A mouse model for hand-arm vibration syndrome

Hand-arm vibration syndrome (HAVS) occurs in workers who use vibrating hand tools. Symptoms of HAVS include finger paresthesia and numbness, a loss of manual dexterity and grip strength, and vasospasms in the fingers in response to cold. Although the relationship between vibration exposure and HAVS is well-established, it is not clear how vibration causes tissue damage. The purpose of our research is to identify the fundamental physiological mechanisms involved in the development of HAVS. Toward that end, we have developed a vibration exposure system in which mice are placed in a small cage with a rigid floor that vibrates vertically. The system is capable of exposing mice to sinusoidal vibration at 125 to 1250 Hz with accelerations of up to 49 m/s(2) rms. Exposures last for 4 hours/day, 5 days/week for up to 24 weeks. Initial results indicate that 11 weeks of 125 Hz vibration did not significantly affect the body weights of the mice, and that 12 and 24 weeks of vibration did not significantly affect the liver, kidneys, or stomach. These results suggest that this model can be used to examine the effect of vibration on the mouse foot and lower leg without confounding effects from systemic damage.