Lower limb involvement in spinal function and low back pain.
OBJECTIVE
To evaluate evidence for involvement of the lower limb in spinal function and low back pain (LBP).


METHODS
A hypothesis based on a critical review of the relevant biomechanical and clinical literature.


RESULTS
The spine resembles an inverted pendulum that supports the weight of the upper body; its stability requires a moving base that is provided by the joints of the lower limb, especially the hip. However, the sacroiliac joints are unlikely to be important for spinal function. The changing pattern of gait and development of lumbar lordosis, in early childhood, provide evidence for the inter-dependence of spinal curvature and lower limb action. Clinical signs associated with LBP may be associated with an inability to rotate the trunk about the hips. These include disorientation of the pelvis and weakness or tightness of muscles around the hip. The "sway back" posture seen in LBP involves flexion of the hip, knee and ankle to compensate for abdominal and back muscle weakness.


CONCLUSIONS
In order to understand the varied clinical presentation of LBP patients, the function of the spine should be considered in the context of the whole body, especially the lower limb.
McGregor
A H
AH
Biosurgery & Surgical Technology, Faculty of Medicine, Imperial College London, Charing Cross Hospital Campus, London, UK. a.mcgregor @imperial.ac.uk
Hukins
D W L
DW
D001696:Biomechanical Phenomena; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D035002:Lower Extremity / Q000503:physiopathology*; D013131:Spine / Q000503:physiopathology*