How Joints Move

Joints move in three planes of motion: Sagittal, frontal, and transverse. This translates to flexion/extension (bending forward/backwards), lateral flexion (bending side to side), and rotating left and right. When you are restricted in one of these planes of motion it can give the sensation of your back “being out of place”. These restrictions don’t allow for proper motion of the joint, which can lead to pain and compensations. This also leads to lack of proprioceptive information coming from the joint, which means the joint isn’t getting proper information to the brain so the joint is basically “blind” in space and has a harder time telling where it is.

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What’s going on in there?

One of the causes of joint restrictions is micro-traumas, which can also act on the deep muscles of the spine. These deep muscles are saturated with sensory receptors called Muscle Spindles which detect changes in length. The muscle spindles send information about changes in length of muscle to the brain. Basically muscle spindles are the brains “eyes” within your muscles.

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When muscle spindles are over stimulated they cause the muscles to shorten and stay in constant tension which can reduce motion. This reduction in motion gives us the sensation that our “back is out of place” as stated above when we don’t have proper movement in all three planes.

In order to restore the motion and function of the joint we perform an adjustment through the restricted motion. The joint is taken to the lock out position and a quick and shallow thrust is applied through the restricted plane. The audible pop you often hear is just gas being released from the joint. With motion restored the joint is able to get proprioceptive information to the brain and also put a fast stretch on the muscle spindles, which helps to re-set the tone of the muscles.

The Race: Mechanoreceptors vs Nociceptors

Mechanoreceptors are sensory receptors that respond to mechanical pressure and distortion. Most mechanoreceptors are located in the cutaneous region (skin). Nociception is the sensory nervous system’s response to certain harmful or potentially harmful stimuli. Nociceptors can trigger a painful response.

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In the body mechanoreceptors travel faster than nociceptors, and beat out nociceptors to get information to the brain. We have all done this unknowingly when you hit your shin on something then rub it to make it feel better; you are stimulating mechanoreceptors to beat out the painful nociceptor response. An adjustment also stimulates the mechanoreceptors, and overrides the nociceptive (pain) signals. This is why adjustments have been shown to be effective in helping with pain management. 


Adjustments help to restore proper motion to the joints to establish proper joint function, as well as get information from the joint to the brain. Adjustments are also powerful for people in pain since it can override the pain signals to the brain. If you have any questions or want to learn more contact TROSS today for a complimentary consultation! TROSS proudly serves the Cottleville, St. Peters, St. Charles, O’Fallon, and St. Louis area!