Potentiation of Spinal injury in lifting

Abstract

Bradford and Spurling in 1945 calculated that pressures in the region of 1,600 lb/sq. ins. occur in the lower part of the spine during straight legged lifting. This calculation viewed the body mechanically rather than biomechanically. There is in fact a postural reaction to the load of swaying backwards, and an unavoidable increase in intratruncal pressure. The later work by Floyd and Silver, 1955, showed erectores spinae to be electromyographically silent in the early phase of loaded extension. Whilst this is true the contribution of these muscles to this movement is also a function of the weight lifted, the time taken and the extent of flexion considered relative to the mobility of the individual. The work led to even greater concern about the dangers to which the spinal column is subjected in this movement.