Vibration perception threshold testing in patients with diabetic neuropathy: ceiling effects and reliability


  • R.W.M.v.D. current address: School of Healthcare Studies, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, UK.

    M.M.S. current address: Merck Research Laboratories, PO Box 2000, RY 33404, Rahway, NJ 07065, USA.

    J.A.D. current address: Food and Drug Administration, Center for Veterinary Medicine, Division of Compliance, 7500 Standish Place, HFV-230, Rockville, MD 20855, USA.

Peter R. Cavanagh PhD, Center for Locomotion Studies, 29 Recreation Building, Penn State University, University Park, PA 16802, USA. E-mail:


Aims  To test the reliability of a new vibrometer (Maxivibrometer) which was constructed so that vibration perception threshold (VPT) could be determined without the disadvantage of the off-scale measurements frequently experienced with the Biothesiometer.

Methods  The two devices were compared and tested on a group of diabetic neuropathic subjects and a group of healthy, matched control subjects. VPT was tested on the plantar surface of the feet.

Results  The Maxivibrometer gave an actual measurement in all cases even if subjects were severely neuropathic. The replication-to-replication and day-to-day intraclass correlation coefficients for the Maxivibrometer VPT were, except in one case, above 0.94, indicating excellent reliability. The Biothesiometer VPT could also be measured with excellent reliability but only within a limited range of mild to moderate neuropathy, so it appears to be an appropriate screening tool. The replication-to-replication intraclass correlation coefficient was 0.93.

Conclusions  Because VPT could be measured over a wide range with the Maxivibrometer, it was demonstrated that loss of sensation in diabetic neuropathy can progress far beyond the maximum VPT value of the Biothesiometer. The wide measurement range and the excellent reliability make the Maxivibrometer a valuable research tool to quantify loss of sensation, particularly in the presence of severe neuropathy and to record changes over time.

Diabet. Med. 18, 469–475 (2001)