How does the sit spin work? A one-foot rotation in a crouch with the thigh of the skating leg at least parallel to the ice: build-up, mistakes and safety.
The honest answer first: a sit spin is a one-foot rotation in which the thigh of the skating leg is at least parallel to the ice. That is how the ISU rules define the sit position: "the upper part of the skating leg at least parallel to the ice" [1]. This is the criterion the technical panel checks in competitions.
A position needs at least two uninterrupted revolutions to count; a rotation with fewer than three revolutions counts in the rules only as a skating movement, not as a spin [1]. For you as a recreational skater that means: count the revolutions and work towards at least three carried cleanly.
Honestly: the sit spin is not among the required elements of the adult curriculum levels 1 to 6, which we used as a reference for the basic school. It is a build-up element and requires a stable upright spin. The rulebook is the only source that defines the position; it contains nothing on how to learn it. The hints below are practical experience.
Practise the deep lowering first without ice: bend the skating leg until the thigh is horizontal, extend the other leg forward or to the side, back upright. This is the position from the rulebook [1]. Milestone: you hold the position for ten seconds without wobbling.
Spin a stable upright spin. When you are calm in the centre, bend the skating leg slowly a little. Not straight into the full crouch, but in stages. Milestone: you keep the rotation even with a half-bent skating leg.
Go down so far that the thigh is at least parallel to the ice [1]. The free foot extends forward or is crossed in front, the arms stay close to the body. The upper body may lean slightly forward, the hip stays above the skating foot.
Hold the position for at least two uninterrupted revolutions [1], better three. Count aloud. Afterwards get up by straightening the skating leg, not by jumping up.
Check your preferred direction first, then the other. Variants such as pancake or broken leg you learn only with a coach.
Think of an image: "I am sitting on an invisible stool". In a review of 12 studies with 566 participants, an external focus was on average more effective than an internal one for skill acquisition, although the studies were small and the result should be read with caution [4].
Your progress shows in depth and calm (rule of thumb, not a study): does the thigh reach the horizontal in the video? Does the centre stay in one place? Do you go from two to three revolutions in the position? If the depth is right in three out of five attempts, increase the revolutions. If knee or hip hurt, go back to less depth and more warming up.
This guide explains and motivates; it does not replace supervised training. The sit spin loads knee and hip strongly. A review names spine and lower extremity as the main injury regions in figure skaters and lists among possible influences the repetition of complex elements and extreme ranges of motion [2]. This applies to competitive skaters; for recreational skaters there are no reliable data. So increase repetitions slowly, warm up and stop if knee or hip pain occurs. In a video analysis of 216 ice-skating falls in children the head hit the ice in 13% [3]. So wear a helmet.
Practise the position at the boards while standing: hold on lightly to the boards, go into the sit position and hold it without rotating. That way you learn where parallel to the ice really is and train the strength in thighs and hip before rotation is added (practical experience).
A one-foot rotation in a deep crouch. According to the ISU rules the thigh of the skating leg must be at least parallel to the ice [1].
In the rules a position needs at least two uninterrupted revolutions, and a rotation with fewer than three revolutions counts only as a skating movement, not a spin [1]. For recreational skating this is a benchmark.
Only when the upright spin works securely. The sit spin is not among the required elements of the adult levels 1 to 6 (our own classification); a coach tells you when your skating leg is strong enough.
A review names the lower extremity as a frequent injury region in figure skaters [2]. For recreational skaters reliable figures are missing. Build up slowly and stop if it hurts.
The Camel Spin: Rotating Horizontally