As a physical therapist, I am not a big fan of stretching the hamstrings and I often advise patients against doing so.

Why? Because most people do not stretch the hamstrings correctly. This often causes more problems in the hamstring such as micro-tearing of the muscles. It can also lead to problems in other affected areas, such as herniated discs in the back.

Before I explain further, you should understand exactly where the hamstring is located. It is important to know that the hamstrings are a muscle group comprised of three different muscles on the back of the leg. People often confuse this muscle group with the quadriceps, which are located in the front of the leg. The hamstrings are used to bend the knee while the quadriceps are used to straighten the knee joint.

The quadriceps and hamstrings should be equal in strength but many times quadriceps are much stronger. Here is a quick way to test for this muscles imbalance:

Bend your leg and then try to straighten it while a friend resists your efforts. Chances are, you'll be able to straighten your leg even with the added resistance. Now try to bend your leg back in while your friend resists the movement. Can you bend your knee as easily as you straightened it? If not, you have weakness in your hamstrings and what you really need to focus on is strengthening your hamstrings, not stretching them.

When your hamstrings are weak, you start to develop tiny "knots" in the muscles because they are working overtime to keep up with the stronger quadriceps. Imagine putting a bunch of knots in a piece of string and asking it to work at the same capacity it did without the knots. This causes discomfort, and many people think stretching will alleviate the pain. When you try to stretch these "knots," the muscles start to tear.

One of the worst things you can do is having someone stretch your hamstrings for you. I cringe when I see trainers doing this.

If you really want to stretch your hamstrings, make sure you do so safely. First, start with a foam roller — preferably one with spikes on it because a flat one is not going to get deep enough into the muscles to get out the knots. Spend 5 to 10 minutes rolling out the hamstrings on the spiked foam roller. If you find areas of pain, stay on those spots for about 20 to 30 seconds each. After that, you can start to stretch the hamstrings.

When stretching your hamstrings in a standing position, prop your foot up on a stool and hinge forward at your hips. You will feel a stretch in the hamstrings. You can also do this seated. In either position, do not bend from your back, which puts significant pressure on your discs and risks herniating them. Focus on keeping your back straight. To avoid back issues completely, consider lying on your back and using a strap to stretch your hamstrings. Hold the stretch for 30 seconds and repeat it six times on each side.

It is important to remember not to overstretch your hamstrings. Taking the proper precautions is important to keep yourself free from injury.

Heather Moore, PT, DPT, is the owner of Total Performance Physical Therapy, a physical and aquatic therapy center in North Wales and Hatfield, Pa. She received her master's and doctorate in physical therapy from the University of Maryland-Baltimore.