Frenzel equalisation technique for freediving. The ultimate guide

The frenzel manouever is named after a German doctor Hermann Frenzel and was developed in 1938 to be thought to dive bomber pilots during the World War 2. The manoeuvre is used to equalise the middle ear and today is performed by both SCUBA and freedivers.

Check out our own video on how to Frenzel

Why do we need to equalise?

Boyles law states that ‘At a fixed temperature, the volume of a gas is inversely proportional to the pressure exerted on that gas’. Our body tissue is made of water which is non compressible. However, gases are compressible so diving deep has an effect on the airspaces in our body. As we descend, the volume of the air inside our middle ear decreases and we feel an introflection (bending inwards) of the ear drum, leading us to perform an equalisation. We are compensating for a reduction in volume in the middle ear caused by an increase in pressure.

Frenzel vs valsalva technique

There are two main techniques we learn during a beginners course and these are the Frenzel and Valsalva method. The valsalva should be disregarded completely. This technique will stop working eventually and is exhausting to use which goes against the whole point when it comes to relaxation. The valsalva uses the diaphragm and intercostal muscles to push air into our middle ear which only means you are working against pressure. The distance from the lungs to the middle ear is far greater than the distance between the glottis and middle ear. Finally, these muscles are bigger than the subtle muscles we need to use for the Frenzel technique.

The diagram above shows all the airspaces (apart from the lungs) as well as the doors, that need to be moved to create pressure and shift air into the middle ear. If you want to know more about these airspaces and doors, we go into detail over here.

Anatomy used during Frenzel Equalisation

The glottis

The glottis plays another important role and connects the oral cavity to the lungs. It is located near the vocal cord and isolates the digestive track from the airways. It is involved in both frenzel manoeuvre as well as transfer of air from lungs to cavities. The glottis is a Dynamic door.

The tongue

The tongue is the muscle which we use to create a lock and pressurise the oral and nasal cavity to send air into the middle ear.

Soft Palate

The soft palate connects the oral and nasal cavities & plays one of the most important roles for equalising. It consists of two positions; closed and open (relaxed / neutral position). In order for us to equalise the ear, the palate must be in the open position. This allows the air inside the oral and nasal cavity to be pressurised. Once there is pressure and the soft palate is in the open position, air is forced into the eustachian tubes and has access to the middle ear and ear drum. Because we have total control of the soft pallet, it is considered a dynamic door.

Eustachian tube

Your eustachian tube is a canal which connects your middle ear cavity to the upper part of your throat and back of your nasal cavity. This is known as the nasopharynx. The pressure within your middle ear is managed by your eustachian tube to ensure it is equal to the pressure outside your body. They are normally closed and only open with certain movements.

Middle ear

Your middle ear is part of the ear between your eardrum and the oval window to your inner ear. During a dive, the volume of air inside your middle ear decreases and puts pressure on your ear drums, casing them to bend inwards. The ear drums are extremely sensitive to changes and this is why it’s important to equalise before you feel any pressure or especially, pain. If you eustachian tubes remain closed or are not opened enough during equalisation, you may experience pain or discomfort. If you continue to descend, you may rupture your ear drums.

How is the frenzel technique performed?

To perform the frenzel:

  • The glottis (or vocal folds) should be closed,
  • Create a lock with the tongue; T lock or K lock
  • Pinch the nose with your fingers
  • The tongue should move back and up.

This changes the volume inside the oral cavity and creates pressure. In most cases, the soft pallet is in the neutral or open position. This is the most efficient and relaxed way to equalise, utilising the smallest group of muscles.

Common problems when learning Frenzel

There are a few problems that set people back from learn how to frenzel. Those who cannot frenzel are using an inefficient technique called valsalva. At no point do we want to be doing this whilst freediving. Let’s go through them

  • Unable to close the gottis – You cannot actually feel the glottis being closed so you would need to send your awareness to what you are doing. If you are able to create pressure but the stomach or chest is moving then then glottis is open.
  • Not enough air in the oral cavity – more often than not, the tongue is in the incorrect position. This causes a very small airspace inside the oral cavity which makes it harder to compress. The more air we have inside the oral cavity the easier it will be to equalise.
  • Over thinking – There are so many videos online which over complicate matters. ‘Close the glottis, create the lock, keep soft pallet in neutral position’ etc etc…. The truth is there are easier ways of doing things. We already know the movement through speech and daily interactions.
  • Unable to move the tongue properly – We are all made differently which means sometimes it’s a little difficult to perform certain actions. Things take time to learn so make sure you engage in someone who can assist you and set you on the right path.

Dry equalisation skills

Whatever level you’re at, do not expect to learn how to equalise in the water. Dry practice for the Frenzel technique is essential to increase both awareness and motor control of the muscles involved. Practicing them on dry removes the stress of breath-holding under water which will help you learn the fastest way possible.

We can learn these skills using different types of EQ tools and each tool has its own purpose. Think of learning equalisation from the lowest type of stress possible, adding difficulty as you go along. This is exactly how you should use these tools.

Common problems in the water

It is without a doubt that as soon as you learn how to frenzel on land, problems happen in the water. Let’s go through them.

Inability to shift air – As a freediver descends, the air spaces get smaller and one of those spaces is the oral cavity! Remember when we mentioned above that the smaller amount of air you have inside the oral cavity, the harder it is to equalise? As we dive, we must remember to drop the tongue to shift air from the lungs to the oral cavity!
Cannot equalise upside down – There are a few reason for this to happen. Firstly, if we are not relaxed enough this can create tension in the throat causing the soft pallet to close.Being upside down can sometimes disorientate us in a way that we lose focus . Secondly, because air travel from a high pressure to a low pressure, there is a downward force acting on the glottis.
Inability to relax – Make sure to take things easy. Do not rush any part of the process and make sure you are totally relaxed before you dive. Physically and mentally. Tension can lead to all sorts of problems.
Body position – This can effect a few things. For some people, if our head is tucked in too much, this can cause the tongue to take up lots of space in the oral cavity. It is actually ok to tilt your head slightly if you’re having this problem but not too much otherwise you’ll come into other problems. Which we will talk about now. As we descend, our lungs begin to compress and so does the ribcage. We have to help them compress by being relaxed and in a tucked in position. If we try to pull the rib cage apart by opening up, air will be harder to shift and so will equalising.

Learn how to Frenzel online

Over here at Deep Med, your instructor Fabrice is an instructor under the Share equalisation method founded by Federico Mana. Federico is the pioneer of this method and has fine tuned it over the span of 10 years, helping thousands of freedivers Frenzel and Mouhtfill. All of this is completely online!

All you would need is an EQ tool, balloon, ring light and a mirror for self practice at home. More on tools here.