Endocrine Abstracts

Background: Plantar pressure and pressure-time integral are two important factors for creating foot ulcer in diabetic patients. Increasing foot contact area with a metatarsal pad has been reported as one of the best strategies to decrease the risk of ulcer; but there is no clear guideline to determine optimal length of metatarsal pad.

Objective: The purpose of present study was to determine the effects of metatarsal pad length on peak plantar pressure and pressure-time integral in diabetic foot.

Methods: A total of 15 diabetic patients aged between 57–63 years without foot ulcers participated. Peak plantar pressure and pressure-time integral data were recorded using the RS-scan system. The data has been gathered in five conditions: (i) bare foot, no padding (control), (ii) a metatarsal pad with %18 of foot length, (iii) a metatarsal pad with %20 of foot length, (iv) a metatarsal pad with %23 of foot length and (v) a metatarsal pad with %25 of foot length.

Results: The results demonstrated a significant reduction of peak plantar pressure and pressure-time integral in all metatarsal pad lengths compared to the control (P=0/05). Peak pressure significantly decreased in metatarsal areas 1,3 and 4 by increasing metatarsal pad length (P=0.001); but there were not significant differences for metatarsal areas 2(P=0.4) and 5(P=0.06). Significant difference was observed between five conditions for pressure-time integral (P=0.001). So, pressure-time integral significantly reduced in the metatarsals 1 and 2 by pad 18 and 20% and significantly increase by pads 23 and 25%. Moreover, pressure-time integral significantly increased in the metatarsals 3,4 and 5 by pad 18% and significantly decreased by pads 20, 23 and 25%.

Conclusions: These findings indicate that peak pressure on metatarsal heads decrease by increasing metatarsal pad length, but the effect of the pad on the plantar pressure-time integral depend on the metatarsal area and pad length. Considering pad length relative to foot length can be a step towards developing an evidence-based practice for constructing optimal insole in therapeutic shoe. According to present study, we recommend that a pad with 23% of foot length could be ideal.