Comparing Mulligan Mobilization and Neural Mobilization Effects in Patients with Cervical Radiculopathy

Introduction

Cervical Radiculopathy is a condition characterized by dysfunction of cervical spinal nerve roots which occurs as a result of compression or inflammatory pathology from a space occupying lesion such as a disc herniation, decreased disc height and degenerative changes of the uncovertebral joints anteriorly and zygoapophyseal joints posteriorly. It usually presents with pain in the neck and one arm, with a combination of sensory loss, loss of motor function, or reflex changes in the affected nerve-root distribution. The average annual incidence rate of cervical radiculopathy is 83 per 100,000 for the population in its entirety, with an increased prevalence occurring in the fifth decade of life (203 per 100,000). Population-based data from Rochester, Minnesota, indicates that cervical radiculopathy has an annual incidence rate of 107.3 per 100,000 for men and 63.5 per 100,000 for women, with a peak at 50 to 54 years of age.1 Ahistory of physical exertion or trauma preceded the onset of symptoms in only 15 percent of cases. A study reported a prevalence of 3.5 cases per 1000 population.^1,2,3

People with neck pain combined with upper extremity symptoms experience greater levels of disability than do people with neck pain alone.⁴ The greatest risk is at the interspace between the fifth and seventh cervical vertebrae.⁵ According to a study, monoradiculopathy involving C7 nerve root was the most frequent, followed by C6. A confirmed disc protrusion was responsible for cervical radiculopathy in 21.9% of patients; 68.4% were related to spondylosis or both. Therefore, majority of spondylosis patients have cervical radiculopathy rather than disc protrusion.⁶

Mulligan mobilizations can be used for cervical radiculopathy and it demonstrated success on some occasions in relieving marked root pain.⁷ Evidence suggests that, immediately following the spinal mobilizations (down-slope mobilization) and progressed by Sustained Natural Apophyseal Glides (SNAGS), the person can feel considerable decrease in pain, less difficulty in cervical movements.⁸

The use of neural mobilization by physical and occupational therapists has become common in clinical practice. There is sufficient biomechanical evidence that peripheral nerve under tension undergoes strain and glides within its interfacing tissues. Evidence supports that upper limb tension test causes strain within the peripheral nervous system. However, it is also evident that upper limb tension test places strain on other multisegmental tissues and has high inter-rater and intra-rater reliability.⁹ In cervical radiculopathy, the key concern is to take pressure off the nerve root and improve its blood flow and oxygenation. This may be achieved by the application of neural mobilization.

Cervical radiculopathy is a condition in which there is a narrowing of spinal canal and neural foramina and it reoccurs even after medical management. In physiotherapy management, traction relieves nerve root impingement temporarily and modalities like Interferential Therapy (IFT) reduces pain through pain gate mechanism.¹⁰, ¹¹

To overcome the problem of re-occurrence and to make the treatment feasible, it would be appropriate if the nerves were decompressed from the entrapment area, so that it reduces the pain. Hence, there is a clear need for implementing the manual hands-on techniques like Neural mobilization and Mulligan mobilization in subjects with cervical radiculopathy. Many studies have shown the effectiveness of cervical mobilization and neural mobilization. These two techniques act in such a way that it decompresses the nerve root, which undergoes compression in cases of cervical radiculopathy. However, no study has been conducted to compare the effectiveness of these two approaches in same clinical condition. The major purpose of this dissertation was to throw light on this aspect and to contribute new knowledge with scientific merit. This study aimed at comparing the effect of Mulligan mobilization and neural mobilization in patients with cervical radiculopathy.

Methods

Thirty subjects between the age group of 20 to 50 years (both male and female) with cervical radiculopathy were selected after fulfilling the inclusion and exclusion criteria. Inclusion criteria were as follows: 1. Both genders were included, 2. Age between 20-50 years.12 3. Subjects with neck pain radiating down to the arm, 4. Patients with positive findings for spurling test, Upper Limb Tension Test (ULTT), cervical distraction test and cervical rotation test towards the symptomatic side <6002, 5. Subjects who were willing to participate in the study and willing to take treatment for cervical radiculopathy. Exclusion criteria were as follows: 1. Systemic disease potentially affecting the musculoskeletal system, 2. Patients experiencing primary shoulder or upper extremity problem of local origin, 3. Patients with any cardiovascular disorders¹³ and respiratory disorders, 4. Patients with any other pathological conditions involving cervical spine like vertebro basilar insufficiency and canal stenosis, 5. Patients having osteophytes in cervical vertebrae, 6. Patients who were undergoing treatment for neck pain with other means of physiotherapy at the time of the study, 7. Hypermobile joints of cervical vertebrae, 8. Cervical fractures, spinal surgery or other spinal pathologies (i.e. ankylosing spondylitis, spondylolysthesis),¹³ 9. Peripheral nerve lesions like neurotemesis and axonotemesis. Once informed consent was obtained from the subjects, they 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 performed by a physiotherapist.

Before commencement of the treatment, subjects in both the groups underwent a pre-test measurement with the help of three measures – Neck Disability Index (NDI) for disability and Patient Specific Functional Scale (PSFS) for functional activities³ and Range of motion (ROM) of cervical. Subjects in group-A were given Mulligan mobilizations (SNAGs). Subjects were placed in sitting position and therapist stood behind the patient with therapist’s thumbs on spinous process of particular vertebra. Mobilization was given by active movement followed by passive overpressure based on the movement restricted.¹⁴ The duration of treatment was three sets of ten repetitions each.¹³ Subjects in group-B were given neural mobilization. Subjects were placed in supine position and remained relaxed with the feet uncrossed. The patient was slightly angled obliquely for easier access to the scapula. The therapist depressed the scapula with concomitant upper extremity joint positioning as per median nerve bias i.e., ULTT2 (shoulder abduction, elbow extension with forearm supination, wrist and fingers extended and ulnar deviated and thumb abduction). The wrist was used as a tension factor and at the point where tension was felt by the therapist and perceived by the subject. Grade 3 oscillations were given rhythmically and slowly to each joint from proximal to distal. A total of 20 oscillations (1 oscillation/1 second) were given to each joint with a total duration of 15 minutes.¹⁵

Both the groups received intermittent cervical traction following which they were taught to perform exercises focusing on strengthening of deep neck flexors. For strengthening deep neck flexors, the patient was taught to perform cranio-cervical flexion exercises, by placing the patient in supine position with the cervical spine in neutral and instructed to flatten the curve of the neck by nodding the head. This position was held for 10 seconds and was repeated 10 times.¹⁶ The total duration of treatment for both the groups was of one week or seven sessions.^17,18,19 The post-test measurement was taken after one week. The intention of keeping one week as duration was the practical issue most of the clinicians’ experience where patients won’t be able to continue for longer duration due to various reasons. Hence, it was targeted to find out clinical efficacy in short duration for cervical radiculopathy patients. Future studies can be conducted to concentrate on long term duration efficacy.

Data analysis

In the present study, two groups were compared to determine effectiveness of Mulligan mobilization versus neural mobilization in patients with cervical radiculopathy. The entire analysis was performed using PASW SPSS 18. To test the significance of the two groups, i.e Mulligan and neural mobilization with respect to PSFS, NDI and ROM, independent samples t-test was performed. To check the effect of pre-and post-treatment on PSFS, NDI and ROM, paired samples t-test was performed. The difference of values between pre-test and post-test were analyzed. It was done for the values taken before first session and at the end of 7th session. The mean difference of the Neck Disability Index, Patient Specific Functional Scale, Range of Motion for Group A were compared to Group B and the actual pattern of variation in all the categories was observed. With the acquired ‘t’ value from the pretest and posttest, the accurate level of significance was analyzed and interpreted. * and NS indicate the significance and nonsignificance respectively at 5% level.

Results

Discussions

Cervical radiculopathy is one of the disabling conditions in the fifth decade of life. The symptoms of this condition are one of the most serious functional limiting factors for a patient in the society. Several research papers as well as clinical findings provide information about the causes of cervical radiculopathy.⁷ Management with specific treatment is required for the same condition. Many studies have investigated the effectiveness of physical therapy in patients with cervical radiculopathy.^{20, 21} Most commonly, exercise therapy and electro therapy are used as a treatment choices for cervical radiculopathy. But identification of appropriate conservative management strategies appears to remain a clinical enigma.

In the present study, the aim was to analyze and compare the efficacy of Mulligan mobilization and neural mobilization in patients with cervical radiculopathy. This study was conducted on thirty subjects of both genders with a mean age of 36.63 years, who have cervical radiculopathy. The subjects were randomly divided into two groups: Group A (Mulligan group), Group B (Neural mobilization group) with mean age of 36.46 and 36.8 years respectively.

Several studies have reported that Mulligan mobilization is effective in reducing disability, in improving range of motion and functional levels.^34,22,23 In the present study, it was found that Mulligan mobilization was also effective in terms of same outcome measures. L Exelby (2002) reported that application of Mulligan mobilizations in the management of spinal conditions can assist in the correction of dysfunctional movement.³⁴ Andrea Moulson, Tim Watson (2006) reported that cervical SNAGs have a sympathoexcitatory effect on the upper limbs in relation to potential mechanisms for manipulation induced analgesia.²² K Konstantinou et al., (2002) concluded that there was an increase in ROM (54.4%) and reduction in pain intensity (27.5%) immediately after the application of Mobilization With Movement (MWM) in lower back pain.²³

In our study, we found that neural mobilization was clinically effective in reducing disability and improving the range of motion and functional levels. Several studies have supported our results.^{19,24,25,26,27,28} Manisha P, Ganesh B, Ravi SR (2011) opined that neural mobilization programme will be useful in improving the neural function in sub clinical stage.¹⁹ Brown, CynthiaL, et al., (2011) stated that neural mobilization may be clinically significant in the dispersion of intraneural fluid in the presence of intraneural edema found in pathological nerves such as those found in compression syndromes.²⁴ Ghadam Ali Talebi, Mohammad Taghipour – Darzi, Amin Norouzi – Fashkhami (2010) stated that neural mobilization techniques can increasingly be useful in the treatment of abdominal neural tensions and removing chronic radiculopathy symptoms.²⁵ Gladson R, Bertolini F et al., (2009) reported neural mobilization to be more effective for sciatica compression.26 Kaur Gurpreet, Sharma Shallu (2011) stated that neural mobilization is very effective in reducing radiculopathy symptoms causing the lower back pain of neurogenic origin.²⁷ Cleland Joshua, Hunt Gary, Palmer Jessica (2004) observed neural mobilization techniques to be very effective for the improvement of ROM and relief of pain in lower extremity neurogenic pain.²⁸

Despite having many supportive researches, few authors reported findings that are contradictory to those stated above.^9,29 Mark T Walsh (2005) concluded in his study that there was limited evidence reporting favorable outcomes when using neural mobilization to treat specific patient populations and the appropriate parameters of dosage (i.e., duration, frequency, and amplitude) remain to be confirmed. He also contradicted stating that neural mobilization not only produces strain on the nerve, but also on other multi segmental tissues. 9 Scrimshaw, Sally V Maher, Christopher G (2001) refuted neural mobilization as there is no convincing evidence to break the adhesions of nerve at the root level after spinal surgery.²⁹

It is interesting to understand the mechanisms of treatment effects for each method. There are researchers who suggest that the nerve mobilization results in longitudinal excursion within the nerve.^30,31,32 Jason M Beneciuk et al., (2009) stated that sliding techniques resulted in less strain and larger longitudinal excursion of the median nerve at the wrist when compared to tensioning techniques. Sliding techniques have been theorized to play a role in the dispersion of inflammatory products and limiting fibroblastic activity. Moreover, tensioning techniques have been suggested to play a role in reducing intraneural swelling and circulatory stasis by altering intraneural pressure associated with these techniques.₃₀ Michel W Coppieters, David S Butler (2008) found that sliding techniques result in a substantially larger excursion of the nerve than tensioning techniques (e.g: median nerve at wrist: 12.6 versus 6.1 mm, ulnar nerve at the elbow: 8.3 versus 3.8 mm) and that this larger excursion is associated with a much smaller change in strain (e.g: median nerve at wrist: 0.8% (sliding) versus 6.8% (tensioning)).³¹ Robert J Nee et al., (2010) found that strain in a nerve segment at the end of a neurodynamic test will be greatest if the joint nearest that nerve segment is moved first in the neurodynamic sequence.³² Michael Ogbonnia Egwu (2008) stated that the oscillatory pressure techniques of spine mobilization therapy are known to have both neurophysiologic and mechanical effects. Mobilization techniques stretch tissues by taking them into an area of plastic deformation of the stress-strain curve. Also, these oscillatory pressure techniques stretch cervical connective tissue and joint capsules to point C or D of stress-strain curve, which is ideal for stretching tissues to produce a salvo of beneficial neuro inhibitory and mechanical effects.³³

Both the groups showed significant improvement in ROM. This may be due to the fact that pain was found to be the limiting factor. Therefore, as the treatment techniques helped in relieving the pain, the ROM simultaneously improved. The present study had demonstrated that both Mulligan mobilization and neural mobilization were effective in reducing disability and improving ROM, PSFS. Neural mobilization did show better results in reducing disability and improving ROM, and functional level. Statistically, there was no significant difference between two groups. Therefore, these interventions can be applied in clinical setup for better improvements.

Limitations of the study

1. Less number of subjects in each group taken for the study.

2. Long term carryover of the treatment effect was not evaluated.

3. The amplitude of neural tissue mobilizations varies subjectively and needs more clear description to avoid bias in the studies.

Recommendations for further studies

1. Further studies can be done with a larger sample size.

2. Study can be done with long term follow-up, so that long term effects will be known.

3. Other techniques of mulligan mobilization can be used.

4. Studies may further be conducted on other nerves

Conclusion

After analyzing the data of the present study, it can be concluded that both Mulligan mobilization (SNAGs) and neural mobilization are effective in reducing the disability, in improving ROM and functional levels in subjects with cervical radiculopathy. When two interventions, Mulligan mobilization and neural mobilization were compared, neural mobilization was found to be superior in reducing disability and improving the ROM, functional levels than Mulligan mobilization in the management of cervical radiculopathy. However, there was no statistically significant differences in between the groups. From this, we concluded that both Mulligan mobilization and neural mobilization were effective in the subjects with cervical radiculopathy and can be applied by clinicians in clinical set up for better improvements.

Conflict of interests

None.