Spinal Range of Motion

Spinal Range of Motion

spine range of motionEach of the vertebrae and the occiput of the skull have movable joint surfaces and supporting structures. While many of the spinal bones are shaped somewhat differently, they are constructed in such a way that they will articulate with their superior and inferior neighbors smoothly and with an appropriate range of motion. All the while, muscles and ligaments support and limit the bones in order to maintain stability in the cervical spine.

Bones of the neck are arranged relatively close together and the thickness of the bone is thinner compared to vertebral bones of the thoracic and lumbar spine. However, they interact with each other in much the same way. Each rotate, side-bend, flex, and extend wherever such movement is necessary, albeit in a somewhat different manner and in varying degrees of motion.

spinal range of motion

vertebrae with gliding facet joints

There are facets on the top and bottom of each vertebral bone on which a neck bone glides on its neighbors above and below. When there is muscle spasm or hypertonicity in the intrinsic muscles between bones, these facet joints become locked down. Facets could become stuck on one side only or on both sides. They could also be stuck open or stuck closed. And how they are stuck affects our range of motion of that joint.

spinal range of motion restricted

Dorsal dish from facets locked in extension

Long-lever muscles can also affect these joints. The erector muscles are an example of such long-lever muscles and they parallel the spine on either side. They’re responsible for helping us stand upright, as the name suggests. In the case of the erectors, they have many connection points along the spine. The erectors are also the primary muscles called upon by the brain to brace the spine when the brain believes the spine or central nervous system is in danger.

When erectors on one side of the spine are in spasm for a long period of time, they can lock down spinal facets on the hypertonic side to one or more vertebral segments. When three or more bones in sequence are affected, it is possible to see a scoliotic side-to-side curve develop there.

When the lockdown happens front-to-back, we may see a flattening of the normal spinal curve that we call a “dorsal dish” where the spinal segments are locked. The patient may feel a pinching sensation when this occurs. More often, the patient is actually unaware of any dysfunction in those segments and they may be pain-free. However, they may become aware of some range of motion limitation and just not know why.

Spine & Rib Problems

rib ligaments

Ribs attach to vertebrae by ligament

When spinal segments become locked, it is possible for the associated ribs to be affected. Ribs connect to vertebrae and neighboring ribs by ligaments, and there are also muscles between ribs called intercostals. All this means is that ribs are not as fixed in place as one would think.

While any of the non-floating ribs could conceivably rotate, we see more patients reporting symptoms beneath their shoulder blades and above. When it happens under the shoulder blade, you usually get a pain at the rib angle; that is, the point on the back where the rib starts to round before it becomes the outer side of the rib cage. This point, at the rib angle, is where the apex of the curve appears.

rotated rib

Rotated ribs cause one sided raised rib cage with torso flexed

This apex is far more evident in scoliotic spines, but scoliosis does not automatically follow simple rotated ribs. What may be evident, however, is a rounded side of the back appearing higher than the opposite side when the patient leans forward. When the raised side is not visible when the person is upright, yet raises when leaning forward, there is very likely a functional component to the rib rotation. Functional problems may be correctable.

Another problem that arises from time to time is when the first rib is pulled up close to the collarbone. When the first rib is raised, the rib and collarbone may compress the Brachial Plexus, the nerve and arterial bundle that serves the arm. This medical condition is referred to as Thoracic Outlet Syndrome or TOS. (NOTE: TOS may have other root causes as well.) Symptoms of TOS are tingling, numbness, or cold sensation in the fingers, pain in the elbow, weakness in grip, wrist, elbow, or arm. The first rib can be mobilized, returned to its proper place, and TOS symptoms could be resolved.

The breastbone, the sternum, articulates with the clavicle. Again, a ligament connects the two, and can be sprained or dislocated by accident, injury, or just slightly when the ligament is a degenerated condition. The sternoclavicular joint normally has a small amount of movement (also read about the shoulder), and can be displaced enough to cause some discomfort in the area.

Specific range of motion links:

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