It seems like every hamstrings stretch position involves a straight knee, a flexed hip and pulling the foot back.
So why do we pull the foot back? Necessary for the stretch, harmless habit or harmful distraction?
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.
At the lower end, it attaches just below the knee with two muscles attaching on each side of the knee.
Its referred to as a biarticular muscle – “bi” meaning two and “articular” referring to joints. Its biarticular because it crosses two joints – the hip and the knee.
The 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 held straight while the hip is gradually flexed or bent forward.
And 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 the hamstrings, 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 hamstrings muscle in the back of the thigh to the calf muscle.
So what you’ve done is turned a hamstrings stretch into a Sciatic nerve stretch!
Helpful, harmless or hurting?
Overall it is not a good thing to pull the foot back.
It increases tension on the Sciatic nerve, taking pressure off the hamstrings muscles. That makes 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.