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Butterfly Block Stretch

The butterfly block stretch is the supported version of the classic groin opener: sitting with soles together while blocks (or cushions) prop up the outer thighs. The support lets tight hips relax into the stretch instead of guarding against it — the difference between a stretch that works and one that just aches. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.

Muscles worked

Inner thighs · adductor longus Inner thighs · gracilis Inner thighs · adductor magnus

Sets & reps by goal

Goal	Sets × Reps	Rest
Strength	2 × 5 slow knee lifts against the support	30 s
Muscle	3 × 30 s supported hold	30 s
Endurance	2 × 60–90 s supported hold	30–45 s

Level — Beginner

The most accessible groin stretch there is — the props are the point, not a crutch.

Proper form — 5 cues

Sit tall with the soles of your feet pressed together, knees fallen wide.
Slide a block or firm cushion under each outer thigh so the legs rest supported.
Hold your ankles — not your toes — and sit up out of your hips.
Let the weight of the legs sink into the blocks with zero pushing.
Stay for slow breaths, letting the knees settle lower only as the support allows.

Breathing: Long, slow exhales; imagine the knees dropping one millimetre with each breath out.

The 3 mistakes Maddy corrects most

Choosing blocks that are too low. If the thighs hang unsupported above them, the hips guard exactly as they would without props. Fix: Stack height until the legs genuinely rest — you can lower the support next month.

Pressing the knees down with the hands or elbows. Force triggers the protective reflex in the adductors, tightening what you are trying to release. Fix: Hands stay on the ankles; gravity plus time does everything here.

Slumping into a rounded back. The collapsed posture moves the stretch away from the groin and into the lumbar spine. Fix: Sit on a folded towel to tilt the pelvis forward and keep the spine long.

Common questions

Why use blocks in the butterfly stretch at all?

Because unsupported tight hips do not relax — the adductors contract slightly to protect the joint, and you spend the whole stretch fighting your own guarding. Blocks give the legs somewhere to rest, the nervous system reads the position as safe, and the muscles actually lengthen. Less strain, better outcome — that is the entire trick.

How long until my knees reach the floor?

Timelines vary hugely with anatomy — hip socket shape sets a hard limit that no stretching changes — so the floor is not the goal; comfortable, useful range is. With a few supported minutes most days, people typically notice easier sitting and deeper squats within several weeks. Measure progress by how the position feels, not by knee altitude.

Is this stretch okay during pregnancy?

The supported butterfly is commonly recommended in prenatal movement classes precisely because the props reduce strain — but pregnancy also loosens ligaments, making over-stretching easier to do without noticing. Keep the intensity gentle, avoid pushing range, and clear your stretching routine with your midwife or doctor first.

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