Whether it's after a tough workout or just the result of hunching over your laptop all week, chances are you've dealt with muscle tightness or knots before.

You've probably also tried some of the go-to remedies for getting relief — a heating pad, stretch routine, massage or maybe even foam rolling.

But, there's another way to deal with tight muscles that's trending: massage guns.

"Massage guns, which are also called percussion massagers, are handheld devices that use vibration and deep oscillation to massage irritated muscles," explains Dr. Corbin Hedt, physical therapist specializing in orthopedics and sports medicine at Houston Methodist.

Why does a massage gun work?

"Muscle knots are essentially small bundles of muscle fibers that, for one reason or another, are stuck in a contracted state," explains Dr. Hedt. "They're not getting the chemical input that usually tells them to relax, so these fibers become stuck or 'glued' together."

When this happens, the nerves bundled within the knotted muscle get confused and the resulting neural output is pain.

How massage guns and percussive therapy alleviate that discomfort is not well understood, acknowledges Dr. Hedt. But he says it's likely very similar to why massage therapy helps.

"We know from massage therapy research that applying a mechanical stimulus to a muscle can spread the fibers out and force them back into an elongated position, resolving any tightness or knots that may be present," explains Dr. Hedt. "A massage gun is just another way of applying a mechanical stimulus to a muscle. In this case, it's accomplished via the pulsing oscillations provided by a percussive tool rather than by hand during a massage."

Are massage guns worth it?

With a slew of options now on the market, massage guns aren't just for athletes anymore. They're for anyone willing to shell out some money to up their recovery game.

But are massage guns actually worth a price tag that can range from $30 to $600?

"From a physical therapy perspective, I certainly think a massage gun is a useful recovery tool," says Dr. Hedt. "One study actually shows that percussive massagers can provide the same benefit as a 15-minute massage in as little as two minutes of using it."

In terms of pricing, says Dr. Hedt, there is no current evidence that more expensive products necessarily provide for a greater outcome. Typically, the cost will likely be associated with ease of use, longevity/quality of materials, battery life, and options for customization (movable head, various speed differentials, head selection). These can all be weighed by the individual consumer to determine what product may be most beneficial for them.

However, when determining whether to invest in a massage gun, he notes that it's important to understand when to use one and what to expect (and not expect) from one.

When should you use a massage gun?

"Massage guns are best for reducing the tightness and irritating knots that sometimes form in your muscles after exercise, especially if you exercise frequently or your workouts are intense," says Dr. Hedt. "There's also early evidence that percussive guns may help reduce the intensity and duration of soreness after a big workout."

But Dr. Hedt warns not to think of a massage gun as a preventive tool.

"I don't think there's a benefit to using a massage gun aimlessly every day as a sort of preventive routine," says Dr. Hedt. "There's no evidence showing that prophylactic massage will prevent knots. Instead, a massage gun is generally a tool to turn to when you're feeling discomfort."

And using a massage gun also doesn't mean you can drop your stretching routine.

"Massage guns are good at targeting a specific area that's tight, and while there are studies showing that range of motion improves immediately following massage gun usage, it's hard to say whether these tools will ever be shown to be more beneficial than a good dynamic stretching routine," adds Dr. Hedt.

Most importantly, if you're experiencing persistent muscle discomfort or pain, it's always best to get it checked out by a sports medicine doctor.

"The source of your pain might be something more complex than what your massage gun can handle and that would benefit from physical therapy," says Dr. Hedt.

Can massage guns replace foam rolling?

If you've had trouble with muscle knots and soreness in the past, chances are you've used a foam roller once or twice before.

The problem is, foam rolling can be painful. Really painful.

While explanations of how a massage gun works sounds pretty similar, can it really replace foam rolling?

"A few studies look favorably towards massage guns for reducing muscle stiffness and knots, as compared to foam rolling," says. Dr. Hedt. "Plus as users of these recovery tools, people tend to look more favorably at massage guns, too, since they cause less intense of a stimulus and muscle groups can be targeted and isolated more effectively."

However, Dr. Hedt adds that there still might be benefit to the discomfort that comes with foam rolling.

"If your muscles are just tight, sometimes inducing an unpleasant input of pain can act on your nervous system in a beneficial way, ultimately alleviating some of your discomfort even if it doesn't actually 'correct' anything within the tissue," adds Dr. Hedt.

Which massage gun attachment should you use?

"When it comes to the various attachments, the best rule of thumb is to go by what's most comfortable for you and the area you're targeting," says Dr. Hedt.

For instance, the blunted head attachment is probably best for larger muscle groups, like your thigh muscles; the rounded head attachment is likely best for smaller sites and more isolated targeting.

The larger and smaller foam head attachments are also probably best for large to small muscle groups, such as the calves, thighs and shoulders.

Are massage guns safe to use?

"Massage guns are safe to use for those who are cleared for exercise and don't have an underlying condition that might prevent them from being able to massage a muscle," says Dr. Hedt. "That being said, there are areas of your body you should avoid, particularly the front of your neck and torso — where you have many important organs. Also, you can't stretch bone, so be sure to avoid bony sites of your body."

As far as how to use a massage gun the right way, Dr. Hedt shares some do's and don'ts:

• DO use a massage gun on large, bulky muscle groups, such as your quadriceps, hamstrings, glutes, calf and upper trap muscles.
• DO massage the muscle group you're targeting for about two minutes.
• DON'T use a massage gun on the front of your torso or neck.
• DON'T massage bony sites, such as the front of your shins, tops of your feet, head and joints.