Gait rehabilitation by means of a new
body-weight measuring system.
Eli Isakov1, A. Avni2. 1. Orthopedic
Rehabilitation Dept. and Kinesiology
Lab., Loewenstein Hospital, Sackler
Faculty of Medicine Tel Aviv
University, Ra'anana, Israel. 2.
Andante Medical Devices Ltd., Omer,
Israel.
body-weight measuring system.
Eli Isakov1, A. Avni2. 1. Orthopedic
Rehabilitation Dept. and Kinesiology
Lab., Loewenstein Hospital, Sackler
Faculty of Medicine Tel Aviv
University, Ra'anana, Israel. 2.
Andante Medical Devices Ltd., Omer,
Israel.
Introduction: Current methods for gait rehabilitation are directed towards instructing partial
weight bearing (PWB) or to encourage full weight bearing (FWB) on an affected limb. In
clinical practice it is possible to distinguish two groups of patients in need of gait
rehabilitation. In the first group, controlled PWB is recommended after surgical fixation of a
fractured lower limb bone, following unsuccessful joint replacement, after reconstruction of
knee ligaments and in those patients with joint infection, sprain of the ligaments or stress
fractures in the lower limb. In the second group of patients after lower limb amputation,
cerebrovascular hemiparesis, THR or TKR, and in gait disorders due to muscle weakness for
various reasons, FWB is encouraged. Ambulation with PWB or FWB is a sensorimotor skill
taught by physical therapists. The current methods for gait rehabilitation are subjective and
based on verbal instructions, use of full-length mirrors and bathroom scales. An objective
and practical method of measuring correct weight bearing in such patients during
ambulation does not exist.
Objectives: To assess the validity of body weight measurements obtained during
ambulation by comparing the results of a new body weight (BW) measuring system
(SmartStep, Andante Medical Devices Ltd.) with those obtained from a commercially
available force plate.
Subjects and Methods: Nine healthy subjects, mean age 26.4 ±3.8 yr, participated in the
study and were fitted with a proper size insole. The SmartStep system consists of a light-
weight inflatable insole, a control unit for calibration, data recording and delivery of a bio-
feedback audio signal and PC software. Loading the lower limb during ambulation,
increases the pressure in the insole pockets and thereby activating the relative pressure
sensors. The resulting electric signals were stored in the control unit attached to the
patients’ ankles. Data were collected simultaneously from the insole and from the force
plate. SmartStep and force plate data were analyzed using accuracy test, general linear
models, Pearson correlation, as well as calculation of the absolute margin between the
obtained data.
Results: Analysis of the SmartStep System and force plate results showed that the overall
accuracy of the SmartStep was statistically significant (p=0.004) as well as correlation level
(R2=0.907). These findings indicate that the SmartStep is extremely accurate as a predictor
of force plate measurements. In addition, the SmartStep System was tested for the
repeatability of the results. Standard error of mean proved that the SmartStep System could
repeat the same results with a minimal standard deviation of 0.53 kg.
Conclusions: his study provides evidence of the validity of the SmartStep System for
measuring body weight during ambulation. Since the SmartStep System also supplies an
audio or vibrotactile feedback signal, it can be calibrated to provide a signal each time the
patient is overloading or underloading his body weight on the affected lower limb relative to
specified thresholds. Therefore, SmartStep System may be used as a useful clinical and
practical tool in gait rehabilitation.
Presented at the European Federation for Research in Rehabilitation Congress; Lublijana –
Slovenia, June 2004.
weight bearing (PWB) or to encourage full weight bearing (FWB) on an affected limb. In
clinical practice it is possible to distinguish two groups of patients in need of gait
rehabilitation. In the first group, controlled PWB is recommended after surgical fixation of a
fractured lower limb bone, following unsuccessful joint replacement, after reconstruction of
knee ligaments and in those patients with joint infection, sprain of the ligaments or stress
fractures in the lower limb. In the second group of patients after lower limb amputation,
cerebrovascular hemiparesis, THR or TKR, and in gait disorders due to muscle weakness for
various reasons, FWB is encouraged. Ambulation with PWB or FWB is a sensorimotor skill
taught by physical therapists. The current methods for gait rehabilitation are subjective and
based on verbal instructions, use of full-length mirrors and bathroom scales. An objective
and practical method of measuring correct weight bearing in such patients during
ambulation does not exist.
Objectives: To assess the validity of body weight measurements obtained during
ambulation by comparing the results of a new body weight (BW) measuring system
(SmartStep, Andante Medical Devices Ltd.) with those obtained from a commercially
available force plate.
Subjects and Methods: Nine healthy subjects, mean age 26.4 ±3.8 yr, participated in the
study and were fitted with a proper size insole. The SmartStep system consists of a light-
weight inflatable insole, a control unit for calibration, data recording and delivery of a bio-
feedback audio signal and PC software. Loading the lower limb during ambulation,
increases the pressure in the insole pockets and thereby activating the relative pressure
sensors. The resulting electric signals were stored in the control unit attached to the
patients’ ankles. Data were collected simultaneously from the insole and from the force
plate. SmartStep and force plate data were analyzed using accuracy test, general linear
models, Pearson correlation, as well as calculation of the absolute margin between the
obtained data.
Results: Analysis of the SmartStep System and force plate results showed that the overall
accuracy of the SmartStep was statistically significant (p=0.004) as well as correlation level
(R2=0.907). These findings indicate that the SmartStep is extremely accurate as a predictor
of force plate measurements. In addition, the SmartStep System was tested for the
repeatability of the results. Standard error of mean proved that the SmartStep System could
repeat the same results with a minimal standard deviation of 0.53 kg.
Conclusions: his study provides evidence of the validity of the SmartStep System for
measuring body weight during ambulation. Since the SmartStep System also supplies an
audio or vibrotactile feedback signal, it can be calibrated to provide a signal each time the
patient is overloading or underloading his body weight on the affected lower limb relative to
specified thresholds. Therefore, SmartStep System may be used as a useful clinical and
practical tool in gait rehabilitation.
Presented at the European Federation for Research in Rehabilitation Congress; Lublijana –
Slovenia, June 2004.
Reliability Study
Copyright © 2010 Andante Medical Devices, Inc. All Rights Reserved.
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