In the last newsletter in our Low Back Pain Series, I discussed all the anatomical sources for low back pain. In this article, I will dive deep into muscle strains, spasms and facet joint pain as a source of low back pain and how they are interconnected.

Did you read our last Health Highlight? You will find the definition of a Strain vs Sprain.

Muscles along the spine help to move the spinal joints, also referred to as facet joints. Facet joints are the joints found between vertebrae. Each vertebrae is connected with potentially 4 different joints. Each vertebrae joins with the vertebrae above at its 2 inferior facets and then to the vertebrae below at its 2 superior facets making four full joints. Four full joints requires the presence of 3 vertebrae. Have I lost you? Take a look at the video below.  

Muscle strains and spasms are commonly found within the spinal musculature as a source of back pain. Before we discuss strains or spasms further, let us first look at the phases of a muscle contraction, as this is important for understanding the information that follows. 

An isometric contraction is a muscular contraction that occurs at rest with no joint movement. An example would be contracting our quads with our knees straight to see the muscular definition. As we move a joint through a motion, there is a muscle moving concentrically, i.e. the biceps during the biceps curl. The forearm is moving closer to the shoulder and the biceps muscle is shortening. At the same time, the triceps is moving through an eccentric contraction. The triceps has to lengthen, for the biceps to shorten. There is always a muscle going through the opposite motion when there is movement. This helps control the motion. As the biceps is lengthened back down to the start of a curl position, it moves through an eccentric contraction and the triceps is moving through a concentric contraction as the elbow straightens out.

Muscles are injured the most during an eccentric contraction, or the lengthening phase of a contraction. The eccentric contraction often occurs as we are decelerating or slowing down acting like the brakes on a car. A muscle is lengthened during an eccentric contraction. When we have to decelerate quickly or oppose a large resistance, the muscle fibers can tear. The degree to which they tear determines the grade of the muscle strain.

In the spine, the muscles are oriented parallel to the spine. When we bend forward to our toes, the spinal muscles are lengthened and eccentrically contract while our hip flexors shorten and concentrically contract. If we lift something heavy in this position, with the spine slightly flexed, the spinal muscles are placed in a lengthened position or contracted eccentrically. If the force is too much for our spinal muscles to overcome, a strain will occur. This is the reason why we encourage our spine to remain in a neutral position, neither flexed or extended, to encourage a counter action in our hamstrings and glutes to eccentrically contract.

When spinal muscles are tight, the spine will be held in a position of slightly more spinal extension or backwards bending. As the muscle goes to contract when already tight (or partially contracted), they will pull the joint closer together. If the joint is already close together from a tight muscle, a contraction now can move the joint even further together causing the joint surface to compress or rub together. The spinal joints do NOT like to be overly compressed. The result will be joint jamming or irritation that presents as low back pain to the patient.  At the same time, the muscle that is tight and trying to contract further, will reach its full contraction length and can go into spasm, a period of sustained contraction that is often very painful.  

Depending on the motions of the muscle, the initial muscle tone and the joint initial position, the resulting injury can be a muscle strain, a muscle spasm or a joint irritation.  Or, all 3.  Often the muscle tone is just fine to begin with.  But, the joint is put into a position that causes irritation and the resulting muscle reaction is a spasm or a tightening up.  

The good news though is that treatment at the joint, through a high velocity low amplitude adjustment affects the nervous system at the level of the adjustment to cause a reflexive inhibition (a relaxation) within the surrounding muscles.  And the reason many feel very relaxed after a chiropractic visit.  

With a muscular strain, I always instruct the patient to NOT stretch for the first few days.  The reason for this is that the muscle fibers have been “pulled apart” or sustained micro tears.  Stretching pulls muscle fibers apart, which if done aggressively, can pull these micro tears further apart.  Easing into stretching is advised past the first few days.  

Depending on the grade of the muscle injury, treatment frequency will vary accordingly.  However, basic muscle strain treatment will focus first on the acute care, ice and rest from its main contractile motion.  As pain levels decrease and if there was any inflammation/bruising, gentle motion can begin to occur through the pain-free range of motion.  Isometric contractions can begin to initiate and maintain muscular tone.  Once full range of motion is attained, further strengthening through concentric (shortening) contractions with the appropriate resistance can begin.  With full functional abilities back in the muscle, eccentric or lengthening contractions are always helpful to work into an exercise program to enhance this component of the muscles strength as this was likely the contraction phase that caused the strain.  

For muscular spasms, without any further joint irritation or muscle strains, I will advise to use heat over the area.  Heat will bring blood to the area and important nutrients to heal and relax the muscle.  Stretching is an important component to a spasm because the closeness of the fibers is what initiated the spasm.  In addition, a chiropractic adjustment is recommended for most patients (if they are a candidate for manipulation) for the reflexive inhibition that occurs to the surrounding muscles.  Strengthening through full range of motion is encouraged once the muscle has improved in tone and the spasm is no longer holding on.  

For joint irritations, the best treatment is movement.  This can be done through chiropractic adjustments or mobilizations.  Care is taken if there is a suspicion of a sprain to a facet joint, as the joint may be hypermobile (move too much) as a result of the sprain.  In either case, strengthening of the surrounding musculature is needed to encourage adequate and accurate joint mobility.  

As explained, muscular strains, spasms and joint irritations tend to occur together.  They can occur on their own, but there is a strong connection between these injuries such that one doesn’t usually happen without another.  Many minor cases of these injuries will resolve on their own, however, being assessed by a healthcare provider, will provide proper guidance towards a full recovery and perhaps the prevention of a reinjury down the road.  

If you or someone you know in the Hamilton, Ontario area is currently experiencing low back pain, please use the link below to book an appointment with Dr. Marnie Mabee D’Andrea.  We strive to provide you with an accurate diagnosis, exceptional treatment and timely return to your regular activities.