Osteoporosis is a considerable health problem which affects many of the nation's elderly and contributes significantly to the national health cost. The significance of theis work is in determining the relationship between the strength of the vertebra, its bone mineral mass and areal density measured using dual photon absorptiometric techniques. Excised vertebra will be mechanically loaded to failure to determine the compressive strength of the anterior portion of the vertebra. The bone mineral mass and areal density will be measured using the conventional DPA scanning technique and a new technique which employs a conventional gamma camera and computer for the detector and analysis system. The gamma camera significantly improves resolution and data collection efficiency compared to the current DPA technique, and measurements are now possible in the lateral spine. Measurement of the lateral spine is advantageous in that it provides a direct measurement of the load bearing anterior portion of the vertebra. The objective of this study is to determine whether a measurement of areal density restricted to the vertebral body is superior for estimating the strength than the integrated measurement obtained in the frontal projection in current DPA systems. Successful validation of the gamma camera and computer as a superior system for meaningful measurement in the osteoporotic patient will allow accurate and sensitive bone densitometry to be performed in a broad base of existing clinical installations.