View Full Version : Partial Weight Bearing Devices

Mel Siff
03-01-2001, 05:44 PM
Zoe Robertson writes:

From Al Finch

I have conducted several studies using a tethering system which can
dynamically unweight an individual during gait for any percent of their body
weight. The device is called the Conva-Lift and it has been patented and FDA
approved for patient use. I have over the past few years conducted studies to
examine the effectiveness of this
system. The studies has included partial weight bearing and its effects on
the ground reaction forces during various degrees of tethered gait, effects
on knee torques while performing partial squats under different unweighting
conditions, I examined the effect of an upper body vest and how the active
traction can reduce low back muscle activity (EMG) by 82% in only 10 minutes
of tethered gait and the last project conducted last year
and presented at the national ACSM conference held in Indianapolis June 2000,
we looked at the kinematic of tethered treadmill gait (co-author Rick
Hauser). ............ >

*** The scientific use of this type of variable load reduction device for
standing and treadmill research actually appears to have been pioneered
several decades ago in the former Soviet Union by Dr Ygor Ratov at the State
Central Institute of Sports Science in Moscow. He studied not only the
biomechanics involved, but also the metabolic processes for different amounts
of load reduction. Besides sporting applications, his system was used for the
study and rehabilitation of spinal and other injured patients.

Another larger, more sophisticated version of his system employing a small
robot which ran in a an overhead rail above a 100 metre indoor sprint track
was used to alter the loading and study the kinematics of sprinters at the
State Central Institute of Physical Culture. I still have photographs of all
of these systems which I took in Moscow more than 10 years ago, but a
stylised diagram of some of the apparatus appears in Yessis M "Secrets of
Soviet Sports Fitness and Training" 1987: 193-194. Other articles on Dr
Ratov's work appear in the "Soviet Sports Review" edited by Dr Yessis.
Possibly Dr Zatsiorsky, who is also a member of this group and who knew Dr
Ratov personally, could supply further information on the many years of
research done by Dr Ratov's team using this apparatus

Dr Mel C Siff
Denver, USA

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