Learn Prasarita Padottanasana properly: choose your stance, keep your back long, use blocks and do not stay head-down long if eye pressure matters.
How far apart must your feet be for the wide-legged forward bend to work? The honest answer: far enough that your back stays long and the inner thighs pull, not tear. Prasarita Padottanasana ("wide-legged forward foot stretch") is a forward bend in a wide stance. The head sinks toward the floor, the back stays long and hamstrings and inner thighs are stretched.
The posture is considered a friendly entry to forward bends because standing, you support the legs and gravity guides you down without you having to sit on the floor. But it has pitfalls: if you set your feet too wide you overload inner thighs and knees; if you let the head hang too long you get a heavy head. Both can be avoided.
It is worth being realistic: in a meta-analysis of 47 studies, a single stretching bout improved flexibility slightly, clearly for sit-and-reach and hamstrings, but not for the hip adductor test (inner thigh) [2]. That is the muscle group you stretch in this posture. In the long term, mainly static stretching increases range of motion [3]. So it takes weeks, not one session.
Set the feet about one leg length apart, the outer edges of the feet parallel or the toes turned slightly in. Place your hands on your hips. Start narrower than you think.
Push your hip back and fold forward with a long back until the torso is horizontal. Place your hands on blocks or the floor directly under the shoulders. The knees are soft, the thighs active.
Milestone: You hold 30 seconds in the half fold with a long back.
If it is comfortable, let the head and torso sink lower. Breathe evenly. After 5 breaths at most, come up with your hands on your hips. With eye pressure problems, the head stays at chest height.
Put your hands on your hips, tighten the legs and come back with a long back. Wait briefly until your circulation is stable before moving on.
Milestone to move on: You hold 5 to 8 breaths with hands on blocks and a long back. Then you are ready for half moon.
Forward bends with the head below the heart raise intraocular pressure. In a study of 20 people (10 with glaucoma, 10 without), in the healthy group it rose from about 18 to about 26 mmHg in the standing forward fold (from 17 to 27 with glaucoma) and returned to baseline within two minutes after sitting up [1]. That was not the same pose, but the same head-down position (transfer). If you have glaucoma, clarify head-down postures with your eye doctor. The hamstrings are also a known problem area in yoga [5]. If you "breathe through" stretch pain, you only raise tolerance, not muscle length [4]. If you feel dizzy, rise at once. This guide explains and motivates; it does not replace supervised training.
Pull the feet inward without moving them. Stand on a mat with feet wide and press them as if you wanted to drag them toward each other. This is a practice trick: the inner thighs switch on, the stretch becomes more even and the pelvis stable. Whoever folds with active legs usually has more length in the back. Try it: fold once with slack legs and once with active legs and compare how long your back feels.
About one leg length is a practice value. More important is that your back stays long and the inner thighs pull without hurting. Start narrower and go wider if it feels good.
Five to eight breaths are enough for beginners. You can hold head-down for less time because eye pressure rises [1]. For flexibility, meta-analyses found no demonstrable difference from the length of a single session [2][3].
There are data on a similar posture (standing forward fold): eye pressure rose in healthy people as well as in people with glaucoma [1]. In this case, keep the head no lower than the chest and ask your eye doctor.
Prasarita Padottanasana is distinguished into four variations that mainly change the arm position (for example hands on the floor, hands on the hips or hands behind the back). As a beginner you stay with hands on the floor or on blocks and check the others later. This is a practice classification.
Because the adductors (inner thighs) are stretched in the straddle. They hardly react to a single stretching bout [2], so it gets better with regularity.
Half Moon (Ardha Chandrasana): A One-Legged Balance That Challenges Your Glutes