Biomechanism of the dog (part 1)
Over the past years, the dog has become a constant companion of the human being. During free time you are active and keep the dog rather busy. As a result of the numerous activities for dogs, the number of orthopaedic problems increase and you have no option but to visit an orthopaedist. This fact is confirmed by cruciate ligament operations within dogs which has become the daily bread of surgeons. It is generally noticed that the increase in orthopaedic problems remains without any real diagnosis, even if diagnostic devices have been used, e.g. CT and/or MRT. The cause often refers to the biomechanics of the dog. Due to increased activities on the one hand, and the new influence of diverse play options on the other hand, the borderline and critical case of biomechanism of the dog is partly overloaded and overstrained. Another reason, however, is that puppies and young dogs are reaching their extreme limits of endurance, in terms of ankles, ligaments and tendons due to physiological (unhealthy) movements during the phase of growth. Young dogs especially are getting quite often injured due to rough playing and romping, running fast turns, as well as zigzag movements.
Many dog owners are still under the impression that puppies are not allowed to walk long distances, or for long periods of time. However, growing puppies will be intellectually encouraged on the strength of well-aimed and carefully directed walking on various different soils and landscapes which, in turn, helps to build up optimal masses of muscles. A deeply ingrained prejudice for „short walks“ has to be seen in connection with the development of the dysplasia of the hip. It still has to be said that a close genetic connection exists between muscle masses and appearance of dysplasia of the hip. This factor explains why greyhounds, which hold large muscle masses, do not bear any HD. This statement may be correct but ignores the fact that muscles can only be built up by means of regular movements, especially through healthy and controlled moves. I consider healthy movements to be step by step, at a trot and canter without any fast turns and « stop and goes ». The optimal way to build up muscular strength is to trot up hills (also suitable for puppies). It is always a question of measurement. After seven year’s experience with the « Therapy of the Puppy-Passport » the conclusion is quite clear, i.e. that the build-up of muscular strength is not solely related to a genetical component but has to be set in correlation with the biomechanics of the skeleton construction and system of the puppy. Provided the biomechanism of the puppy (shoulder and pelvic girdles) is controlled during growth and for a period of time (from 12th until 28th week) and, if necessary, is given therapy on a manual basis, the effectiveness of the muscle building is definitely better. Surprisingly, puppies/young dogs which only have a first checkup and screening after 6 months already show clear asymmetries in the skeleton-system with muscular atrophy (less muscles). However, this can be compensated for and cured rather fast during the period of growth. Please refer to www.othovet.ch / Welpenpass. To ensure the best possible and most healthy development of the haunch, we can clearly state that an optimal biomechanism of the spinal column and limbs is required. This will be successfully covered in the Puppy and Youngdog Passport.
If we refer to the biomechanics of the dog, three different factors have to be taken into consideration. Firstly, and contrary to a human being, the shoulder girdle has a muscular joint to the trunk. Secondly, the pelvic girdle which is attached to the lumber spine and thirdly, the anatomy of the spine which, depending on the region, shows variable movement of the vertebra substances and which is responsible for the entire mobility of the dog. If these anatomical barriers of the spine are not respected, illnesses can occur which can lead to clinical manifestations, especially for middle-aged and old dogs. In this context please refer to spondylosis.
Now, let’s move to a practical example regarding the biomechanics of the dog.
The dog shown in the video has showm an orthopaedic problem for quite some time which has been examined and treated. In the picture where the dog is walking, the dog clearly shows a changing mobility pattern: the hindquarter is shifted to the right-hand side. Once seated, the position of the knees is different and the left shoulderlimb shows a changed position outwardly. Due to the orthopaedical illness and the pains, the appetite diminished considerably and, furthermore, the therapy with cortisone resulted in a reduction of the musculature. After one month, and after two orthopaedic treatments, the mobility pattern of the back is practically straight, the position of the knees when in a seating position, is normal, except the left shoulderlimb which is still slightly moving outwards. Within 5 weeks the dog increased its weight by four kilos.
The spinal column shows two different regions with regard to mobility. On the one hand, the cervical spine with a very wide mobility, because in this region the facet joints (vertebral joints) are put in a 45 degrees direction. Crossing of the lower cervical spine with the subsequent thoracic spine, the opening in the chest cavity, is very important anatomically, because the secondary bending of the cervical and thoracic spine of the shoulder girdle and, therefore, fulfils an important task in the Orthostatic (posture and stability). Due to this fact it has to be understood that Guard dogs suffer from illnesses of the cervical vertebrae on the one hand, but, on the other hand, from shoulder problems too. Special attention has to be given to Guard dogs as it is of utmost importance to examine shoulder problems in connection with cervical vertebrae and to treat the same.
Bsp. Hyperflexion der Halswirbelsäule
The other region is the lumbar spine. This specific area is characterised by the vertebral joints which run vertically and which, in turn, limits the lateral mobility. However, if you observe dogs on an agility course you notice an extreme lateral bend of the whole body including the lumbar spine. Fast sports like, among other things, Agility or Flyball claim this region of the lumbar spine very strongly. As a result of fast turnarounds, cushioned jumps or fast „stop and go“, this region is prone to injuries on the one hand, but is also marked by degenerative changes of the vertebral bodies and joints. Basically, the lumbar spine is extremely exposed to mechanical stress due to the high demand of mobility and agility.
Abbildungen: Wirbelsäule des Hundes
The region of the dorsal spine assumes the sandwich position. On the one hand, it is a protective cage for the heart and lungs, on the other, for the liver and stomach. Due to this fact, the rib chest would have to be extremely stable and strong. However, this is only partly the case. The reason for this is the rib joints which are situated near the vertebral joints. These are very sensitive under pressure and tensile forces. The intercostal muscles (between the ribs) may protect the ribcage to a minimal extent only. Anyone who has already had a rib crushed or broken is aware of how painful this can be. In addition, nerve fibres run along each rib which react very sensitively and become inflamed under blunt trauma (crash and body checks). The consequences are pains which lead the dog to be rather sluggish and looking for a rest.
Besides young dog illnesses like elbow dysplasia (FCP) and osteochondrosis (OCD), the shoulder belt attracts attention mainly due to problems in the shoulder joint and forefoot carpal joint (hand or carpal joint). Usually illnesses of the shoulder are related to a blunt trauma (accident), or to just changed biomechanics, caused by strains and burdens over a longer period of time. Consequences are biceps tendon illnesses; inflammation of the shoulder joint; impingement of the bicep tendon; rupture of tendons; muscle disorders, e.g. the contracture of the infraspinatusmuscle of a hunting dog, or a “frozen shoulder "! As the “frozen shoulder“ is not described in veterinary terms, this does not mean that the problem does not exist. Loosely translated, “frozen shoulder“ is simply equivalent to shoulder stiffness. A blunt trauma can result in such stiffness. Or, it is a consequence of changed biomechanics because the dog moves the shoulder joints in a changeable/unnatural way which, in turn, leads to an immobilisation of the shoulder joint capsule. Apart from the changed mobility, the pain is an important indication which leads dogs to show strongly different movement patterns!
Illnesses in the Carpal joint are also caused by blunt trauma. For example, stepping into a hole while running in a field whereby the forefoot root joint is overstretched. Or they are consequences of overloadings, on the one hand by the dispensation of the hind leg or back, on the other hand by dispensations of the contralateral shoulder link masses! Therefore, inflammations in the joint occur with repletion of the joint sack (Bursitis), as well as inflammations of the carpal accessoriums (pisiform), inflammations and injuries of the ligaments in the carpal joint. A final point to mention is the limited mechanical use of the individual joint compartments in the carpal joint. Again, the reason can relate to a blunt trauma or to strain and overloading!
As a special case the Mastiff is to be mentioned!
As you can see in the picture, the right paw shows an axis abnormality in the carpal joint and in the toes. The cause relates to a blunt trauma from running on a field. Radiologically the axis abnormality is visible. This is called a chondrodystrophycal deformation. Part of this deformation can be corrected by targeted leashing and a supportive immobilisation, so that the dog has only minimal restrictions to its life.
Last example
As a last example of changed biomechanics, we notice the gait of a changed shoulder girdle due to growth disturbances in the bone of the ulna and radius. Due to the changed form, i.e. the changed position in the elbow and carpal joints, it is possible that the function is changed in such a way that one of the possible long-term consequences can lead to osteoarthritis. A possible prevention is the supporting of these bone and joint structures. The movement pattern with the support, according to the orthopaedic mobilisation, looks smoother and more flexible.
