Within the world of integrated therapies that utilize muscle testing as a primary tool for assessment, one of our primary goals is to use muscles as our “in” to locate sources of neurological dysfunction. Sometimes this dysfunction is coming from different mechanoreceptors like golgi tendon organs, muscle spindles, or vibrational receptors. Sometimes the dysfunction is coming from nociceptive input that creates weakness or withdrawal responses. Sometimes the dysfunction may be coming from aberrant information within the ascending sensory pathways of the spinal cord. Sometimes it’s related to dysfunctional organs. Perhaps meridian dysfunctions, emotionally-driven triggers, or even beliefs and memories. No matter what the potential cause, how muscles behave when tested can tell us a lot about what is going on neurologically within the entire system.
A muscle should always have the strength necessary for volitional contraction, but also should be able to reflexively inhibit normally. If neither of these hold true after testing a muscle, we know there is an underlying neurological dysfunction driving the aberrant muscle response (however, bear in mind that sometimes neurological dysfunction can be driven by mechanical or tissue restriction as well - it is important to address both). While we could potentially dive in to a myriad of potential factors that might affect how a muscle may test, for the sake of simplicity, I want to dive into a single concept for now: hypertonicity.
In the world of neurological manual muscle testing, when we refer to a muscle as being “hypertonic”, we aren’t simply referring to how a muscle feels from a palpatory standpoint. We are more so speaking to its function, or lack thereof. A muscle that is hypertonic typically feels “tight” or high tone (hyper=high; tone=tone...derp). But more importantly, a hypertonic muscle does not have the ability to reflexively inhibit. The possible repercussions of this can be significant for several reasons:
- Hypertonic muscles do not contract efficiently. This will inevitably lead to more restriction and adhesions within the muscle and connective tissue over time, as well as making your nervous system more likely to create new compensations.
- Hypertonic muscles are far more susceptible to strain, particularly during high-velocity movements. Forcing a muscle to lengthen even while under contraction is literally how we tear muscles (and in controlled amounts, this is the literally the mechanism for muscle hypertrophy).
- Hypertonic muscles become fatigued and hypoxic more quickly. This is often because a hypertonic muscle is picking up the slack for a synergistic muscle. If your calves have to do the work for your hamstrings and glutes as well, those calves won’t feel good fore very long.
- Hypertonic muscles are a large contributor to limited mobility. We all know mobility is the name of the game when it comes to improving your movement. If you've got tons of hypertonic muscle all over your body, chances are your movement is pretty limited.
Hypertonic muscles are typically hypertonic because underneath the compensatory mechanism of hypertonicity, the muscle is likely actually very chronically inhibited. Hypertonicity can actually be an advantageous short-term stabilization strategy, but it is a poor long term solution for true muscle function.
Hypertonic muscles often become hypertonic because hypertonicity might be the nervous system’s best strategy in that moment in order to allow the muscle to be strong for the task at hand. If a muscle is inhibited, yet you are executing a movement that requires that muscle to contract and display strength, the body can sometimes create a compensatory dysfunction in order to allow that muscle to be strong. This is simply creating an additional layer of dysfunction on top of another, unfortunately, and maybe lead to further problems down the road, even if it might be a good short-term solution.
Ultimately, our goal within the realm of training and therapy is to balance the systems of the body in a way that allows for the most resiliency, greatest positive adaptation to stressors, and to improve our ability to feel good and perform well. It’s that simple. If you feel like you have all kinds of tension riddled throughout your body, chances are you’ve got a myriad of hypertonic muscles that need to be addressed. The quickest and most effective way of doing so is finding a skilled P-DTR practitioner who utilizes these concepts well. Otherwise, good luck spending hours upon hours upon hours performing self myofascial release techniques. Plenty more information regarding these concepts, so stay tuned!