Uttanasana: To Bend the Knees or to Not Bend the Knees?

The image above shows three versions of Uttanasana: 1) with bent knees, 2) with a microbend in knee and 3) with straight legs and a rounded back.
Which pose is the best? I know you want a clear answer……but I’m sorry …IT DEPENDS
But….. Nr. 3 isn’t what you are looking for. There is no more connection between the lower and the upper spine and the lower back get very round and a lot of tension. And many of us have already a lot of tension in our back.
You might still have a young age and your body can adjust a lot, and if you are only practice yoga once in a while its probably also not gonna hurt your body in a very bad way. But if you already have passed the 30, or you are a regular yoga bee, then you have to pay a bit more attention on the alignment of your poses.
Number 2 is not bad at all, but be careful when you practise a lot of yoga, or when you maybe still want to practise other sports as well. Like running, biking, boxing and other powerful sports. As with micro- bending knees its very difficult to tilt your pelvis forward. And only with the pelvis slightly forward you get the right connection in the lower spine.
Without feeling it directly there can be still a lot of weight on your lower spine in nr. 2. Also the hamstrings get a strong full pull. when you practise everyday yoga, be careful. Remember that most yoga injuries develop gradually over years of consistent over-stretching and misalignment. So I would say, only do this pose when you understand what you are doing and have no lower back issues.
When you bend your knees in Uttanasana, the hamstrings become a bit loose, which makes it easier to tilt the pelvis forward to create space in lower spine. Place your hands on blocks or knees to slowly get stronger in the muscles around the spine. Make sure you are using your bandha’s as well.
How can you safely practise Uttanasana and stretch your hamstrings?
The hamstrings are comprised of three muscles: the semimembranosus, semitendinosus, and biceps femoris. Each of these three muscles originate at the sit bones, travel along the back of your thigh, and insert below the knee on the shin bones.

Photo credit: The Daily Bandha
To stretch the hamstrings, it is important to:
- bend at the hips, not the lumbar spine (lower back)
- you should not feel tension in lower back, when stretching your hamstrings
- tilt the pelvis forward, ( for your feeling a more hollow lower back)
- engage the quadriceps (muscles on the front of your thighs)
- lengthen the muscle in two directions (shown by the arrows in the image to the right)
In class, you may hear some of the following cues in Uttanasana:
- Align your hips over your ankles by bringing more weight on to the front of your feet.
- Press the feet down into the floor and lift the knee caps to engage the quadriceps
- Open the back of the knees by reaching up towards your sit bones and down towards your heels
- Deepen the crease of your thighs and lengthen along the front of your torso
- Release your head and neck
- shoulders away from your ears
People with flexible hamstrings they are often the people who go a bit too far sometimes in this pose, as it feels good and easy, perfect! But again be careful when you practise every day. Pay attention that you are not just pulling and pulling and the ego starts running away with you. These low back and hamstring injury’s takes really long to heal.
And what if you have really tight hamstrings? When your hamstrings are tight, the tight muscles pull the sit bones down. This tilts the pelvis back and down, placing strain (and pain) on your low back. Even when you don’t feel it, you will after doing it several times over and over again…..Rather than bending your knees, work gradually to lengthen the hamstrings before going into the full pose. Here’s how:

Start on your back. Stretching your hamstrings on your back, keeps your back safe while you work to lengthen your hamstrings. relax the shoulders on the floor when possible. The angle of the leg and floor can differ by each person.
Place your hands on the wall. Working in Uttanasana with your hands on the wall keeps the back neutral while giving you space to tilt the pelvis forward while lengthening your hamstrings. See if you can feel the position where your lower back is free and relax.

Place your hands on the seat of a chair.Once you begin to increase the length of your hamstrings, start to work your hands closer to the floor to continue lengthening your hamstrings. Great to practise at home or even at the office.

Spread your feet wider apart. Having your feet wide gives your pelvis more room to tilt forward. Play with different distances of your legs.
Place your hands on blocks. Here we are moving deeper into the pose as the hamstrings become more flexible. Remember the yoga block is your best friend during yoga class 🙂

Use your breath and be patient.Lengthening a muscle takes time and patience! If you go too deep too fast, you may trigger your stretch reflex, which causes the hamstrings to contract rather than stretch.
Accepting your body, means that even when you have been practising for years, its still sometimes needed to back off and start from the raw beginning again. Take blocks, bent your knees and let your body decide again when its ready, not your mind.
Last note:
Knee Hyperextension – If you have a tendency to hyperextend your knees, it is helpful to practice Uttanasana with a small, microbend in the knees to prevent further stretch and tear on the ligaments in your knees. Work to find a lifting action in your knees to engage your quads.
Herniated Disc, Osteoporosis, Scoliosis – While it is safe to practice Uttanasana with a flat-back, neutral spine, deep forward folds are to be avoided with these conditions.
ALWAYS bend the knees when you are bending over to pick something up off the floor.
Uttanasana is a powerful pose that tones the legs, stimulates digestion, and relieves stress. Forwards folds bring our focus inward, which has a calming effect on the brain.
Enjoy, be safe and SMILE! 🙂
Mareille