It seems like every gym session involves a classic static hamstrings stretch – a straight knee, a flexed hip and pulling the foot back.
Is it necessary? Does it help or hinder performance?
And why do we pull the foot back?
We’ll also compare static hamstrings stretches to dynamic stretching and foam rolling for hamstrings flexibility and performance.
Hamstrings muscle anatomy
The hamstrings is actually a group of four muscles.
The upper attachment for all four muscles is the Ischial Tuberosity – the bone you sit on.
The four muscles share a common tendon attachment, known as the Common Hamstrings Origin or CHO.
In the middle of the thigh, the muscles are grouped in pairs.
On the outside, or lateral side, of the leg is the Biceps Femoris muscles (two muscles).
On the inside, or medial side, of the leg is Semimembranosus and Semitendinosus.
At the lower end, all muscles attaches just below the knee with two muscles attaching on each side of the knee.
The medial group, Semimembranosus and Semitendinosus, wrap around the knee and attach on the tibia (shin bone) at a point known as Pes Anserine.
The lateral group, Biceps Femoris, wraps around the outside of the knee and joins at the Fibular head (the bump on the outside just below the knee joint).
The Hamstrings are referred to as a biarticular muscle – “bi” meaning two and “articular” referring to joints.
It’s “biarticular” because it crosses two joints – the hip and the knee – and generates movement at either or both, depending on the action of other muscles.
Static hamstrings stretching action
To stretch any muscle, it needs to be pulled to its lengthened position.
For biarticular muscles, this usually involves moving one joint to a fixed position and then using the other to add further tension.
For the hamstrings stretch, the knee is often kept straight while the hip is gradually flexed or bent forward.
The best way to visualise the movement is to push your belly button towards your knee.
This will arch your lower back and tilt your pelvis to focus the stretch on the hamstrings.
And you’ll need a reasonable amount of force to be effective if your goal is flexibility.
This is particularly effective in young adults, but be cautious with older adults as tissue elasticity is reduced.
Don’t use the old “touch your toes” prompt as this increases stretch on lower back and hip muscles, reducing the hamstrings focus.
And foot or ankle movement won’t add anything to the stretch – remember the muscle ends just below the knee!
So pulling the foot back?
Therein lies the question!
If the hamstrings finishes just below the knee and doesn’t cross the ankle joint, what will pulling the foot back achieve?
For a static hamstrings stretch, it achieves nothing.
The foot movement actually tensions the Sciatic nerve, which is why the stretching feeling increases.
Keen observers will note that the stretching feeling actually moves from the middle of the hamstrings muscle to the top or middle of the calf muscle.
So what you’ve done is turned a static hamstrings stretch into a Sciatic nerve stretch!
Is static hamstrings stretching helpful, harmless or hurting?
Static hamstrings stretching is generally harmless for most young adults and teens.
It has the potential to reduce performance (that’s right, performance can be worse after stretching).
It’s also unnecessary for most people – their hamstrings aren’t “inflexible” or they don’t require hamstrings flexibility in their sport (for example, distance running).
If your goal is to improve performance, you’ll get a better result out of foam rolling or dynamic stretching.
For the static hamstrings stretching technique where you pull your foot back, it can be potentially harmful and less effective for hamstrings flexibility.
It increases tension on the Sciatic nerve, taking the pressure off the hamstrings muscles and making the intended stretch less effective.
Pulling on the Sciatic nerve can also irritate the nerve, potentially leading to pain and other issues.
However there are some athletes that can benefit from adding in the Sciatic nerve component.
Dancing and martial arts both require the leg to move into stretched positions.
So it is worthwhile ensuring that the muscle AND the nerve are both tolerant of stretch.
But for everyone else, pulling the foot back is a harmful and unnecessary addition to a hamstrings stretch.