Have you ever been told you have pain or were injured because “x” muscle was weak?
“Your knees hurt because your gluteals are weak”
The fear-mongering persists and continues to spread throughout social media. Our biases and previous education blockade our willingness to consider new, credible information. I know, as I experienced the same biases and refused to accept current pain research for the first two years of my practice.
Learn from my mistakes.
Let’s tackle those myths about pain and weakness through a couple of recent studies (which build off mounds of other research).
Addressing gluteal (aka butt muscle) weakness
The gluteus maximus is one of the most powerful muscles in the body. It is a primary driver for two of the most vital movement tasks: squat and deadlift. Every time you sit down, stand up, or pick something off of the floor, the gluteals are one of the main muscles assisting you.
The gluteus medius is a much smaller muscle that largely assists with rotating your hip. It is vital for many functional movements as well. It is not, however, the cause of all knee, hip, back, and foot pain as many physical therapists and personal trainers would have you believe.
Another note on the gluteus medius, you can strengthen it with normal exercises. You don’t need silly band work to “activate” the gluteus medius. The squat and deadlift — and all of its variations — will work the gluteus medius vary well. Even if you could target the gluteus medius, there may not be anything special about the outside hip muscles.
This recent research trial compared training the posterolateral hip (gluteus medius region) and the anteromedial hip (ground region, your adductors) in 52 women with patellofemoral pain. Each group became stronger in their respective region (abduction vs. adduction) but there was no difference in pain or function at 6 weeks and 6 months.
There are no “imbalances” to correct. In fact, you could argue this study increased “imbalances” in the adduction group. But, as previous research has shown, we are not cars in need of alignment. Posture doesn’t explain pain and no single factor, including strength, can predict injury.
Now, strength is still important, as it is a primary marker of health and fitness, directly tied to all-cause mortality, but the relationship between strength and pain is unclear, even for muscles directly related to the location of pain or injury — such as the quadriceps with respect to the knee.
Knee weakness and knee pain
This study grouped 377 people with knee osteoarthritis into one of three categories: high-intensity strength training (n = 127), low-intensity strength training (n = 126), or attention control (n = 124). This was a robust study lasting 18 months. The participants in the training groups exercised three times per week for one hour (including a five-minute warm-up and 15-minute cooldown). The high-intensity group trained between 75 and 90% of their 1 rep max while the low-intensity group trained at 40% of their one-rep max.
At the end of the study, there were no differences in pain or functional outcomes. Does this mean the high-intensity strength training wasn’t helpful? Hardly. Functional measures have a low ceiling and greater strength can be beneficial for many daily tasks. Does this mean we need to strengthen the quads to reduce knee pain in people with knee OA?
The knee is not the only region where local weakness is used in an attempt to explain pain.
Hip weakness and hip pain
A 2018 study recruited people with hip pain. Each participant completed a series of questionnaires that assessed psychosocial factors that influence pain. These included pain catastrophizing, depression, pain self-efficacy, and quality of life. The participants also reported their activity and pain levels. Lastly, the researchers measure waist girth, body mass index (BMI), muscle strength, and hip circumference.
After the assessments were performed, each participant received an MRI of the hip to look for gluteal tendinopathy — degeneration in a tendon that attached to the hip. After all of the participants were screened, 208 had confirmed gluteal tendinopathy and were included in the study.
The participants were separated into low, moderate, and severe pain groups. The aim of the study was to compare physical and psychological characteristics between subgroups of varying severity of pain and disability. They found higher pain catastrophizing (an exaggerated pain experience and the feeling of helplessness) and depression scores, lower pain self-efficacy scores (the ability to manage pain independently), greater waist girth and BMI, lower activity levels, and poorer quality of life in the severe pain group. Hip strength and hip circumference did not differ between subgroups of severity.
What does this mean?
Hip strength was likely not a factor in determining a participant’s pain experience.
Don’t discount the importance of strength
I see strength used as a marker for diagnosis in the clinic frequently. Sometimes it is used to describe a movement pattern that is then blamed as the culprit for pain and injury. Take running for example.
Clinicians and coaches often search for the ideal running mechanics, despite the research suggesting there isn’t an ideal, universal way to run. Regardless, hip weakness is often blamed for many running “faults” such as ankle pronation and hip adduction. Let’s set aside the research that shows ankle pronation is not a predictor of pain and injury for now.
This research study showed abduction and external rotation strength of the hip is not correlated with joint ranges when running. So if you did want to alter running mechanics for the purpose of injury prevention, building strength is not the solution.
You need to train the specific movement pattern you want to change. This is true for any movement. Do banded hip work won’t change squat and deadlift mechanics — it will make you stronger with the banded hip work.
The research I have shared does not mean strength training is not important for health. You don’t only build strength for ego lifting and setting personal records in the gym. Strength is a vital component of health, but its relationship with pain is less clear than many people think.