Understanding and Managing Chronic Low Back Pain

Chapter 1

Introduction

During the course of their lives 70 – 80% of individuals will experience low back pain (LBP) (Deyo and Weinstein, 2001; Godwin and Goodwin, 2000; van Tulder, 2001); furthermore, over 80% of such patients report recurrent episodes (Waddel, 1998). It is estimated that 80 – 90% of patients will have recovered within 6 weeks, regardless of treatment (Bronfort et al, 1996; Jackson, 2001; van Tulder et al, 1997). However, 5 – 15% will develop chronic low back pain (CLBP; 12 weeks) (Bigos et al, 2001; Quittan, 2002; Tortensen et al, 1998): this is more difficult to treat (Cottingham and Maitland, 1997; Frost et al, 2000; Hidebrandt et al, 1997) and treatment has variable results (Carpenter and Nelson, 1999; Rainville et al, 1997) Current evidence suggests that exercise and intensive multidisciplinary treatment

programmes are likely to be beneficial for CLBP (Liddle et al, 2004).
Exercise is thought to decrease fear-avoidance behaviour and facilitate functional improvement, despite ongoing pain (Liddle et al, 2004). This is an important component of the popular behavioural and cognitive therapy model of the CLBP management (Frost et al 2000; Hartigan et al, 2000; Lively, 2002; Pfingsten, 2001); this not-withstanding, there does not appear to be a consensus of opinion on the most effective programme design to maintain exercise benefits (Bronfort et al, 1996; Carpenter and Nelson, 1999; Kenny, 2000; Taimela et al, 2000). Long term maintenance of these benefits requires patient education and motivation towards behavioural change and exercise compliance (ACSM, 2000).
Programme supervision is thought to play a part in enhancing exercise compliance (ACSM, 2000) Panjabi (1992) proposed a mechanism for the development and recurrence of spinal pain.

His spinal model assumes that three systems- the articular, muscular, and neural systems- work together to provide stabilization by controlling intervertebral movement. Arising from the Punjabi spinal model came, studies which popularised specific spinal exercise (core stability exercise, motor control exercise). Changes in the recruitment of deep spinal muscles thought to be responsible for the control of spinal stability have been reported in people with spinal pain. The onset of activity of the deep abdominal muscles, transverses abdominis, is delayed in people with recurrent episodes of low back pain (Hodges and Richardson, 1996; 1998). However, it is a fact that in normal human movement postural reflexes are organised well ahead in anticipation of movement or perturbation to balance (Lederman, 2009). It has been suggested that earlier activity of transverses abdominis may be a compensation for its long elastic anterior fasciae (Macdonald et al,

2006).
Atrophic changes have been identified in multifidus, a deep paraspinal muscle, after episodes of low back pain (Rantanen et al, 1993; Hides et al, 1996). In the advent of these literatures, a protocol has been developed for retraining control of the stabilizing muscles around the spine and pelvis (Richardson et al, 1999). During a typical implementation of the specific stabilization exercise protocol, the patient is taught to recruit the deep muscles of the spine and gradually reduce unwanted over-activity of other muscles. However, this is easier said than done, the novice patient is more likely to contract wide groups of abdominal and lower trunk muscles (Sapsford et al, 2001; Urquahard et al, 2005) this is because training focus on a single muscle is even more difficult. Muscle-by-muscle activation does not exist (Georgopoulos, 2000). Progression is achieved by incorporating cocontraction of the stabilizing muscles into functional tasks (Richardson et al, 1999). Muscular control of the lumbar spine can be referred to as core stability and the muscles involved are classified according to function (O‘Sullivan et al, 2002). The local stabilisers are more efficient at providing segmental stability during movement whereas the global stabilisers only provide general stabilisation and primarily produce spinal movement (Marshall and Murphy, 2003).
The global muscles may become dominant if there are insufficiencies in the local system. These trunk muscle recruitment patterns have been found to be altered in chronic LBP (Van Dieen et al, 2003). Rehabilitation may initially be aimed at achieving an isolated contraction of the local stabilisers, by attainment of a neutral lumbar spine (O‘Sullivan et al, 2002), followed by low level progression exercises to integrate the core stabiliser muscles into more dynamic functional movements (Arokoski et al, 2001). There is some evidence of its efficacy in reducing reoccurrence in patients with chronic low back pain when it is carried out routinely (Ferreira, et al 2006); however the issue of compliance and the specificity of contracting the deep spinal muscles by the patients is a challenge. The use of diagnostic ultrasound has helped in targeting these deep muscles, but the expertise and experience of the therapist is a factor. Facilitation by the therapist is to be used to guide the patient execute and contract the specific deep spinal muscles accurately, so the effect will be maximized.
The evidence base to support the use of core stability exercises for rehabilitation has tended to focus on higher level exercises for later rehabilitation. Several undergraduate research projects (Wray et al, 2006; Ellis et al, 2007) carried out at Cardiff University have provided strong evidence that low level exercises and facilitation techniques are successful in recruiting appropriate muscle activity in healthy samples. However these works have not been published. This investigation needs to be continued in other sample groups. The present pilot research aims to recruit an opportunistic sample of individuals with chronic LBP to evaluate these same low level exercises, progressions and facilitation techniques.