Women are capable of having three kinds of female orgasm that have been dubbed the volcano, the wave and the avalanche, a study has found.

Researchers working alongside sex toy company Lioness studied the pelvic floor muscle contractions from a group of around 50 female volunteers as they climaxed. They found that their muscles contracted in three distinct ways.

These results were published in the Journal of Sexual Medicine.

Female arousal involves increased blood flow to the genitals, especially the clitoris, and triggers muscle twitching and spasming in the lead up and climax of an orgasm. It differs from male orgasms in various ways, the largest being duration. As reported by Science Alert, female orgasms can last over 20 seconds, while male orgasms only last between three to 10 seconds.

The purpose of the male orgasm is fairly obvious: to produce semen and reproduce. Female orgasms, however, are thought to have no true evolutionary function, rather are a relic of an ancient adaptation to induce ovulation.

These results showing that there are three types of female orgasm provide a unique insight into the intricacies of female sexual function, especially when faced with the results of a 2020 study, also published in the Journal of Sexual Medicine, that found that 41 percent of a sample of U.S. women were at risk for female sexual dysfunction, with 21 percent dissatisfied with their overall sexual life.

Many women find it very hard to reach orgasm, with some studies finding that while men reach orgasm in around 90 percent of sexual activities, only around 50 percent of women do.

In the latest study, scientists measured muscle contractions using a Bluetooth vibrator called the Lioness, made by Lioness. The device, when inserted inside a woman’s vagina, measures the force of her pelvic floor contractions via two sensors at either side. According to the study, the Lioness also measures temperature, accelerometer, and gyroscope measurements at a sampling rate of 12 Hz. Via Bluetooth, this data is then uploaded to a secure internet server.

The 54 participants were instructed to stimulate themselves to orgasm and keep the device on for two minutes post-climax so that it could record all muscle contractions in their pelvic floors. They were also asked to perform control tests where they did not achieve orgasm.

The data from this research showed that women have either a wave orgasm, volcano orgasm, or avalanche orgasm, distinguished by the patterns of pelvic floor contractions. Overall, the study found that 11 women experienced the volcano orgasm, 17 experienced an avalanche orgasm, and 26 experienced the wave orgasm.

According to the paper, “wave” patterns show successive contractions of tension and release at orgasm, “avalanches” occur when the pelvic floor has higher tension that is released all at once during an orgasm, and “volcanoes” involve the pelvic floor staying at a steady lower tension before dramatically increasing at climax.

One key finding was that each woman consistently only experienced one of the three types, with very little crossover. Someone who has one type of orgasm isn’t likely to be able to experience either of the other types, although it hasn’t been established whether or not this is impossible or just less common. Lioness noticed this pattern in 2017, which has just now been backed up by the study.

Lioness said in 2017 that the data they have collected from over 3,000 anonymous users supports the findings of this study. However, the sample size of the study, a mere 54 participants, is very small, and a much larger cohort is required to solidly prove these findings.

“The Lioness allows researchers a new opportunity to examine orgasm patterns in women within more ecologically valid environments that are conducive to sexual responding (e.g., one’s home),” the team concluded in the study. “The device has good test-retest reliability and should be able to detect differences in orgasm patterns in response to treatments for sexual arousal, desire, and orgasm disorders.”