Intermediate

PNF Hamstring 90/90 Stretch

The 90/90 position holds the hip at ninety degrees and lets you extend the knee against your own resistance, so you isolate the hamstring without loading the spine. This is a smart choice for anyone whose low back rounds during toe-touch stretches. Contract by curling the knee, relax, then straighten it further.

Equipment
Body Weight
Body part
Hamstring
Type
Stretching
Muscles worked
Target
Biceps Femoris, Semitendinosus

How to do it

  1. 1

    Lie on your back and bring one hip to ninety degrees, holding behind the thigh with both hands, knee bent.

  2. 2

    Slowly straighten the knee until you feel a firm stretch in the hamstring while keeping the thigh vertical.

  3. 3

    Contract: try to curl the heel back down toward the floor against the tension, holding the isometric at about 25 percent for six to ten seconds.

  4. 4

    Relax the leg fully for two to three seconds and exhale.

  5. 5

    Straighten the knee further into the new range while keeping the thigh at ninety degrees, and hold briefly.

  6. 6

    Repeat the cycle three to four times, then switch legs.

Tips

  • Keep the thigh locked at ninety degrees; letting it drift away from your chest toward the floor slackens the hamstring and shrinks the stretch.
  • Keep the opposite leg flat or lightly bent so the pelvis stays neutral.
  • Keep the head and shoulders relaxed on the floor throughout.

Variations

Common mistakes

  • Both hands behind the thigh means the arms tire before the hamstring is finished and the last cycle gets hurried; hook the fingers together, or loop a strap behind the thigh so the shoulders are not what stops you.
  • The knee is already locked straight at setup, which leaves the cycles nothing to gain; start a few degrees short of straight so each release has somewhere to go.
  • As the heel curls down, the whole thigh follows it toward the floor, the hip opens past ninety, and the stretch quietly disappears; the thigh stays put and only the knee moves.
  • The ankle is pointed hard, so the calf reaches its limit before the hamstring does and you cannot tell which one stopped you; keep the foot relaxed or lightly flexed.
  • The curl is done at full effort and the hamstring cramps mid-cycle, because a muscle asked to contract near full length needs very little persuading; a quarter of your strength is the idea.

Frequently asked

How many rounds of the PNF hamstring 90/90 stretch should you do when you are new to the exercise?
Three or four contract-relax cycles per leg, one set on each side, two or three times a week. Each cycle is a six-to-ten-second curl at about a quarter effort, a complete release for two or three seconds, then straightening the knee into the new range. Because the thigh stays vertical, progress is easy to see: measure how close the shin gets to vertical rather than how close the leg gets to your face. Stop the set once a cycle adds nothing.
How do I make the PNF hamstring 90/90 stretch easier or harder?
Easier: hold the thigh with a strap looped behind it so the shoulders can rest, bend the opposite knee with the foot flat, and keep the working thigh slightly closer than vertical. Harder: press the back of the thigh against a doorframe so the hip cannot drift, keep the opposite leg flat on the floor, and flex the foot as the knee straightens so the calf joins the last few degrees. Running the same cycle standing with the foot on a chair is harder again.
What is the PNF hamstring 90/90 stretch good for, and who should choose it?
Holding the hip at ninety degrees means the pelvis cannot tip and the low back stays flat on the floor, so the hamstring is isolated without the spine joining in, which is exactly what people whose backs round during toe-touch stretches need. It suits lifters and runners with stiff hamstrings and a grumpy low back. It is a poor choice on a recently strained hamstring, since the curl loads the muscle at length, and it is not the drill for the last minutes before heavy pulling.

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