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Table of Contents
ORIGINAL ARTICLE
Year : 2020  |  Volume : 2  |  Issue : 2  |  Page : 99-105

Effect of integrated neuromuscular inhibition technique on trigger points in patients with nonspecific low back pain: Randomized controlled trial


Department of Orthopaedic Manual Therapy, KAHER, Institute of Physiotherapy, Belagavi, Karnataka, India

Date of Submission19-Jun-2019
Date of Decision26-Jun-2019
Date of Acceptance22-Apr-2020
Date of Web Publication04-Jan-2021

Correspondence Address:
Dr. Sarana Souza Monteiro
KAHER, Institute of Physiotherapy, Belagavi, Karnataka
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijptr.ijptr_49_19

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  Abstract 


Background and Objective: Trigger points in the myofascial system form the major reason for pain and tenderness in nonspecific low back pain (NSLBP). These points can be treated using manual therapy techniques such as integrated neuromuscular inhibition technique (INIT). Due to lack in the literature about its effect in NSLBP condition, the present study was undertaken to evaluate the effects of INIT on trigger points in patients with NSLBP.
Materials and Methods: Forty-four patients with NSLBP were randomly assigned to either of the two study groups using envelope method. Group A (n = 22) was treated with stretching and strengthening exercises, whereas Group B (n = 22) was treated with INIT. Both the groups received hot moist pack and therapeutic ultrasound as common treatment. Five consecutive sessions of intervention were given over 5 days. Outcome measures in terms of pain pressure threshold (quadratus lumborum [QL] and erector spinae [ES]), lumbar range of motion (ROM), and disability were measured at baseline and end of the fifth session of treatment.
Results: The within-group analysis showed a reduction in pain, improved ROM, and disability in both the study groups (P < 0.001). However, the between-group analysis reported that INIT was more effective than the control group in terms of reducing trigger point tenderness of QL (P = 0.0011) and ES (P = 0.0001) as well as reducing functional disability (P = 0.0481) but not the ROM (P > 0.05).
Conclusion: The present study concluded that INIT is superior to stretching and strengthening exercises in reducing trigger point tenderness and better functionality in patients with nonspecific low back pain.

Keywords: Erector spinae, Ischemic compression, Muscle energy technique, Quadratus lumborum, Strain counterstrain


How to cite this article:
Metgud SC, Monteiro SS, Heggannavar A, D'Silva PV. Effect of integrated neuromuscular inhibition technique on trigger points in patients with nonspecific low back pain: Randomized controlled trial. Indian J Phys Ther Res 2020;2:99-105

How to cite this URL:
Metgud SC, Monteiro SS, Heggannavar A, D'Silva PV. Effect of integrated neuromuscular inhibition technique on trigger points in patients with nonspecific low back pain: Randomized controlled trial. Indian J Phys Ther Res [serial online] 2020 [cited 2021 Oct 18];2:99-105. Available from: https://www.ijptr.org/text.asp?2020/2/2/99/190043




  Introduction Top


Low back pain (LBP) is any discomfort or pain felt in the body which is localized between the costal margins and above the inferior gluteal fold ranging from the first lumbar vertebra to anywhere between till the first sacral vertebra.[1],[2] Nonspecific low back pain (NSLBP) is the pain which is not linked to any pathology in specific, like in the cases of inflammatory disorders, infections, tumors, osteoporosis, radiculo-arthropathies, and fractures.[2]

The estimated prevalence of NSLBP is 23% and incidence of 11%–22% in the general population.[1] Studies say that nearly 50% of the population at the age of 30 years will have experienced a significant incidence of LBP.[3] LBP is a worldwide problem with a lifetime prevalence of 84%.[2]

It is said that trigger points form the major part of pain suffered by people with musculoskeletal dysfunction.[4] NSLBP is one such condition in which trigger points are formed in paraspinal muscles such as erector spinae (ES) and quadratus lumborum (QL).[5] The presence of trigger points could be due to repetitive loading on the muscle tissue. One of the probable causes of the formation of these trigger points is the presence of dysfunctional endplates, which causes a decrease in the sarcomere length of the muscle fiber. These trigger points need to be released or treated to avoid further aggravation of symptoms. Trigger points can be categorized as either active or latent. Active trigger points are those that cause pain at rest or with activity of the muscle containing the trigger point. According to the authors, a latent trigger point does not cause pain but may cause restricted movement and weakness of the muscle containing the trigger point.[6]

Literature suggests that trigger points can be treated effectively with various manual therapy techniques such as ischemic compression (IC),[5] positional release technique/strain counterstrain (SCS) technique,[7] deep transverse friction massage,[7] and muscle energy technique (MET)[8] in patients with LBP, thereby resulting in deactivating trigger points and reducing pain intensity. However, controversies do exist in the literature.[8]

Although clinical trials have been conducted to study the efficacy of individual techniques that include MET, IC, and SCS techniques in neck and myofascial pain syndrome, it was hypothesized that a combination of the three techniques may be more effective in treating the trigger points as suggested by Leon Chaitow. This method is termed as an integrated neuromuscular inhibition technique (INIT). Chaitow and Crenshaw state that the combination of IC, MET, and SCS produces the most effective, targeted approach to trigger point release. They suggested that the benefit of this technique lies in its multifaceted approach. It allows for delivery of the techniques in a single coordinated manner.[4] Effectiveness of INIT was examined in a comparative study against postisometric relaxation maneuver to deactivate the taut bands in the neck region, particularly the trapezius muscle, and found that INIT had better improvement, concluding that a combination of the three techniques has a better outcome.[9]

Further, there occurs a vacuum in literature about the use of combination of the three techniques, which is known as INIT method of management in patients with NSLBP necessitating additional research to be carried out to fill the gap in literature. Hence, the objective of the present study was to evaluate the effects of INIT on severity trigger points of QL and ES in patients with NSLBP.


  Materials and Methods Top


Study design

The study was a randomized controlled trial that was performed on voluntary participants with lower back pain at a tertiary care hospital, Belagavi, Karnataka. The research had been approved by the institutional research and ethics committee. Before the beginning of the study, a written informed consent was obtained from all participants.

Participants and randomization

Individuals between 18 and 35 years of age with NSLBP were screened for inclusion and exclusion criteria. Individuals were informed about the aims and procedure of the study. They were included if they had NSLBP in the past 3 months, the presence of trigger points in the low back region, reduced lumbar range of motion (ROM), and a minimum score of 10% on the Modified Oswestry Disability Questionnaire (MODQ). Individuals were excluded if they had any history of recent spinal surgeries, vertebral fractures, lumbar radiculopathy, pregnancy, diagnosed with any recent systemic illnesses or infections, and diagnosed with any other comorbid conditions related to the spine such as prolapsed intervertebral disc.

After screening 80 participants, a total of 44 participants were included in the study and randomly allocated using envelope method to Control Group A (stretching and strengthening exercise along with conventional therapy) and Experimental Group B (INIT along with conventional therapy) [Figure 1].
Figure 1: CONSORT flow diagram

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Measurement of treatment outcomes

Pain was assessed using pressure algometer. The trigger points were identified bilaterally by the therapist using palpation method on the ES and QL muscles, and the analog pressure pain algometer was applied vertically at approximately 2 kg/cm/s to these points slowly. The participant was instructed to report forthwith verbally when the sense of pressure changed to a sense of pain. The reading was recorded on the pressure algometer in the unit of pounds (lbs).[10]

MODQ was used to assess to what extent back pain has affected the functional capacity of the participant. This scale consists of 10 items in the form of daily living tasks with each item scoring from 0 to 5, where 0 is no difficulty in performing that activity and 5 is inability to perform that activity. The participants had been advised to answer the questionnaire by marking every item with the most suitable response. In case of language barrier, the questions were translated and explained to the participant in their vernacular language and their response was noted.[11]

Modified Schober's test was used to assess the flexion and extension ROM of the lumbar spine. The posterior superior iliac spine was located and marked with a midpoint. A point 10 cm above from the midpoint was labeled, and another point was marked 5 cm below the midpoint. The participant was then asked to bend forward, and the movement of lumbar flexion was reported as the distance between the two points. The participant was then asked to bend backward, and the distance was reported as a movement of lumbar extension.[12]

To determine lumbar side flexion (ROM), the finger-to-floor test was used. In this, the participant was standing with the arms by the side. The measurements were taken from the tip of the middle finger to the ground. The participant was then asked to bend laterally, and the distance from the middle finger's tip to the ground was again measured and the difference was documented.[13]

Intervention

Participants were randomly allocated to either Control Group A (stretching and strengthening exercise + conventional therapy) and Experimental Group B (INIT + conventional therapy). The intervention for both the groups was given for 5 consecutive days.

Conventional therapy

The common treatment given to the participants of the two study groups consisted of conventional therapy that included heat therapy for the trigger points unilaterally in the QL and ES muscles in the low back region using hot moist pack for a duration of 15 min, followed by therapeutic ultrasound. Ultrasound was applied for 6 min with a frequency of 3 MHz and a power of 0.8–1 watt/cm2 at the trigger points in the lower back region.[14],[15],[16]

Control Group A (stretching and strengthening exercise with conventional therapy)

The control group received stretching exercises for QL and ES muscles with a hold duration of 30 s for three repetitions. The strengthening exercises were given to the abdominals, oblique, and back extensor muscles that included partial curl-up, cross curl-up, and side bridge for the anterior muscle group and bird dog exercise for the rear muscle group. Each exercise was given for ten repetitions, followed by a rest period of 2 min[17],[18] [Figure 2]a, [Figure 2]b, [Figure 2]c, [Figure 2]d, [Figure 2]e, [Figure 2]f.
Figure 2: Stretching and strengthening exercise. (a) Erector spinae stretch. (b) Erector spinae stretch. (c) Partial curl-up. (d) Rotation curl-up. (e) Side bridge. (f) Back extensor strengthening exercise

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Experimental Group B (integrated neuromuscular inhibition technique with conventional therapy)

The experimental group received INIT which included IC, SCS, and MET for the low back region for the QL and ES muscles. IC was given by the therapist on the trigger point which was maintained for 90 s [Figure 3]a. This was followed SCS technique in which the participant was passively positioned in a comfortable position either in trunk flexion, extension, or lateral flexion, maintaining the previously held pressure at the trigger point by the therapist [Figure 3]b. This was followed by the MET, where the participant was in supine position, and the patient had to laterally flex the trunk away from the side which was affected. The individual was asked to side bend toward the affected side. This was held for 10 s which was followed by a stretch on the opposite side for 30 s [Figure 3]c. The entire sequence was repeated five times.[4]
Figure 3: Integrated neuromuscular inhibition technique. (a) Ischemic compression. (b) Strain counterstrain. (c) Muscle energy technique

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Statistical analysis

The Statistical Package for the Social Sciences software version 20.0(SPSS for windows, Armonk, NY: IBM corp., USA) was used for statistical analysis. Statistical tests such as Kolmogorov–Smirnov test for normality, paired t-test, and independent sample t-test have been used. The data collected followed normality distribution. A comparison between the groups was using an independent t-test. Pre- and postdata were compared using a paired t-test. A probability value of < 0.05 was considered as statistically significant.


  Results Top


[Table 1] provides details on the demographic profile and the baseline characteristics of participants. A comparison between the groups implied normal demographic distribution. Most of the individuals in the study were slightly overweight; therefore, the body mass index was more toward the upper limit of normal range.
Table 1: Summary of the demographic data

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There was a statistically significant reduction in the mean of pressure pain threshold (PPT) scores of ES with a greater percentage of change in Experimental Group B with 47.13% (P < 0.0001) as compared to Control Group A with 7.79% (P = 0.11) [Table 2]. There was a statistically significant reduction in the mean of PPT scores of QL in Experimental Group B as compared to Control Group A (P < 0.0001). The percentage change in the INIT group (51.01%) was greater than the control group (10.12%) [Table 3].
Table 2: Within- and between-group comparison of pre- and posttest scores of pain pressure threshold of erector spinae (lbs)#

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Table 3: Within- and between-group comparison of pre- and posttest scores of pain pressure threshold of quadratus lumborum (lbs)

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A comparison of pre- to posttest for lumbar flexion and lumbar extension ROM showed a significant difference with percentage of change in Group A being 4.10% for flexion and 9.64% for extension and Group B being 4.26% for flexion and 14.28% for extension (P < 0.01) [Table 4] and [Table 5]. A comparison between pre and post test values of lateral flexion (Right and Left) showed statistical significance [Table 6] and [Table 7]. However, between-group analyses for all the above-mentioned movements showed an insignificant difference, indicating that both the groups were equally effective.
Table 4: Within- and between-group comparison of pre- and posttest scores of lumbar flexion

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Table 5: Comparison of pre- and posttest scores of lumbar extension (cms) between both groups

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Table 6: Comparison of pre- and posttest scores of lateral flexion (right) (cms) between both groups

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Table 7: Comparison of pre- and posttest scores of lateral flexion (left) (cms) between both groups

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Analysis of MODQ scores showed a percentage of change in Group A to be 11.59% (P = 0.0002) and in Group B 19.63% (P < 0.01). The between-group analysis also showed a significant difference with P = 0.0349 [Table 8].
Table 8: Comparison of pre- and posttest scores of the Modified Oswestry Disability Questionnaire (%) between both groups#

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  Discussion Top


In the present study, the percentage of females diagnosed with NSLBP was greater than males. The global prevalence of NSLBP stated that females are at a greater risk of developing LBP, which was explained to be due to low pain threshold sensitivity in females.[19],[20]

Myofascial trigger points (MTrPs) are painful points felt on palpation of the tightened fibers of the skeletal muscle which need to be released or treated to avoid further aggravation of the symptoms.[21]

The INIT group showed to be superior to the control group in terms of pain and functionality. This can be due to the fact that INIT incorporates the application of combination of IC, positional release, or SCS technique and MET. A combination of these techniques is recognized to be effective in deactivating trigger points. The findings of the present study are in consensus with another study where INIT was given for trapezius muscle.[9] The results of the study showed a reduction in pain and better functionality. This can be explained by a few factors. The first factor is that there is an increase in muscle stretch tolerance. Second, MET diminishes the periarticular block that enhances tissue extensibility and joint mobility. Third, the SCS technique restores the contracted muscle fibers to their normal resting length which could be based on the barrier-release concept. This concept explains that when pressure is applied to the trigger points in the form of compression force, there is an activation of mechanoreceptors that lead to local rise in ischemia and blood flow. Further, the tightened muscle is kept in a position of ease where there is resetting of the muscle spindles which are the receptor organs responsible for maintaining the tone in the muscle. Therefore, once the muscle spindles are realigned, there is an increase in the length of the muscle.[9]

The improvement in the INIT group in the present study can also be explained by individual effects of each of the three techniques applied. There are various therapeutic mechanisms proposed to explain the effects of IC technique; the pressure applied on the taut band on the muscle fiber increases the length of the sarcomere on the affected MTrP and thus decreases the pain. Another explanation given is the formation of reactive hyperemia in the MTrP which causes a reduction in pain.[22]

The effectiveness associated with MET could be attributed to the effect of the Golgi tendon organs that are activated during the stretch of a muscle which has a negative effect on the motor neuronal discharges and hence reducing the reflex contraction caused by the stretch reflex. This eventually leads to the relaxation of the musculotendinous unit causing the sarcomere to return to its original length, thus increasing the length of the muscle fiber from its shortened position to its normal length.[23] Isometric muscle contraction performed during MET is said to cause a change in the flow of blood and lymph pressure gradients causing decongestion in paraspinal muscles.[24],[25],[26] The improvement in functional disability is in accordance with another study conducted by William E et al. where METs were administered to patients with acute LBP over a period of 4 weeks. The study showed a marked improvement in the Oswestry Disability Index which assesses the overall functional evaluation of the patient.[27]

In the SCS technique, the trigger point is pressed causing the mechanoreceptors to be activated and cause a local rise in ischemia and blood flow and the tightened muscle is kept in a position of ease where there is resetting of the muscle spindles which are receptor organs responsible for maintaining the tone in the muscle; therefore, once the muscle spindles are realigned, there is an increase in the length of the muscle, which is the explanation to the decrease in pain and increase in ROM in the current study.[28]

It is a proven fact that pain can cause limitation in activity levels.[23] This may further lead to a reduction in the available ROM, thus causing negative effects on the daily task performance. Thus, a reduction in pain intensity may have improved daily task performance which may have further reduced the individual's activity limitation.

The drawbacks of the present study were that the strength of the abdominals and back extensors was not assessed before giving strengthening exercises and that there was a lack of follow up to monitor the long-term effects of the intervention. The future scope of this study is that more studies can be carried out with more precise outcome measures to check for muscle activity at the low back region with devices of high validity and reliability.


  Conclusion Top


The present study provides evidence to prove that INIT resulted in deactivating trigger points in patients with NSLBP than stretching–strengthening exercises. The study also gives evidence that the combination of IC, SCS, and MET (INIT) can aid in better functional outcomes along with alleviated pain in patients with NSLBP with the presence of trigger points.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

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Abha S, Angusamy R. Efficacy of post-isometric relaxation versus integrated neuromuscular ischemic technique in the treatment of upper trapezius Trigger points. Ind J Physiother Occup Ther 2010;4:1e5.  Back to cited text no. 9
    
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Sehar N, Rajah H, Hussain H, Ahmed S. Effects of moist heat therapy pre and post back extension exercises on non-specific back pain in middle aged females. IJRS 2018;7:2-6.  Back to cited text no. 15
    
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Aguilera FJ, Martín DP, Masanet RA, Botella AC, Soler LB, Morell FB. Immediate effect of ultrasound and ischemic compression techniques for the treatment of trapezius latent myofascial trigger points in healthy subjects: A randomized controlled study. J Manipulative Physiol Ther 2009;32:515-20.  Back to cited text no. 21
    
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Fernández-de-las-Peñas C, Alonso-Blanco C, Fernández-Carnero J, Miangolarra-Page JC. The immediate effect of ischemic compression technique and transverse friction massage on tenderness of active and latent myofascial Trigger points: A pilot study. J Bodyw Mov Ther 2006;10:3-9.  Back to cited text no. 22
    
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Fahmy E, Shaker H, Ragab W, Helmy H, Gaber M. Efficacy of spinal extension exercise program versus muscle energy technique in treatment of chronic mechanical low back pain. Egypt J Neurol Psychiatry Neurosurg 2019;55:1-6.  Back to cited text no. 25
    
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  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8]



 

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