Futomomo

Safety

In a 2023 case series of rope-bondage injuries in Cureus, one person developed femoral-nerve symptoms that the authors link to a binding around the thigh, likely compressing the nerve where it passes under the inguinal ligament at the top of the thigh.
A ShibariClasses lesson on the tie has heard of anecdotal nerve injuries from futomomo suspensions, with symptoms that mostly point to numbness on a patch of the front of the thigh, and, citing a Place des Cordes flyer, treats the peroneal nerve as a further reason to keep the rope away from the knee end. Clinical studies of posture-related peroneal neuropathy place the compression most often at the fibular head, with foot drop as the usual sign.
The same lesson relays a reader's report of a mild tibial-nerve irritation at the back of the lower leg, between ankle and calf, that cleared within about two days. As the most sensible prevention it names good feedback, with the person tied staying alert to any unusual sensation on the floor or in the air.

Uses

Futomomo appears both on the floor and in the air. Shibari Study notes its use in floor work (newaza) as well as in suspension (tsuri). A ShibariClasses course on the tie, taught by the London educator Nina Russ, covers many forms, including versions suited to suspension, but shows a futomomo suspension only in a short demonstration. A folded leg tied this way often becomes one of the points a body is lifted from: Shibari Study’s entry on kata ashi zuri, single-leg suspension, mentions a full suspension in which the lifted leg is tied into futomomo. It also combines with other ties, for example as one of the ways a gyaku ebi is built.

Difficulty and risk

Sources place the tie at different points of a learning path. Autostraddle teaches a futomomo-style leg tie as one installment of an introductory series, while the ShibariClasses course states plainly that it is not a suspension tutorial and points advanced students to a separate suspension course for futomomo suspensions. Kinbaku World lists it as intermediate to reflect the suspended uses.

The rope sits on the thigh, the lower leg and close to the knee, and sources name three nerves there. The 2023 Cureus case series recorded one femoral-nerve injury attributed to a thigh binding. The ShibariClasses lesson on nerve issues reports anecdotal numbness on the front of the thigh after futomomo suspensions, points to the peroneal nerve near the knee, and passes on a report of tibial-nerve irritation lower down the leg. Its author believes floor versions are safe unless the rope is tied excessively tight, and expects the greatest risk in suspensions that load rope onto the front of the hip and thigh.