Atlas/SPINE LOCKS/Boston Crab
Spine locks·Lumbar spine and knees · Gi & no-gi

Boston Crab.

Spine lock via leg control hyperextending lumbar region

// BOSTON CRAB
6
DANGER / 10
Risk level
Low
lumbar spine and knees
Tap urgency
Gradual
tap response
Difficulty
2
/ 5 — setup
Danger level
6
/ 10
Positions
2
entry points
Perm. damage
Yes
irreversible risk
//01—About this submission

What it is

Spine lock via leg control hyperextending lumbar region

What you do

The step-by-step execution breakdown lives in the app — mechanics, tips, and the full entry sequence.

Open1submission detailin the App Store↗
//02—Stats breakdown
Setup complexity
2/10
Learning priority
3/10
Escapability
6/10
Versatility
2/10
Danger level
6/10
//03—Safety notes
01

Tap immediately when feeling lower back or knee pressure.

02

Never attempt to roll or twist while caught—severe spinal injury risk.

03

Back flexibility varies dramatically between individuals; assess before drilling.

04

Avoid completely if you have herniated discs or spinal history.

05

Use minimal pressure in training; focus on positioning only.

//04—IBJJF belt legality
WHITE — LEGALBLUE — LEGALPURPLE — LEGALBROWN — LEGALBLACK — LEGAL
//05—Entries by position

2 ways in.

All2entriesin the App Store↗
CONTROLLING50
Reverse Mount
Facing their legs, heavy pressure - attack legs, take back
12 ↗ transitionsControlling
CONTROLLING20
Turtle
Control hips, get seatbelt, insert hooks, take the back
20 ↗ transitionsControlling
// Boston Crab · Spine locks

Drill it.
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