When it comes to being functionally healthy, balance is critical. I’m not talking about the kind that keeps you from falling down–though obviously that’s pretty important too. I’m referring to the balance between muscles that are designed to work in tandem–balance between those in the front of the body and those in back, between big, strong, showy muscles and smaller, less noticeable ones, between tight ones and overstretched ones, and so on.
The shoulder joint is one of the most illustrative examples of muscle balance…and of the consequences of muscle imbalances, with rotator cuff disorders–e.g. strain, tear, impingement–being one of the most common consequences. Without getting too deep into the nitty gritty details, it’s worth describing some of the relevant imbalances.
The big chest muscles in front (Pectoralis, or Pecs) tend to be overly strong and tight compared to the smaller muscles of the shoulder blade in back (e.g. Rhomboids, Lower Trapezii, Rotator Cuff muscles). Ultimately, this basic imbalance puts the rotator cuff in a very vulnerable position, often leading to impingement or tears. Several things contribute to the development of this discrepancy: our lifestyles keep us hunched forward over a desk for hours on end which keeps the pec muscles shortened and tight; strong pecs look great in the mirror so we love to spend extra time on them in the weight room; and pecs are an example of postural muscles which means they have an inherent propensity to become overactive and tight. Compounding the disparities, the scapular (shoulder blade) muscles are phasic muscles, ones destined to weaken over time. Unfortunately, these particular muscles are also less cosmetically desirable than the pecs, so they tend to get short shrift at the gym…further exacerbating the imbalance. Adding insult to injury, the bigger, stronger, tighter pecs exert a constant forward pull on the scapula, causing the smaller muscles attached to it in back to be put under constant stretch. Over time, this constant pull makes them lax and less effective at their job of controlling the scapula….another blow to the already-problematic front-to-back imbalance.
You can see that in this context, it’s not the absolute strength of any individual muscle that’s so important; it’s their relative strength to each other. In other words, dis-proportionality is what creates problems. Correcting or avoiding the issue is just a matter of paying enough attention to stretch the things that tend to get tight and strengthen the things that tend to be weak or ignored. So in this example of the shoulder, stretching the chest muscles and strengthening the scapular muscles would go a long way towards countering any impending imbalances. You don’t even have to sacrifice big pecs to do it– you just have to strengthen proportionately.
TIP: Pay special attention to the concept of muscle balances in your workouts– front to back, side to side, big to small, tight to lax, etc. Given the way the body’s engineered, your Functional Health depends on it.