In the gancho one leg hooks around the partner's leg and releases again. Build it safely via the boleo, with space rules, typical mistakes and clear milestones.
The honest answer first: the gancho (Spanish for "hook") is a figure in Argentine tango in which one leg briefly hooks around the partner's leg and releases again. It means a soft, brief contact, not a hold and not a clamp. The gancho usually arises from the movement of the boleo: the swinging leg lands at the partner's leg and releases immediately.
That makes the gancho a building-block figure on the low boleo. Anyone who cannot let the leg swing calmly cannot hook it in a controlled way. At the same time it is one of the figures that demands a lot of agreement and feeling: heel and knee are the risk points, and a hook that is too hard hurts.
The basis is a stable trunk. In an ultrasound study with ten tango dancers and ten untrained women, the deep abdominal muscle (transversus abdominis) grew progressively thicker from open through close embrace up to the volcada, meaning it was activated more strongly [1]. A stable trunk keeps the hips calm while the leg works.
Realistic: a gancho that feels safe for both often takes weeks to months of regular practice (rule of thumb, not a study result). The details differ from school to school.
The gancho presupposes the low boleo. Milestone: four low boleos in a row where the leg falls softly back beside the standing leg each time.
Agree where the leg may go and how soft the contact should be. Without agreement there is no gancho. Two people with light contact couple their movement without noticing: in a study with 54 participants (folk dancers, so only a hint), even a fingertip touch aligned the sway of two partners [2]. That means even a brief, quiet contact affects the partner. Milestone: both can say where the leg lands.
Practise the hook in socks or flat shoes, slowly and with minimal contact. The leg touches the partner's leg from the side, hooks briefly and releases. No pressure, no holding. Milestone: the partner says the hook feels light.
After the hook the leg releases softly. The leader frees the way by realigning the torso. Milestone: the exit works without stumbling and without pulling back.
Increase tempo and height only under supervision. A teacher sees whether the heel lands wrong or the knee is twisted. Imitating it without supervision is risky. Milestone: the teacher confirms position and pressure.
The gancho is a figure with injury risk for both: heel, knee and ankle are affected. So practise it slowly, in flat or sturdy shoes, with clear agreement, and stop immediately if it hurts. In a survey of 218 Dutch competitive ballroom dancers (standard and Latin, so only a hint about dancing in general), about 81% reported at least one injury, most often in foot, ankle and lower leg [3]. Warm up knees, hips and ankles. You build up the gancho only with a teacher. On a crowded floor you leave it out. This guide explains and motivates; it does not replace supervised training.
Practise the gancho first on a chair leg: hook a leg softly around a chair leg and release it without the chair wobbling. You notice whether you touch or grab. After that comes the sacada.
The gancho is a figure in Argentine tango in which one leg briefly hooks around the partner's leg and releases again. It usually arises from the boleo and requires soft contact and clear agreement.
It can injure knee, ankle and the partner's leg if the contact is too hard or the heel lands wrong. With slow build-up, flat shoes, clear agreement and a teacher the risk is much smaller.
When you dance the low boleo in a controlled way and have a calm sense for contact. Then a teacher can show you the gancho. How long it takes is individual, often a few weeks to months (rule of thumb, not a study result).
On a crowded floor rather not: it needs space and agreement. Dance it only when the path is free and your partner agrees. Otherwise leave it out.
Usually because the boleo is not yet calm or agreement is missing. Go a step back: low boleo, soft contact, feedback after every repetition. If it hurts, stop and ask your teacher.
Sacada in Argentine Tango: Stepping Into the Partner's Space