensitization that is arised from nerve root or nerve trunk inflammation, resulting in adverse response to mechanical provocation of nerve tissue.^4,5

Neural tissue movement can be achieved by special techniques such as neural mobilization. Neural mobilization maneuvers are treatment techniques that produce specific mechanical changes in the nervous system, which may result in physiological changes that help relieve symptoms.^6,7 These physiological changes may include decreased intraneural edema,^8,9 reduced mechanical and thermal hyperalgesia, decreased allodynia,¹⁰ and increased cutaneous vasodilation, as evidenced by increased skin temperature, indicating a sympathetic inhibitory effect.¹¹ Basson et al.,¹² in their systematic review, concluded that neural mobilization improves pain and function in groups of patients with nerve-related LBP and nerve-related neck and arm pain.

A slider is a neural mobilization exercise that produces a sliding movement of neural tissue relative to neighboring tissue, in which a longitudinal force is applied at one end of the nerve while tension is released at the other. A tensioner is an exercise that increases tension in the neural tissue, in which a longitudinal force is applied to increase the distance between each end of the nerve.⁷ The difference between slider and tensioner exercises in the application method may result in different responses.13, 14, 15, 16, 17 Sliders may be more useful to reduce pain and improve excursion of the nerves, whereas tensioners may be used to improve the viscoelastic and physiological functions of neural structures.⁷

Previous studies have investigated the effect of slider and tensioner exercises in isolation or in combination in patients with carpal tunnel syndrome,^18,19 cervical radiculopathy,20, 21, 22 and radicular LBP.^23,24 Studies that have investigated the differences between the slider and tensioner exercises were conducted on cadavers, animals,^13,15 or asymptomatic participants.^14,17 To our best knowledge, studies that have compared the 2 exercises in patients with low back–related leg pain are lacking.

Therefore the aim of this study was to determine the short-term effect of slider and tensioner exercises on pain and range of motion (ROM) of straight leg raise (SLR) and slump tests in patients with low back–related leg pain with features of peripheral nerve sensitization compared with control patients. The hypothesis was that there are statistically significant differences in pain and ROM of SLR and slump tests among the groups (slider, tensioner, control).

Methods

Study Design and Setting

This study was a prospective, controlled trial. The primary investigator was blinded to the patient's measurements, the examiner and independent observer were blinded to the patients’ group, and patients were blinded to the treatment assignment. Patients were alternately assigned in a parallel design (1:1:1) to the slider, tensioner, or control group. The first patient was assigned to slider group, the second patient assigned to the tensioner group, and the third patient to the control group, and so forth.

The study was conducted at the outpatient physical therapy department in 3 secondary hospitals in Dammam, Saudi Arabia; namely the Security Forces Hospital, King Fahd Hospital of the University, and Dammam Medical Complex. This study was approved by the institutional review board at Imam Abdulrahman Bin Faisal University (IRB-2014-04-321) and registered at ClinicalTrials.gov (NCT03621878). All patients provided consent to participate.

Participants

The sample size was calculated using G*power software version 3.0.10. Data from Tambeker et al.²⁵ were used (effect size = 0.82, α = 0.05, power = 0.95). The calculation resulted in a total of 51 participants. The recruitment of patients started on December 23, 2015, and the trial was concluded on June 15, 2017. Patients with unilateral low back-related leg pain with dominant peripheral nerve sensitization were recruited. The patients were diagnosed with peripheral nerve sensitization if they fulfilled the criteria suggested by Schäfer et al.,⁴ which included a self-reported Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) score > 12, a negative sensory and motor neurologic examination, and positive neural tissue provocation tests (SLR test or slump test). Patients with peripheral nerve sensitization were included if they were adults and had a leg pain duration < 3 months. Patients, who sought treatment for their symptoms, were included regardless of their pain severity level. Patients with 1 or more of the following criteria were excluded from this study: motor or sensory deficits, history of back or lower-extremity surgeries, bilateral referred pain, and patients with contraindications to transcutaneous electrical nerve stimulation (TENS) as described by Jones and Johnson.²⁶

Physicians from the neurology and neurosurgery departments examined consecutive patients for sensory or motor deficits and referred the patients with radicular pain and without neurologic deficits to the physical therapy department. In the initial visit, the primary investigator explained to each patient the aims and the general procedures of the study, and all patients provided written informed consent. The examiner started examination for eligibility with S-LANSS assessment and examination of SLR and slump tests. If eligible, the patient was assigned to 1 of the 3 study groups: slider, tensioner, or control.

Outcome Measurements

Outcomes were measured by the examiner. An independent observer recorded hip and knee ROM for the symptomatic side during the examination. The outcome measurements were carried out at baseline, after the first session, after the third session, and after the sixth session.

The visual analog scale (VAS) was used to measure pain intensity. It consisted of a 10-cm horizontal line with “no pain” at one end and “worst imaginable pain” at the other end. The patient was asked to mark his current leg pain on the line. VAS is a valid and reliable measurement of pain intensity,²⁷ with a minimal clinically important difference of 1.8 to 1.9 cm.²⁸

The ROM of the SLR test was measured as the angle of hip flexion in relation to the horizontal. The SLR test has a minimal detectable change (MDC) of 5.7° for hip flexion angle²⁹ and interrater reliability of 0.32 to 0.86.³⁰ The patient was in supine position with his neck in neutral without pillows. The examiner supported the knee in full extension using the proximal hand, whereas the distal hand was used to maintain the ankle in a neutral position. The examiner passively raised the leg until the patient reported reproduction of symptoms or until the examiner felt significant resistance to SLR.^31,32 A bubble inclinometer (Fabrication Enterprise Inc, White Plains, NY) was secured just proximal to the ankle joint using double adhesive tape. The inclinometer was directed toward the medial aspect of the leg so that the examiner could not see it. The independent observer adjusted the fluid to zero level before testing and recorded the ROM during the test.

The slump test has an excellent reliability of 0.90 and an MDC of 1.94° for knee flexion angle.¹⁶ In the slump test, the patient was seated at the edge of the bed with legs dangling freely and the knee at an angle of 90° flexion. The patient's trunk was placed in slump position with neck flexion and hands together behind the back. The distal hand of the examiner was used to maintain the ankle in neutral position. The proximal hand was used to maintain the slump position of the patient's trunk. The examiner verbally instructed the patient to maintain his or her neck in flexed position. The examiner used his distal hand to passively extend the examined knee until the patient felt his or her symptoms, or until the examiner felt significant resistance.³² The bubble inclinometer was secured just proximal to the ankle joint using double adhesive tape. The inclinometer was directed toward the medial aspect of the leg so that the examiner could not see it. The independent observer adjusted the inclinometer to 0° as a reference to where the knee was in the start position of 90° knee flexion and recorded the angle of knee extension during the test.

Interventions

Each patient received therapeutic sessions over 2 weeks (3 sessions per week). Patients in all groups received TENS. In addition, the tensioner group received the tensioner neural mobilization exercise, and the slider group received the slider neural mobilization exercise. Patients were not allowed to take medication for pain during the study or to receive any other form of treatment outside of the study.

A TENS device (Sonicplus 692V, ENRAF-NONIUS, Rotterdam) was applied at a pulse frequency of 100 Hz.³³ A single channel with 2 surface electrodes was used for stimulation over a session period of 15 minutes.³⁴ The electrodes were placed on the painful paraspinal areas of the back. The intensity was set to enable a clear tingling sensation above the sensory threshold of the patient.³⁴

The patient performed the tensioner exercise in a sitting slump position. The patient sat on the edge of the bed with the neck and trunk in flexion, hips and knees in 90° flexion, and ankles in resting plantar flexion. The patient was asked to move the neck into flexion, the treated knee into extension, and the treated ankle into dorsiflexion simultaneously (phase 1). Then the patient extended the neck, flexed the knee, and plantar flexed the ankle simultaneously (phase 2). The patient was encouraged to achieve the exercise with tolerated pain. The exercise was performed for 10 repetitions over 2 sets. The patient was given a 2-minute resting time between the sets.^7,16

The patient performed the slider exercise in a sitting slump position. The patient sat on the edge of the bed with the neck and trunk in flexion, hips and knees in 90° flexion, and ankles in resting plantar flexion. The patient was asked to move the neck into extension, the treated knee into extension, and the treated ankle into dorsiflexion simultaneously (phase 1). Then the patient flexed the neck, flexed the knee, and plantarflexed the ankle simultaneously (phase 2). The patient was encouraged to achieve the exercise with tolerated pain. The exercise was carried out for 10 repetitions over 2 sets, with a 2-minute rest between the sets.^7,16

Statistical Analysis

SPSS software (version 23, IBM Corporation, New York) was used for statistical analysis. Descriptive data of the mean and SD were obtained for all data. The baseline between-groups comparisons were performed using 1-way analysis of variance. A 2-way mixed design analysis of variance with post hoc (Bonferonni correction) was used to calculate the differences in outcome measurements over time (baseline, first, third, and sixth session) as a within-group factor and groups (control, slider, and tensioner) as a between-group factor. The effect size was also calculated with Cohen's d to estimate the magnitude of differences within and between groups (small [d = 0.2], medium [d = 0.5], and large [d = 0.8]).³⁵ The significant level was set at P < .05.

Results

Figure 1 is a flow diagram describing the patients’ recruitment. Table 1 shows that there were no significant differences between the groups for all the demographic and clinical variables at baseline, indicating homogenous groups.

Fig 1.

CONSORT diagram of patients’ enrolment. Rx, Treatment, TENS, Transcutaneous electrical nerve stimulation

Table 1.

Baseline Characteristics of All Groups

Variables	Slider	Tensioner	Control	Statistics	P Value
Age (y)	36.7 ± 8.1	33.5 ± 8.7	40.2 ± 9.5	F(2.48) = 2.503	.092
Sex (M/F) (n)	17/0	17/0	17/0
BMI (kg/m2)	28.2 ± 5.6	28.2 ± 6.1	27.1 ± 3.8	F(2.48) = 0.260	.772
VAS (cm)	5.1 ± 2.2	5.1 ± 2.0	5.6 ± 1.8	F(2.48) = 0.475	.652
ROM (degrees)
Hip flexion in SLR	58 ± 16	46 ± 16	52 ± 15	F(2.48) = 2.198	.122
Knee extension in slump	44 ± 18	43 ± 15	38 ± 17	F(2.48) = 0.732	.486
Symptomatic side
Right (n)	6	9	6	χ2 (2) = 1.457	.483
Left (n)	11	8	11

Values are expressed as mean ± SD unless otherwise.

BMI, body mass index; ROM, range of motion; SLR, straight leg raise; VAS, visual analog scale.

Regarding pain intensity, the 2-way mixed design analysis of variance revealed a significant group-by-time interaction (F [6,144] = 3.539, P = .003). Compared with the baseline measurement, pain decreased significantly at all sessions in the tensioner group and at sessions 3 and 6 in the slider group. Although pain decreased significantly in the control group at only session 6, there were significant differences between the control group and both the slider and tensioner groups in favor of the later groups. No significant differences were found between the slider group and tensioner group at any session (Fig 2 and Table 2).

Fig 2.

Results of pain intensity. Bars indicates standard deviation. Solid line: p < .050, dotted line: p < .001. For more statistics values see Table 2.

Table 2.

Mean Difference in Within-Group and Between-Group for Pain (in centimeters)

Within-Group Mean Difference (95% CI) (Cohen's d)
Control Group			Slider Group			Tensioner Group
C1-C2	C1-C3	C1-C4	S1-S2	S1-S3	S1-S4	T1-T2	T1-T3	T1-T4
0.7	0.5	1.0 a	0.3	1.5 a	2.4 a	1.5 a	2.5 a	3.0 a
(-0.1 to 1.6)	(-0.4 to 1.5)	(0.0-1.9)	(-0.6 to 1.1)	(0.6-2.4)	(1.5-3.3)	(5.7-18.8)	(7.6-23.06)	(13.2-29.9)
(0.41)	(0.30)	(0.56)	(0.14)	(0.68)	(1.11)	(0.73)	(1.25)	(1.71)
The between-group mean difference (95% CI) (Cohen's d)
C2-S2	C2-T2	S2-T2	C3-S3	C3-T3	S3-T3	C4-S4	C4-T4	S4-T4
0.1	1.3	1.2	1.5a	2.5*	1.0	2.0 a	2.6 a	0.5
(-1.3 to 1.5)	(-0.1 to 2.7)	(-0.2 to 2.6)	(0.1-2.0)	(1.1-4.0)	(-0.5 to 2.4)	(0.7-2.3)	(1.3-3.9)	(-0.7 to 1.8)
(0.07)	(0.64)	(0.56)	(0.75)	(1.28)	(0.45)	(1.02)	(1.56)	(0.29)

C1, control group baseline measurement; C2, control group first session measurement; C3, control group third session measurement; C4, control group sixth session measurement; CI, confidence interval; S1, slider group baseline measurement; S2, slider group first session measurement; S3, slider group third session measurement; S4, slider group sixth session measurement; T1, tensioner group baseline measurement; T2, tensioner group first session measurement; T3, tensioner group third session measurement; T4, tensioner group sixth session measurement.

^aIndicates significant P value.

As for the ROM of the SLR test, a significant group-by-time interaction was found (F [6,144] = 2.957, P = .009). Compared with the baseline measurement, the ROM of SLR test increased significantly in both the slider and tensioner groups at all sessions, with a moderate to high effect size in the slider group, and a high effect size in the tensioner group. In the control group, there was a significant increase in the ROM of the SLR test at sessions 1 and 3 but with a low to moderate effect size. Interestingly, the improvement was progressive in the following sessions for both the slider and tensioner groups, but not for the control group. There were no significant differences between the slider and tensioner groups at any session (Fig 3 and Table 3).

Fig 3.

Results of hip flexion range of motion of the straight leg raise test. Bars indicates standard deviation. Solid line: p < .050, dotted line: p < .001. For more statistics values see Table 3.

Table 3.

Mean Difference in Within-Group and Between-Group for Hip Flexion Range of Motion of SLR Test (in degrees)

Within-Group Mean Difference (95% CI) (Cohen d)
Control Group			Slider Group			Tensioner Group
C1-C2	C1-C3	C1-C4	S1-S2	S1-S3	S1-S4	T1-T2	T1-T3	T1-T4
6.7*	7.4*	5.9	5.9*	9.8*	16.7*	12.5*	16.5*	22.2*
(-11.4 to -2.0)	(-14.37 to -0.6)	(-13.5 to 1.8)	(-10.6 to -1.2)	(-16.6 to -2.9)	(-24.3 to -9.1)	(-17.3 to -7.9)	(-23.4 to -9.7)	(-29.9 to -14.6)
(0.46)	(0.50)	(0.35)	(0.37)	(0.62)	(0.87)	(2.84)	(1.09)	(1.55)
The between-group mean difference (95% CI) (Cohen d)
C2-S2	C2-T2	S2-T2	C3-S3	C3-T3	S3-T3	C4-S4	C4-T4	S4-T4
5.1	0.4	-4.7	8.2	3.6	-4.6	16.7*	10.9	-5.8
(-15.7 to 5.6)	(-11.0 to 10.3)	(-5.9 to 15.3)	(-18.3 to 1.8)	(-13.6 to 6.5)	(-5.4 to 14.7)	(-29.2 to -4.3)	(-23.3 to 1.67)	(-6.6 to 18.3)
(0.34)	(0.02)	(0.29)	(0.55)	(0.25)	(0.32)	(0.83)	(0.71)	(0.33)

C1, control group baseline measurement; C2, control group first session measurement; C3, control group third session measurement; C4, control group sixth session measurement; CI, confidence interval; S1, slider group baseline measurement; S2, slider group first session measurement; S3, slider group third session measurement; S4, slider group sixth session measurement; SLR, straight leg raise; T1, tensioner group baseline measurement; T2, tensioner group first session measurement; T3, tensioner group third session measurement; T4, tensioner group sixth session measurement.

*Indicates significant P value.

Concerning the ROM of the slump test, significant group-by-time interactions were found (F [6,144] = 2.521, P = .024). The ROM of the slump test did not change in the control group. On the other hand, the ROM of slump test increased at all sessions compared with baseline in both the slider and tensioner groups with a high effect size. There were no significant differences between the slider and tensioner groups at any session (Fig 4 and Table 4).

Fig 4.

Results of knee extension range of motion of the slump test. Bars indicates standard deviation. Solid line: p < .050, dotted line: p < .001. For more statistics values see Table 4.

Table 4.

Mean Difference in Within-Group and Between-Group for Knee Extension Range of Motion of Slump Test (in Degrees)

Within-Group Mean Difference (95% CI) (Cohen d)
Control Group			Slider Group			Tensioner Group
C1-C2	C1-C3	C1-C4	S1-S2	S1-S3	S1-S4	T1-T2	T1-T3	T1-T4
2.9	4.3	5.3	14.4*	14.2*	18.8*	12.2*	15.3*	21.5*
(-9.42 to 3.657)	(-11.96 to 3.375)	(-13.66 to 3.079)	(-20.9 to -7.8)	(-21.9 to -6.6)	(-27.1 to -10.4)	(-18.8 to -5.7)	(-23.0 to -7.6)	(-29.9 to -13.2)
(0.16)	(0.27)	(0.31)	(0.94)	(0.86)	(1.11)	(0.81)	(1.06)	(1.51)
The between-group mean difference (95% CI) (Cohen d)
C2-S2	C2-T2	S2-T2	C3-S3	C3-T3	S3-T3	C4-S4	C4-T4	S4-T4
18.1*	14.6*	3.5	16.6*	16.2*	-0.4	20.1*	21.5*	-1.4
(-28.6 to -7.6)	(-25.1 to -4.1)	(-14.046 to 6.98)	(-26.5 to -6.7)	(-26.1 to -6.4)	(-10.2 to 9.5)	(-30.8 to -9.5)	(-32.1 to -10.8)	(-9.3 to 12.0)
(1.22)	(0.88)	(0.26)	(0.16)	(1.15)	(0.02)	(1.25)	(1.40)	(0.09)

C1, control group baseline measurement; C2, control group first session measurement; C3, control group third session measurement; C4, control group sixth session measurement; CI, confidence interval; S1, slider group baseline measurement; S2, slider group first session measurement; S3, slider group third session measurement; S4, slider group sixth session measurement; T1, tensioner group baseline measurement; T2, tensioner group first session measurement; T3, tensioner group 3 third session measurement; T4, tensioner group sixth session measurement.

^aIndicates significant P value.

Discussion

To our best knowledge, this is the first clinical trial conducted to investigate the difference between slider and tensioner exercises on pain and ROM of neural tissue provocation tests in patients with low back–related leg pain with peripheral nerve sensitization. Generally, the results showed significant improvements in all outcomes in favor of the slider and tensioner groups but not the control group, with no differences between the slider and tensioner groups.

Our findings showed that the VAS pain score improved significantly and progressively in both the slider (1.5-2.5 cm) and tensioner (1.5-3 cm) groups. In the control group, pain did not show any significant improvement until the last session. However, this change (0.9 cm) did not reach the minimal clinically important difference of VAS (1.8-1.9 cm).²⁸ In addition, the decrease of pain in the last session was statistically elevated in both treatment groups compared with the control group. Patients in the tensioner group had the advantage of an immediate reduction in pain after the first session unlike the slider group.

Previous studies that have investigated slider and tensioner exercises on patients with low back–related LBP are scarce. Ali et al.²³ and Pallipamula and Singaravelan²⁴ found that the slump slider exercise in combination with other treatments improved pain. Čolaković and Avdić³⁶ applied the SLR tensioner exercise in a side-lying position in combination with a lumbar stabilization program and found a significant decrease in pain compared with active ROM exercises and the lumbar stabilization program. Applying slider or tensioner exercises on other neurogenic conditions, such as cervical radiculopathy, also improved pain.^20,22 Generally, slump and SLR mobilization exercises are effective in reducing pain and improving function in chronic nerve-related LBP.¹² On the other hand, there was no improvement in pain among patients with LBP³⁷ or carpal tunnel syndrome.¹⁹ In Patel's study, the slump stretching exercise was sustained for 30 seconds and repeated 3 times per session.³⁷ The difference in the results may be attributed to the differences in the exercise used and the patients’ diagnosis and characteristics.

In the current study, cumulative improvement in ROM of SLR over sessions was demonstrated in both the slider (range 6°-16°) and tensioner (range 13°-30°) groups. In the control group, there was an improvement of only 7° after the first session, which stayed the same until the last session. Previous studies found improvement in ROM of SLR in patients with radicular LBP after using slider²⁴ or tensioner exercises.^24,25,36,38 Other studies, on the other hand, found that adding slump tensioner did not improve the ROM of the SLR test in patients with LBP who had no radicular symptoms.³⁷Again, the differences in interventions and patients characteristics between our study and the study by Patel³⁷ may contribute to this discrepancy in the results.

In our study, the knee extension ROM of the slump test improved significantly in both the slider (range 15°-19°) and tensioner (range 12^o-21°) groups but not in the control group. This improvement was more than the MDC of 1.94°.¹⁶ In healthy participants, slider and/or tensioner exercises improved the hip flexion ROM of SLR test and the knee extension ROM of slump test.^17,39,40

Understanding the physical and physiological effects of both the slider and tensioner exercises is important to recognize the differences between these exercises. A limited number of studies have been conducted to investigate the differences between the 2 exercises. Most of these studies focused on investigating the biomechanical aspects of these exercises on nerves. The major biomechanical difference between the 2 exercises is the amount of excursion and strain produced by each. Cadaveric and in vivo studies revealed that the tensioner exercise produced higher nerve strain and the slider exercise was associated with higher nerve excursion.13, 14, 15^,41,42

Neural mobilization is used to regain the movement of the nerve tissue, restore nerve tissue homeostasis, and promote the nerve to return to its normal functions.⁴³ The literature has hypothesized possible physiological changes that may have led to the improvement of patients in this study using neural mobilization. These changes may include decreased intraneural edema, thus reducing hypoxia and relieving symptoms; decreased neurogenic inflammation by eliminating antidromic impulses generated in C-fibers at the dysfunctional site; and reduced nociceptive input to the dorsal horns of the spinal cord.^7,44 In the current study, the improvements were demonstrated within 2 weeks of intervention (3 sessions per week) with only 2 sets of 10 repetitions of neural mobilization exercises. Because there is not much evidence, it is recommended for future research to address the effect of different doses of neural mobilization.

Limitations

A limitation with this study is the lack of randomization. Randomization would have prevented selection and accidental bias, and would have created more homogenous and comparable groups, and would have eliminated potential bias in treatment assignments. Therefore, there is a probability that the observed differences between group measurements are owing to chance and that no true differences exist between the treatment groups.⁴⁵ Another limitation of the study may be that we did not include nerve palpation as 1 of the criteria of peripheral nerve sensitization. However, in addition to LANSS and the negative signs of neurologic dysfunction, we relied primarily on SLR and slump tests as neural tissue provocation tests. Walsh and Hall³² used SLR and slump tests as the reference standard for sciatic nerve mechanosensitivity. They considered patients, who were positive on both SLR and slump tests, as positive for sciatic nerve mechanosensitivity. Moreover, we used only pain and ROM as outcomes. Adding functional and quality of life measurements would have demonstrated the impact of neural mobilization on patients’ activities and social lives. In addition, general ROM exercises for the lower limb were not added as a control intervention, taking into consideration that the use of positive verbal communication during the slider and tensioner exercises might produce a placebo analgesic effect.⁴⁶

Conclusion

This is the first study to our knowledge that investigated the difference between the slider and tensioner exercises on pain and ROM of SLR and slump tests in patients with low back–related leg pain who demonstrated predominant characteristics of peripheral nerve sensitization. Both exercises demonstrated statistically and clinically meaningful improvements compared with the control group. There were no differences in the outcomes between the slider and tensioner exercises.

Funding Sources and Conflicts of Interest

No funding sources or conflicts of interest were reported for this study.

Contributorship Information

Concept development (provided idea for the research): M.A.A.

Design (planned the methods to generate the results): M.A.A., M.S.A.

Supervision (provided oversight, responsible for organization and implementation, writing of the manuscript): M.S.A., A.M.A.

Data collection/processing (responsible for experiments, patient management, organization, or reporting data): M.A.A., A.M.A.

Analysis/interpretation (responsible for statistical analysis, evaluation, and presentation of the results): M.A.A., M.S.A., A.M.A.

Literature search (performed the literature search): M.A.A.

Writing (responsible for writing a substantive part of the manuscript): M.A.A., A.M.A.

Critical review (revised manuscript for intellectual content, this does not relate to spelling and grammar checking): M.A.A., M.S.A., A.M.A.

Practical Applications.

• •The findings of the study add insight into the effect of the slider and tensioner techniques in patients with lumbosacral radiculopathy.
• •Three sessions per week for 2 weeks of slider and tensioner techniques improved pain and hip and knee ROM.
• •Although the trend was in favor of the tensioner, there were no significant differences between the tensioner and slider techniques.

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