A futumomo tie may look harmless, but like every technique used in shibari, it carries certain risks. We’ll review them in this lesson.
In the lesson where we analyzed this form from a biomechanical perspective, we already covered some of the main risks related to how it’s constructed.
Here, we’ll focus on the risks that arise from its actual use.
People often use this tie for suspensions, which is, frankly, quite reckless.
Even though the thigh—the central anatomical element in this tie—is made up of strong, resilient muscles, it’s not as versatile as it might seem.
In other words, it only functions properly when it has something to push against.
When we’re standing, that support and feedback come from the ground.
But once the body is lifted into suspension, that support disappears, and the body begins to seek it through kinetic chains formed between the muscles and the ropes.
Here’s the catch: when the hips are flexed, the thigh muscles can’t properly activate to push or support the body’s weight.
That’s why it’s common to see suspensions where a person hangs from a futumomo (sometimes one on each leg), completely vertical, with knees pointing upward and the head hanging toward the floor.
The Roast Chicken
Picture a roast chicken for a moment.
Now, try a little thought experiment we’ll call the “roast chicken theorem.”
We all know how easily its bones pull away from the body with just a light tug.
Now imagine replacing the person hanging by their futumomo ties with that roast chicken.
Exactly. That’s what’s happening.
All of the body’s weight is hanging from the ligaments that connect the femur to the hip, because the muscles can’t do their job in that position.
And obviously, those tissues were never meant to bear that kind of load.
Will it cause immediate injury?
Usually not. But it will cause tissue damage—damage that accumulates over time.
Reminder: the leading cause of death among adults over 65 in the West is hip fracture, often resulting from falls due to structural failure in the joint.
So, let’s avoid that kind of acrobatic setup unless we know exactly what we’re doing, understand proper technique, and—most importantly—are fully aware of the risks involved.
Is there a way to do that suspension safely?
Yes. By maintaining an angle that allows the person to push against the ropes with their muscles, redirecting the forces along a tangential vector instead of a vertical one.
However, that’s a calisthenic acrobatic technique that requires both training and good physical conditioning, and it’s beyond the scope of this course.