Iliopsoas injuries are very common for agility and other sporting and working dogs. In the hind leg area, they might even be the most common tissue to get overuse-type of injuries in agility.
Location
Iliopsoas actually consists of two different muscles: M. Psoas Major and M. Iliacus [1,4]. Psoas Major muscle originates from vertebral ends of ribs 12 and 13, the transverse processes of cranial lumbar vertebrae. The Iliacus originates from the sacropelvic surface of the ilium. M. Psoas Major and M. Iliacus both insert together into the dog’s trochanter minor.
Function
Psoas Major is activated in a lot of situations when the dog is moving. The muscle should be active when the dog is jumping, changing directions, sifting positions (lay down – stand up) and even when the dog is moving straight. This might also be part of the reason why overuse injuries of this area are so common. For example, if you suddenly start to train running contacts, it’s never the only load for the iliopsoas muscle – the muscle must work in many other situations as well so on top of the new load, the iliopsoas is still loaded in many other activities at home and agility training. This is different from some other muscles that mostly work in a limited number of activities, for example the abductors of the legs. The abductors don’t have to work much when the dog is walking on leash so even if you start to practice weavepoles, the abductors get more rest in daily activities compared to the iliopsoas area. So, there could be a possibility that the use of the iliopsoas area in daily activities on top of the load in agility contribute together to the overuse injuries of this area and therefore there are more overuse injuries to this are. But this is just speculation, not scientifically proven!
We are speaking a lot about iliopsoas with agility dogs, but it’s not rare to see iliopsoas overuse or acute injuries also with non-athlete dogs. Acute injury may happen with just one slip of the hind leg in a bad angle and overuse injury may happen also for dogs whose owner is usually passive and at holiday starts to hike causing a sudden increase in the load for the dog. As you can see, it really doesn’t need that much for the iliopsoas to get overused.
It’s also important to understand that exercising your dog is making their life quality better and good effects of exercises easily overrun the risks. We definitely recommend exercising and an active lifestyle with your dog. The most important thing is to understand that any loads need to be increased gradually so that when your dog is going to hikes or there is any other new load for the dog, its body is already used to that!
Injuries
It’s speculated that most acute iliopsoas strains occur with eccentric contraction when the muscle is contracting while lengthening [1]. Symptoms of iliopsoas muscle injuries can vary from severe lameness to mild tenderness during muscle palpation or provocation.
Often when the iliopsoas gets provoked, the owner can name some changes in the dog’s load. This can be, for example, moving running contact training to full height of dog walk, or increased training amounts or longer training sessions.
In agility, there are multiple situations where the iliopsoas can get into trouble. We have speculated that often (not always) iliopsoas overload cases have possible weakness in that actual muscle but also in the surrounding muscles. If the dog has a weak pelvic area, it’s possible that the dog overloads the iliopsoas muscle when jumping over obstacles when it’s trying to control the pelvic area. There are multiple jumps during the agility course and if this happens 20 times/ course, the muscle can easily get overloaded. So, even small technical issues and poor function in other muscles can cause the iliopsoas to overload. If an iliopsoas patient has trouble with pelvic control, it’s important to first get the pain and irritation of the iliopsoas under control, but after the initial recovery process it’s important to improve the dog’s pelvic control so that it will avoid overuse of iliopsoas in the future.
Injuries of iliopsoas are a very common cause to apply physiotherapy. Iliopsoas injuries can be acute trauma or more chronic, meaning that the injury has come with some time of overusing the muscle for some reason. Majority of iliopsoas pathologies are found from tendons of the insertion. Majority of strains are found at low grade phase (80.8 %). In 62.8 % of cases there are acute and chronic changes together. [2]
It’s important to find a correct diagnose as soon as possible so that dog gets needed attention by physiotherapist.
How to spot an injury?
Many dogs with iliopsoas injury struggle to jump or they totally refuse to jump. They can have lameness after sport or shorten their natural stride length from hind legs. There can also be swelling that localizes to the iliopsoas area, but this is often hard to spot, because it’s not as easily palpated as swelling in the lower parts of the legs. It’s also possible that dogs start to compensate the pain by switching the load more to other tissues. This can cause muscle tightness to lumbar back or to the healthy hind leg or front legs. Iliopsoas strain can also give only mild symptoms like slight decrease in agility performance – the dog might, for example, knock more bars at jumps than usually or make errors at weavepoles. It’s also possible that the dog slows down its speed a little, which is actually a smart way to make the load smaller.
If a dog has an iliopsoas injury, the iliopsoas muscle is often sore. If there is any suspicion of injury, you can palpate the muscle at home also before applying to orthopedist.
With this video, you can see how the iliopsoas muscle palpation is done. If the iliopsoas is sore, it’s very common that the surrounding tissues also have some soreness.
Be very careful when performing this palpation. If iliopsoas is sore, the dog can react to palpation even with aggression. If you get any signs of sore tissue, for example the dog licking his or her lips, turning their head, or yielding away from palpation, you should call to make an orthopedist appointment.
You can also test iliopsoas muscle by extending your dog’s hip and simultaneously performing internal or external rotation to the hip joint [1].
If orthopedist is suspecting an iliopsoas injury on your dog, they have possibility to examine it more efficiently by ultrasound, so don’t hesitate to go even if you are quite sure of injury placement.
Rehabilitation
If the iliopsoas injury is an overuse-type of injury, it’s super important to find the reason why this muscle has been overly active in the dog’s activities. Most often causes are weakness in some other muscle or poor control in dog’s body or more specifically at the pelvis or hip area.
If your dog has developed an overuse injury to the iliopsoas during your regular training habits, then it’s important that the rehabilitation doesn’t stop to where you were before the injury. If the muscle wasn’t strong enough to handle the load then, it for sure is not when you give it 6-8 weeks of rest and mild exercises. Towards the end of physiotherapy, the exercises should be really sport-specific in order to help your dog handle the load in the future and the old injury in the body.
Returning to sport should be done very carefully. The load in the training should increase gradually. It’s not okay to return to normal training right after the iliopsoas is better, because when your dog has been off from agility, it usually loses some sport specific muscle strength. With a competent physiotherapist you can minimize the muscle loss, but it always happens in some level.
Good ways to start agility training is to use some jumping technique exercises for the first few times in the agility hall, or do exercises with only one or two jumps, so that dog doesn’t achieve it’s full speed during the first training sessions. As discussed before, full length strides and speed create more stress to the iliopsoas area.
After the iliopsoas seems to be fine, you should usually take a few weeks or month to gradually increase the load to the previous level. It’s also good to go check your warm up routines with your physiotherapist so that the iliopsoas and it’s surrounding tissues are always given a proper warm up before sports.
Injury prevention
The most important way in short term is always to warm up the dog properly before agility. You can find our article of proper warm ups here. When talking about the iliopsoas, you should do exercises for hind legs so that the muscles are ready to work. At long term the best prevention is to strengthen the dog’s hind legs AND pelvic area to have proper strength qualities for agility. It’s also important to have regular appointments for physiotherapy and massage so that if iliopsoas gets irritated it can be spotted immediately.
Agility is a tough sport and when dogs are performing this sport, they need to be in good condition all the time and their physical training should be comprehensive. Load also increases with the dog’s size, which means that any overweight in sporting dogs is dangerous and can easily cause injuries.
So let your athlete dog to be as fit as possible and avoid these vicious iliopsoas injuries!
Article written by Agiology team.
Agiology team consists of physiotherapists and animal physiotherapists.
References
[1] Spinella, G., Davoli, B., Musella, V., Dragone, L. 2021. Observational Study on Lameness Recovery in 10 Dogs Affected by Iliopsoas Injury and Submitted to a Physiotherapeutic Approach. MDPI. Animals.
[2] Cullen, R.E., Canapp, D.A., Carr, B.J., Dycus, D.L., Ibrahim, V., Canapp, S.O. 2017. Evaluation of Iliopsoas Strain with Findings from Diagnostic Musculoskeletal Ultrasound in Agility Performance Canines – 73 Cases. Veterinary Evidence Online, Vol 2, Issue 2.
[3] Fry, L.M., Kieves, N.R., Shoben, A.B., Rychel, J.K., Markley, A.P. 2022. Internet Survey Evaluation of Iliopsoas Injury in Dogs Participating in Agility Competitions. Vet. Sci., 08 July 2022
[4] Budras, K-D., McCarthy, P.H., Fricke, W., Richter, R. 2007. Anatomy of the Dog. Schlutersche.
