Thenar muscle blood flow and bone mineral in the forearms of lumberjacks

Abstract

Forty lumberjacks who had used a chain saw for 0-20 yr and who had no general disease affecting the bones were studied by measuring the thenar muscle blood flow of both hands by the 133Xe local clearance method. Bone mineral in the left forearm in the region of cancellous and cortical bone was assessed by the 241Am gamma ray attenuation method. Vibration was found to decrease the blood flow in the saw bearing left hand compared with the right hand of lumberjacks. The bone mineral density (g/cm3) was lower in the forearm bones of the lumberjacks than in controls of the same age with healthy bones. Moreover the poorer the thenar muscle blood flow, the greater was the decrease in the mineral density of the distal radius. Measurement of the mineral density of the forearm bones by the gamma ray attenuation method can be used for early detection of bone lesions in traumatic vasospastic disease.