How does your spine work?

The spine is made up of 26 vertebral bones that stack on top of one another. The lumbar spine is the lowest five vertebrae before the pelvis begins. Between each of the vertebrae are squishy fluid-filled discs that act as shock absorbers. To prevent the bones from slipping and sliding on the discs, we have lots of ligaments holding the bones in place, acting like supportive tape. The vertebrae are also surrounded by muscles that, when activated, create coordinated movements of the spine. The spinal cord runs down the middle of the vertebrae and nerves run off the spinal cord to send signals between the body’s muscles, sensory systems, organs and the brain.

What is a chiropractic manipulation?

Chiropractic manipulation (also known as an adjustment) is a technique where practitioners apply a controlled thrust to a joint when it is at its physiological end range of motion. The amount of force varies, but the thrust moves the joint more than it would on its own. Joint manipulation is different from joint mobilization, which doesn’t involve a thrust and is performed within a joint’s natural range of motion. Chiropractic manipulation or adjustments can be delivered to the spine or any other joint in the body.

What happens to my body during a spinal manipulation?

There are several things that occur with a spinal manipulation, both mechanically at the site of the adjustment and neurophysiologically in the brain. The first thing a manipulation does is produces a shower of input into the spinal cord. The spinal cord then sends this information to the brain. Some of these signals also work locally around the manipulated area to reset receptors in muscles and joints and change the brain’s perception of them. Some signals calm our stress responses and others diminish pain signals.

When a manipulation is performed, the muscles attached to the joint are impacted. Muscles have built in protective measures to prevent them from getting overstretched, called a reflex arc. When a muscle is quickly stretched, the stretch receptors in the muscle send a signal to the spinal cord which results in a signal directly back to the muscle telling it to contract. The reflex arc is helpful in preventing damage, but it also contributes to the pain-spasm-pain cycle. This means that pain occurring in a muscle from something like a strain causes spasm of the muscle and produces more pain. It is thought that through a quick stretch of the muscle, there is a disruption to the pain-spasm-pain cycle. The mechanical stimulus applied during spinal manipulation may change sensory input to the brain and cause a decrease in pain, like rubbing your elbow after you hit it against a sharp object. An exciting couple of studies have also shown that spinal manipulation results in increased muscle strength and brain activation in healthy subjects, as well as unhealthy subjects.

The autonomic nervous system (ANS) has been shown to be positively impacted by spinal manipulation. The ANS is responsible for regulation of all involuntary actions of the body, such as heart rate, blood pressure, respiratory (breathing) rate, pupillary response, sweating and salivary gland production. It also controls our internal organs, such as the heart, liver, kidneys, bladder, pupils of our eyes and digestive glands. The ANS even interacts with the nociceptive system on numerous levels, such as impacting inflammation. The literature has demonstrated positive changes in blood pressure, pupillary reflex, heart rate variability and blood flow to the skin following spinal manipulation.

If you have questions about spinal manipulation, or any chiropractic care, send us a message. We’re here to help.