Hamstring flexibility is something that most people believe that they need tons of.
There is a perception that the inability to be as flexible as a dancer or gymnast is a bad thing.
I always thought that this was a weird topic because I was never sure what a lot of flexibility did for people.
In order to solve this problem we need to take a look at how to test for tight hamstrings, why the hamstrings get tight, and are they really a cause for concern.
First when testing for flexibility there are usually three ways to do it.
One is a standing toe touch. This is the one that most people want to have success in. People typically want to be able to reach down and touch their toes.
Another is the seated toe touch. Again we are reaching for our toes, just from a seated position.
These two methods are classically flawed examples of hamstring flexibility. 95% of people are going to get their range of motion from the low back.
The low back is a segment that is built for stability, so a ton of motion through there is a risk factor for back pain.
Excessive motion through the lumbar spine can also have performance implications. The inability to stabilize the spine leads to poor performance in the weight room, running, and other activities.
But the bottom line is that these tests are too highly influenced by the low back to be a hamstring test.
Enter the straight leg raise.
The Functional Movement Screen uses the straight leg raise as one of its screens for movement restrictions.
They do not call it a hamstring flexibility test, however. They call it a core stability test.
I used to question, how does a test that is directly influenced by the length of the hamstrings become a core strength test?
This is how it works and you will need a partner.
Lie on your back. Lift one leg up (active) without bending at the knee and keep the opposite leg down against the floor.
Note how far you get up. A good test score is past 90 degrees or motion.
Next, do the same thing but have the partner gently move the hamstring (passive) to its full range of motion.
If the test is improved then you were limited by your core control on the first test. Your hamstrings were more flexible than you could actively move them.
Had the hamstrings moved to the same range both actively and passively to less than 90, then tight hamstrings are in place.
In addition to core control there are a few other ways that the hamstrings can get tight.
They could be truly short. Although possible since we set more than ever, this is usually not the case.
Neural tension is also a cause. This means that the nerves are constantly turned on and not allowing the hamstrings to reach full flexibility.
Protective tension is the last way that I will discuss. The hamstrings group connects from the pelvis to below the knee. It influences two joints.
If there is a lack of stability in the knee or the hips/low back, he hamstrings will have to tighten accordingly.
Anytime a joint cannot provide its own stability, somewhere else in the body will compensate.
Bad training protocols can create a lot of motion through the low back and the hamstrings start to act as stabilizers.
It used to be though that tight hamstrings were a risk factor for back pain, but that notion has been dismissed. It is probably due to the fact that motion in the low back is the risk factor and tight hamstrings are just a compensation.
When it is time to determine how much hamstring flexibility you should have, it all depends.
When someone discusses wanting more hamstring flexibility, 2 questions come to mind.
Are you limited in any activity by your hamstrings?
If the answer to the 2nd question is “No” then close the book on this discussion.
The why is usually going to be from misguided notion that we all need to be Gumby.
Tight (ish) hamstrings are actually advantageous for sports that require power development.
If the hamstrings are super flexible it becomes difficult to use the Stretch Shortening Cycle (SSC), which in a nutshell puts the muscle under stretch in order to use that energy to develop force.
The SSC helps improve jumping, running, and agility ability. Call me crazy but these are essential for sport.
So to wrap up, there are two questions you need to ask yourself when it comes to wanting more range of motion through the hamstrings.
If you are limited in activities because your hamstrings are tight, then you need to address that.
Conversely, if there are no restrictions due to tight hamstrings then forget about them. It might be an advantage to have less flexible hamstrings if it is not required.