Strength vs. Stability: Why You Need Both for True Joint Health

Yoga Variation of Side Plank

I hate to admit this, but it took me a very long time, as a physical therapist, to discern the difference between strength vs. stability.  For a while, I wasn’t really sure if there was a difference.  Alas friends, there is. 

Mostly, I treat people who are neither strong nor stable.  Every so often, I do treat people who are quite strong, but who have no stability.  Never have I ever treated anyone who was super stable.  Never.  Ever.

For the purposes of this blog, let’s say that strength is the ability to activate and use the large muscles of the body:  glutes, quads, biceps, triceps etc. to sit, stand, walk, run, jump.  You get the picture. 

Stability is a bit of a different animal.  Stability is the co-activation of several smaller muscles that encircle a joint to make sure the joint is holding & moving in place.  Ideally, in neutral. 

Let’s take the rotator cuff muscles (RTC) of the shoulder.  This is usually an easy one to visualize as most of us have at least heard of the rotator cuff.  It’s a group of 4 muscles (pictured below) that attach onto the head of the humerus (top of the arm bone).  They all have their own joint action and sometimes, I’ll strengthen them in that particular action.  But their main purpose is to work together as a unit to hold the shoulder joint steady, in its socket, while the arm moves in different directions. 

Rotator Cuff Muscles of the Shoulder

To start training this, you have to be in neutral, in something akin to a modified side plank.  Though many of you are probably thinking ‘I do side planks all of the time, this is easy’, I’m going to almost guarantee that you’ve never actually been in neutral while doing so.  Even my strongest Cross-fitters fail at this. 

Getting into this position and holding steady is the start and then eventually progressing into movement.  This is how you train the RTC to work together in order to create stability.

Good stability is never easy.  If it feels easy, you can bet that you’re not doing it right.  It starts on a bed of impeccable core activation and ends at the shoulders and hips working together in harmony…just as they must in our daily life.   

Want to improve your strength and stability?

Let’s work together to build a more resilient, pain-free body.

Schedule an appointment Union Yoga & Physical Therapy in Annandale, VA.