Back in the ring and interesting to review downforces on front limbs

Back to competition
 

Jaidi back in competition

Last week we did our first competition since I started working hard on Jaidi's rehabilitation. On the Saturday we did two competitive rounds and had 2/2 clear rounds with a 4th and 6th place. More importantly I thought Jaidi worked smooth and jumped well. We didn't particularly push but kept a nice '80%' type of pace.

In contrast the next day, he had 2 jumps down in a round so I called it a day. In all probability he was tired from previous day as we hadn't done too much 'full course' agility in the previous weeks.

So all in all a successful re-entry back into competitive agility, but also a reminder to take the re-hab one step at a time. So, I continue with the schedule laid out in my previous blog for his hind areas. Additionally we can move to reduce some tension in the RH shoulder area. Probably compensatory for the hind end issues.

A dog landing absorbs x 4.5 of its body weight

Working with the shoulder

According to a survey [1] Shoulder problems were the most reported Agility related injury. Not really surprising when one considers that:

• A dog landing on its lead leg absorbs all the body weight multiplied by 4.5 times bodyweight [2] downward force. 

To put that into context, Jaidi (18.5 kgs) has a pressure of 80kgs going through his front limb on a single leg landing!

Weight shift is 80% on the down side of A Frame

• The front limbs absorb most of the kinetic force alighting from contacts. Again to add context, an A Frame has an angle of around 40°. This shifts the dogs centre of gravity to 80% on the front end.

 An interesting article by Dr. Shannon Budiselic [3] suggests Agility dogs show these shoulder issues:
 

1. Medial Shoulder Instability 
2. Supraspinatus Tendinopathy
3. Teres major Strain
4. Bicipital Tenosynovitis -
    

Stretching the shoulder,  www.sleddogcentral.com

Previous diagnosis on Jaidi had indicated that it is around his Supraspinatus muscle. Additional to that he demonstrates a lack of extension in the shoulder joint on stretching. Therefore we will concentrate on that area. Again as explained in my previous blog, I like to have quantitative measurements to indicate success / failure of treatment programs. In this case I compare right to left shoulder in full extension in the sitting position:

• Jaidi will allow full extension in the left (good) shoulder for some 5 - 10 seconds before showing discomfort (i.e. a little fatigue in this position without extra support of the shoulder joint normally used in stretching techniques)
• The right shoulder is less than 5 seconds before he wants to bring it back to normal position

Now this test is not an 'exact science' and Jaidi prefers his stretching sessions in the recumbent position, but it gives us a ready reckoner on progress. 

So after an initial treatment of Ultrasound (see previous article on aim of this), we will work with massage and stretching to improve his extension.

Just out of interest

Agility Dogs with Bicipital Tenosynovitis commonly have difficulty with performing two-on/two-off contacts, knock bars with their forelimbs, or are reluctant to jump. On gait analysis, they often have a weight-bearing lameness (subtle to severe) on one side that becomes worse with activity. Pain and spasm may be noted when flexing the shoulder while at the same time extending the elbow. [4]

[1] A Survey of Injuries Occurring in Dogs Participating in Agility, By I. Martin Levy, M.D., Charles B. Hall, Ph.D.,Natasha Trentacosta, and Monica Percival

[2]  Kinetics of jump landing in agility dogs. Pfau T1, Garland de Rivaz A, Brighton S, Weller R.Vet J. 2011 Nov;190(2):278-83. doi: 10.1016/j.tvjl.2010.10.008. Epub 2010 Nov 18.

[3] http://equilibriumvrc.wordpress.com/2013/03/21/part-1-canine-shoulder-rehab-perspectives-agility/ 

[4] Shoulder Conditions in Agility Dogs By Sherman O. Canapp, Jr., D.V.M., M.S., Diplomate ACVS