What causes muscle spasms and knots?
There are many causes for muscle spasms - the ones most often seen in physical therapy are those that arise from trauma, guarding, poor blood circulation in physical exertion, overuse and overloading. Other causes can be electrolyte imbalances and drug side effects.
When a body or an extremity gets hit with a noxious stimulus - either a fall, a hit, or sometimes even surgery - the body tends to want to protect itself from another traumatic event (guarding). It does this by over-stimulating the muscles, causing that particular part of the body to tighten and stiffen to protect itself from being hit again. Some of you may have experienced this from a fall or a surgery, where you feel pain for days on end even though the apparent injury site is healing. The pain is often agonizing and the body is slow to recover because the muscles (and your psyche) need to be coaxed to relax again. This process is not as easy as it sounds: there definitely is a neural component, a mechanical component and a psychological component to muscle pain. Your physical therapist is armed with all the tools needed to calm your muscles down: manual therapy to decrease tensile stiffness, joint mobilizations to improve joint mobility and regain range of motion, exercises and stretches to gradually return you back to function, and most of all, reassurance that you will get through this. It is a delicate balance - one that most experienced physical therapists can appreciate.
Muscle spasms from overuse and overloading
Most muscle spasms and "knots" are due to overuse of muscle in lifting or carrying a load. Oftentimes, injury happens when the muscle is too weak or too fatigued to perform a task. Imagine a line of men trying to pull a weight that is too heavy for them. Eventually, they will start to complain, then try to overexert, then scream, then worse: falter and fall apart. This is much like what happens in a strained muscle. In truth, fatigue is ideal for muscle building (i.e. hypertrophy) - but excessive forces that a muscle cannot bear are usually damaging and need more time to recover.
