Aim: Adherence to offloading devices for diabetic foot ulcers (DFU) is poor and postural instability influences adherence. Prior research suggests an ankle-high removable cast walker (RCW) in tandem with a contralateral shoe lift might increase users’ balance relative to a traditional knee-high RCW without a lift. This study compared compensatory responses to perturbations under both conditions.

Methods: Twenty-five individuals (48% male; age: 68±8 years) with diabetic peripheral neuropathy participated. Participants completed trials under three conditions: bilateral standardized shoes, knee-high RCW, and ankle-high RCW with contralateral shoe lift. Stepping thresholds (ST) were assessed for two types of perturbations:1) From a stopped position, a treadmill rapidly accelerated at 3.5m/s² to reach a set peak-velocity and then decelerated and stopped. The smallest peak-velocity to elicit a step was identified as the ST. Participants were separately oriented on the treadmill to elicit anterior and lateral ST; 2) A waist mounted spring scale was pulled until a target load was reached, then the spring was rapidly released. ST was the lowest load necessary to force a step upon release. Anterior and posterior waist-pull perturbations were done.Participants also rated their stability in each footwear condition via a 10cm visual analog scale. Data analyses focused upon the primary comparison of the two offloading conditions.

Results: The knee-high RCW resulted in significantly decreased ST for two of the four tests (treadmill anterior: mean difference .037m/s2, p=.048 and anterior waist-pull: mean difference 2.2lbs, p<.001) relative to the ankle-high RCW with a contralateral lift. Participants reported a large and statistically significant reduction in perceived stability with the knee-high RCW (mean difference= 0.93cm, p=0.030) .

Conclusions: Future prospective studies should assesses whether the differences noted in this study translate into differences in RCW adherence by patients with DFU.


R.T.Crews: None. N.J.Rosenblatt: None.


National Institute of Diabetes and Digestive and Kidney Disease

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