Lumbar kyphosis contributes to postural imbalance and fall risk
MedWire News: Lumbar kyphosis that affects spinal inclination and postural balance may represent a risk factor for falls in elderly osteoporotic patients, study findings show.
In contrast, the researchers found no significant correlation between angle of thoracic kyphosis and postural balance.
“Vertebral fractures following falls, which result in thoracic and/or lumbar kyphosis and decreased spinal mobility, are one cause of impaired quality of life in osteoporotic patients,” note Y Ishikawa and colleagues from Akita University in Japan.
They investigated spinal curvature or inclination as a possible risk factor for postural instability and therefore falls in 93 patients with osteoporosis, aged an average of 70 years. None of the patients had neurological or other metabolic disorders other than osteoporosis.
The mean angle of thoracic kyphosis was 37.3°, which is within the normal range, while the mean angle of lumbar kyphosis was smaller than normal, at –11.4°.
With regard to postural sway, the team reports in the journal Osteoporosis International that mean anteroposterior sway was significantly greater than mean lateral sway.
The angle of thoracic kyphosis showed no correlation with age or spinal inclination, whereas significant correlations were found between the angle of lumbar kyphosis and age and spinal inclination and between spinal inclination and age.
Similarly, the angle of thoracic kyphosis was not associated with any of the seven parameters of postural sway, while the angle of lumbar kyphosis showed significant, although weak, positive correlations with all seven parameters.
Spinal inclination showed significant moderate positive correlations with all seven parameters of postural sway.
Ishikawa and colleagues note that “in elderly osteoporotic patients, since lumbar mobility is more severely limited, particularly range of extension of the lower lumbar spine, compensation for thoracic kyphosis by the lumbar spine may be inhibited, causing greater postural instability associated with lumbar kyphosis.”
They say: “The lumbar spine seems to play a more important role in maintaining spinal posture than the thoracic spine.”
The researchers also found that patients with spinal kyphosis reportedly displayed greater reliance on hip strategies than ankle strategies to compensate for postural imbalance, which might relate to the greater imbalance with anteroposterior sway compared with lateral sway.
They conclude: “Lumbar kyphosis is an important factor related to postural instability and expectation of falls in patients with postural deformity.”
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By Lucy Piper