Halasana (Plough Pose)

Halasana is the plough pose, named for hala, the plough, because the shape of the body with the legs reaching over the head resembles the curved blade of an Indian plough. It usually follows Sarvangasana in a traditional sequence, and it takes everything that pose asks of the neck and asks for more.

Here is the plain fact about it. Of all the postures in common practice, this one puts the cervical spine into the most extreme forward bend, and it does so under the weight of the whole body. In the usual photograph the toes are on the floor behind the head and the practitioner looks serene. In an ordinary adult body with ordinary hamstrings, forcing the toes to the floor means the spine rounds hard and the load lands squarely on the neck.

Which is why my instruction is simple and unfashionable: put a chair behind your head and rest your feet on it. Not as a modification for beginners. As the normal way to do the pose. The stretch through the back is complete, the neck angle is reasonable, and it can be held long enough to become restful, which is where the real value of the posture lies.

Tuck your chin to your chest as far as it will go. That is roughly the position your neck is in for this pose. Now add your body weight above it.

Seven small vertebrae, built to carry a head of four or five kilograms and to move freely in every direction, are being asked to hold the extreme of their flexion range under load. The published systematic review of yoga adverse events attributes neck injuries specifically to this family of inverted postures.

What protects the neck:

• The blanket stack. Shoulders on, head off, six to eight centimetres. Non negotiable.
• The chair under the feet. It stops the pelvis dropping and the spine rounding, which is what drives the load into the neck.
• The hands on the back, high up the ribs, actively lifting.
• A still head. Never turn it while inverted. Not once, not for a second.
• A short hold. Thirty seconds to a minute unsupported. Two or three minutes only with the feet on a chair.

If you have any neck history at all, and cervical spondylosis is very common in adults who work at desks, this pose is not for you. Do the supine forward fold or legs up the wall instead and lose nothing that matters.

This is the pose with the clearest measured evidence about eye pressure, and it is worth knowing because it is rarely mentioned in class.

A study of intraocular pressure during four common yoga positions, in subjects with and without glaucoma, measured pressure in Halasana rising from around 18 mmHg to 22 or 23 mmHg within one minute, a rise of roughly a third. The pressure returned to baseline within two minutes of sitting up. The rise occurred in both groups, glaucoma or not.

For a healthy eye a transient rise of that size is unremarkable. For an eye with glaucoma, where damage accumulates from pressure over time, repeatedly raising it by a third is worth a conversation with your ophthalmologist before you continue. It is not a reason to panic and it is not a reason to shrug either.

Two practical points follow. First, if you are over forty and have never had your eye pressure measured, have it measured, since raised pressure is common and silent. Second, if you have glaucoma or a family history of it, ask your eye doctor specifically about inverted postures rather than about yoga in general, because the answer is about the position, not the practice.

Halasana and Sarvangasana are known in India as the thyroid poses, on the reasoning that the chin pressed into the chest compresses and then flushes the gland. The claim deserves a careful answer.

What the evidence shows: yoga programmes that included these poses have been studied in hypothyroidism, and a 2024 systematic review reported reductions in TSH and in levothyroxine dose across six months of practice.

What the same review says, and what usually gets left out: it included three randomised trials, judged them at moderate risk of bias, found them too heterogeneous to combine into a meta analysis, and stated that the mechanism is unclear. No study isolated these poses from the rest of the programme, so there is no evidence that the plough itself acts on the thyroid gland.

Do not change your thyroid medication because of a yoga practice. Keep taking what you are prescribed, keep your blood tests, and if a practice seems to be helping, tell your doctor and let them decide about the dose. The fuller picture is on the yoga for thyroid page.

Set a chair behind your head with a folded blanket on the seat. Set up your blanket stack, roll up with bent knees, and rest the fronts of the shins or the tops of the feet on the chair. Support the back with the hands, or let the arms rest on the floor once you are settled and stable.

Now stay for two or three minutes and do nothing. Let the breath be ordinary. The back of the body lengthens by itself, the shoulders release, and the mind slows down in a way it does not in the strenuous version because you are not holding anything up.

This is the form I have taught for many years, and it is the one I would offer if I could only teach one version. It gives the lengthening, it gives the quiet, and it takes the neck out of the argument. Follow it with two minutes lying flat and then Savasana, and the effect on the room is unmistakable.

Anyone practising for sleep will find it works well as the last active pose in a bedtime sequence.

Thirty seconds to one minute in the unsupported version. Two to three minutes with the feet on a chair, once you are settled and the neck is silent.

Coming out matters as much as going in. Bring the hands to the floor, bend the knees, and roll the spine down one vertebra at a time, slowly. Then lie flat with the knees bent and the feet on the floor for a full minute before you sit up. Sitting up immediately from an inversion is how the dizzy moment happens.

The counter movement is a gentle chest opening: lie back over a folded blanket placed lengthways under the shoulder blades for a minute, letting the head rest back and the throat soften. After a minute of extreme neck flexion, the neck wants to go the other way a little before you finish. Then Savasana.

If you are practising both, the order is shoulder stand first, then plough, then the counter movement, then rest. Not the other way round.

Seven of the nine condition pages on this site advise against the plough. These numbers assume a healthy neck, a teacher, and feet that reach the floor without strain.

The feet on a chair version is not a lesser pose. It is the one I would rather see, and it is the only one I would give to a desk neck.

The plough puts the whole spine into flexion with body weight behind it and the neck at the bottom of the pile. Seven of the nine condition pages on this site advise against it, and the reasons do not overlap by accident.

• Yoga for neck and shoulder pain and yoga for beginners over 40 rule it out on the cervical spine.
• Yoga for back pain rules it out because loaded spinal flexion is the exact movement a sore lower back least wants.
• Yoga for high blood pressure and yoga for diabetes rule it out on pressure, in the head and behind the eyes respectively.
• Yoga for PCOS and yoga for weight loss leave it out because nothing it offers is unavailable elsewhere.

If you do practise it, Matsyasana follows it and is not optional, and the safer relative for most people is the bridge, Setu Bandhasana.