ANATOMY OF AN EAR
The ear is the organ of hearing and balance. Understanding its anatomy can help better illustrate why it’s essential to equalise. The ear consists of three distinct spaces filled with either air or liquid: the external, middle and inner ear.
As divers descend in the column of water, environmental pressure on the body increases in a linear fashion across the body.
To prevent pressure-related injuries such as bleeding, 0edema (swelling) of soft tissues, leakage of fluid into the air space and membrane rupture, divers must actively enable air from the throat to enter through the eustachian tubes into the middle ear by using equalisation techniques.
Why You Must Equalise
HOW TO EQUALISE
There are several techniques divers can employ to effectively equalise their ears.
Requires no effort. Occurs during ascent
- VOLUNTARY TUBAL OPENING
Try yawning or jaw wiggling
- VALSALVA MANOEUVRE
Pinch your nostrils and gently blow through your nose
- TOYNBEE MANOEUVRE
Pinch your nostrils and swallow (good technique, if equalisation is needed during ascent)
- FRENZEL MANOEUVRE
Pinch your nostrils while contracting your throat muscles and make the sound of the letter “k”
- LOWRY TECHNIQUE
Pinch your nostrils and gently try to blow air out of your nose while swallowing (think Valsalva manoeuvre meets the Toynbee manoeuvre)
- EDMONDS TECHNIQUE
Push your jaw forward and employ the Valsalva manoeuvre or the Frenzel manoeuvre
For the rest of this article and other stories from this issue, see Scuba Diver No.113 Issue 3/2018