Subject-specific compressive tolerance estimates

Spinal load models have become an increasingly valuable tool for the evaluation of the stress placed on the spine. In order to get an accurate representation of these spinal loads, they must be compared to known tolerance values. Bone mineral content and density of the lumbar spine of 23 males and 21 females was measured using a dual energy x-ray absorptiometry. Compression tolerance values were predicted by previously published studies based upon bone mineral levels. Anthropometric measurements were recorded and related to the compression tolerance values through the use of multivariate linear regression techniques. Compression tolerance values based on the bone mineral content or density explains more of the individual variability than solely age-based estimates. Several anthropometric variable regression models were developed that resulted in moderate to good predictive power (R(2) = 0.62 to 0.81). The current study describes a useful alternative to traditional tolerance estimates that accounts for individual differences requiring non-invasive and time-efficient procedures.