Lesson 3 – Dysfunction and Injury

As you can see, there are many component parts of the system, each have their own role to play in movement.  There is a balance within the MSK system which needs to be maintained for optimum function.   Let’s think of these component parts as cogs in an engine.  If one (or more) of these cogs stops working correctly (dysfunction) then then a few things happen: 

  1. The engine as a whole does not function as it should.  It sputters and becomes clunky, rather than being quiet and smooth. It becomes inefficient.
  2. The other cogs have to do more work. They become overloaded and overheated and are under much more strain. 

Eventually, the engine breaks down…….. INJURY 🤔

TASK: Check back on your definitions of injury and dysfunction.  Do they fit with this description above?

Chicken or the egg?

Does injury lead to dysfunction or does dysfunction lead to injury? 

The answer is: both.  It all comes down to how movement patterns.  In an ideal world the gait would be perfectly symmetrical.  Weight bearing would be even between bilateral pairs of limbs.  Approximately 60% of the weight would be carried over the forelimbs and 40% over the hindlimbs.  The balance of muscle strength, flexibility and range of movement of the joints would ensure a fluid and straight movement.  That would be perfect but one of two things can happen here to affect this ideal gait: 

  1. A traumatic injury can occur – the animal will become lame (gait asymmetry) 
  2. A dysfunction occurs (gradual onset) and over time the gait becomes more and more asymmetrical.  This loads structures incorrectly and adds pressure in the wrong places which ultimately causes injury. 

TASK:  Think about the cases you see in practice.  How many do you think are truly acute traumatic injuries?  Or how many do you think have actually had an underlying dysfunction for some time? 

Aetiology

In answer to the previous question……..Many of the injuries you see in practice have been brewing under the surface for a while.  For example: a cruciate rupture is rarely due to a genuine trauma but more often due to a chronic degeneration of the ligament over time.  One day, injury occurs and the dog is brought into the clinic, lame.  Often the owner will tell you that “he was fine one minute and lame the next”.  But in reality the MSK system and gait would have been adapting for quite some time.  

⭐ Regular health checks in your practice could include some gait assessment and correction of some of these early changes.  These ‘clinics’ could include some advice for owners to aid prevention of later injury.