10 dangerous exercises that lead to injuries

While any exercise performed with poor technique could put you in harm's way, some moves are more commonly botched than others. We called on six leading physical therapists to share, which exercises could land you in rehab if done incorrectly. Don't say you weren't warned.

Pump 'em out as fast as you can, right? Wrong!

"As exercisers drop in and out of abdominal flexion, losing their muscle tension in the midsection, the low back gets wrenched in and out of extension with little support," says Alycea Ungaro, PT. She's the owner of Real Pilates in New York City.

She explains that twisting at high speeds is a recipe for herniated discs and muscle spasms.

"In addition, many people clutch the back of their heads and crane their necks back and forth subjecting their cervical spine to injuries as well."

Your better bet: Slow the crunch down drastically if you feel you have to perform it.

If you don't realize vulnerable positions you're placing your body in, you won't be able to help prevent injury.

"The lat pull-down places a lot of stress on the anterior joint capsule of the shoulder and can eventually lead to impingement or even rotator cuff tears," says Jessica Malpelli, DPT. She's a therapist at the Florida Orthopedic Institute.

If something in your shoulder doesn't feel right, stop and find another exercise. Even doing the lat pull-down in front of your head can be a safer approach.

Yes, it's one of the best strengthening exercises around. The catch: It requires impeccable technique.

While many people think this movement is all arms, it's actually powered from your lower body, specifically the posterior chain including the glutes and hamstrings. It's important to learn the correct way to move the weight before you start swinging it.

"Because of the speed and the force of the swinging motion of the kettlebell, the shoulder is at significant risk for injury," says John Gallucci Jr., MS, ATC, PT, DPT. He's the president of JAG Physical Therapy.

"If performed incorrectly, the repetitive swinging motion could result in rotator cuff injury and/or inflammation of other structures in the shoulder."

To avoid landing on the examination table, make sure the power is generated from glutes and hamstrings.

"Rows can be great for shoulder and upper back," says Malpelli, "but often patients perform them bent over at the waist. Being in that much lumbar spine flexion can cause a disc to displace posteriorly, potentially hitting a nerve." Hinging from the waist also causes your shoulders to roll forward, which can contribute to poor posture (and is counterproductive to the row exercise in general).

If you're going to do row, try performing them lying face down on a Swiss ball or bench.

If performed correctly, it's a great exercise for the back and hips. However, dead lifts are one of the easiest ways to hurt your back if you don't know what you're doing. Why?

"Most commonly a person will fall into hyperextension through the low back while lowering and lifting weight, which could result in lumbar disc injury or muscular spasm," says Gallucci.

Translation: Many lifters will round their back when picking up or putting down the bar — and often they may not even realize it.

"Also, if the weight isn't distributed through the feet properly and is shifted too far forward, then the glutes and hamstrings won't fire and the lumbar extensors are overworking, which again could result in a low back spasm," explains Gallucci. If you're a newbie to this lift, we recommend asking a trainer for help.

Lifting anything overhead is challenging to your body, and even more so to the nervous system. Add a squat to that and form can quickly go out the window.

"An overhead squat is a full-body exercise, so for example, a person who doesn't have enough mobility in their hips, knees and ankles will have trouble getting into a deep squat even without the overhead press," says McGinnis. "The actual overhead motion adds strain to shoulder, cervical, thoracic and lumbar regions."

If you insist on attempting this move, make sure you cease going down as soon as your form is compromised.

"Stop when your low back starts to arch excessively, your knees drive forward past your toes or your arms move forward," says McGinnis. "Whatever depth that is, that is the bottom of your squat."

It may look functional and maybe even fun, but it's never a good idea to forcefully rotate your spine backward. There are so many small and delicate discs in the back that can herniate with the slightest wrong movement, so anything bending you backward should be done slowly and with serious caution, says Jason D'Amelio, MS, ATC-L, ART-C. He's the owner of Total Athletic Performance Training in New York City.

"The reason that I dislike this exercise is because there is no movement in sports that requires you to aggressively rotate backwards," he says. In most athletic rotation and swinging movements (think: swinging a baseball bat or golf club), the most powerful part of the movement is when the body rotates forward, not backward.

The backward rotation does nothing for the client from an athletic standpoint, D'Amelio says. He recommends opting for medicine ball throws for rotary power, but only laterally and throwing the ball forward.

Maybe it's time to rethink using this piece of equipment just because everyone else is. It may actually be doing more harm than good.

"Using a leg extension machine isn't functional -- there is no natural movement in life were you sit and straighten your knee with a 100-pound load against it," says Joe Tatta, DPT. He's a physical therapist at Premier Physical Therapy & Wellness in New York City.

When you isolate any muscle and put an intense amount of weight on it, you run the chance of creating muscle imbalances. Plus, many people flex their toes when performing this exercise, overworking already tight muscles such as the hip flexors.

"It also places undue stress across your knee joint affecting the delicate cartilage under the patella," says Tatta. Need another option? Try squats instead.

Can't pump out 20 straight? That may not be such a bad thing, especially if your alignment isn't quite there yet. This exercise targets the lats, which is one of the most underused muscles in the body, especially for women. To get the benefits of a pull-up, the lats must be activated.

"You need to have your chest up with your abs engaged, and lead the pull with your elbows," says Sulyn Silbar, orthopedic massage therapist and owner of Body + Mind NYC. "Most people cannot do them properly, as their lats aren't working or aren't strong enough, and therefore the body compensates by using the upper traps and chest to do the movement." This can lead to short, tight pecs, or worse, shoulder issues.

Learn the pull-up using a band and checking your form in the mirror or with a certified trainer before you start knocking them out.

It's time for a separation of church and exercise. While the setup for a preacher curl is to, in fact, activate the bicep muscle, the position makes the rest of your body vulnerable.

"It puts the muscle in an active insufficiency, which means the muscle is already shortened, and puts your shoulders in an anterior tilted position and in abduction, which means they are farther apart," says David Reavy, PT, OCT. He's a therapist at React Physical Therapy in Chicago.

"There is no stabilization of your core or lats because your shoulder blades are out of place and you are in a forward posture. You are strengthening in a bad position."

Instead, Reavy recommends bicep curls be done in a half-kneeling position.

While there may not be any "bad" exercises, there can be poor executions of those movements. When in doubt, seek out expert advice to make sure your programming and exercise technique aresound.