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Reliability and Validity of Clinical Measurement of the Lumbar Spine in Patients with Chronic Low Back Pain
Reliability and Validity of Clinical Measurement of the Lumbar Spine in Patients with Chronic Low Back Pain MARY NEWTON
MEd BA MCSP
Rcwarch Physiotherapist. Gartnavel General Hospital, Glaagow
GORDON WADDELL B S M~ D FKCS
Consultant Orthopicdic Surgeon, Weatem Infirmary. Glaagow
Key words: Lumbar spine.
range of movement. objective nieasurenienr, reliability. \.aliditj. low back pain.
SUlllmary: Thib study tested
the reliability and validity ot three method.; of meawring lumhar >pine niobiliry: inclinometer. kyphonicter dnd fingersto-tloor. Sub.jects uere trti people without symptoms and 50 patients with low back pain. Inter-tester reliability for the inclinometer method as good and validity w n i conlirmed by X-rdy measurement.\. Inter-tester reliahility of the tinger\-to-floor method was also good although the niethod ia not considered valid
Biography: Mary Newton trained a t the Western Intirmarq, Glasgr)~. and gained experience mith handicapped children in Denmark, spinal injuies in Stoke Mandeville Hospital. and latterly our-patienth in G l a s p \ . She completed an MEd in 1988 at Glasgoa University and i b current11 working as a research physiotherapist funded by the Scottish Home and Healrh Department Gordon Waddell is a n orthopaedic burgeon with a particular interest in hpinal diwrders and the asisessnient of lo\+ hack pain and disahilip.
Introduction PATIENTS with low back pain make up about 6 0 % of patients referred t o a physiotherapy department. In order t o assess the severity of the condition, plan treatment and assess progress it is necessary to provide objective measurements (Rothstein, 1985). This also allows effective communication between therapists and doctors, provided the measurements are valid and reliable. In clinical research it is also essential for such measurements to be available. A review of the literature revealed various methods of measuring lumbar mobility: fingers-to-floor, skin distraction or modified Schober, flexirule, kyphometer and inclinometer. A recent survey of physiotherapists (Sweet, 1989) revealed that fingers-to-floor is still the most common way of measuring lumbar flexion. Several studies show that it is reliable (Frost e t a / , 1982; Gill e t a/, 1988). However, it is not a valid measure of lumbar flexion (Moll and Wright, 1976) as it measures a combination of spinal movement, hip movement and hamstring extensibility. Even if it is not a good measurr f specific lumbar mobility it should not be overlour
796
advantage of giving a valid measure of lumbar flexion and is quick and easy to do in a clinical setting (Rae e t a / , 1981). The main disadvantage is that it only provides a crude index of movement and does not actually measure the range of flexion. Flexirule is a draughtsman’s device which can be moulded to the shape of the lumbar spine. The contour then has to be drawn on a sheet of paper and tangents drawn to obtain an angle of measurement, making it a laborious method t o use. Also the inter-tester reliability of the method has been found to be doubtful (Lovell et a/, 19891, although intra-tester reliability has been reported 8s good (Burton, 1986; Hart and Rose, 1986; Lovell e t a / , 1989). The kyphometer is basically a protractor with t w o parallel arms. It has been demonstrated to be reliable (Ohlen, 1989) but has not been widely used, in a clinical setting. Recent studies have suggested the possibility of using an inclinometer as a method of measuring lumbar mobility (Mayer et a / , 1984; Merritt e t a / , 1986, Gill et a / , 1986). The inclinometer can either be a simple builder‘s inclinometer or a commercial model manufactured for clinical use. The advantage of the inclinometer is that the components of hip and lumbar movement can be separated. The inclinometer can also be used t o measure extension, lateral flexion, straight leg raising, lordosis and kyphosis to provide a comprehensive range of measurements. From the review of the methods used, the inclinometer seemed the most promising of the devices. I The aim of this study, which formed part of larger study to develop objective clinical evaluation of lumbar impairment (Waddell e t a / , 1991), was to select the best method of measuring lumbar mobility. The main emphasis was on the reliability and validity of the inclinometer method as this appeared to have the most theoretical advantages and to be the most suitable for routine clinical use. The kyphometer was evaluated to compare it to the inclinometer. Reliability of the fingers-to-floor method was also assessed as it is still the method in widest use. Most of the studies reviewed used S2 t o T12IL1 as landmarks from which to measure, but some used S2 t o Tll/T12 (Ohlen, 1989; Spangfort, 1989) and therefore it was necessary t o compare measurements taken at the t w o different levels.
Materials and Methods Subjects
A total of 5 0 patients w i t h low back pain and 10 normal people were studied. The subjects were aged between 20 and 55 years which is the common age range for patients w i t h low back pain. The patients had all been referred t o an orthopaedic out-patient department w i t h low back pain. Design Four sequential studies were carried out allowing refinement of the examination technique. The results of each study were analysed and modifications made if necessary before moving on to the next study. Physiotherapy, December 1991, vol 77, no 72
The patients were then positioned ready for a lateral X-ray and lordosis was measured in this position by the inclinometer and kyphometer followed by an X-ray. The patients were asked t o bend forward as far as they could go and flexion was measured by the inclinometer and kyphometer followed by an X-ray while the patients maiqtained the flexed position. The X-rays were measured by drawing lines parallel t o the upper vertebral end plates of S1 and lower vertebral endplates of T12, dropping perpendicular lines from these, and measuring the angle of inclination at their intersection (fig 2).
Fig 1: Cybex inclinometer
Materials The inclinometer used was a hand-held computerised model (EDI-320) manufactured by Cybex Inc, Ronkonkoma, New York (fig 1). A Debrunner’s kyphometer was used, manufactured by Portek AG, Postfach 2016, Bern, Switzerland. Procedure The examiners were an orthopaedic consultant and a research physiotherapist. The measurements taken were flexion, extension and lateral flexion for the inclinometer, flexion for the kyphometer and flexion for fingers-to-floor.
Study I The purpose of this study was: 1. To compare the use of the inclinometer with the kyphometer. 2. To compare the use of different surface landmarks for measuring. Ten normal subjects took part in this study which was carried out by the research physiotherapist.
Study 2 The purpose of this study was to examine the inter-tester reliability of the inclinometer and fingers-to-floor methods on 2 0 patients with low back pain. The validity of the measurements was checked by erect and lateral flexion X-rays taken on the same day but not simultaneously. The patients were measured during a routine clinical examination by the orthopaedic consultant and then independently by the research physiotherapist who was blind t o the consultant‘s findings.
Study 3 The purpose of this study was: 1. To determine the accuracy of the skin markings used t o identify the lumbar vertebrae. 2. To reassess the validity of the methods of measuring lumbar mobility. Ten patients were X-rayed as part of their routine clinical examination. The clinical measurements were taken by the research physiotherapist at the same time as the X-rays were taken. The spine was marked at T12/L1 and S2 and metal markers were taped to the spine. The patients then had an A/P X-ray taken to determine if the metal markers correctly identified the landmarks. The metal markers were removed.
Physiotherapy, December 1991, vol77, no 72
Fig 2: Schematic diagram representing the radiographic measurements
Study 4 The purpose of this study was to determine the inter-tester reliability of the inclinometer method of measuring lumbar mobility, and incorporated the above methods into the full clinical examination. Twenty patients with low back pain attending an orthopaedic out-patient department were measured during a routine clinical examination by the orthopaedic consultant and then independently by the research physiotherapist who was blind t o the surgeon’s findings. The skin marks were carefully removed t o avoid contamination of the study. Method The measurements were taken in the following carefully standardised way. Anatomical landmarks were identified with the patients in prone lying. S2 was found by palpating the inferior border of the posterior superior iliac spines. Then, by counting up the spinous processes and checking that the iliac crests approximated t o L4/5, the junction of T12/L1 was identified. Midline skin marks were made at S2, T12/L1 and T 9 with a ballpoint pen. The patients then performed a warm-up of flexion/extension twice, rotation twice, lateral flexion twice and one more flexionlextension. A warm-up was included as it has been suggested that it improves performances (Roberts era/ , 1988) and has been included in other studies (Keeley er a/, 1986). It is important t o standardise the starting position (Youdas era/ , 1991) as reliable measurement of movement depends on achieving a consistent erect position (Spangfort, 1989; Troup, 1989; Ohlen, 1989). The position used in this study was: patients in bare feet with heels together and knees straight, looking straight ahead at a point on the wall at eye height, hands hanging loosely at sides. 797
~-
Fig 3
Fig 4
Fig 6
Fig 5
Fig 7
798
Lunibar flexion w a s measured w i t h t h e inclinometer by making recordings at S2 and TIZILI with the patients erect (figs 3, 4). Then t h e patients were instructed t o bend forward, reaching as far as possible towards their toes. While t h e patients were fully flexed t h e inclinometer again recorded at T12ILl (fig 5) and was then moved t o S 2 (fig 6) where the final recording was made. These four readings permitted simple calculation of lumbar flexion, pelvic flexion and total combined flexion. While in full flexion t h e fingers-to-floor distance was measured with a tape measure. Lumbar extension was measured at t h e same skin marks, taking the first recording w i t h the patients erect. The patients were then instructed t o arch backwards as far as possible, looking u p t o t h e ceiling. The examiner
Fig 8
supported t h e patients w i t h one harid o n their shoulders to inairitairi their balance. Recordings were repeated in this position and measures of lumbar, p e l v i c a n d t o t a l e x t e n s i o n were recorded. Lateral flexion was also measured at TIZILI. A n extended bar was used on t h e inclinometer. The first reading was obtained w i t h the bar lined up between the spinous processes at T 9 and TI2 (fig 7 ) . The patients were then instructed t o lean over t o the side as far as possible keeping t h e fingers i n contact w i t h the leg, making sure that b o t h feet stayed flat on the floor and t h a t no flexion or rotation occurred. A reading was obtained at one side (fig 8 ) , ttieri the patients returned t o the erect position before bending in the opposite direction w h e n the other reading was taken. Physiotherapy, December 1991, vol 77, no 72
Results The results were calculated using intra-class correlation coefficients to express the reliability of the measurements (Shrout and Fleiss, 1979). Study 1 showed that there was a high correlation between measurements using the t w o different instruments (0.89). There was a mean difference of only 3 O between using the t w o different landmarks for measuring lumbar flexion and so the more common T12IL1 landmark was used for the subsequent studies. Study 3, the X-ray study, showed reasonable correlation between the clinical measurements and the X-ray measurements and between the t w o different methods of measurement. Correlation between the inclinometer method and X-ray was 0.76, kyphometer and X-ray 0.68, and between the inclinometer and kyphometer 0.92. The skin markings were subject to an error of 4 cm. The results of studies 2 and 4, the t w o inter-tester reliability examination studies, are summarised in the table. Inter-observer reliability of lumbar movements lintra-class correlation coefficients) Study 2
Study 4
~
Flexion
pelvic lumbar total
Extension
pelvic lumbar total left right
Lateral flexion Fingers-to-floor *p> 0.01
1.p
0.96-f 0.94-f 0.98t 0.41 0.66-f 0.48" 0.84-f 0.781. 0.98-f
0.891. 0.87-f 0.941.
-
0.86-f 0.921. 0.951.
-
< 0.001
Study 2 showed poor correlation between the clinical measurements and the X-ray measurements (0.46). These results were improved by taking the X-ray measurements at the same time as the clinical measurements in study 3 (0.76). The results for lateral flexion were also poor in the first clinical study (0.84, 0.78) but modification of the examination technique improved these results (0.92, 0.95). Only total extension could be measured reliably as separate pelvic and lumbar extension were not reliable.
Discussion This study highlighted the need for using a carefully standardised technique of measurement to obtain reliable measurements. Clinical measurements must be valid and reliable t o be useful. This study has shown that fingers-tqfloor is a reliable method of measuring lumbar function but is not a valid method of measuring specific lumbar movement. The kyphometer is a valid and reliable method of measuring lumbar flexion but it is awkward to use. For this reason it is unlikely to become the method of choice in a busy clinical setting. The inclinometer is a valid aiid reliable method of measuring lumbar mobility, easy t o use and versatile. Although total extension was reliable it was not possible to separate reliably pelvic and lumbar extension. Large variations in the reliability of measuring extension have been reported (Moll eta/, 1972; Reynolds, 1975; Frost eta/, 1982; Keeley eta/, 1986; Gill eta/, 1988; Merritt eta/, 1986). All these studies used different methods of measuring extension and different positions, eg standing and lying. In the clinical Physiotherapy, December 1991, vol 77, no 72
setting extension does not seem to be routinely measured. But as an extension regime is being incorporated into some treatment and prevention routines for patients with low back pain (McKenzie, 1981) a reliable method of measuring extension is important. Lateral flexion also proved difficult to measure and required careful technique. The literature suggests there is no satisfactory way of measuring lateral flexion (Lankhorst e t a/, 1982) but this study found good reliability using the inclinometer method.
Conclusion This study has shown fingers-to-floor t o be a reliable method of measuring lumbar function. Although it is considered a measure of lumbar flexion, hip flexion and hamstring extensibility, it is a quick, easy and reliable measure of improvement in function. The inclinometer was found t o be a reliable and valid method of measuring lumbar mobility. It is also quick and easy t o use and has the advantage of being able t o measure a comprehensive group of tests of lumbar mobility. The study has highlighted the necessity of using a carefully standardised technique of measurement for assessing patients w i t h chronic low back pain. ACKNOWLEDGMENTS We are most grateful t o the Chief Scientist Office of the Scottish Home and Health Department and t o the Mactaggart Trust for their support of this work.
REFERENCES Biering-Sorensen, F (1984). 'Physical measurements as risk indicators of low-back trouble over a one-year period', Spine, 9, 2, 106-119. Burton, A K (1986).'Regional lumbar sagittal mobility: Measurement by flexicurves', Clinical Biomechanics, 1, 20- 26. Frost, M, Stuckey, S , Smalley, L E and Dorman, G (1982). 'Reliability of measuring trunk motions in centimeters', Physical Therapy, 62, 1431-37. Gill, K, Krag, M H,Johnson, G B, Haugh, L D and Pope, M H (1988). 'Repeatability of four clinical methods for assessment of lumbar spinal motion', Spine, 13, 50-53. Hart, D Land Rose, S J (1986).'Reliability of a non-invasive method of measuring the lumbar curve', Journal of Orthopaedic Sports Physical Therapy, 8 , 180-184. Keelev, J, Mayer, T G, Cox, R, Gatchel, R J, Smith, J and Mooney, V (1986). 'Quantification of lumbar function Part 5: Reliability of range of motion measures in the sagittal plane and an in vivo torso rotation technique', Spine, 11, 31-35. Lankhorst, G J, van de Stadt, T W, Vogelaar, J K, van der Korst, J K and Prevo, A J H (1982). 'Objectivity and repeatability of measurements in low back pain', Scandinavian Journal of Rehabilitation Medicine, 14, 21-26. Lovell, F W, Rothstein, J M and Personius, W J (1989). 'Reliability of clinical measurements of lumbar lordosis taken with a flexirule', Physical Therapy, 69, 96-105. McKenzie, R A (1981).The Lumbar Spine, Mechanical diagnosis and Therapy, Spinal Publications, Lower Hutt, New Zealand. Matvas, T A and Bach. T M (1985). 'The reliability of selected tcbriiiiques in clinical artnrometrics', Australian Journal of Physiotherapy, 31, 175-199. Mayer, T G, Tencer. A F, Kristoferson, S and Mooney, V (1984). 'Use of non-invasive techniques for quantification of spinal range-ofmotion in normal subjects and chronic low back dysfunction patients', Spine, 9, 588-595. Mellin, G P (1989). 'Comparison between tape measurements of the forward and lateral flexion of the spine', Clinical Biomechanics, 4, 121-123. Merritt, J L, McLean, T J, Erickson, R P and Offord, K P (1986). 'Measurement of t r u n k flexibility i n normal subjects: Reproducibility of three clinical methods', Mayo Clinic Proceedings, 61, 192-197.
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Million, R, Haavik Nilsen, K, Jayson, M I V and Baker, R D (1981). 'Evaluation of low back and assessment of lumbar corsets with and without back supports', Annals of Rheumatic Diseases, 40, 449-454. Moll, J M H, Liyanage, S P and Wright, V (1972). 'An objective clinical method to measure spinal extension', Rheumatology and Physical Medicine, 11, 6. 293-312. Moll, J M H and Wright, V (1976). 'Measurement of spinal movement' in: Jayson, M (ed) The Lumbar Spine and Back Pain, Sector Publishing Ltd, London, for Pitman Medical Publishing Co Ltd. Ohlen, G (1989). 'Spinal sagittal configuration and mobility. A kyphometer study', Stockholm: Karolinska Institute. M D thesis. Rae, P, Venner, R M and Waddell, G (1981). 'A simple clinical technique for measuring lumbar flexion', Journal of the Royal College of Surgeons of Edinburgh, 29, 5, 281 - 284. Reynolds, P M G (1975). 'Measurement of spinal mobility: A comparison of three methods', Rheurnatology and Rehabilitation, 14, 180-185. Roberts, W N, Liang, M H, Pallozzi, L M and Daltroy, L H (1988). 'Effects of warming up on reliability of anthropometric techniques
in ankylosing spondylitis', Arthritis and Rheumatism, 31, 5 4 9 - 552. Rothstein, J M (1985). Measurement in Physical Therapy, Churchill Livingstone, New York. Shrout, P E and Fleiss, J L (1979). 'Intraclass correlations: Uses in assessing rater reliability', Psychological Bulletin, 86,4 2 0 - 4 2 8 . Spangfort, V E (1989). Personal communication. Sweet, C (1989). Personal communication. Troup, J D G, Hood, C A and Chapman, A E (1968). 'Measurements of the sagittal mobility of the lumbar spine and hips', Annals of Physical Medicine, 9, 308-321. Troup, J D G (1989). Personal communication. Waddell, G, Main, C J, Morris, E W, Venner, R M, Rae, P S, Sharmay, S H and Galloway, H (1982). 'Normality and reliability in the clinical assessment of backache', British MedicalJournal, 284, 1519-23. Waddell, G, Allen, D B and Newton, M (1991). 'Clinical evaluation of disability in low back pain' in: Froymoyer, J W (ed) The Adult Spine: Principles and practice, Raven Press Ltd, New York. Youdas, J W, Carey, J R and Garrett, T R (1991). 'Reliability of measurements of cervical spine range of motion - A comparison of three methods', Physical Therapy, 71, 2, 98-106.
Marketing Physiotherapy Services The Chartered Society of Physiotherapy is running.a series of marketing courses in 1992 as part of its events programme. Nicky Davison, who is a Chartered physiotherapist and management consultant, will be tutoring these courses. Here she looks at what marketing means for physiotherapy. DO we really know about marketing? Some of us think we do while many of us have a rough idea what marketing might be. We may have heard of 'the four Ps' - product, price, place and promotion - and we think w e know how these may relate in the new NHS market place. But do we? Marketing at its simplest is the process of matching the abilities of an organisation to the needs of its customers so that both get what they want. The 'four Ps' make up the marketing mix; they are the four controllable variables which the effective marketer can mould into a single 'profitable' entity which satisfies consumers. Profitable in this case relates t o the services which we offer within the internal market. Many of us have already identified these four variables; the product is the service we provide, the price is the cost to the customer, the place is where our service is provided, and the promotion is the way in which we increase public awareness of our service. But w h o are our customers?
Customers We might answer that the patients are our customers; certainly they are the people we care about and whom w e are committed t o serve, but are they really our customers? In the NHS they are not paying directly for our services, after all. This is a complex question because in every situation the range and scope of customers, and their needs, are different. In an NHS Trust, for example, our customer might be the purchaser who buys services on behalf of the GPs and their patients. On the other hand, physiotherapists may be in a position to negotiate directly with GPs for the provision of services. In this case the customer is the GP. Where a health authority has set up a resource management initiative, in which physiotherapy services form part of a therapies directorate, this is a different
800
situation. This directorate is expected to form individual contracts with each clinical directorate for the provision of services. In this case, each clinical director is the customer w h o buys our services on behalf of hisiher patients. Yet another situation might be where physiotherapists opt out and become independent. In this case, the customers could be health authorities, Trusts, GPs, private and voluntary services. These examples are just a few of the many variations with which the physiotherapy service is n o w faced when trying t o match its skills and expertise t o the needs of patientsicustomers.
Competitors However, this is not the only consideration. Obviously if there are so many options available to us, they are also available t o our competitors. So w h o are they? Traditionally, competition has existed only in private practice where, in theory, our competitors have been other physiotherapists and people such as osteopaths and chiropractors. However, there are many other areas of competition; for example, occupational therapy and physiotherapy roles have considerable overlap, and there is reason to be concerned that some authorities may consider that only one profession is essential. In this case, occupational therapists could also become our competitors. More threateningly, perhaps, other local physiotherapy units and departments are likely t o be our strictest competition in a true internal market. It is an essential part of marketing to be able t o identify who our competitors are, where they practise, if possible how much they cost, and h o w they promote their services. In this way, when we compete with them, we either sell our services at a lower cost, or we promote the specialist aspects
of our service which makes us unique and thus better value for money. The marketing process also needs to include an understanding of the environment in which services are delivered. We have all been aware of vast environmental changes of late, not least being the Government reforms. As we look around us there is evidence that environmental change is increasing. For example, we have seen the changes in communist Europe and, in 1992, there will be free trade in the European Community. We need t o be in a position t o anticipate these and other changes nearer home so that we can take advantage of the opportunities and cope with any threats. This in turn means that we need t o look carefully at the way our organisations are structured and managed.
Change What changes do we need t o consider? Before looking at what has changed we need t o understand those influences which could have a direct effect upon us and our services. We then have to assess how these have changed and whether we need to consider change within our organisation and/or profession in response. Typically w e should monitor social, economic, political and technical influences, in order to identify when change takes place, so that we can act if necessary. We also need to monitor our competitors t o see whether they too are changing and why, so that we can respond quickly to maintain our quality of service and thus continue to meet the needs of the customer and, ultimately, the patient. Finally, we must still remain committed to the care of our patients. By understanding h o w to make the most of 'the four PS', the environmental influences affecting our patients, the market requirements and the work of our competitors, we will be in a better position to respond quickly to patient needs as they arise. For information about the first t w o t w o day workshops, contact the Events Unit at Bedford Row.
NICKY DAVISON MCSP Physiotherapy, December 1991, vol 77, no 72
MEd BA MCSP
Rcwarch Physiotherapist. Gartnavel General Hospital, Glaagow
GORDON WADDELL B S M~ D FKCS
Consultant Orthopicdic Surgeon, Weatem Infirmary. Glaagow
Key words: Lumbar spine.
range of movement. objective nieasurenienr, reliability. \.aliditj. low back pain.
SUlllmary: Thib study tested
the reliability and validity ot three method.; of meawring lumhar >pine niobiliry: inclinometer. kyphonicter dnd fingersto-tloor. Sub.jects uere trti people without symptoms and 50 patients with low back pain. Inter-tester reliability for the inclinometer method as good and validity w n i conlirmed by X-rdy measurement.\. Inter-tester reliahility of the tinger\-to-floor method was also good although the niethod ia not considered valid
Biography: Mary Newton trained a t the Western Intirmarq, Glasgr)~. and gained experience mith handicapped children in Denmark, spinal injuies in Stoke Mandeville Hospital. and latterly our-patienth in G l a s p \ . She completed an MEd in 1988 at Glasgoa University and i b current11 working as a research physiotherapist funded by the Scottish Home and Healrh Department Gordon Waddell is a n orthopaedic burgeon with a particular interest in hpinal diwrders and the asisessnient of lo\+ hack pain and disahilip.
Introduction PATIENTS with low back pain make up about 6 0 % of patients referred t o a physiotherapy department. In order t o assess the severity of the condition, plan treatment and assess progress it is necessary to provide objective measurements (Rothstein, 1985). This also allows effective communication between therapists and doctors, provided the measurements are valid and reliable. In clinical research it is also essential for such measurements to be available. A review of the literature revealed various methods of measuring lumbar mobility: fingers-to-floor, skin distraction or modified Schober, flexirule, kyphometer and inclinometer. A recent survey of physiotherapists (Sweet, 1989) revealed that fingers-to-floor is still the most common way of measuring lumbar flexion. Several studies show that it is reliable (Frost e t a / , 1982; Gill e t a/, 1988). However, it is not a valid measure of lumbar flexion (Moll and Wright, 1976) as it measures a combination of spinal movement, hip movement and hamstring extensibility. Even if it is not a good measurr f specific lumbar mobility it should not be overlour
796
advantage of giving a valid measure of lumbar flexion and is quick and easy to do in a clinical setting (Rae e t a / , 1981). The main disadvantage is that it only provides a crude index of movement and does not actually measure the range of flexion. Flexirule is a draughtsman’s device which can be moulded to the shape of the lumbar spine. The contour then has to be drawn on a sheet of paper and tangents drawn to obtain an angle of measurement, making it a laborious method t o use. Also the inter-tester reliability of the method has been found to be doubtful (Lovell et a/, 19891, although intra-tester reliability has been reported 8s good (Burton, 1986; Hart and Rose, 1986; Lovell e t a / , 1989). The kyphometer is basically a protractor with t w o parallel arms. It has been demonstrated to be reliable (Ohlen, 1989) but has not been widely used, in a clinical setting. Recent studies have suggested the possibility of using an inclinometer as a method of measuring lumbar mobility (Mayer et a / , 1984; Merritt e t a / , 1986, Gill et a / , 1986). The inclinometer can either be a simple builder‘s inclinometer or a commercial model manufactured for clinical use. The advantage of the inclinometer is that the components of hip and lumbar movement can be separated. The inclinometer can also be used t o measure extension, lateral flexion, straight leg raising, lordosis and kyphosis to provide a comprehensive range of measurements. From the review of the methods used, the inclinometer seemed the most promising of the devices. I The aim of this study, which formed part of larger study to develop objective clinical evaluation of lumbar impairment (Waddell e t a / , 1991), was to select the best method of measuring lumbar mobility. The main emphasis was on the reliability and validity of the inclinometer method as this appeared to have the most theoretical advantages and to be the most suitable for routine clinical use. The kyphometer was evaluated to compare it to the inclinometer. Reliability of the fingers-to-floor method was also assessed as it is still the method in widest use. Most of the studies reviewed used S2 t o T12IL1 as landmarks from which to measure, but some used S2 t o Tll/T12 (Ohlen, 1989; Spangfort, 1989) and therefore it was necessary t o compare measurements taken at the t w o different levels.
Materials and Methods Subjects
A total of 5 0 patients w i t h low back pain and 10 normal people were studied. The subjects were aged between 20 and 55 years which is the common age range for patients w i t h low back pain. The patients had all been referred t o an orthopaedic out-patient department w i t h low back pain. Design Four sequential studies were carried out allowing refinement of the examination technique. The results of each study were analysed and modifications made if necessary before moving on to the next study. Physiotherapy, December 1991, vol 77, no 72
The patients were then positioned ready for a lateral X-ray and lordosis was measured in this position by the inclinometer and kyphometer followed by an X-ray. The patients were asked t o bend forward as far as they could go and flexion was measured by the inclinometer and kyphometer followed by an X-ray while the patients maiqtained the flexed position. The X-rays were measured by drawing lines parallel t o the upper vertebral end plates of S1 and lower vertebral endplates of T12, dropping perpendicular lines from these, and measuring the angle of inclination at their intersection (fig 2).
Fig 1: Cybex inclinometer
Materials The inclinometer used was a hand-held computerised model (EDI-320) manufactured by Cybex Inc, Ronkonkoma, New York (fig 1). A Debrunner’s kyphometer was used, manufactured by Portek AG, Postfach 2016, Bern, Switzerland. Procedure The examiners were an orthopaedic consultant and a research physiotherapist. The measurements taken were flexion, extension and lateral flexion for the inclinometer, flexion for the kyphometer and flexion for fingers-to-floor.
Study I The purpose of this study was: 1. To compare the use of the inclinometer with the kyphometer. 2. To compare the use of different surface landmarks for measuring. Ten normal subjects took part in this study which was carried out by the research physiotherapist.
Study 2 The purpose of this study was to examine the inter-tester reliability of the inclinometer and fingers-to-floor methods on 2 0 patients with low back pain. The validity of the measurements was checked by erect and lateral flexion X-rays taken on the same day but not simultaneously. The patients were measured during a routine clinical examination by the orthopaedic consultant and then independently by the research physiotherapist who was blind t o the consultant‘s findings.
Study 3 The purpose of this study was: 1. To determine the accuracy of the skin markings used t o identify the lumbar vertebrae. 2. To reassess the validity of the methods of measuring lumbar mobility. Ten patients were X-rayed as part of their routine clinical examination. The clinical measurements were taken by the research physiotherapist at the same time as the X-rays were taken. The spine was marked at T12/L1 and S2 and metal markers were taped to the spine. The patients then had an A/P X-ray taken to determine if the metal markers correctly identified the landmarks. The metal markers were removed.
Physiotherapy, December 1991, vol77, no 72
Fig 2: Schematic diagram representing the radiographic measurements
Study 4 The purpose of this study was to determine the inter-tester reliability of the inclinometer method of measuring lumbar mobility, and incorporated the above methods into the full clinical examination. Twenty patients with low back pain attending an orthopaedic out-patient department were measured during a routine clinical examination by the orthopaedic consultant and then independently by the research physiotherapist who was blind t o the surgeon’s findings. The skin marks were carefully removed t o avoid contamination of the study. Method The measurements were taken in the following carefully standardised way. Anatomical landmarks were identified with the patients in prone lying. S2 was found by palpating the inferior border of the posterior superior iliac spines. Then, by counting up the spinous processes and checking that the iliac crests approximated t o L4/5, the junction of T12/L1 was identified. Midline skin marks were made at S2, T12/L1 and T 9 with a ballpoint pen. The patients then performed a warm-up of flexion/extension twice, rotation twice, lateral flexion twice and one more flexionlextension. A warm-up was included as it has been suggested that it improves performances (Roberts era/ , 1988) and has been included in other studies (Keeley er a/, 1986). It is important t o standardise the starting position (Youdas era/ , 1991) as reliable measurement of movement depends on achieving a consistent erect position (Spangfort, 1989; Troup, 1989; Ohlen, 1989). The position used in this study was: patients in bare feet with heels together and knees straight, looking straight ahead at a point on the wall at eye height, hands hanging loosely at sides. 797
~-
Fig 3
Fig 4
Fig 6
Fig 5
Fig 7
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Lunibar flexion w a s measured w i t h t h e inclinometer by making recordings at S2 and TIZILI with the patients erect (figs 3, 4). Then t h e patients were instructed t o bend forward, reaching as far as possible towards their toes. While t h e patients were fully flexed t h e inclinometer again recorded at T12ILl (fig 5) and was then moved t o S 2 (fig 6) where the final recording was made. These four readings permitted simple calculation of lumbar flexion, pelvic flexion and total combined flexion. While in full flexion t h e fingers-to-floor distance was measured with a tape measure. Lumbar extension was measured at t h e same skin marks, taking the first recording w i t h the patients erect. The patients were then instructed t o arch backwards as far as possible, looking u p t o t h e ceiling. The examiner
Fig 8
supported t h e patients w i t h one harid o n their shoulders to inairitairi their balance. Recordings were repeated in this position and measures of lumbar, p e l v i c a n d t o t a l e x t e n s i o n were recorded. Lateral flexion was also measured at TIZILI. A n extended bar was used on t h e inclinometer. The first reading was obtained w i t h the bar lined up between the spinous processes at T 9 and TI2 (fig 7 ) . The patients were then instructed t o lean over t o the side as far as possible keeping t h e fingers i n contact w i t h the leg, making sure that b o t h feet stayed flat on the floor and t h a t no flexion or rotation occurred. A reading was obtained at one side (fig 8 ) , ttieri the patients returned t o the erect position before bending in the opposite direction w h e n the other reading was taken. Physiotherapy, December 1991, vol 77, no 72
Results The results were calculated using intra-class correlation coefficients to express the reliability of the measurements (Shrout and Fleiss, 1979). Study 1 showed that there was a high correlation between measurements using the t w o different instruments (0.89). There was a mean difference of only 3 O between using the t w o different landmarks for measuring lumbar flexion and so the more common T12IL1 landmark was used for the subsequent studies. Study 3, the X-ray study, showed reasonable correlation between the clinical measurements and the X-ray measurements and between the t w o different methods of measurement. Correlation between the inclinometer method and X-ray was 0.76, kyphometer and X-ray 0.68, and between the inclinometer and kyphometer 0.92. The skin markings were subject to an error of 4 cm. The results of studies 2 and 4, the t w o inter-tester reliability examination studies, are summarised in the table. Inter-observer reliability of lumbar movements lintra-class correlation coefficients) Study 2
Study 4
~
Flexion
pelvic lumbar total
Extension
pelvic lumbar total left right
Lateral flexion Fingers-to-floor *p> 0.01
1.p
0.96-f 0.94-f 0.98t 0.41 0.66-f 0.48" 0.84-f 0.781. 0.98-f
0.891. 0.87-f 0.941.
-
0.86-f 0.921. 0.951.
-
< 0.001
Study 2 showed poor correlation between the clinical measurements and the X-ray measurements (0.46). These results were improved by taking the X-ray measurements at the same time as the clinical measurements in study 3 (0.76). The results for lateral flexion were also poor in the first clinical study (0.84, 0.78) but modification of the examination technique improved these results (0.92, 0.95). Only total extension could be measured reliably as separate pelvic and lumbar extension were not reliable.
Discussion This study highlighted the need for using a carefully standardised technique of measurement to obtain reliable measurements. Clinical measurements must be valid and reliable t o be useful. This study has shown that fingers-tqfloor is a reliable method of measuring lumbar function but is not a valid method of measuring specific lumbar movement. The kyphometer is a valid and reliable method of measuring lumbar flexion but it is awkward to use. For this reason it is unlikely to become the method of choice in a busy clinical setting. The inclinometer is a valid aiid reliable method of measuring lumbar mobility, easy t o use and versatile. Although total extension was reliable it was not possible to separate reliably pelvic and lumbar extension. Large variations in the reliability of measuring extension have been reported (Moll eta/, 1972; Reynolds, 1975; Frost eta/, 1982; Keeley eta/, 1986; Gill eta/, 1988; Merritt eta/, 1986). All these studies used different methods of measuring extension and different positions, eg standing and lying. In the clinical Physiotherapy, December 1991, vol 77, no 72
setting extension does not seem to be routinely measured. But as an extension regime is being incorporated into some treatment and prevention routines for patients with low back pain (McKenzie, 1981) a reliable method of measuring extension is important. Lateral flexion also proved difficult to measure and required careful technique. The literature suggests there is no satisfactory way of measuring lateral flexion (Lankhorst e t a/, 1982) but this study found good reliability using the inclinometer method.
Conclusion This study has shown fingers-to-floor t o be a reliable method of measuring lumbar function. Although it is considered a measure of lumbar flexion, hip flexion and hamstring extensibility, it is a quick, easy and reliable measure of improvement in function. The inclinometer was found t o be a reliable and valid method of measuring lumbar mobility. It is also quick and easy t o use and has the advantage of being able t o measure a comprehensive group of tests of lumbar mobility. The study has highlighted the necessity of using a carefully standardised technique of measurement for assessing patients w i t h chronic low back pain. ACKNOWLEDGMENTS We are most grateful t o the Chief Scientist Office of the Scottish Home and Health Department and t o the Mactaggart Trust for their support of this work.
REFERENCES Biering-Sorensen, F (1984). 'Physical measurements as risk indicators of low-back trouble over a one-year period', Spine, 9, 2, 106-119. Burton, A K (1986).'Regional lumbar sagittal mobility: Measurement by flexicurves', Clinical Biomechanics, 1, 20- 26. Frost, M, Stuckey, S , Smalley, L E and Dorman, G (1982). 'Reliability of measuring trunk motions in centimeters', Physical Therapy, 62, 1431-37. Gill, K, Krag, M H,Johnson, G B, Haugh, L D and Pope, M H (1988). 'Repeatability of four clinical methods for assessment of lumbar spinal motion', Spine, 13, 50-53. Hart, D Land Rose, S J (1986).'Reliability of a non-invasive method of measuring the lumbar curve', Journal of Orthopaedic Sports Physical Therapy, 8 , 180-184. Keelev, J, Mayer, T G, Cox, R, Gatchel, R J, Smith, J and Mooney, V (1986). 'Quantification of lumbar function Part 5: Reliability of range of motion measures in the sagittal plane and an in vivo torso rotation technique', Spine, 11, 31-35. Lankhorst, G J, van de Stadt, T W, Vogelaar, J K, van der Korst, J K and Prevo, A J H (1982). 'Objectivity and repeatability of measurements in low back pain', Scandinavian Journal of Rehabilitation Medicine, 14, 21-26. Lovell, F W, Rothstein, J M and Personius, W J (1989). 'Reliability of clinical measurements of lumbar lordosis taken with a flexirule', Physical Therapy, 69, 96-105. McKenzie, R A (1981).The Lumbar Spine, Mechanical diagnosis and Therapy, Spinal Publications, Lower Hutt, New Zealand. Matvas, T A and Bach. T M (1985). 'The reliability of selected tcbriiiiques in clinical artnrometrics', Australian Journal of Physiotherapy, 31, 175-199. Mayer, T G, Tencer. A F, Kristoferson, S and Mooney, V (1984). 'Use of non-invasive techniques for quantification of spinal range-ofmotion in normal subjects and chronic low back dysfunction patients', Spine, 9, 588-595. Mellin, G P (1989). 'Comparison between tape measurements of the forward and lateral flexion of the spine', Clinical Biomechanics, 4, 121-123. Merritt, J L, McLean, T J, Erickson, R P and Offord, K P (1986). 'Measurement of t r u n k flexibility i n normal subjects: Reproducibility of three clinical methods', Mayo Clinic Proceedings, 61, 192-197.
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Million, R, Haavik Nilsen, K, Jayson, M I V and Baker, R D (1981). 'Evaluation of low back and assessment of lumbar corsets with and without back supports', Annals of Rheumatic Diseases, 40, 449-454. Moll, J M H, Liyanage, S P and Wright, V (1972). 'An objective clinical method to measure spinal extension', Rheumatology and Physical Medicine, 11, 6. 293-312. Moll, J M H and Wright, V (1976). 'Measurement of spinal movement' in: Jayson, M (ed) The Lumbar Spine and Back Pain, Sector Publishing Ltd, London, for Pitman Medical Publishing Co Ltd. Ohlen, G (1989). 'Spinal sagittal configuration and mobility. A kyphometer study', Stockholm: Karolinska Institute. M D thesis. Rae, P, Venner, R M and Waddell, G (1981). 'A simple clinical technique for measuring lumbar flexion', Journal of the Royal College of Surgeons of Edinburgh, 29, 5, 281 - 284. Reynolds, P M G (1975). 'Measurement of spinal mobility: A comparison of three methods', Rheurnatology and Rehabilitation, 14, 180-185. Roberts, W N, Liang, M H, Pallozzi, L M and Daltroy, L H (1988). 'Effects of warming up on reliability of anthropometric techniques
in ankylosing spondylitis', Arthritis and Rheumatism, 31, 5 4 9 - 552. Rothstein, J M (1985). Measurement in Physical Therapy, Churchill Livingstone, New York. Shrout, P E and Fleiss, J L (1979). 'Intraclass correlations: Uses in assessing rater reliability', Psychological Bulletin, 86,4 2 0 - 4 2 8 . Spangfort, V E (1989). Personal communication. Sweet, C (1989). Personal communication. Troup, J D G, Hood, C A and Chapman, A E (1968). 'Measurements of the sagittal mobility of the lumbar spine and hips', Annals of Physical Medicine, 9, 308-321. Troup, J D G (1989). Personal communication. Waddell, G, Main, C J, Morris, E W, Venner, R M, Rae, P S, Sharmay, S H and Galloway, H (1982). 'Normality and reliability in the clinical assessment of backache', British MedicalJournal, 284, 1519-23. Waddell, G, Allen, D B and Newton, M (1991). 'Clinical evaluation of disability in low back pain' in: Froymoyer, J W (ed) The Adult Spine: Principles and practice, Raven Press Ltd, New York. Youdas, J W, Carey, J R and Garrett, T R (1991). 'Reliability of measurements of cervical spine range of motion - A comparison of three methods', Physical Therapy, 71, 2, 98-106.
Marketing Physiotherapy Services The Chartered Society of Physiotherapy is running.a series of marketing courses in 1992 as part of its events programme. Nicky Davison, who is a Chartered physiotherapist and management consultant, will be tutoring these courses. Here she looks at what marketing means for physiotherapy. DO we really know about marketing? Some of us think we do while many of us have a rough idea what marketing might be. We may have heard of 'the four Ps' - product, price, place and promotion - and we think w e know how these may relate in the new NHS market place. But do we? Marketing at its simplest is the process of matching the abilities of an organisation to the needs of its customers so that both get what they want. The 'four Ps' make up the marketing mix; they are the four controllable variables which the effective marketer can mould into a single 'profitable' entity which satisfies consumers. Profitable in this case relates t o the services which we offer within the internal market. Many of us have already identified these four variables; the product is the service we provide, the price is the cost to the customer, the place is where our service is provided, and the promotion is the way in which we increase public awareness of our service. But w h o are our customers?
Customers We might answer that the patients are our customers; certainly they are the people we care about and whom w e are committed t o serve, but are they really our customers? In the NHS they are not paying directly for our services, after all. This is a complex question because in every situation the range and scope of customers, and their needs, are different. In an NHS Trust, for example, our customer might be the purchaser who buys services on behalf of the GPs and their patients. On the other hand, physiotherapists may be in a position to negotiate directly with GPs for the provision of services. In this case the customer is the GP. Where a health authority has set up a resource management initiative, in which physiotherapy services form part of a therapies directorate, this is a different
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situation. This directorate is expected to form individual contracts with each clinical directorate for the provision of services. In this case, each clinical director is the customer w h o buys our services on behalf of hisiher patients. Yet another situation might be where physiotherapists opt out and become independent. In this case, the customers could be health authorities, Trusts, GPs, private and voluntary services. These examples are just a few of the many variations with which the physiotherapy service is n o w faced when trying t o match its skills and expertise t o the needs of patientsicustomers.
Competitors However, this is not the only consideration. Obviously if there are so many options available to us, they are also available t o our competitors. So w h o are they? Traditionally, competition has existed only in private practice where, in theory, our competitors have been other physiotherapists and people such as osteopaths and chiropractors. However, there are many other areas of competition; for example, occupational therapy and physiotherapy roles have considerable overlap, and there is reason to be concerned that some authorities may consider that only one profession is essential. In this case, occupational therapists could also become our competitors. More threateningly, perhaps, other local physiotherapy units and departments are likely t o be our strictest competition in a true internal market. It is an essential part of marketing to be able t o identify who our competitors are, where they practise, if possible how much they cost, and h o w they promote their services. In this way, when we compete with them, we either sell our services at a lower cost, or we promote the specialist aspects
of our service which makes us unique and thus better value for money. The marketing process also needs to include an understanding of the environment in which services are delivered. We have all been aware of vast environmental changes of late, not least being the Government reforms. As we look around us there is evidence that environmental change is increasing. For example, we have seen the changes in communist Europe and, in 1992, there will be free trade in the European Community. We need t o be in a position t o anticipate these and other changes nearer home so that we can take advantage of the opportunities and cope with any threats. This in turn means that we need t o look carefully at the way our organisations are structured and managed.
Change What changes do we need t o consider? Before looking at what has changed we need t o understand those influences which could have a direct effect upon us and our services. We then have to assess how these have changed and whether we need to consider change within our organisation and/or profession in response. Typically w e should monitor social, economic, political and technical influences, in order to identify when change takes place, so that we can act if necessary. We also need to monitor our competitors t o see whether they too are changing and why, so that we can respond quickly to maintain our quality of service and thus continue to meet the needs of the customer and, ultimately, the patient. Finally, we must still remain committed to the care of our patients. By understanding h o w to make the most of 'the four PS', the environmental influences affecting our patients, the market requirements and the work of our competitors, we will be in a better position to respond quickly to patient needs as they arise. For information about the first t w o t w o day workshops, contact the Events Unit at Bedford Row.
NICKY DAVISON MCSP Physiotherapy, December 1991, vol 77, no 72