10 Joint Locks Everyone Should Know
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Figure-Four Extension·Straight Circle Martial Arts·Added by Admin
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Figure-Four Extension
Genusフィギュアフォー伸ばし(Figyua Fō Nobashi)
HybridTranslation: figure-four extension
Overview
The figure-four extension wrist lock uses a figure-four grip configuration to hyperextend the opponent's wrist — bending it backward beyond its natural range of motion. [1],[2] The attacker grips the opponent's hand with one hand and reinforces with a figure-four by gripping their own wrist, then presses the back of the opponent's hand toward the forearm. [1] The figure-four provides mechanical advantage that makes the lock extremely difficult to resist with wrist strength alone. [1] This is commonly applied when the opponent grips a collar or sleeve in gi grappling. [1],[2]
History & Origin
Figure-four wrist locks appear in Japanese jujutsu (kote-gaeshi and related techniques) and aikido as fundamental joint manipulation methods. [1],[2] In BJJ, wrist locks were historically underutilized but have gained prominence as practitioners like Jamil Hill-Taylor and Claudio Calasans demonstrated their effectiveness in high-level competition. [1]
Effectiveness
The figure-four extension combines the figure-four grip with elbow hyperextension for a powerful armlock. [1]
Lineage
Figure-four extension locks are part of the judo and BJJ armlock curriculum. [1]
Competition Record
Figure-four armlocks are used in competition across all grappling formats. [1]
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Biomechanical Mechanism
Primary Action — Hyperextension of the elbow joint — the hips drive upward against the posterior humerus while controlling the wrist
Joints Involved — Elbow (extension beyond normal ROM), wrist (stabilized), shoulder (isolated and controlled)
Force Vector — Posterior-to-anterior force on the upper arm with fixed distal anchor at the wrist creates a lever arm across the elbow
Leverage Principle — Hips act as the fulcrum — the longer the lever (full arm extension), the less force needed to hyperextend
Position & Entry
From any grip exchange — During grip fighting, isolate the opponent's wrist with two-on-one control and apply sudden flexion or rotation
From guard (gi) — When opponent posts a hand on the mat or chest, trap the wrist and apply downward pressure for the wrist lock
From mount or side control — Opponent posts to escape, trap the wrist against the mat and apply the lock
Variants
Standard wrist lock (kote gaeshi) — two-handed rotational lock on the wrist
Gooseneck wrist lock — flexion lock bending the wrist down toward the forearm
Standing wrist lock — applied during grip fighting or a standing exchange
Ground wrist lock — catching the opponent's posted hand from mount, side control, or guard
Videos
1 video
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Ratings
Risk of injury to the person this technique is applied to
5
High5/10
Wrist lock variant targeting carpal and radioulnar joints through forced deviation or torsion
Skill level needed to execute this technique reliably
Advanced
Whether this technique is allowed under major competition rule sets
Illegal
— kansetsu-waza
IJF Sport and Organisation Rules 2025, Article 27PDFLegal
— IBJJF — Legal at all belt levels
IBJJF Rules Book v6.0, June 2024PDF— ADCC — Legal — all submissions legal in ADCC
ADCC Rules Update, April 2025PDF— Unified MMA — Legal submission technique
Unified Rules of MMA, August 2025PDF— FIAS Sport Sambo — Legal
FIAS International Sambo Competition RulesPDF— FIAS Combat Sambo — Legal
FIAS Combat Sambo RulesPDFTraining Notes
✓The figure-four wrist extension uses a figure-four grip to amplify the extension force — one hand controls the wrist while the other threads behind the hand and grabs the first wrist (Danaher, New Wave Jiu Jitsu, 2020)
✓The figure-four grip creates a closed loop: the attacker's arms encircle the opponent's hand, providing inescapable control and multiplied leverage
✓This lock is commonly applied from mount: when the opponent posts a hand on the attacker's hip to bench press, the figure-four wraps around the hand and extends the wrist
✓The figure-four makes the extension lock much harder to defend: both of the attacker's arms work against one wrist — overwhelming any resistance
✓The lock finishes by driving the attacker's forearm against the back of the opponent's hand while pulling the wrist toward the attacker — a two-directional force
✓The figure-four wrist extension appears in aikido (nikkyo) and traditional jujutsu — these arts developed the technique for standing control and takedowns
✓The figure-four wrist lock is often a surprise: opponents focused on defending chokes and armbars forget about the wrist, creating a sudden submission opportunity
Common Mistakes
!Not threading the arm deeply enough — the figure-four must fully encircle the hand; a shallow grip allows the opponent to pull free
!Applying the extension without controlling the forearm — the forearm must be pinned (to your body, to the mat) for the figure-four to generate force
!Using only arm strength — drive body weight through the figure-four; muscling it is less effective and more tiring
!Not recognising the setup — the figure-four wrist lock is available whenever the opponent posts or pushes with a flat hand
!Releasing the grip when the opponent resists — maintain the figure-four; even if the lock doesn't finish, the grip can transition to other attacks
!Applying at full speed — the figure-four amplifies force dramatically; apply very slowly in training
!Not training figure-four wrist locks from multiple positions — this lock works from mount, guard, side control, and standing; train all entries
Related Techniques
Counter Techniques
Setup Chain
1Establish Position — achieve the controlling position needed for this submission
2Create the Threat — begin the submission setup to force a defensive reaction
3Secure the Hold — lock the submission grip with proper body mechanics
4Finish — apply increasing pressure until the opponent taps or the joint/choke takes effect
Sources & References
Primary Source
Japanese BJJ — shi-no-ji (四の字, figure-four) standard modifier
1BookJapanese BJJ — shi-no-ji (四の字, figure-four) standard modifier
Japanese terminology sourced from Japanese BJJ — shi-no-ji (四の字, figure-four) standard modifier
2OtherJapanese Martial Arts Hybrid Terminology
Mixed Japanese-Western terminology — combines traditional Japanese terms with katakana loanwords
3CitationJapanese BJJ — shi-no-ji (四の字, figure-four) standard modifier
Japanese terminology sourced from Japanese BJJ — shi-no-ji (四の字, figure-four) standard modifier
Community
Athletics
Requires
fine motor control, grip sensitivity, quick hand transitions
Favours
dexterous hands with strong fingers
Key muscles
forearm flexors and extensors, intrinsic hand muscles
Frequently Asked Questions
What are the two control points I need to focus on when applying a figure-four extension?
You need two points of control: one point pulling inward and one point pushing downward. Straight Circle Martial Arts emphasizes that maintaining these two distinct pressure points is essential to making the lock work effectively.
Why is it important to make my opponent bend their arm before applying this lock?
If you don't get your opponent to bend first, they can lock you out by straightening their arm. Straight Circle Martial Arts stresses that ensuring the arm is bent is critical before you slip into the lock position.
What should I do if there's slack in my grip during the figure-four extension?
If you leave slack, your opponent can bend or escape the lock. Straight Circle Martial Arts recommends pulling the control point in tightly and keeping tension throughout to prevent escape.
How should I position my arms to maximize the effectiveness of this technique?
You want to grab like holding a motorcycle—with a curved grip—and create a triangle shape pointing downward into your opponent as you drive them to the floor. The key is maintaining the proper curve in your hands and support structure throughout the movement.
How does the Figure-Four Extension work?
The figure-four extension wrist lock uses a figure-four grip configuration to hyperextend the opponent's wrist — bending it backward beyond its natural range of motion. The attacker grips the opponent's hand with one hand and reinforces with a figure-four by gripping their own wrist, then presses the back of the opponent's hand toward the forearm.
Where does the Figure-Four Extension come from?
Figure-four wrist locks appear in Japanese jujutsu (kote-gaeshi and related techniques) and aikido as fundamental joint manipulation methods. In BJJ, wrist locks were historically underutilized but have gained prominence as practitioners like Jamil Hill-Taylor and Claudio Calasans demonstrated their effectiveness in high-level competition.
Is the Figure-Four Extension legal in competition?
IBJJF: legal — Legal at all belt levels; IJF: banned — Only elbow joint locks (kansetsu-waza) permitted in judo — all other joint lo…; ADCC: legal — Legal — all submissions legal in ADCC; Unified MMA: legal — Legal submission technique; FIAS Sport Sambo: legal — Legal; FIAS Combat Sambo: legal — Legal
How dangerous is the Figure-Four Extension?
Danger rating 5/10. Wrist lock variant targeting carpal and radioulnar joints through forced deviation or torsion
How do I set up the Figure-Four Extension?
The standard setup chain: Establish Position → Create the Threat → Secure the Hold → Finish.
How do I defend against the Figure-Four Extension?
Standard counters include: Early Recognition — identify the submission attempt early and begin defence immediately / Posture and Base — maintain strong posture and base to prevent submission setups / Grip Fight — deny the attacker their preferred gripping configuration.
What are the variants of the Figure-Four Extension?
Common variants: Standard wrist lock (kote gaeshi) (two-handed rotational lock on the wrist); Gooseneck wrist lock (flexion lock bending the wrist down toward the forearm); Standing wrist lock (applied during grip fighting or a standing exchange); Ground wrist lock (catching the opponent's posted hand from mount, side cont…).
How effective is the Figure-Four Extension in competition?
Figure-four armlocks are used in competition across all grappling formats.
What are common mistakes when doing the Figure-Four Extension?
Top errors to watch for: Not threading the arm deeply enough — the figure-four must fully encircle the hand; a shallow grip allows the opponen… / Applying the extension without controlling the forearm — the forearm must be pinned (to your body, to the mat) for th… / Using only arm strength — drive body weight through the figure-four; muscling it is less effective and more tiring / Not recognising the setup — the figure-four wrist lock is available whenever the opponent posts or pushes with a flat….
What are other names for the Figure-Four Extension?
The Figure-Four Extension is also known as Figyua Fō Nobashi, Figure-4 Wrist Extension, Kote-gaeshi variant.