When we touch an item or a texture, the sensory impulses from the hand are transmitted to the brain. The act of touch is controlled by the hand but the perception of sensation is processed in the brain. The sensory impulses are transmitted via nerve trunks in the hand and brain to the spinal cord, and via the long nervous pathways in the cord, they reach the sensory cortex of the brain.

Vibrations from a hand-held vibrating tool are transferred to the hand where they may have a negative influence on mechanoreceptors, nerve fibres, blood vessels and muscles. In the nerves, an intraneural oedema may occur and  myelin sheaths as well as nerve fibres may be damaged. 

High frequency vibrations may exert their effect distally in the fingers while low frequency vibrations may be transmitted proximally in the arm.

In the walls of blood vessels there may be structural and functional changes which may influence microcirculation and induce a tendency for vasospasm – so called ”white fingers”.

In muscle tissue there may be degenerative as well as regenerative cellular changes. Also in brain cortex there may be  functional reorganisations resulting in overlapping of cortical  areas corresponding to individual fingers.

All individuals are not equally vulnerable to vibrations. Some individuals can work most of their life without developing problems while others may acquire symptoms already after a few years. The reason is probably differences in ”biological vulnerability” to vibrations, but factors like type of tools, working manner and exposure time are also important.

When a vibration injury is established, there is no effective treatment available. Therefore, prophylactic measures are essential, and methods to detect an early, beginning injury are very important so that the working situation can be modified.