Article

BACKGROUND: To date, few pharmacologic or rehabilitation interventions for
sublesional osteoporosis (SLOP) or low bone mass of the hip and knee regions
after spinal cord injury (SCI) have produced significant or sustained increases
in lower extremity bone mineral density. Whole body vibration (WBV) is a
potential intervention for the prevention and/or treatment of SLOP. OBJECTIVE: To
identify the optimal WBV conditions (ie, plate, frequency, amplitude, and subject
posture) among men with chronic SCI during passive standing and facilitate the
implementation and future evaluation of the efficacy of WBV and passive standing
for prevention and treatment of SLOP in men with SCI. DESIGN: This phase 0 device
development study assessed the lower extremity propagation characteristics of WBV
in men with and without SCI by using a variety of a priori specified plates,
frequencies, amplitudes, and postures that facilitate lower extremity vibration
absorption while minimizing vibration propagation to the head. SETTING: A
tertiary SCI rehabilitation center in Toronto, Canada. PARTICIPANTS: Healthy men
with chronic paraplegia (n = 5) and those without SCI (n = 7), ages 20-50 years,
weight 68-113 kg, and height 168-188 cm. INTERVENTIONS: An EasyStand standing
frame (Altimate Medical Inc, Morton, MN) was fitted onto 2 commercially available
vibration platforms: WAVE (WAVE Manufacturing Inc, Windsor, Ontario, Canada) and
Juvent (Juvent Medical Inc, Somerset, NJ). Accelerometers were attached to the
participants' forehead, hip, knee, and ankle to measure vibration propagation.
Vibration parameters evaluated were posture (knee angles of 140 degrees , 160
degrees , and 180 degrees [180 degrees for Juvent only]), vibration frequency (25
Hz, 35 Hz, and 45 Hz), and vibration amplitude (0.6 mm and 1.2 mm [WAVE only]).
The subjects were exposed to all combinations of posture, frequencies, and
amplitudes during the experiments (total parameter combinations: 12 WAVE and 9
Juvent). MAIN OUTCOME MEASUREMENTS: Peak-to-peak vibration and transmissibility
of vibration were recorded and computed for each accelerometer at the tested
locations. RESULTS: Variations in frequency generated the most noticeable changes
in propagation characteristics, followed by variations in knee angle and
amplitude. CONCLUSIONS: WBV therapy delivered with use of the WAVE platform with
a knee angle of 140 degrees , plate frequency of 45 Hz, and amplitude of 1.2 mm
met our a priori criteria for the "optimal WBV condition." Future studies should
evaluate the therapeutic efficacy of the WAVE platform by using these parameters
to maintain or augment bone mass among persons with SCI and SLOP.
CI - Copyright (c) 2012 American Academy of Physical Medicine and Rehabilitation.
Published by Elsevier Inc. All rights reserved.

Langue : ANGLAIS