In orthopedics, the core comprises a specific group of muscles in the trunk/pelvis. (Others use core generally to mean trunk.) Core muscle strength is beneficial. Just as arm, chest, and foot strength are beneficial! Core muscles are not exemplary. They’re no more our “foundation” than our foot muscles or those running the length of our spine.

Many erroneously treat orthopedic low back pathology by strengthening the core. Assuming core muscle strength can be accurately assessed, if one or more of them is weak, the question is why. Muscles become weak (and painful) from pulls/tears. However, these are very rare when it comes to the large muscles of the core. (Tears follow a consistent, predictable pattern, too, which should make them obvious to an attentive clinician.) Pain can create weakness, but absent a clear tear, the pain usually originates from something other than the muscle.
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The number one reason any muscle is weak (the large majority of cases) is because its electricity from nerves has been inhibited – either at the spine or extremity joints. It’s a joint problem. Therefore, in most cases strengthening a weak muscle (or entire group!) is simply attacking a symptom, which won’t fully resolve the problem. -- Laura

This topic has been coming up a lot with my patients recently. Many patients report that they don’t feel pain exactly - they feel tight, or, more usually, really tight. This can apply to the neck, low back, and extremities. Determining the reason a patient feels tight (the diagnosis) and helping fix it is, of course, my job.

True muscle tightness certainly exists. What do I mean by “true muscle tightness?” I mean that the reason you feel tight in a muscle, say the hamstring muscle, is because the hamstring muscle is actually tight. This is most typically a result of an increased or altered load on a muscle – like a workout - and sets in 1-2 days after the change in demand. This tightness may be called soreness, and is a result of normal breakdown in the muscle itself and/or inflammation in the muscle. While people might choose to intervene to reduce this tightness (such as going for a walk, stretching, getting a massage, etc.), it is imperative to note that this tightness is normal, and will pass within a few days on its own. People don’t usually seek medical care for this.

True muscle tightness can come from less strenuous events too. For example, if you wear a new pair of shoes while walking around a city for hours, you might experience tightness in a muscle or two the next day since your muscles experienced a new load due to the different position of your feet. Alternatively, if you were in a cast for 8 weeks, your muscles may also feel tight while they are immobilized. And, of course, if you tear a muscle, if will feel tight as inflammation and then immature scar tissue replaces the torn muscle tissue. In all of these scenarios, the cause of the tightness is normal, obvious, and reversible.

Again, patients usually don’t come to me reporting tightness of the normal variety (since normal muscle tightness will pass on its own). So what makes patients feel tight if it’s not normal true muscle tightness? There are two possibilities:

1.  The abnormal sensation of tightness is referred from a joint, either nearby or distant.

A common situation here is a spine joint being out of place and referring a feeling of tightness to a separate area. It can be nearby, like the neck joints sending tightness signals to the upper shoulders. Or it can be more distant, like the low back joints sending tightness signals to the calf. Extremity joints can also send tightness signals. With extremity joints, the signal usually stays close to the problematic joint. The hip joint may send a feeling of tightness down the thigh a bit, for instance. This tightness can be constant or it can come and go.

2. The abnormal sensation of tightness is nerve tension/tightness.

Nerves run throughout our body, passing through and next to muscles. If a nerve is compressed somewhere along its path, it will lose the ability to lengthen, making it indeed tight. The most frequent example of this is the sciatic nerve. When compressed in the low back, it can create a feeling of tightness in the back of the thigh, calf, or foot. Most people, however, just blame the muscle in the area of tightness, not understanding that a nerve is also in that area! This tightness, also, can be constant or it can come and go.
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There are movements and simple tests I use in the clinic to determine what is causing the tightness. A simple slump test is used to help differentiate if a hamstring muscle or a sciatic nerve is tight, for instance. The take home message is this: true muscle tightness is usually normal, but persistent or recurring (chronic) tightness is not normal, and is almost always arising from a location away from the site where the tightness is felt. You shouldn’t be stretching, foam rolling, or massaging your arm, back, or leg muscles all the time. Find the joint or nerve causing the feeling of tightness and fix that to get relief for good. -- Laura

I remember learning about dead butt syndrome (DBS) during a presentation at the clinic where I worked several years ago, two years into my career. I believe the sales rep was there to push taping products, but this topic somehow came up. (Please note: while some refer to all the gluteal muscles becoming weak, others specify the gluteus medius muscle in particular.) This gentleman explained that since people sit all day without using their gluteus muscles, they become weak. Made sense to me! And it had a fun name.

However, when I began using the term with patients whose gluteus medius muscles were in fact weak, and fielding patients' questions regarding the topic, I became skeptical. For one, if sitting dormant all day was the root cause, why wouldn't mostmuscles weaken? And, secondly, if it was sitting combined with lack of daily use of the gluteus medius muscles - lack of moving the hips laterally - that was the trigger, wouldn't the lateral movers of other joints suffer then too?
So I did a bit of "research:" I read a few articles intended for the public. The consensus is that DBS not only affects expert sitters, but also people who exercise, but who don't target the glute muscles enough. That sounds strange. Those could be very different cohorts. Or, the exercisers could also be expert sitters when they're not moving. Here are my two chief complaints with what I found to be the commonly proposed etiology of DBS:

1. Asserting that the glutes are weak because of reciprocal inhibition does not resonate with me. This argument states that, with prolonged sitting, hip flexors get tight and contracted and therefore inhibit the muscles opposite them - the glutes. For starters, tight and contracted are not necessarily the same thing. I'll allow that hip flexors may get tight the more we sit with them maintained in a shortened state, but given they get some stretch with each step we take, pathological hip flexor tightness is a hard sell for me. Very often what is diagnosed as hip flexor tightness is actually femoral nerve tightness. (There are clinical tests to distinguish between the two.) Additionally, hip flexors don't contract, that is, actively work, while you're seated. They're normally pretty quiet as you just sit there. Lastly, my understanding is that reciprocal inhibition is when the body momentarily relaxes an antagonist to allow the agonist to do its work - which in and of itself does not create weakness. In sum, while I certainly agree that many people have weak gluteus muscles (one or more of them) I can't get behind this explanation.
2. One author writes, DBS "can lead to lower back pain and hip pain, as well as knee and ankle issues, as the body tries to compensate for the imbalance." Can weakness lead to pain? Sure. Is it more likely, though, that the weak glutes, low back pain, hip pain, and lower extremity pain are all manifestations of one pathology? That is, most likely a lumbar spine that is a little, or a lot, malaligned? The words "compensate" and "imbalance" are actually my two least favorite words in the world of physical medicine. While it doesn't seem far-fetched to think, "Hey, my left knee has been hurting for awhile and now my right hip is starting to hurt because I'm walking differently," what if we instead asked: What can be causing both left knee pain and right hip pain? You must have a solid diagnosis first. The answer to that question, of course, is almost always the spine.

Another article states, "It may seem bizarre for a muscle to just stop functioning out of nowhere." Yes! It is indeed very bizarre! Except when you recall that nerves send power to muscles ... and when there is a problem with the flow of electricity through those nerves, muscles will stop functioning seemingly out of nowhere! This inhibition-driven weakness, while not normal, is extremely common. (In fact, if I tested the primary muscles of the upper and lower extremities of 100 people, I bet not one person would demonstrate full strength. That means not one person would have uninterrupted flow of electricity from their spine to their muscles.) The good news is, once you restore the flow of electrical power from the spine - I use specific movements with my patients to accomplish this - muscles should immediately regain normal strength.
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So what is going on with DBS? In the large majority of cases, prolonged sitting (the more slouched, the worse) creates a malalignment in the low back which impedes the flow of electricity via the nerves to the glutes, depriving them of their juice to be strong. The same scenario can create pain in the glutes as pinched nerves can carry pain along their path (or any altered sensation such as tingling or degrees of numbness). That'swhy your butt is dead. To fix it, you'll need to address your low back in order to decompress the nerves. And then, once the power is back on, if your gluteus muscle strength doesn't return completely since the muscles had been dead for so long, you can move on to targeted strengthening exercises to rebuild them. -- Laura

I consistently hear my patients - and people in general - tell me about their muscle problems. "My upper trap is tight." "My quad is weak." "My piriformis is killing me." "I pulled my calf muscle." "My infraspinatus is in spasm." "My hip doesn't rotate because my muscles are tight." Have you stopped to consider how a muscle would get into such trouble?

While muscle pathology coming from the muscle exists, it is indeed rare. Symptomatic muscle tears and strains are not common. (Often, muscle tears are simply incidental findings on MRI - meaning that while the tear is there, it is not the source of the patient's problem, and may have been there for years.) Muscle tightness and weakness are more common than tears, but are not usually the fault of the muscle itself. Even though we tend to adopt certain unilateral movement patterns (as a result of being right-handed, for example), this should not cause discernible differences in muscles on one side of the body versus the other. And muscles usually don't just spontaneously become painful, tight, or weak all by themselves.

So, if we can't blame muscles, what can we blame? Joints!

Joints commonly move out of their proper position. Haven't you sat on a bent knee and then had to shake it out once you stood up to get it back in place to walk? Or rested on your neck in an awkward position and then had to wait a few seconds for it to straighten out? McKenzie-trained therapists would say the joint has deranged, or, rather, that there is a joint derangement. In these two examples, the derangement is normal and very quickly resolves on its own. However, joints are often deranged more seriously. And when they are, they can refer sensations via nerves of tightness, pain, and weakness away from the joint ... appearing in the muscles.

In extremity joints, the pain is typically referred locally along the nerves. For example, if the shoulder joint is deranged, pain often appears in the lateral upper arm. With an ankle derangement, pain can refer to the bottom of the heel. Joint derangements also frequently create nearby muscle weakness since nerves provide both sensation and electricity to the muscles. Derangements in the joints of the spine behave somewhat differently since these joints can influence the major nerves to the extremities. A joint derangement in the spine can, like extremity joints, refer symptoms locally; a derangement in the low back can create symptoms in the quadratus lumborum or psoas nearby, for instance. But if a major nerve exiting from the spine is impinged, local and/or distant pain/tightness/numbness/tingling/weakness can result. For example, I commonly see tightness in the hand, cramping in the calf, weakness in the hip flexors, tingling in the foot, or pain in the shoulder blade or buttocks as a result of a derangement in the joints of the spine.

The good news is that joint derangements are usually rapidly fixable! McKenzie-trained therapists like myself are trained to differentiate between true muscle pathology and joint derangements creating symptoms that can mimic muscle problems.  Over 70% of orthopedic problems are joint derangements. So let's start blaming joints - not muscles! And let's also start fixing them quickly through specific movements. -- Laura