Everywhere I see TENS units. This electrical stimulation device gets a lot of attention despite the associated knowledge.
In the rehabilitative world, TENS units are able to perform many tasks, but athletes mostly use these devices to decrease pain.
Pain is a confused term in the world of athletics, especially since there is no 'pain' receptor in the body. Precisely, there are multiple 'nuisance' receptors, but nothing specifically for pain receptors.
Pain is a complex issue and the source of pain is plentiful. Pain can originate from the 'nuisance' receptors, the limbic system, sensory system, past experience, beliefs and knowledge, expectations, and many more areas.
For the purpose of this article, we'll discuss the 'nuisance' receptors and TENS.
Nuisance and sensation is interpreted by the same cell (wide dynamic range cell). When the body only has nuisance, then the cell will only read nuisance. If the body only has sensation, then it will only read sensation. If nuisance and sensation coincide, then the cell attempts to interpret both sets of data. Luckily (at least for us), the cells are easily overloaded. Once the cell is overloaded, the amount of pain is minimized, as the cell is only able to interpret so much data.
This is the mechanism behind the TENS unit (at least how many people use the devices). For example, if you have an injury the wide dynamic range cell (WDR) is overloaded with nuisance signals. If you apply a TENS unit, then the wide dynamic range cell receives competing sensory information. This is similar to someone shaking their hand after hand after slamming it into a door or a baby sucking on their thumb when it hurts, the WDR cell can only take so much data!
A TENS unit is beneficial for providing short term relief, but does not solve the underlying cause. During a shoulder injury muscles tighten, inhibiting other muscles while the joint looses its sense of position. These three facets prevent improvement and are problematic for recovery. Luckily there are tools for improvement. The Swimmer's Shoulder System discusses many of these ideas and explains this topic in more detail, providing long, not short-term solutions. Purchase your copy today!