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Effect of a Cervical Lateral Glide on the Upper Limb Neurodynamic Test 1

Key Words Mobilisation, cervical spine, elbow extension, neural tissue. by Jacob Saranga Ann Green Jeremy Lewis Chris Worsfold

A blinded placebo-controlled investigation

Summary Background and Purpose This study investigated the effect of the cervical lateral glide technique applied at the facet joint between the fifth and sixth cervical vertebrae, on the range of elbow extension, a component of the upper limb neurodynamic test 1. Methods Twenty asymptomatic subjects, naïve to the effects of manual therapy, were randomly allocated to a varied order of procedures that included cervical lateral glide technique, placebo technique, and control procedure. Elbow extension range was measured with an electrogoniometer before and after each procedure. The lead investigator was blinded to the data output. A pilot study before the main investigation established the reliability and accuracy of measuring elbow extension range with the electrogoniometer. Results The results of a Friedman’s analysis of variance suggested that there was a significant difference between the three conditions (p < 0.0001). Results of multiple comparison analysis using the Wilcoxon signed rank test suggested that the cervical lateral glide technique resulted in a change in elbow extension over 7º (p < 0.001) where minimal change occurred in the placebo and control conditions. Conclusions The cervical lateral glide technique applied to the facet joint between the fifth and sixth cervical vertebrae significantly increased the elbow extension component of the upper limb neurodynamic test 1 in asymptomatic subjects, compared with those receiving a placebo technique and a control group. It is hypothesised that two mechanisms may have led to this increase. The first involves a change to the nerve root interface at the cervical intervetebral foramen. The second is that the cervical lateral glide technique reduced the tone of muscles supplied by the mobilised segment resulting in the observed increase in elbow extension.

Saranga, J, Green, A, Lewis, J and Worsfold, C (2003). ‘Effect of a cervical lateral glide on the upper limb neurodynamic test 1: A blinded placebo-controlled investigation’, Physiotherapy, 89, 11, 678-684. Physiotherapy November 2003/vol 89/no 11

Introduction Examination of the ner vous system through assessment of reflexes, muscle power and sensation has been common practice in the neuromusculoskeletal discipline for many years. More recently there has been a trend, particularly within the physiotherapy profession, also to include palpation of peripheral nerves, as well as ‘neurodynamic’ tests as part of this assessment (Elvey, 1986; Butler, 1991, 2000; Selvaratnam, 1995; Fidel et al, 1996; Vicenzino et al, 1996, 1998; Wainner et al, 2003). In the upper limb, four tests have been proposed, collectively called the upper limb tension tests (Butler, 1991), more recently the upper limb neurodynamic test in order to encourage a shift away from a purely mechanical (tension, provocation) view of these tests (Butler, 2000). Over the past decade various treatment approaches have been advocated once the presence of restricted neural tissue has been identified. These techniques have included neural stretches and neural mobilisation techniques (Butler, 1991; Butler and Slater, 1995; Selvaratnam, 1995), as well as treatment directed at the adjacent structures that might impede on neural tissue mobility (Elvey, 1986; Butler, 1991; Selvaratnam, 1995; Vicenzino et al, 1996, 1998). The cervical intervertebral foramen is one such structure, and Elvey (1986 page 229) recommended that a cervical lateral gliding technique would allow movement of structures within the intervertebral foramen without undue tension being applied to the neural tissues. Since its description the cervical lateral glide has been used extensively as a technique to improve neural mobility (Vicenzino et al, 1994, 1996, 1998; Coppieters and Stappaerts, 2000). In a study on the effect of the cervical

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lateral glide technique on 34 asymptomatic subjects Vicenzino et al (1994) reported that the technique produced significantly greater increases in skin conductance, but not on skin temperature, than did placebo or control in two different positions of neural tension testing (upper limb neuro-dynamic test 1 and 2b). Vicenzino et al (1996) examined the effect of the cervical lateral glide technique applied to the motion segment consisting of the fifth and sixth cervical vertebrae on 15 patients suffering from lateral epicondylalgia. A number of variables were measured including the effect of the technique on the flexibility of the upper limb neurodynamic test 2b (Butler, 1991), reflected as a change in glenohumeral abduction range. Their results suggested that the cervical lateral glide produced significant increases in abduction range (measured using an electrogoniometer) and concluded that the technique had an influence on the flexibility of the upper limb neurodynamic test 2b. More recently, Vicenzino et al (1998) investigated the effect of a cervical lateral glide, directed contralaterally to the affected upper limb at the fith and sixth cervical vertebrae on the flexibility of the upper limb neurodynamic test 2b in 24 subjects with lateral epicondylalgia. The results suggested that the technique significantly increased the flexibility of the neural tissues when compared to a control procedure and placebo technique. The upper limb neurodynamic test assesses the mobility of the upper quadrant neural tissues by applying a sequence of movements that mechanically elongate the nerves being tested (Elvey, 1986; Maitland, 1986; Butler, 1991, 2000; Selvaratnam, 1995; Shacklock, 1995; Magee, 1997; Lewis et al, 1998). Butler (2000) suggests that the upper limb neurodynamic test also produces movement of the nervous system in relation to inter facing structures. These are the structures that are anatomically related to the neural tissue and have the potential to restrict normal neural mobility (Penning, 1992). The test described by Selvaratnam (1995), known as the upper limb neurodynamic test 1, involves shoulder depression, glenohumeral abduction and external rotation, forearm supination, wrist and finger extension and elbow extension. Selvaratnam (1995) recom-

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mends elbow extension as the final manoeuvre of the test due to the relative clinical ease of measuring elbow extension range. The results of the upper limb neurodynamic test 1 determine whether subsequent tests should be per formed (Butler, 2000). Furthermore the test has been found to be positive in the presence of minor peripheral neuropathies and cervical radiculopathies (Greening and Lynn, 2000; Wainner et al, 2003). The purpose of this study was to investigate the effect of the cervical lateral glide technique on elbow extension in the upper limb neurodynamic test 1. The experimental hypothesis for this study was that the cervical lateral glide technique applied to the facet joint between the fifth and sixth cer vical vertebrae would increase the flexibility of the structures tested by the upper limb neurodynamic test 1. Methods Design A single-blind study was designed which included an experimental condition, a placebo and a control condition. Participants were subjected to all three conditions in a randomised order. The upper limb neurodynamic test 1, assessed by measuring range of elbow extension, was the selected outcome measure (Butler, 2000). The experimental condition was the cervical lateral glide described by Maitland (1986). Ethical Approval and Patient Consent Ethical approval for this study was granted by Coventry University Ethics Committee. Each subject was provided with an information document and signed an informed consent sheet before taking part. All subjects were able to withdraw at any stage of the investigation.

Authors Jacob Saranga BPT MCSP MMACP MSc(Manipulative Therapy) is a senior lecturer and Ann Green MSc MCSP ILTM is associate head of physiotherapy and dietetics in the School of Health and Social Sciences, Coventry University. Jeremy Lewis PhD MCSP MAPA MMPA MMACP MSc(Manipulative Physiotherapy) is a research co-ordinator and Chris Worsfold MSc MCSP PGDip(Manipulative Physiotherapy) is a senior physiotherapist in Chelsea and Westminster Healthcare NHS Trust. Address for Correspondence Jacob Saranga MSc, Senior Lecturer, Physiotherapy and Dietetics subject group, School of Health and Social Sciences, Coventry University, Priory Street, Coventry CV1 5FB. E-mail [email protected]. uk

Subjects Twenty asymptomatic subjects (12 women and 8 men) with a mean age of 32 years (SD 8.6), a mean height of 167 cm (SD 8.2), and a mean weight of 67 kg (SD 14.2) participated in the investigation. Subjects were naïve to the effects of manual therapy, therefore anyone with previous experience of manual therapy was excluded as well as subjects with current cervical and upper quadrant symptoms. Physiotherapy November 2003/vol 89/no 11

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Procedure Each subject was randomly allocated to a presentation order of the three procedures. The investigator was unaware of the treatment allocation as she did not observe the procedure and collected the elbow extension measures independently. A physiotherapist with a postgraduate degree in manipulative physiotherapy performed each of the techniques on all the subjects and was blinded to the measured elbow extension range. Subjects were investigated in the supine position on the same treatment plinth. An electrogoniometer (Penny and Giles, Biometrics Ltd, UK) was attached to the subject’s dominant arm and was used to measure elbow extension range. Shoulder girdle depression was maintained at 60 mm Hg using a pressure biofeedback device (Chattanooga, Australia). This method of maintaining a constant shoulder position has been reported (Edgar et al, 1994; Lewis et al, 1998). The subject’s glenohumeral joint was passively positioned at 110° abduction and this angle was maintained using a universal goniometer (Baseline™, UK) with one arm of the device held along the lateral border of the trunk and the other along the humerus. The subject’s forearm was then passively taken to the end range of available supination, wrist and finger extension, and glenohumeral external rotation. The final movement was passive elbow extension taken to the point of Fig 1: The cervical lateral glide technique

maximum resistance confirmed by the subject (Maitland, 1986). Following a pilot study before the main investigation, the procedure was repeated five times and elbow extension range was measured on the sixth occasion. The second measurement of elbow extension was made after application of the cervical lateral glide (fig 1), the placebo technique and the control technique. The cervical lateral glide technique (Maitland, 1986) was performed on the facet joint between the fifth and sixth cervical vertebral segment on the contralateral side and directed towards the side of the arm being investigated for three repetitions, each of 60 seconds. The technique, a grade III mobilisation (Maitland, 1986), was repeated three times, each set of mobilisations lasting for 60 seconds. There was an interval of one minute between each repetition. The head and cervical spine were kept in a neutral position. The facet joint was identified by palpation (Elvey, 1986; Maitland, 1986). The placebo technique (fig 2a) was designed to imitate the experimental technique and involved placing the investigator’s hands lightly over the subject’s neck in the same position as the cer vical lateral glide without any movement being elicited. The control technique (fig 2b) involved the same subject position with the investigator standing motionless at the end of the bed without having any physical contact with the subject, similar to a technique reported by Vicenzino et al (1996). Pilot Study To give some indication of the error measurement using the electrogonimeter, ten measurements of elbow extension range were made on each of three consecutive days, on one subject, by one assessor. The intraclass correlation coefficient of these measurements was 0.92 with a 95% confidence interval of 0.77-0.98 (although the limitations of the intraclass correlation coefficient as an indication of reliability should be acknowledged) and the standard error of measurement (SEM) was 0.5˚. This suggests that a change of greater than 0.5˚ between two measurements can be attributed to real change rather than occurring as a result of measurement error.

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(a)

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(b)

Fig 2: Placebo (a) and control (b) techniques

The validity of the electrogoniometer was established by comparison with a universal goniometer (BaselineTM, United Kingdom). One subject was measured by one assessor, with the output of the goniometers read by an assistant. One measurement was taken with each goniometer at ten different angles of elbow range. Using the analysis recommended by Bland and Altman (1986), the mean difference between the two measurement methods was found to be 0.2˚ with 95% limits of agreement between –0.64˚ and 1.04˚. This suggests that measurements taken with the electrogoniometer will be within two degrees of measurements taken with the universal goniometer on 95% of occasions. Although the limitations of using one subject and one assessor should be acknowledged, this suggests that the electrogoniometer has some validity in the measurement of elbow range. Results The data were not normally distributed and therefore did not satisfy the criteria for parametric statistical analysis and the three conditions were analysed using the non-parametric Friedman’s analysis of variance test. The Wilcoxon signed rank procedure was used to determine if there was a difference between the conditions. The p value was adjusted for the performance of multiple comparisons by

using Bonferroni corrections at p < 0.017 (Altman, 1991; Sim and Wright, 2000). Boxplot comparisons of the three conditions are presented in figure 3 overleaf. The results of a Friedman’s analysis of variance suggested that there was a significant difference between the three conditions (χ2 = 25.162; p < 0.0001). Results of the multiple comparison analysis using the Wilcoxon signed rank test suggested significant differences between the cer vical lateral glide technique and the placebo (Z = --3.854, p < 0.0001), and the control techniques (Z = –3.769, p < 0.0001), and that no statistically significant difference existed between the placebo and control techniques (Z = –0.805, p < 0.421). Discussion The findings of this study suggested that the cer vical lateral glide technique applied at the facet joint of the fifth and sixth cervical segments and directed towards the arm being investigated may be capable of significantly increasing the elbow extension component of the upper limb neurodynamic test 1, which may indicate greater neural extensibility. Furthermore the results suggest that the other two conditions tested (placebo and control) did not affect the elbow extension component of the upper limb neurodynamic test 1. Physiotherapy November 2003/vol 89/no 11

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20

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20 Cervical lateral glide

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20 Control

Fig 3: Boxplot representing changes for the three conditions, illustrating median, 25th and 75th centiles (boxes) and highest and lowest values (whiskers)

Evidence of a change in the range of elbow extension indicates that a clinician may be able to influence the peripheral nervous system. Hypotheses have been proposed which attempt to explain the mechanism of action of manual therapy techniques. One is that the cervical lateral glide technique affects the interface at the intervertebral foramen and thus increases the movement of the neural tissues passing through this space. This is thought to result in an increase in the observed elbow extension range (Elvey, 1986; Shacklock, 1995). The suggestion is that the ‘dynamic roominess’ around the nerve roots has been increased (Penning, 1992). This hypothesis depends on the cervical lateral glide influencing the anatomical relationships between the opposing surfaces of the intervertebral joint and the soft tissues. The ability of manual therapy procedures to achieve changes in joint position is hypothetical and open to conjecture (Elvey, 1986; Penning, 1992; Shacklock, 1995; McGregor et al, 2001). It is also possible that spinal manual therapy may result in a reduction of muscle tone (Zusman 1994, Katavich 1998). Through this mechanism the cervical lateral glide technique may have reduced the tone of the muscles supplied by the emergent nerves, including the biceps brachii muscles (Williams et al, Physiotherapy November 2003/vol 89/no 11

1995). The hypothetical reduction in tone may have allowed a greater range of elbow extension. Vicenzino et al (1996) used a cer vical lateral glide technique that mobilised the facet joint of the fifth and sixth vertebrae towards the contralateral side. The findings of both the present study and that reported by Vicenzino et al (1996) suggest that the cervical lateral glide technique is capable of improving the joint range by using apparently opposing techniques. This may support a more neurophysiological basis for the effect of mobilisation rather than a mechanical role. Further research is required before the mechanisms of mobilisation are better understood. Open magnetic resonance image scanning may provide one method of achieving a greater insight. With a total of 125˚ of elbow movement required for activities of daily living ranging from 15˚ to 140˚ in asymptomatic subjects (Moorey et al, 1981) an increase of 7.1˚ of elbow extension from one treatment may prove clinically significant. There are several limitations associated with the present study. Although every effort was made to maintain a consistent grade III mobilisation force, the magnitude of the force was not controlled, which may have influenced the findings. The study population of 20 asymptomatic subjects provided some insight into the

Research report

effect of the technique, and the study should be repeated with a population of symptomatic subjects to enhance its external validity. By definition the asymptomatic subjects had a full range of elbow movement, so the effects noted are relevant to tissues in the absence of pathology. It is not possible to draw inferences about the effect that this technique will have on a symptomatic group. Future research may aim at comparing the effect of an ipsilateral and contralateral cer vical lateral glide on the flexibility of the neural tissues, as well as joint range of movement. Further studies are needed to investigate the influence of grade of mobilisation, and mobilisation technique on these variables.

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Conclusion The cer vical lateral glide technique applied to the facet joint of the fifth and sixth cer vical segment significantly increased the elbow extension component of the upper limb neurodynamic test 1 in asymptomatic subjects, compared with placebo technique and a control group. The resulting increase in elbow extension indicates that clinicians may be able to influence the peripheral nervous system using this technique. Further research is required involving symptomatic subjects and larger cohorts to substantiate these results and determine whether the increases in range of movement observed in this study are reflected by improvements in general function.

References Altman, D G (1991). Practical Statistics for Medical Research, Chapman and Hall, London, chap 14. Bland, J M and Altman, D G (1986). ‘Statistical methods for assessing agreement between two methods of clinical measurement’, Lancet, February 8, 307-310. Butler, D S (1991). Mobilisation of the Nervous System, Churchill Livingstone, Edinburgh. Butler, D S (2000). The Sensitive Nervous System, Noigroup Publications, Adelaide. Butler, D and Slater, H (1995). ‘Physiological responses to injury: Nervous system’ in: Zuluaga, M et al (eds) Sports Physiotherapy: Applied science and practice, Churchill Livingstone, Melbourne, chap 5. Coppieters, M W and Stappaerts, K H (2000). ‘The immediate effects of manual therapy in patients with cervicobrachial pain of neural origin: A pilot study’, Proceedings of the International Federation of Orthopaedic Manipulative Therapists Conference, Perth, Australia. Edgar, D, Jull, G and Sutton, S (1994). ‘The relationship between upper trapezius muscle length and upper quadrant neural tissue extensibility’, Australian Journal of Physiotherapy, 40, 2, 99-103.

Greening, J and Lynn, B (2000). ‘Possible causes of pain in repetitive strain injury’ in: Devor, M, Rowbotham, M C and WiesenfeldHallin, Z (eds) Proceedings of the 9th World Congress on Pain: Progress in pain research and management, vol 16, IASP Press, Seattle, USA. Katavich, L (1998). ‘Differential effects of spinal manipulative therapy on acute and chronic muscle spasm: A proposal for mechanisms and efficacy’, Manual Therapy, 3, 3, 132-139. Lewis, J, Ramot, R and Green, A (1998). ‘Changes in mechanical tension in the median nerve: Possible implications for the upper limb tension test’, Physiotherapy, 84, 6, 254-261. Magee, D J (1997). Orthopaedic Physical Assessment, WB Saunders, Philadelphia, 3rd edn. Maitland, G D (1986). Vertebral Manipulation, Butterworth, London, 5th edn. McGregor, A H, Wragg, P and Gedroyc, W M W (2001). ‘Can interventional MRI provide an insight into the mechanics of a posterioranterior mobilisation?’ Clinical Biomechanics, 16, 926-929. Moorey, B F, Askew, L J and Chao, E Y (1981). ‘A biomechanical study of normal functional elbow motion’, Journal of Bone and Joint Surgery, American version, 63, 6, 872-877.

Elvey, R L (1986). ‘Treatment of arm pain associated with abnormal brachial plexus tension’, Australian Journal of Physiotherapy, 32, 225-231.

Penning, L (1992). ‘Functional pathology of lumbar spinal stenosis’, Clinical Bioemechanics, 7, 3-17.

Fidel, C, Martin, E, Dankaerts, W, Alison, G and Hall, T (1996). ‘Cervical spine sensitising manoeuvres during the slump test’, Journal of Manual and Manipulative Therapy, 4, 1, 16-21.

Selvaratnam, P J (1995). ‘The upper limb tension test’ in: Zuluaga, M et al (eds) Sports Physiotherapy: Applied science and practice, Churchill Livingstone, Melbourne, chap 26.

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Shacklock, M (1995). ‘Neurodynamics’, Physiotherapy, 81, 1, 9-16. Sim, J and Wright, C (2000). Research in Health Care: Concepts, designs and methods, Stanley Thornes, Cheltenham.

Wainner, R S, Fritz, J M, Irrgang, J J, Boninger, M L, Delitto, A and Allison, S (2003). ‘Reliability and diagnostic accuracy of the clinical examination and patient selfreport measures for cervical radiculopathy’, Spine, 28, 1, 52-53.

Vicenzino, B, Collins, D and Wright, T (1994). ‘Sudomotor change induced by neural mobilisation techniques in asymptomatic subjects’, Journal of Manual and Manipulative Therapy, 2, 2, 66-74.

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Vicenzino, B, Collins, D and Wright, A (1996). ‘The initial effects of a cervical spine manipulative physiotherapy treatment on the pain and dysfunction of lateral epicondylalgia’, Pain, 68, 69-74.

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Vicenzino, B, Collins, D, Benson, H and Wright, A (1998). ‘An investigation of the interrelationship between manipulative therapy-induced hypoalgesia and sympathexcitation’, Journal of Manipulative and Physiological Therapeutics, 21, 7, 448-453.

Key Messages ■ Neurodynamic tests form part of the examination of the nervous system. ■ The cervical lateral glide is a mobilisation technique that has been used to treat pathology associated with neural tissue.

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■ The results of a number of studies have suggested that this mobilisation technique may lead to an improvement in symptoms in symptomatic subjects and range of movement in symptomatic and asymptomatic subjects.