A Study to Compare the Effectiveness of Maitland’s Thrust Manipulation Vs Non-Thrust Manipulation in Mechanical Neck Pain

Introduction

Pain is the most common symptom that the human kind complains.¹ Pain is defined as acute when its duration is less than three months and as chronic when it is more than three months.² Among individuals with chronic pain, 90% localize their pain to musculoskeletal system to a variable extent.³ Musculoskeletal pain constitutes mainly back pain, neck pain, shoulder pain, carpal tunnel syndrome, tenosynovitis etc in the order of prevalence. 

Chronic mechanical neck pain can be caused by the abnormal mechanics of movement and dysfunction of variety of structures within the neck. It is also usually associated with unspecified degenerative changes (cervical spondylosis).⁴

In substantial number of patients, axial neck pain results from muscular or ligamentous factors related to posture, poor ergonomics, stress, and/or chronic muscle fatigue. Pain in shoulder, pain in craniovertebral junction or pain in temporomandibular joint are the primary sources of pain which have postural adaptations and lead to secondary muscular pain in neck.⁵ Unencapsulated free nerve endings in muscle serve as chemo nociceptive and mechano nociceptive units.

Chemo nociceptive nerve endings may respond to metabolites that accumulate during anaerobic metabolism in fatigued muscle, or they may respond to non-neurogenic pain mediators released by injury or ischemia, such as bradykinin, histamine, serotonin, and potassium ions. Mechano nociceptive nerve endings respond to stretch or pressure. Sensitization of these nerve endings may be a primary source of muscle pain.

Prevalence rate is highest in the middle age² and women have more prevalence of neck pain than men.⁶ Prevalence of neck pain varies widely between studies with a mean point prevalence of 7.6% (range: 5.9- 38.7%) and mean life time prevalence of 48.5% (range: 14.2-7.0%).² Epidemiological studies have variously reported the prevalence of cervical pain and stiffness in between 9.5% and 71% of the population.^6-9 A study done by Kramer (1990) reported that in every five patients visiting an Orthopaedic practice, one patient reports suffering from a cervical syndrome.¹⁰

Pain in the neck region is often viewed as a simple clinical problem which can rapidly develop into a complex disorder where physical, psychological, compensation, legal and societal forces all interact to cause disability.¹¹ A study done by G.A.M Ariensa et al., found a significant positive relation between the percentage of working time in a sitting position and neck pain.

Conservative management for mechanical neck disorders (MND) like exercises and ergonomics demonstrated some intermediate and long term benefits.¹² One study showed that exercise for chronic neck pain which involves endurance and strength training may be more effective in improving pain at 12 months in female office workers (very low quality evidence).² But optimal dosage of effective techniques and prognostic indicators for responders to care were not present.¹² Even with the management using electrotherapy modalities like iontophoresis, Transcutaneous Electrical Nerve Stimulator (TENS), interferential therapy, pulsed electromagnetic field, the evidence is either lacking, limited or conflicting.^13,14 Physical treatments (exercise plus massage with or without heat, pulsed electromagnetic field treatment, ultrasound, short wave diathermy), usual care (analgesics, advice, home exercise and bed rest) have been found to be less efficacious in improving pain, range of movement (ROM), level of disability, function, return to work in this one year study.²

Clinical trials have also shown manipulative therapy of spine to be effective in pain reduction and disability.¹⁴ Spinal manipulation or mobilisation are widely used for treating back pain, and their efficacy has been studied in randomised clinical trials.¹⁵ Evidence suggests that spinal manipulation is also an effective treatment for mechanical neck pain.¹⁶ The term spinal manipulative therapy includes both manipulation and mobilisation treatments (Maitland et al., 2001). The difference between these two techniques is the force amplitude and the velocity of the force applied to the target vertebra.¹⁴ Manipulation is a high velocity, low amplitude (non - oscillatory) thrust, whereas mobilization is an oscillatory, non-thrust technique, which is performed slowly and passively.^14-16

Biomechanical changes caused by the manipulation are thought to have physiological consequences by means of their effects on the inflow of sensory information to the central nervous system.^17,18 By releasing trapped meniscoids, discal material or segmental adhesions, or by normalizing a buckled segment, the mechanical input may ultimately reduce nociceptive input from receptive nerve endings in innervated paraspinal tissues. This would be consistent with the observation that spinal manipulation is not painful when administered correctly. In addition, the mechanical thrust could stimulate the mechanosensitive receptive nerve endings in paraspinal tissues, including skin, muscle, tendons, ligaments, facet joints and intervertebral disc.^19-21 These neural inputs may influence pain producing mechanisms as well as other physiological systems controlled or influenced by the nervous system.

Posteroanterior (PA) mobilization is a technique which has been used in the examination and treatment of neck pain and it increases extension and flexion of upper and lower segments respectively. Cervical spine mobilization should be categorized as three-point bending of the entire cervical spine instead of simple gliding of one vertebra over the other which helps in enhancing the cervical lordosis.²¹

To overcome the problem of reoccurrence and to make the treatment feasible, it would be appropriate if the ROM improves, so that it reduces the pain. Hence, there is a clear need for implementing the manual hands-on techniques like thrust manipulations and non-thrust manipulations in subjects with mechanical neck pain. Many studies have shown the effectiveness of thrust and non-thrust manipulations. These two techniques act in such a way that it decreases the hypomobility of a joint and improves the ROM in cases of mechanical neck pain. However, no study has been conducted to compare the effectiveness of these two approaches in same clinical condition. The major purpose of this study was to throw light on this aspect and to contribute new knowledge with scientific merit. This study aimed at comparing the effect of thrust manipulations and nonthrust manipulations in patients with mechanical neck pain.

Methods

Thirty subjects in the age range of 18 to 60 years (both males and females) with mechanical neck pain were selected after fulfilling the inclusion and exclusion criteria.

Inclusion criteria were as follows: Subjects with diagnosis of mechanical neck pain; Both male and female subjects, aged between 18 years to 60 years; Pain in the region between superior nuchal line and first thoracic vertebra;22 Subjects without radiating pain to shoulder; Subjects in chronic stage (>3 months); Subjects willing to participate in the study.

Exclusion criteria were as follows: Vertebro-basilar insufficiency; Radiating pain with weakness, paresthesia and diminished deep tendon reflexes in upper limb and cervical myelopathy; Any surgery around neck; Severe disability; Ankylosing spondylitis; Any structural deformity of spine; Any history of motor collision or recent trauma around neck; Presence of osteophytes in cervical spine; Signs of specific or serious pathology such as malignancy, infection, inflammatory disorder and fracture;²² Subjects already undergoing any other treatment for the mechanical neck pain.

Informed consent forms were obtained from the subjects following which the subjects were randomly divided into two groups, Group A (n=15) and Group B (n=15). Both the groups received equality in treatment quality, were directly supervised and treatments were performed by the Physiotherapist. Subjects in both the groups were given verbal, written instructions and demonstration by the physical therapist about the treatment protocol. The subjects were asked not to take any other treatments in parallel during the study duration to avoid confounders.

Before the commencement of treatment, subjects in both the groups underwent a pretest measurement with the help of three measures – Neck Disability Index for disability, Numerical Pain rating Scale (NPRS) for pain and flexion and extension range of motion (ROM) of cervical region. Subjects in Group A were given Maitland’s cervical manipulation which is a high velocity and low amplitude thrust maneuver. Patient was in supine position. In this manipulation technique, both primary (from the limitation or side of the pain 30⁰ – 45⁰ rotation) and secondary levers (side bending towards the side of pain coupled with lateral shift away, and then a posterior-anterior shift), with clinician’s hand placed above the targeted vertebral area with cradle hold and other hand on posterolateral aspect of occiput were used.²² Subjects in Group B received Maitland’s postero-anterior central vertebral mobilization (at 6^th cervical vertebra). The patient was placed in a prone position with physiotherapist standing at the head of the patient with the thumbs held in opposition and back-to-back, with the tips of the thumb pads on the spinous process of the vertebra to be mobilized. The fingers straddled the sides of the patient’s neck and head. Extreme gentle pressure was applied to produce a feeling of movement. The alternating pressure was applied by the arm combined with trunk. If the patient had considerable pain, the palmar surfaces of the pads of the fingers were used. The duration of the treatment was 30 seconds with 15-20 repetitions.¹⁹

This study was conducted for a duration of one week. Pre-and post measurements of pain, Neck Disability Index (NDI), ROM were taken. The duration of study was restricted to one week due to the practical issues most clinicians experience in OPD setups, where patients are unable to continue treatment for longer durations due to various reasons. Hence, it was targeted to observe the clinical efficacy in short duration. Future studies can be conducted concentrating on long term efficacy.

Data analysis

In this study, two groups were compared to determine the effectiveness of Maitland’s thrust manipulations versus non-thrust manipulations in patients with mechanical neck pain. The entire analysis was performed using PASW SPSS 18. Three types of statistical tools have been used to test the significance of duration and group on the variables like flexion, extension, Neck Disability Index (NDI) and pain. In case of flexion, extension and NDI, repeated measures ANOVA has been used. Since pain is a scaling parameter, non-parametric tests such as Friedman ANOVA and Mann-Whitney U test have been used to test the significance of duration and group. *and NS indicates the significance and no significance, respectively at 5% level.

Results

On performing repeated measures ANOVA, an increase in flexion from baseline to post2 in both the groups was observed. The F values obtained indicate that duration plays a significant role in improving flexion, whereas group had no effect on flexion. 

The F value for duration was 141.032* with p-value=0.000* and for group was 2.290^NS with pvalue=0.141^NS

In case of extension, a significant increase in the mean from baseline to post2 in both mobilization and manipulation groups was observed. The F values indicate that duration plays an important role in improving the extension, whereas group does not have any effect.

The F value for duration was 132.888* with p-value=0.000* and for group was 0.011^NS with p-value=0.918^NS

The data in the above table clearly indicates a decrease in neck disability index from baseline to post2 in both the groups. The F values indicate that duration helps in decreasing the NDI, while group has no effect on the same

The Chi Square value was 55.491* with p-value=0.001* Friedman ANOVA, a non-parametric test was applied to test the significance of duration on the decrement of pain. The Chi square value was 55.491 (p=0.001*) indicating that duration plays an important role in decreasing the pain.

The Mann-Whitney U value was 40.5* with p-value=0.002*

Mann-Whitney U test has been used to test whether the group has an impact on pain or not. Mann-Whitney U value was 40.5* (p=0.002*), thus rejecting the null hypothesis with significant difference between the groups. The values from the table indicate a good decrease in the pain in individuals from the manipulation group.

Discussion

In this study, efforts were made to compare the efficacy of transverse thrust manipulation and cervical posteroanterior mobilization in mechanical neck pain patients. This study was conducted on thirty subjects of both genders, with mean age of 32.61 years, with chronic mechanical neck pain.

The repeated measures ANOVA was done to compare the effectiveness of intervention, on ROM and NDI between pretreatment and post (1 and 2) treatments for both the groups. The repeated measures ANOVA demonstrated that the interventions were effective on NDI score, flexion, extension, and range of motion. It also demonstrated that duration of treatment was effective in improving the same measures. However, there was difference between groups which was statistically not significant with F Value for flexion 0.271^NS (p=0.607^NS), extension 2.290NS (p=0.141^NS) and NDI 0.011^NS (p=0.918NS). Friedman ANOVA and Mann-Whitney u test were performed to compare the effectiveness of intervention on duration for pain reduction and pain impact on both the groups respectively. The tests demonstrated that duration plays an important role in reducing the pain, whereas pain impact was reduced significantly (U=40.5*) (p=0.002*) in both the groups with the manipulation group being superior.

In a short duration (two sessions of intervention), the two treatments were associated with substantial improvements in patient reported symptoms. There was a tendency for the manipulation group to perform better than mobilization group in terms of pain impact (as measured with NPRS) in subjects with chronic mechanical neck pain.

In this study, cervical mobilization was also found to be effective in reducing pain, disability and improving the range of motion. Several studies have supported these results.^23-35 Hong Yu et al., (2011) found that cervical mobilization done with a device showed 80- 90% improvement in all range of motions of neck.²³ Fabianna R. Jesus-Moraleida et al., (2011) found that cervical mobilization modulates neck muscle function by enhancing deep muscle recruitment and eventually reducing superficial muscle excitation.²⁴ Timothy J. Madson et al., (2010) found that, after cervical mobilization, the pre and post mean Neck Disability Index and Visual Analogue Scores (VAS) were reduced in patients with neck pain.²⁵ Bronfort G et al., (2001) found that spinal manipulation therapy showed greater gains in all measures of strength, endurance, and range of motion.²⁶

In spite of having many supportive researches, work reported by some authors is contradictory to these findings.^26,27 Kanlayanaphotporn R et al., (2010) concluded in their study that central PA mobilization technique for treating patients with central or bilateral mechanical neck pain is arguable.²⁸ Anita R et al., (2004) reported a controversial result that mobilization with exercise was more beneficial for pain relief and functional improvement in persistent mechanical disorders.²⁹ Although several studies have reported that manipulation is effective in pain reduction, disability and improving range of motion,^30-32it was found in the present study that manipulation is also effective in terms of same outcome measures in two sessions of treatment.

Martinez-segura R et al., (2006) reported that manipulation is effective in reducing pain in the neck and in increasing cervical range of motion.³³ The existing studies have cleary stated that , an increase in intervertebral motion at the hypo mobile segment can be measured radiologically.²⁰ Wood TG et al., (2001) concluded their study stating that manual (HVLA) manipulation in cervical spine dysfunction is very effective in pain reduction and disability and in improving cervical ROM in this patient population.¹⁸ It is interesting to understand the mechanisms of treatment effects as two methods of treatment resulted in similar outcomes suggesting that both cervical mobilization and manipulation have similar effects on the pain system.

Some studies suggest that spinal manipulative therapy procedures may stimulate inhibitory mechanisms of nervous system at various levels in the spinal cord and may also activate descending inhibitory pathways. For example, the lateral periaqueductal gray (PAG) area of the midbrain. Jean-Yves Maigne et al., (2003) concluded that Spinal Manipulative Therapy (SMT) acts on vertebral motion segment and acts on facet joint distraction with cavitation, where faster separation of joint occurs resulting in reduction in intradiscal pressure. SMT induces short-term analgesic effect.^20,34

The present study had demonstrated that both manipulation and mobilization were effective in pain reduction, disability and in improving range of motion but manipulation was found to be effective in pain reduction in mechanical neck pain patients. It can be hypothesized that thrust manipulation improved range of motion and decreased disability. In addition, the degree of pain was found significantly lower in group A than group B. So, these interventions can be applied in clinical setup for better improvement.

Limitations of the present study

Smaller sample size with only 30 subjects included. Though neck pain is very common in females, the number of female subjects was less in our study. Long term effects of treatment have not been evaluated. No control group was included in this study which could have given accuracy in terms of efficiency of intervention.

Recommendations for the further studies

Further studies can be conducted including larger sample size in each group. Long term follow-up studies are needed to evaluate long term effects. Other techniques of mobilization and manipulation can also be studied. Control group can be inlcuded for the accuracy of intervention.

Conclusion

Significant improvements were observed in both group A and group B in terms of decreasing pain and disability, but group A (Thrust manipulation group) showed greater decrease in pain and disability when compared to group B (Non-Thrust manipulation group). In conclusion, thrust manipulation can be used for pain reduction and to increase cervical range of motion by decreasing the hypomobility in patients with mechanical neck pain. In future studies, myofascial trigger points and muscle imbalance should be considered for study in mechanical neck pain, and also for planning and assessing treatment programs. From this, it can be recommended that both cervical manipulation and cervical mobilization can be applied by clinicians in clinical set up for better improvements in mechanical neck pain condition.

Acknowledgements

It has been my privilege to acknowledge, Dr. Anjali Suresh (PT) madam. I sincerely acknowledge my indebtedness to madam, for her support.

Conflict of interest

None