The quad muscle dent, that scary groove that appears in your quadriceps muscle, has more than one possible cause.

There are several causes of the quad muscle dent.

The quadriceps dent is often described as being one to two inches long, and sometimes horizontal, and other times diagonal.

Occasionally a description for the quad muscle dent comes in as closer to vertical, and may exceed two inches in length, sometimes stretching for almost half the length of the thigh.

This article explains the causes of dents in your quad muscle.

“First of all, any obvious or irregular change in tissue structure — such as ‘denting,’ is worth getting checked,” says Dr. Joseph J. Ruane, a sports medicine specialist with OhioHealth Physician Group.

“Rarely (and I mean rarely) it may be a sign of something bad going on underneath.

“However, it may be reassuring to know that the dent is most often a loss of subcutaneous tissue (the fat under the skin) rather than loss of muscle tissue itself.

“This can result from local trauma (bumping hard into the corner of a desk).

“The fatty tissue is damaged in the impact, and sometimes shrivels and shrinks; leaving a dimple, or dent.

“Sometimes it fills back in, often it may not. Muscles do not atrophy in small, defined sections that leave dents.”

If you’ve been worried sick over the dent in your quad muscle, re-read Dr. Ruane’s last line:

“Muscles do not atrophy in small, defined sections that leave dents.”

Is a Quadriceps Dent Really Atrophy?

Oddly, people who have hypochondria related to MS or ALS have somehow formulated the idea that an early sign of muscle atrophy is some little depression or groove in the muscle.

Nowhere in the annals of medical literature is muscle denting named as a sign of wasting muscle tissue or atrophy, or any kind of disease.

Another cause of the quad groove, in addition to local trauma, is prolonged leaning of the thigh into an object.

A person who spends a lot of time at a counter of sorts may be unknowingly leaning (pressing) their thigh into a hard edge.

Or, perhaps they are seated, and something weighted is resting atop their thighs, such as a heavy briefcase.

Later on, the person happens to notice a small impression or depression in their quadriceps while changing clothes, showering or working out.

They fail to recollect earlier in the day when something was pressing into their leg and “molding” the dent.

The image below shows natural quadriceps musculature.

Shutterstock/JRP Studio

Now…if only a tiny area of your natural muscle grooves is visible, do not take this out of context and think you have ALS or atrophy.

It’s normal for only a small area of natural grooves to be visible, creating a “small” indent.


Another cause of quad denting to consider is the natural anatomy of the muscle, if the fissure is more vertical than horizontal.

A person who has toned thigh muscles, along with low body fat in that area, will likely see vertical dent in the middle of their quads, a few inches to several inches in length.

This fissure may come and go, depending on body position.

Dents are clearly visible in these buff legs.

Acquaint Yourself  with Natural Dents

If you’re not sure what the cause of your quadriceps dents, impressions or grooves are, check out images of bodybuilders’ legs.

They have very visible muscle definition and all sorts of grooves and “topography.”

This way you’ll learn what a normal muscle dent should look like, as opposed to what could be the result of local trauma.

Dr. Ruane’s practice is dedicated to comprehensive, nonsurgical musculoskeletal care. He is active in clinical research and is a nationally recognized speaker and educator.
Lorra Garrick has been covering medical, health and cybersecurity topics for many years, having written thousands of feature articles for a variety of print magazines and websites. She is also a former ACE-certified personal trainer.  
Top image: Shutterstock/KlaraBstock

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