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 Table of Contents  
ORIGINAL ARTICLE
Year : 2018  |  Volume : 12  |  Issue : 1  |  Page : 37-42

The effects of McKenzie exercises in chronic nonspecific low back pain patients with central sensitization: A pilot study


1 School of Physiotherapy, RK University, Rajkot; Sarvajanik College of Physiotherapy, Surat, Gujarat, India
2 Khyati Institute of Physiotherapy, Ahmedabad, Gujarat, India
3 Orthopedic Surgeon, Hajee AM Lockhat and Dr. AM Moolla Sarvajanik Hospital, Surat, Gujarat, India
4 Director, School of Physiotherapy, RK University, Rajkot, Gujarat, India

Date of Submission11-Jan-2018
Date of Acceptance11-Mar-2018
Date of Web Publication19-Jun-2018

Correspondence Address:
Dr. Dibyendunarayan Dhrubaprasad Bid
Department of Musculoskeletal Physiotherapy, Sarvajanik College of Physiotherapy, Rampura, Surat - 395 009, Gujarat
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/PJIAP.PJIAP_27_17

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  Abstract 

BACKGROUND: The possibility of the presence of central sensitization (CS) among chronic nonspecific low back pain (CNSLBP) patients to predict treatment response by related outcome measures has not been adequately explored. The purpose of this pilot study was to determine the feasibility of a study to compare “McKenzie exercise program” (MEP) and “conventional physiotherapy program” (CPP) outcomes for participants with CNSLBP, investigate whether any difference in outcome was related to CS, disability, fear-avoidance beliefs and trunk flexors and extensors muscles endurance, and to inform the design of a main study.
OBJECTIVE: The present study tests whether MEP reduces CS better in CNSLBP patients having CS compared to CPP.
METHODS: Forty-two patients with CNSLBP were randomly allocated into two groups. The experimental group (n = 22) received only MEP and control group (n = 20) received only CPP. Each group received specific weekly treatment five times during the study for 2 months. Outcome measures were CS Inventory-Gujarati (CSI-G) for the presence of CS, numerical pain rating scale (NPRS) for pain intensity, pressure pain threshold (PPT) by pressure algometry, Roland–Morris Disability Questionnaire-Gujarati (RMDQ-G) for disability, Fear-avoidance-beliefs Questionnaire-Gujarati (FABQ-G) for fear-avoidance beliefs, and trunk flexors and extensors endurance tests.
RESULTS: Both the groups showed a decrease in NPRS, CSI-G, RMDQ-G, and FABQ-G scores and increase in PPT and trunk flexors and extensors endurance scores. However, decrease in NPRS, CSI-G, RMDQ-G, and FABQ-G scores and increase in PPT scores were significantly better in the experimental group. In contrast, control group performed significantly better on trunk flexors and extensors endurance scores.
CONCLUSION: McKenzie exercises are effective in reducing pain, pain sensitization, disability and fear avoidance beliefs; however, it does not improve trunk flexors and extensors endurance in CNSLBP patients with or without CS.

Keywords: Central sensitization, chronic nonspecific low back pain, McKenzie exercise program


How to cite this article:
Bid DD, Soni NC, Yadav AS, Rathod PV. The effects of McKenzie exercises in chronic nonspecific low back pain patients with central sensitization: A pilot study. Physiother - J Indian Assoc Physiother 2018;12:37-42

How to cite this URL:
Bid DD, Soni NC, Yadav AS, Rathod PV. The effects of McKenzie exercises in chronic nonspecific low back pain patients with central sensitization: A pilot study. Physiother - J Indian Assoc Physiother [serial online] 2018 [cited 2018 Dec 12];12:37-42. Available from: http://www.pjiap.org/text.asp?2018/12/1/37/234689


  Introduction Top


Chronic nonspecific low back pain (CNSLBP) (i.e., low back pain of at least 12 weeks' duration and without a specific cause)[1],[2] is one of the most common health conditions worldwide [3] and is highly associated with disability,[1] emotional changes,[2] and work absenteeism.[1] Given that chronic low back pain (CLBP) is very prevalent,[4] the costs associated with this condition are very high.[5] Approximately 60% of patients consider themselves not recovered in 1 year from the onset of symptoms, with moderate levels of pain and disability persisting over time.[6],[7] Therefore, many of these patients become frequent users of health-care services to find treatments to minimize the severity of their symptoms.

Central sensitization (CS) is described by the International Association for the Study of Pain as “Increased responsiveness of nociceptive neurons in the central nervous system to their normal or subthreshold afferent input.”[8] CS is also defined as “an augmentation of responsiveness of central neurons to input from unimodal and polymodal receptors.”[9]

In this context, the present study intended to verify McKenzie exercise program (MEP) against the conventional exercise program (CPP). The McKenzie method was proposed by Robin McKenzie in 1981.[10] This method has 3 basic components: (1) evaluation (conducted using sustained postures and repeated movements where the symptoms in the lower back and lower limbs are classified into three syndromes: derangement, dysfunction, and postural syndromes); (2) intervention exercises (based on the direction of preference of patients); and (3) prevention (an educational component aimed to encourage patients to use simple self-management strategies to control their symptoms).[10],[11] In the conventional physiotherapy program (CPP), patients are taught how to contract the core muscles and initial 2 weeks are devoted for this core contraction and educating the patients. In the next week-3–week-4, patients are taught endurance contractions. From week-5 to week-6 patients are taught “stability contractions.” Again from week-7 to week-8, patients are progressed to “stability contraction with ADL- Activities of Daily Living training.” The effectiveness of MEP or CPP in CNSLBP patients is known; however, their use in centrally sensitized patients is not verified till now. Therefore, this pilot study hypothesizes that MEP would reduce CS better in CNSLBP patients having the presence of CS and aimed to (1) compare the effect on various outcome measures and (2) inform the design and feasibility of a future study.


  Methods Top


Patients

Outpatients aged 18–50 years with CNSLBP were recruited from the Lockhat Hospital, Surat with inclusion criteria: (1) CNSLBP for 3 months or longer; (2) no radiation of low back pain; (3) normal neurological findings of lumbosacral nerve, including deep tendon reflexes, plantar response, voluntary muscle action, straight leg raising, and sensory function and exclusion criteria: (1) major trauma or systemic disease; and (2) receiving conflicting or ongoing co-interventions, (3) Having nerve root related symptoms, (4) Having specific conditions such as fractures, neoplasm, spondylolysis, spinal stenosis, spondylolisthesis, ankylosing spondylitis, and previous low back surgery. The Institutional Ethical Committee of Nirmal Hospital Pvt. Ltd., Surat, had approved the research protocol. Subsequently, the protocol was registered in Clinical Trial Registry of India bearing registration number CTRI/2017/007683. All enrolled patients gave their written informed consent, and all procedures were conducted in accordance with the Declaration of Helsinki.

Design

The design of this study was an observational study, using a lottery method; the enrolled patients were allocated into either experimental group (MEP) or control group (CPP). Each patient received a total of five treatments per week for 8 weeks, and follow-up was measured at the end of 4th and 8th week.

Treatment

The experimental group and control group patients received treatments as per protocol.[12],[13]

Outcome measures

  1. CS is measured with CS Inventory-Gujarati (CSI-G)[14] (having 25 questions) can be quantified on a score of 0–100. A score above 40 indicates the presence of CS
  2. Pain intensity, quantified with an 11 point numerical pain rating scale (NPRS) (0–10).[15]
  3. Pain disability measured with the Roland–Morris Disability Questionnaire-Gujarati version [16] (RMDQ-G, 0–24 points). The RMDQ-G consists of 24 questions each with two possible “yes” or “no” responses
  4. Pressure pain threshold (PPT) for tibialis anterior muscle were measured with pressure Algometer.[17]
  5. Fear-avoidance beliefs were measured by Fear-avoidance-beliefs Questionnaire-Gujarati (FABQ-G)[18] having 15 questions and maximum score of 90
  6. Trunk flexors and extensors endurance were measured as hold time of these muscles in seconds.[19],[20]


Statistical analysis

All statistical analyses were performed using the SPSS version 20.0 (IBM, Armonk, NY, USA) for Windows for Windows. Before final analysis, data were screened for transcription errors, normality assumptions, homogeneity of variance, as prerequisites for parametric calculations of the analysis of difference, and analysis of relationship measures. Alpha level was set at 0.05 to control for Type I error, and confidence interval was set at 95% for all statistical analysis.


  Results Top


A total of 42 CNSLBP patients (aged 18–50 years) were randomly allocated into two groups for specific treatment. One patient in each group dropped out as they had not turned up for 8th-week evaluation. The dropout rate was not significantly different between the groups. The analyses were performed on the all the 42 patients using intention to treat analysis, i.e., carrying forward the measurements of the previous 4th week's evaluation [Table 1].
Table 1: Demographic characteristics of subjects in both groups

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Central sensitization inventory-Gujarati

A repeated measure multivariate ANOVA with Greenhouse-Geisser correction (GGC) between-group analysis showed that the experimental and control groups were not different statistically with F = 0.273, P < 0.604 and also showed that a between-group analysis of CS and No CS groups were different statistically with F = 9.963, P < 0.003. The within-group analysis showed the significant statistical difference with F = 284.217, P < 0.000. Experimental/control Group* time of measurement interaction analysis showed that the groups were different statistically with F = 61.486, P < 0.000 The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 3.509, P < 0.039 [Table 2] and [Table 3].
Table 2: Baseline comparisons of subjects in both groups

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Table 3: Means and SD of all variables at each follow-up period

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Multivariate test results showed that the comparison of No CS participants in both experimental and control group for the time measurements were not different statistically at 4th week with F = 0.001, P < 0.972 but significance at 8th week with F = 7.733, P < 0.019. The comparison of CS participants in both experimental and control groups for the time measurements was different statistically at 4th week with F = 3.378, P < 0.065 and 8th week with F = 17.293, P < 0.000.

Numerical pain rating scale

A repeated measure multivariate ANOVA with GGC between-group analysis showed that the experimental and control groups were different statistically with F = 102.68, P < 0.000 and also showed that a between-group analysis of CS and No CS groups were not different statistically with F = 2.010, P < 0.164. The within-group showed the significant statistical difference with F = 816.593, P < 0.000. Experimental/control Group* time of measurement interaction analysis showed that the groups were different statistically with F = 98.24, P < 0.000. The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 5.420, P < 0.011 [Table 2] and [Table 3].

Multivariate test results showed that the comparison of No CS participants in both experimental and control groups for the time measurements was statistically significant at 4th week with F = 23.680, P < 0.000and 8th week with F = 18.404, P < 0.001. The comparison of CS participants in both experimental and control groups for the time measurements was different statistically at 4th week with F = 100.309, P < 0.000 and 8th week with F = 176.989, P < 0.000.

Pressure pain threshold for tibialis anterior

A repeated measure multivariate ANOVA with GGC between-group analysis showed that the experimental and control groups were different statistically with F = 36.773, P < 0.000 and also showed that a between-group analysis of CS and No CS groups were different statistically with F = 14.08, P < 0.001. The within-group analysis showed the significant statistical difference with F = 59.690, P < 0.000. Experimental/control Group* time of measurement interaction analysis showed that the groups were different statistically with F = 41.780, P < 0.000. The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 14.654, P < 0.029 [Table 2] and [Table 3].

Multivariate test results showed that the comparison of No CS participants in both experimental and control groups for the time measurements were different statistically at 4th week with F = 22.192, P < 0.000 but different at 8th week with F = 14.708, P < 0.002. The comparison of CS participants in both experimental and control groups for the time measurements were different statistically at 4th week with F = 19.007, P < 0.000 and 8th week with F = 46.277, P < 0.000.

Roland–Morris Disability Questionnaire-Gujarati

A repeated measure multivariate ANOVA with GGC between-group analysis showed that the experimental and control groups were different statistically with F = 6.845, P < 0.013 and also showed that a between-group analysis of CS and No CS groups were different statistically with F = 10.756, P < 0.002. The within-group analysis showed the significant statistical difference with F = 182.122, P < 0.000. Experimental/control group* time of measurement interaction analysis showed that the groups were different statistically with F = 40.642, P < 0.000. The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 0.408, P < 0.605 [Table 2] and [Table 3].

Multivariate test results showed that the comparison of No CS participants in both experimental and control groups for the time measurements were not different statistically at 4th week with F = 1.179, P < 0.299 and 8th week with F = 5.382, P < 0.039. The comparison of CS participants in both experimental and control groups for the time measurements was different statistically at 4th week with F = 13.394, P < 0.001 and 8th week with F = 95.657, P < 0.000.

Fear-avoidance-beliefs Questionnaire-Gujarati

A repeated measure multivariate ANOVA with GGC between-group analysis showed that the experimental and control groups were different statistically with F = 7.872, P < 0.008 and also showed that a between-group analysis of CS and No CS groups was different statistically with F = 30.462, P < 0.000. The within-group analysis showed the significant statistical difference with F = 325.867, P < 0.000. Experimental/control Group* time of measurement interaction analysis showed that the groups were different statistically with F = 46.534, P < 0.000. The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 0.002, P < 0.749 [Table 2] and [Table 3].

Multivariate test results showed that the comparison of No CS participants in both experimental and control groups for the time measurements were different statistically at 4th week with F = 5.532, P < 0.480 but not different at 8th week with F = 9.952, P < 0.008. The comparison of CS participants in both experimental and control groups for the time measurements were different statistically at 4th week with F = 11.931, P < 0.002 and 8th week with F = 52.592, P < 0.000.

Trunk flexors endurance

A repeated measure multivariate ANOVA with GGC between-group analysis showed that the experimental and control groups were different statistically with F = 25.170, P < 0.000 and also showed that a between-group analysis of CS and No CS groups were different statistically with F = 7.054, P < 0.011. The within-group analysis showed the significant statistical difference with F = 149.598, P < 0.000. Experimental/control Group* time of measurement interaction analysis showed that the groups were different statistically with F = 28.821, P < 0.000. The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 8.104, P < 0.004 [Table 2] and [Table 3].

Multivariate test results showed that the comparison of No CS participants in both experimental and control groups for the time measurements was not different statistically at 4th week with F = 9.748, P < 0.008 but different at 8th week with F = 9.087, P < 0.010. The comparison of CS participants in both experimental and control groups for the time measurements were different statistically at 4th week with F = 11.895, P < 0.002 and 8th week with F = 28.182, P < 0.000.

Trunk extensors endurance

A repeated measure multivariate ANOVA with GGC between-group analysis showed that the experimental and control groups were different statistically with F = 25.242, P < 0.000 and also showed that a between-group analysis of CS and No CS groups were different statistically with F = 3.759, P < 0.060. The within-group analysis showed the significant statistical difference with F = 223.107, P < 0.000. Experimental/control Group* time of measurement interaction analysis showed that the groups were different statistically with F = 48.456, P < 0.000. The CS/No CS Group* time of measurement interaction analysis showed that the groups were different statistically with F = 12.332, P < 0.000 [Table 2] and [Table 3].

Multivariate test results showed that the comparison of CS participants in both experimental and control groups for the time measurements was not different statistically at 4th week with F = 15.230, P < 0.002 but different at 8th week with F = 19.754, P < 0.001. The comparison of No CS participants in both experimental and control groups for the time measurements were different statistically at 4th week with F = 10.466, P < 0.003 and 8th week with F = 29.097, P < 0.000.


  Discussion Top


This pilot study assessed the effects of MEP and CPP on CNSLBP with or without CS for later clinical trials. In our study, patients allocated to the MEP experienced superior improvements in pain-related disability, fear avoidance beliefs, and CS scores but not in pain intensity, after treatment compared with patients allocated to the CPP group. Similar findings have been observed by Garcia et al.[12] for disability and pain scores in their study. However, control group fared better regarding trunk flexors and extensors endurance in our study. A study by O'Neill et al.[17] demonstrated generalized deep-tissue hyperalgesia (i.e., CS) in CLBP patients with radiating pain. In our study also, we were successful to establish the existence of CS among CNSLBP patients to varying degrees by means of CSI-G scores and low-PPT among CLBP patients who are having CSI-G scores above 40. Similarly, Giesecke et al.[21] have reported that patients with CLBP having CS experienced significantly more pain and showed more extensive, common patterns of neuronal activation in pain-related cortical areas. This may explain why some CLBP patients are having disproportionate pain irrespective of their actual pathology has already healed. The reason is probably the occurrence of augmented central pain processing in patients with CLBP. A pilot RCT by Sterling et al.[22] concluded that lateral glide applied to the cervical spine as manual therapy may be effective in reducing sensory hyperexcitability (i.e. of CS) in patients with chronic Whiplash disorder. However, the short-term nature of the central analgesic effects of manual therapy limits its clinical utility as a treatment approach for desensitizing the CNS. It is appealing to speculate that frequent manual therapy sessions may result in long-term activation of descending antinociceptive pathways. In our study, McKenzie exercise is a patient-operated manual therapy which may explain its effects on CS on the line of activation of descending antinociceptive pathways.

Our trial included a number of features to reduce bias. The trial was registered and followed a published protocol.[12] One limitation of our study was not blinding the therapists and patients to the treatment allocation and this could be considered as a limitation of the study because of the risk of a possible preference bias due to differing in expertise. Moreover, we did not include a nontreatment or placebo control group in our study, which also can be considered as a limitation. The rationale for not including a nontreatment group in our study is based on a Cochrane review that investigated the effect of exercise therapy in patients with CLBP [23] which concluded that exercise therapy is at least 10 points (on a scale of 0–100 points) more effective than no treatment. Although we used precisely translated and validated questionnaires, we suspect that the population from Gujarat may have a different understanding of pain concepts and to what degree this would influence our study is not clear.


  Conclusion Top


The present study clearly demonstrated that MEP is effective for reducing CS in terms of CSI-G, pain relief in terms of NPRS, reduction in pressure pain sensitivity in terms of PPT, pain-related disability in terms of RMDQ-G, and fear-avoidance beliefs in terms of FABQ-G in patients suffering from CNSLBP. Large-scale clinical trials are warranted.

Acknowledgment

The authors would like to thank Dr. A. Thangamani Ramalingam (PT) for his constructive comments on the manuscript and statistical calculations.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

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