Isolated lumbar extension exercise as an intervention for chronic low back pain

Low back pain (LBP) is highly prevalent, generally categorised as ‘non-specific’ as clear diagnosis for pain is often absent, and further categorised into acute, sub-acute and chronic, with 69-75% of acute cases developing into chronic. This chronic LBP population accounts for the majority of economic costs worldwide associated with LBP. Although LBP is often ‘non-specific’, many physical dysfunctions are associated with it. Thus LBP can be regarded as multifactorial in nature. Dysfunctions include, but are not limited to: deconditioning of the lumbar extensor musculature, limited range of motion (ROM), gait abnormality and disc disorders. The novel approach of this thesis was to consider lumbar extensor deconditioning, LBP and its associated physical dysfunctions within a multifactorial framework, and the potential improvement of associated dysfunctions from intervention using isolated lumbar extension (ILEX) specifically aimed at addressing lumbar extensor deconditioning. Findings from three empirical studies are reported. The first examined limited ROM ILEX exercise compared with full ROM exercise. Results from this study support that limited ROM training is as effective as full ROM training at improving full ROM ILEX strength, pain and disability. The second study examined the effects of ILEX exercise upon lumbar spine kinematic waveform pattern variability during gait. Results from this study demonstrate that ILEX exercise significantly improves sagittal plane variability in chronic LBP participants. The final study examined the effects of ILEX exercise upon disc hydration determined indirectly through measurement of spinal height using seated stadiometry. Results from this study showed improved ILEX strength, pain and disability but did not demonstrate improvement in disc hydration. These results provide evidence for adopting a multifactorial conceptualisation of LBP in the use of ILEX exercise as a treatment. It is concluded that a wide range of improvements including pain, disability and various aspects of function relating to the multifactorial model are possible through use of a single minimal intervention involving ILEX. This conclusion has potential implications for considering direction of treatments from clinicians towards chronic LBP. Such a minimal intervention offering a wide range of benefits may reduce the need for costly and complex multi-disciplinary interventions.