Core stability exercise in chronic low back pain Paul W. Hodges, BPhty (Hons), PhD Department of Physiotherapy, The University of Queensland, Brisbane, Qld 4072, Australia Exercise is commonly used in the management of chronic musculoskeletal conditions, including chronic low back pain (CLBP). The focus of exer- cise is varied and may include parameters ranging from strength and endurance training, to specific training of muscle coordination and control. The assumption underpinning these approaches is that improved neuromuscular function will restore or augment the control and support of the spine and pelvis. In a biomechanical model of CLBP, which assumes that pain recurrence is caused by repeated mechanical irritation of pain sensitive structures [1], it is proposed that this improved control and stability would reduce mechanical irritation and lead to pain relief [1]. Although this model provides explanation for the chronicity of LBP, perpetuation of pain is more complex, and contemporary neuroscience holds the view that chronic pain is mediated by a range of changes including both peripheral (eg, peripheral sensitization) and central neuroplastic changes [2]. Although this does not exclude the role of improved control of the lumbar spine and pelvis in management of CLBP, particularly when there is peripheral sensitization, it highlights the need to look beyond outdated simplistic models. One factor that this information highlights is that the refinement of control and coordination may be more important than simple strength and endurance training for the trunk muscles. The objective of this article is to discuss the rationale for core stability exercise in the management of CLBP, to consider critical factors for its implementation, and to review evidence for efficacy of the approach. The rationale for core stability exercise Core stability exercise can be defined loosely as the restoration or augmentation of the ability of the neuromuscular system to control and protect the spine from injury or reinjury. The term is variously used to describe a spectrum of exercise approaches that have the common goal to improve lumbopelvic control, with varied rationales. In general, strategies can be divided into two main groups: those that aim to restore the coordination and control of the trunk muscles to improve control of the lumbar spine and pelvis [3,4], and those that aim to restore the capacity (strength and endurance) of the trunk muscles to meet the demands of control [5,6]. Although both compo- nents are necessary, it is useful to consider the rationales for each. The ‘‘muscle capacity’’ model of core stability exercise is based on the well-established premise that stability of the spine is dependent on the contribution of muscle. The contemporary view of spinal stability is based on the Euler model that considers the control of buckling forces [7–9]. This is based on the understanding that buckling failure of the lumbar spine, devoid of muscle, occurs with compressive loading of as little as 90 N. This model argues that muscle activity is required to act like guy wires to stiffen intervertebral joints that they span to maintain the lumbar spine in a mechanically stable equilibrium [7 – 9]. This definition is relatively static and suggests the maintenance of a set position of the spine. Few studies have considered this model in more dynamic terms [10]. Consistent with the proposal that muscle 0030-5898/03/$ – see front matter D 2003, Elsevier Inc. All rights reserved. doi:10.1016/S0030-5898(03)00003-8 Financial support was provided by the National Health and Medical Research Council of Australia and The Swedish Research Council. E-mail address: p.hodges@shrs.uq.edu.au Orthop Clin N Am 34 (2003) 245 – 254