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
 

Close to 1:1 weight bearing

Pleased to say that Jaidi now has a rear limb weight distribution of around 65:45 (L/R). Visually I can see his 'natural' stand is pretty square. Also if I do the 'foot on my palm' test, It is hard to tell the difference in pressure between L & R.


So looking back at my objectives:

1) Repair the iliopsoas strain and restore 'normal' muscle function

I am continuing with PEMF on alternative days with heat, massage, stretching on the others. 

Additionally we are doing standing 'on the 2 same side legs' exercises to directly strengthen the groin muscles.

This proves to be quite a challenge when picking up the RH limbs.  Our target is 5 x 30 second reps, but for now we are doing 10, 15, 20, 25 and 30 seconds.

2) Increase muscle tone on RH rear limb
 
I use a combination of exercises to both cross train and keep things fresh

• Isolation rear limb use. Rotation - raising front end on a gym step doing 360 pivots for 10 steps in one direction and then 10 in opposite direction.
• Swimming, using our local stream I can work with Jaidi facing water flow so all 4 limbs are having to work against the water pressure. 
• Slow walking with a 250g wrist weight above the LH hock
• Lots of daily road walking. Road walking is still a primary muscle building discipline for greyhounds.
• 1 x 10k run week to keep up CV and keep working the faster twitch fibres.

The importance of the later two is that Jaidi must walk / trot at a steady pace using all 4 limbs. It is very easy for a dog to push their weight forward so build tone towards the front end!

3) Reduce muscle tone on LH rear limb
 
Naturally as the weight is distributed more evenly and R rear limb becomes stronger, muscle tone on the L will decrease (i.e. less compensation). I am complimenting this with light massage to the L a couple of times a week to reduce any muscle tension.  
 




[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] http://www.dogworld.co.uk/product.php/2179/Features/31-Robertson


 
 

Jaidi, a loss of power and iliopsoas muscle

Our last few months of competitive agility have been mixed between some good trials and some which I would describe as 'lacking power'! Along with other physio's and chiropractors we have worked hard to relieve muscle tension and restore balance. These sessions did have visibly positive results, both anecdotally and in (competitive) results.

No doubt that the better days coincided with soft tissue and chiropractic work in the proceeding days, but the effects didn't seem to be giving a general, longer term improvement. The visual symptom was distributing more weight to the left side on standing.

In hindsight, we had been concentrating and working in the right areas, but probably on the compensatory factors of an iliopsoas strain. This was diagnosed by our trusted vet Rachel (see my post December 2011), and at last has given an area to focus on to potentially cure the underlying problem.

Probably by now, most agility competitors have heard or even read about these muscles. In short it is a fairly common agility injury and many articles have been written on the subject. For example:

The iliopsoas muscle represents the fusion of the psoas major and the iliacus. The psoas major muscle arises from the transverse processes of the lumbar vertebrae of the lower spinal column at L2 and L3 and the bodies of L4-7, and the iliacus arises from the ventral or lower surface of the ilium(or hipbone)[1].

Palpation of the Jaidi's iliopsoas muscles, and comparing right to left hand side exhibited scar tissue (on the former) compared to smooth tissue (LHS). In all probability it is an older injury with no obvious trauma / single cause. 

Repetitive strain injuries and muscle fatigue can both initiate the same vicious cycle of inflammation and fibroplasia resulting in pain, muscle shortening, and adhesions[2]

The outcome (in our case) is higher development of muscles on the left hind limb (i.e. glutes, quads, hamstring, calves), hence the preference to favour this leg on standing.

So what to do? 

Well, first I like to have some objective unit of measure to make sure we are taking the right course of action. Qualitatively this involves holding each hind limb on the palm of each hand and assessing the distribution. Quantitatively I weigh each leg (separately) at the same time and compare the data. In the ideal situation the 'feel' and weights will be the same, i.e. a 50:50 distribution. Jaidi was around 65:45 (L/R). So my objective is to try and restore this as close to even as possible with 3 areas to focus:  

1. Repair the iliopsoas strain and restore 'normal' muscle function
2. Increase muscle tone on RH rear limb
3. Reduce muscle tone on LH rear limb

Additionally there will be some fine tuning on other areas that have compensated for the original injury.
Initial treatment

The first thing is to break down the scar tissue and start rebuilding the muscle. Ultrasound (US) is the ideal modality for this. My preference is LW (40 KHz) and we started on the first treatment at 500 mW with the aim  to 'stir things up' (start breaking down the scar tissue)[3]. This was followed up by daily sessions at a lower dose, treating the injury site as acute. The benefits of US include bringing nutrients to the site, clearing debris and giving improved strength and elasticity to scar tissue.

Additionally, as US encourages blood flow to the tissue, it makes an ideal time for some light compression (massage) of the area and stretching the quads and groin area.

2nd week

At the beginning of week 2 distribution was 60:40. I moved onto twice daily sessions of PEMF or 'pulse-mag' in conjunction with stretching. PEMF is a modality extensively used in animals but not that common in human treatments in the UK. 

PEMF therapy helps to heal, repair, and regenerate tissue [4]

The main advantage is it non invasive and doesn't require clipping / gel application. Disadvantages are that the treatment needs to be done frequently and it treats 'areas' not specific muscles.

For our application the goal is to encourage blood flow to the hind limb muscles (vasodilation) so continuing the work from week 1.

Next steps

We have now moved to stage 2 which is to build muscle tone in the left limb. For this I intend to do ~ 3 sessions week hydrotherapy (lucky that we have a lovely medium flowing stream close by) and balance exercises on the other days.

Our next weight distribution measurement will be next Monday (25th August).














[1] Non-responsive Hind-limb Lameness in Agility Dogs:Iliopsoas Strains Focus on Canine Sports Medicine By Sherman O. Canapp, Jr., D.V.M., M.S., Diplomate ACVS

[2] Iliopsoas muscle injury in dogs: Quentin Cabon, DMV, IPSAV, Christian Bolliger, Dr.med.vet, DACVS, DECVS


[3] Electrotherapy explained: Low & Reed

[4] PEMF—The Fifth Element of Health: Learn Why Pulsed Electromagnetic Field (PEMF) Therapy Supercharges Your Health Like Nothing Else! Meyers, Bryant A.