Gaby
When we say our knees have gone weak, we usually mean we’re experiencing overwhelming emotions—fear, grief, or attraction to a loved one. But can intense feelings actually make our legs feel shaky?
People can experience knee weakness in certain situations. For instance, strong emotions—especially stress—can trigger physiological changes that lead to wobbly knees. But that weakness can also be a sign of an underlying medical issue.
Here’s what researchers have found
In fact, “knee weakness” is more of a colloquial expression than a clinical term, according to anxiety expert Martin Antony, chair of the psychology department at Toronto Metropolitan University in Canada. He notes that there isn’t a strong correlation in the scientific literature between knee weakness and intense emotions.
“I haven’t seen research specifically linking knee weakness to anxiety. However, several symptoms of panic attacks, such as trembling and chills, are associated with instability,” Antony says.
Bethany Teachman, a psychology professor at the University of Virginia, explained that sometimes the sensation of weak knees is tied to the body’s “fight or flight” response. This refers to a series of changes that occur when stress hormones are released. These changes—like increased blood sugar levels, spikes in blood pressure, sweating, and muscle tension—prepare the body to react to a threat or flee from danger. But they can also lead to feelings of weakness in the knees.
Typically, the body redirects blood flow to the brain and major muscle groups when there’s a need to escape or defend oneself. This adaptation is incredibly valuable. However, it can also cause dizziness and a sense of instability in the knees, as reported by Live Science.
Teachman also pointed out that panic attacks often make people feel detached from their bodies. That detachment can add to the sensation of weak knees.
However, it’s not just about emotional states. Knee weakness can also signal an underlying condition, such as osteoarthritis, quadriceps weakness or injury, or muscle strain.
If knee weakness or instability happens only during a panic attack or other intense emotions, Teachman says the symptoms are likely anxiety-related.
Antony says that if knee weakness lasts much longer than a panic attack or emotional episode, it may indicate an underlying medical problem that needs attention.
