The Sonic Curve is an obstacle, firstly introduced as the fifth obstacle in Stage One on American Ninja Warrior 7 (replacing the Half Pipe Attack from the past three American Ninja Warrior seasons), and appeared again on American Ninja Warrior 8, once again as the fifth obstacle in Stage One.
Competitors must run in a full speed along a series of six angled steps that are increasing in height, decreasing in width, and arranged in a semicircle, in order to make a jump to a rope. Once they are on the rope, they can swing it to the landing platform.
The concept of the Sonic Curve is similar to its predecessor (the Half Pipe Attack), with the rope and landing platform remain the same.
Parkour RunA variant of the Sonic Curve, known as the Parkour Run, appeared as the fifth obstacle in Stage One on American Ninja Warrior 9, replacing the Sonic Curve itself from the past two Amrican Ninja Warrior seasons. It is similar to the Sonic Curve, but it has a few key differences:
- The Parkour Run consists of five angled steps and a rope, with the last step being larger than the others.
- The first four steps are similar with the ones from Snake Run, except the shape is elliptical, rather than circular.
- The fourth step is positioned away from the other steps and is tilted in the other direction, making it similar to the Floating Steps and forcing to switch competitors' momentum.
- The rope is attached to a spinning wheel, like the Metal Spin.
A unique completion on Parkour Run occurred during JJ Woods' run. When he got to the fourth step, he was able to jump off the step to the landing platform, rather than using the traditional method of reaching the fifth step and grabbing the rope to the landing platform. Later, this technique was also done by Drew Drechsel.
This variant of the Sonic Curve was proven to be extremely easy, as no competitor failed on this obstacle.
On SASUKE Ninja Warrior Indonesia 2017, the Sonic Curve appeared as the fourth obstacle during Semifinal Stage 1.
However, unlike on American Ninja Warrior, the steps were made larger and less steeper, as well as the landing platform was made wider. Also, competitors were not allowed to touch the steps with their hands (if they did so, the would be disqualified). This version of the Sonic Curve was proven to be much easier than on American Ninja Warrior, as only 2 competitors failed on this obstacle.
During SASUKE Ninja Warrior Indonesia: Misi Operasi Midoriyama 2 and SASUKE Ninja Warrior Indonesia: International Competition, the number of steps was reduced from 6 to 4 by removing the last 2 steps, resulting the competitors must swing farther from the rope to the landing platform.
- During Meagan Martin's run in Stage One on American Ninja Warrior 7, when she got to Sonic Curve, Akbar Gbaja-Biamila commented, "Ride the Sonic Curve like Sonic the Hedgehog", referencing the SEGA video game character of the same name.
- This obstacle became an inspiration for the debut of the Snake Run on American Ninja Warrior 8, which is instead of an angled tile, competitors have to run along a series of angled disks that differ in angles and are arranged in a 'S' track.