Older persons including those with diabetes are at increased risk for loss of protective sensation in the feet. The 5.07 (10-g) monofilament is recognized as a valid instrument to test for the presence or absence of protective sensation in the foot. Few studies report reliability and no studies report responsiveness for a multisite examination using the 10-g monofilament. The purpose of this study was to determine the responsiveness and reliability for the 10-g monofilament in evaluating protective sensation in the feet.
A convenience sample of 28 (20 women and 8 men) participants between the ages 50 and 78 years were recruited for the study. Sensory testing was performed on 18 different sites (9 per foot) by 3 testers for each participant using the 10-g monofilament. Participants were tested on 2 occasions with approximately 1 week between tests. Participants' eyes were closed for the duration of the examination to blind them to the tester. Testers were blinded to each other and previous test results.
Intratester and intertester reliability were calculated using intraclass correlation coefficients (ICC). Intratester ICC (3, 1) and minimal detectable change at the 95% confidence level (MDC95) were calculated for each tester and then averaged yielding the following: ICC = 0.76 (95% CI: 0.68–0.84), MDC95 = 2.83. Intertester ICC (2, 1) was 0.78 (95% CI: 0.64–0.88). MDC95 was 2.81. This gives an MDC95 for this test of 3 sites.
The results of this study support the use of the 10-g monofilament as a reliable clinical tool to assess changes in protective sensation of the feet for our participant pool. An 18-site sensory examination using the 10-g monofilament must result in sensory change at 3 or more sites to indicate actual change in protective sensation.
1Department of Physical Therapy, School of Allied Health Sciences, University of Nevada, Las Vegas.
2Tru Physical Therapy, Henderson, Nevada.
3Clarian Health Partners, Physical Therapy Wound Management, Indianapolis, Indiana.
Address correspondence to: Daniel Young, PT, DPT, Department of Physical Therapy, School of Allied Health Sciences, University of Nevada, Las Vegas, 4505 S Maryland Parkway, Box 453029, Las Vegas, NV 89154 (email@example.com).