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Lameness and Gait Analysis of the Dog
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Gait Analysis Basics
Introduction
Canine locomotion can be used to assess the function of the body
as a whole by evaluating the functions of it's individual components.
The anatomy of the dog's body is designed symmetrically. The right
side should mirror the left side. In theory then the movements of
the right side should mirror the movements of the left side. This
is true to an extent, with variances due to laterality, in other words
some dogs are right-handed and some dogs are left-handed.
Body Symmetry
To evaluate balanced body movement we can analyze canine locomotion.
The common name for analysis of canine locomotion is "gait analysis".
There are various forms of gait, which are a combined result of body anatomy
and velocity of movement. Gaits can be defined as symmetrical or
asymmetrical. While in a symmetrical gait, the movements of the sides
of the dog mirror each other. Examples of these gaits are the walk,
trot, and pace. In an asymmetrical gait the movements of the two
sides are not the same. The running gallup is an example of this
type of gait.
The Phases of the Trot Gait
The best gaits to use for gait analysis are the symmetrical gaits,
the walk or the trot. It is easier to pick up abnormal movement while
a dog is moving symmetrically. The trot is a two phase gait, and
the gait that is utilized by our CAV motion analysis system we are currently
using for the dog. In the trot gait, one front leg and its' contralateral
rear leg are in support, followed by the other front leg and it's contralateral
rear leg. This gait is usually used by the dog at speeds to fast
to walk but not fast enough for a run. Some breeds use a pace gait
instead of the trot. The pace is similar to the trot except that
the right side legs are in support followed by the left side legs.
Our system is capable of analyzing a dog in a pace gait.
Filming Protocol
This protocol
must be followed to allow the CAV to process the data. *
e-mail questions to Canine
Motion Analysis
Materials
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Yard stick (meter stick), It is very important that the measuring
stick is filmed to define the ratios
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Mark the ends of the stick so that they are visible on the videotape.
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Both ends of the stick should be visible on the tape.
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The stick can be laid next to the gait path.
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An alternative method is to place two markers one yard or meter apart.
they mmust be visible on the videotape.
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VHS or SVHS Camera
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(Any Videotaping system can be used as long as it can be transferred
to a VHS, SVHS, VHS-C or SVHS-C tape.)
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It is best to videotape at a shutter rate of at least 1/500 seconds
or faster.
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Tripod or some other method to stabilize the camera
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VHS or SVHS Tape
Figure 1. Camera Set-Up (Front and Overhead View)
Set-up
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The Camera is to be stationary throughout the filming session.
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The dog will be trotted on a pathway perpendicular to the camera.
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The Camera Height (C-D) should be approximately to the middle of the
thorax. Make sure the whole height of the dog is in the picture.
A height of 2 feet will work for most dogs.
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The Camera Distance (A-B) should be 15 - 30 feet from the Gait Pathway.
A distance of 20 feet is used most commonly. This distance is determined
by the size of the dog.
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We need to get at least two strides in the picture frame (See figure
2).
Figure 2. Two Strides Need to be Filmed. Note that two markers
have been placed on the gait path one yard apart.
Pathway
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It should be as level as possible.
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It's surface should provide good traction so the dog doesn't slip.
For example, don't use freshly waxed tile or marble floor.
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It should be made up of material that doesn't hurt the dog. Do
not use a sharp gravel base.
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Examples of good pathways are:
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A carpet runner on solid floor
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Level dirt or gravel road
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A level field or grassy area can be used, but foot contact must be identifiable.
If the grass is too deep foot contact might be missed.
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A filming area commmonly used with great success is a tennis court (See
figure 3).
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The camera is set up at the middle of the servers line facing towards
the back baseline.
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The dog is then trotted back and forth along the baseline.
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A measuring stick is laid along the baseline for ratio measurments
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It is important that the right side movement is symmetrical to the movement
on the Left.
Figure 3. Filming at a tennis court. Note the measuring stick
on the baseline. The dog is moving in a trot gait. The speed and actions
of the two sides must be symmetrical or the right side data cannot be compared
to the left side. This dog has had markers attached at the joint centers
to assess joint angular movements.
Markers
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Tape can used for the markers.
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Dark Dogs
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White porous tape
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Masking tape
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White or Light Dogs
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Black electrician's tape
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Black duct tape
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Place markers on five anatomical locations on the dog: In front of or
behind the Ear (whichever is needed to see the point on the film) , the
withers, the hip, fornt paw, and rear paw.
 
Filming
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Define the pathway
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Set up the camera as described above
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It is best to use a shutter rate of 1/500 seconds or faster
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Set up the measuring stick as described above
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Film the yard (meter) stick for approximately 30 seconds (or leave the
markers in view of the camera)
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Trot the dog on the pathway from left to right and then right to left
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Lead the dog on the side away from the camera so you don't block the
view from the camera
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Try to get at least ten good right and left sequences
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Put the date, client's name and dog's name on the tape exterior
Robert L. Gillette, DVM, MSE
03/16/04
k9care@sportsvet.com
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