Importance of idiomotion and varying exercise
by Nina Clare
Guide Dogs for the Blind have a very high percentage of osteoarthritis
This statement was very interesting from Martin Fischer's lecture "Dogs in
Motion". My gut reaction was to look at the genetic background. But could it be
more likely the answer lies in the way guide dogs move?
Research has shown that when dogs are walking or running, the strain is not
equally distributed over the joint surfaces.
There are three things that I would like for you to note in the above pictures
(1) During locomotion, there are large areas which do not come into contact with
(2) The areas which do not come into contact with each other are extremely
similar in walk and trot
(3) The risk zone for osteoarthritic lesions is marked as the black areas. This
risk zone lies outside the range of motion during locomotion and is found in the
area bordering the regions of the joint which are not subjected to strain.
Another interesting study in Fischer's lecture looked at the hip joint and the
size of areas that came into contact under increasing loads.
The results showed that at 50% of body weight stress, only 30% of the joint
socket is involved in load bearing compared to just 15% of the ball (femur)
Even when the loads reach four times body weight (400% - this would happen in
gallop) just 65% of the socket and 30% of the ball head (femur) are involved in
So why is this research important and
It all relates to how joint cartilage is nourished. As you can see from the
picture below, the cartilage does not come in contact with blood flow but is
situated on the bone within the hermetically sealed joint. The only way joint
cartilage can receive nutrients is through the synovial fluid.
Nutrients are pushed into the cartilage from the synovial fluid through movement
and loading. As the bones move, the joint fluid gets swished around and pushed
into the cartilage. If there is no pressure, the nutrients are not pushed into
the cartilage and therefore the area of the cartilage does not get as much
nourishment. When linking joint nourishment with the research, it becomes even
clearer how important full use of joint range of motion is to prevent and
The research means that during normal locomotion
(walk, trot, gallop) the dog is not using the full range of the joint and the
joint is not fully nourished.
The next obvious question is, how to get the dog
to use their range of motion more fully to better nourish the joints. In humans,
the answer would be yoga or pilates. In animals, the answer is motion that does
not propel the dog forward (= idiomotion).
Idiomotion could be the dog scratching, digging,
performing play-bow, jumping, landing and other natural movements. So the next
time you see your dog digging up your garden, be glad they are using their joint
range of motion more fully.
So coming back to the original question about
guide dogs. Guide dogs' job requires them to perform the same movements each day
to help their owners. As the dogs' joints do not go through their full range of
motion, it would explain why they have such a high percentage of osteoarthritic
It is vitally important in order to have a healthy joint to load
the joint across the whole surface area. Locomotion (walk, trot, gallop)
only partially loads the joint at specific areas, so additional movement
(scratching, bowing, digging) is required to load the rest of the joint
was very interesting and relevant to my profession as a canine physiotherapist
and hydrotherapist. Exercise prescription focuses on muscle strength building
and flexibility. The flexibility exercises are designed to increase the dogs'
range of motion and to increase joint loading. The research proves just how
important the varied exercises are for the long term health of the joints.
Fischer, M. & Lilje, K. (2014). Dogs
2nd ed. Dortmund: VDH Services Gmbh. 72-80.
Fischer, M. (2018) Dogs in Detail: Dogs in Motion. Seminar. 2nd September