Foot loading with an ankle-foot orthosis: the accuracy of an integrated physical strain trainer

• Published in: International orthopaedics 2012-07, Vol.36 (7), p.1411-1415
• Main Authors: Pauser, Johannes, Jendrissek, Andreas, Brem, Matthias, Gelse, Kolja, Swoboda, Bernd, Carl, Hans-Dieter
• Format: Article
• Language: English
• Subjects: Adult; Ankle Injuries - therapy; Ankle Joint; Female; Foot - physiology; Humans; Male; Materials Testing; Medicine; Medicine & Public Health; Original Paper; Orthopedics; Orthotic Devices; Physical Therapy Modalities - instrumentation; Pressure; Reproducibility of Results; Walking - physiology; Weight-Bearing - physiology
• ISSN: 0341-2695; 1432-5195
• DOI: 10.1007/s00264-012-1501-1

Purpose To investigate the value of a built-in physical strain trainer for the monitoring of partial weight bearing with an ankle-foot orthosis. Methods 12 healthy volunteers were asked to perform three trials. Plantar peak pressure values from normal gait (trial one) were defined as 100% (baseline). The following trials were performed with the Vacoped ® dynamic vacuum ankle orthosis worn in a neutral position with full weight bearing (trial two) and a restriction to 10% body weight (BW) (trial three), as monitored with an integrated physical strain trainer. Peak plantar pressure values were obtained using the pedar ® X system. Results Peak pressure values were statistically significantly reduced wearing the Vacoped® shoe with full weight bearing for the hindfoot to 68% of the baseline (normal gait) and for the midfoot and forefoot to 83% and 60%, respectively. Limited weight bearing with 10% BW as controlled by physical strain trainer further reduced plantar peak pressure values for the hindfoot to 19%, for the midfoot to 43% of the baseline and the forefoot to 22% of the baseline. Conclusions The Vacoped ® vacuum ankle orthosis significantly reduces plantar peak pressure. The integrated physical strain trainer seems unsuitable to monitor a limitation to 10% BW adequately for the total foot. The concept of controlling partial weight bearing with the hindfoot-addressing device within the orthosis seems debatable but may be useful when the hindfoot in particular must be off-loaded.