January 07 Technique - Compression Locks
0
Arm Compression·sambosteve
Train sambo at http://nycombatsambo.com
Arm Compression
Family腕圧迫(Ude Appaku)
TraditionalTranslation: arm compression
Overview
Arm compression techniques (biceps slicers and forearm crushes) work by trapping the opponent's arm over a fulcrum — typically the attacker's wrist, forearm, or shin — and forcing the arm to fold, crushing the biceps or forearm muscle against the underlying bone. [1],[2] The biceps slicer is the most common arm compression, applied by placing a forearm or shin in the crook of the opponent's elbow and pulling the wrist to close the angle, compressing the biceps against the radius and ulna. Arm compressions can also indirectly hyperextend the elbow, making them effective combination threats with armbars. [3] In IBJJF competition, arm compressions (biceps slicers) are only legal at brown and black belt levels; in ADCC and MMA, they are unrestricted.
History & Origin
Arm compression techniques appear in multiple grappling traditions. In sambo, the biceps crush has been a recognized competition technique since the sport's early development, consistent with sambo's emphasis on practical finishing techniques. [1] In Brazilian Jiu-Jitsu, the biceps slicer gained prominence as a complementary attack to the armbar — when a defender straightens the arm to resist the armbar, the slicer becomes available. [2],[3] Modern no-gi grapplers use arm compressions as part of integrated armlock systems.
Effectiveness
Arm compressions (bicep/calf slicers) crush the muscle against the bone, causing intense pain and potential muscle damage. [1]
Lineage
Compression locks were developed in catch wrestling and sambo, adopted into BJJ and MMA. [1]
Competition Record
Arm compressions are legal at brown/black belt in IBJJF and fully legal in ADCC and MMA. [1]
Images
No images yet for this technique.
Sign in to suggest an image.
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 guard — Control the wrist and posture, pivot hips perpendicular, throw leg over the head and extend hips to hyperextend the elbow
From mount — Isolate the arm, transition to S-mount or perpendicular, swing leg over and finish
From side control — Step over the head, isolate the near arm, fall back into the armbar position
Variants
Standard armbar — hips drive upward against the extended arm with legs clamping the shoulder
Belly-down armbar — rolling to face the mat to prevent the opponent from stacking
S-mount armbar — transitioned from S-mount position for tighter control before falling back
Spinning armbar — rapid pivot from guard or side to catch the arm during transition
Videos
1 video
Learn This Technique
No instructional courses yet for this technique.
Sign in to suggest a course.
Ratings
Risk of injury to the person this technique is applied to
6
High6/10
Bicep and forearm compression locks crush muscle against bone, causing intense pain
Skill level needed to execute this technique reliably
Advanced
Whether this technique is allowed under major competition rule sets
Illegal
— IJF — Only elbow joint locks permitted in judo — compress...
IJF Sport and Organisation Rules 2025, Article 27PDFRestricted
— IBJJF — Brown and black belt only
IBJJF Rules Book v6.0, June 2024PDFLegal
— ADCC — Legal
ADCC Rules Update, April 2025PDF— Unified MMA — Legal
Unified Rules of MMA, August 2025PDF— FIAS Sport Sambo — Legal
FIAS International Sambo Competition RulesPDF— FIAS Combat Sambo — Legal
FIAS Combat Sambo RulesPDFTraining Notes
✓Arm compression (bicep slicer/bicep crusher) compresses the bicep muscle against the forearm by hyper-folding the elbow over a fulcrum — causing intense pain and potential injury (Danaher, New Wave Jiu Jitsu, 2020)
✓The bicep slicer typically occurs when defending an armbar: if the defender bends the arm to prevent the extension, the attacker can insert a forearm or shin behind the elbow and fold the arm
✓The fulcrum placement is critical — the attacker's forearm or shin must be positioned directly behind the elbow joint for maximum compression
✓Arm compression is legal in IBJJF from brown belt, in ADCC at all levels, and in MMA — know the rule set before attempting
✓The arm compression can be combined with an armbar threat: the opponent must choose between extending the arm (risking the armbar) or bending it (accepting the slicer)
✓The compression damages the bicep muscle and can hyperextend the elbow simultaneously — it is a two-threat submission
✓Catch wrestlers call this the 'short arm scissors' — it has deep roots in catch wrestling tradition (Gotch, Conditioning and Catch-As-Catch-Can Wrestling, 1908)
Common Mistakes
!Applying without a secure fulcrum — the forearm or shin must be firmly positioned behind the elbow; a loose fulcrum slides out
!Not controlling the opponent's shoulder — if the opponent can rotate or pull the arm free, the compression releases
!Cranking rapidly — the arm compression causes sudden intense pain; apply gradually to give the partner time to tap
!Attempting without the armbar threat — the compression works best when the opponent is defending the armbar; without that context, they can simply extend and escape
!Placing the fulcrum too high or too low — the fulcrum must be directly behind the elbow joint, not on the upper arm or forearm
!Not using body weight — drape your weight over the folded arm to add compression; arm strength alone is insufficient
!Ignoring the knee threat — in some arm compression positions, you are also threatening a knee lock; be aware of all concurrent submissions
Related Techniques
Counter Techniques
Setup Chain
1Control the Arm — isolate and grip the target arm
2Position the Hips — align hips perpendicular to the arm for maximum leverage
3Pinch Knees — squeeze knees together to prevent arm extraction
4Extend for the Finish — bridge hips up while pulling the wrist down to hyperextend the elbow
Sources & References
Primary Source
Japanese grappling — bicep/forearm compression
1BookJapanese grappling — bicep/forearm compression
Japanese terminology sourced from Japanese grappling — bicep/forearm compression
Standard Japanese martial arts terminology (kanji/hiragana)
3OtherJapanese Martial Arts Standard Terminology (武道用語)
Established Japanese martial arts naming convention — native Japanese term (和語/漢語)
4CitationJapanese grappling — bicep/forearm compression
Japanese terminology sourced from Japanese grappling — bicep/forearm compression
Community
Athletics
Requires
hip flexibility, hip bridge power, leg clamping strength
Favours
long legs for controlling the opponent's torso
Key muscles
hip extensors (glutes), adductors, quadriceps, hamstrings
Notes
Arm compressions (bicep slicers/crushers) use the shin or forearm across the opponent's arm to compress the bicep against the bone. Banned in IBJJF below brown belt. Less common than joint locks but extremely painful and effective. (IBJJF Rules v6.0; BJJ competition records)
Frequently Asked Questions
Why should I lock the compression on my bicep instead of my forearm?
According to sambosteve, locking on your bicep is more effective because your wrist is pointed upwards, creating better pressure, whereas locking on your forearm leaves your wrist flat and doesn't generate as much pain.
How do I set up an arm compression when my opponent is defending?
sambosteve recommends using a 'swimming motion' to slide your opponent's hand to your armpit while they're pushing up—make them think you're targeting their wrist, then let their own resistance help you secure the lock on your bicep.
What's the finishing technique for an arm compression lock?
Once you have the lock secured on your bicep, set up a slingshot motion by sliding back, then push their wrist down to complete the submission.
How does the Arm Compression work?
Arm compression techniques (biceps slicers and forearm crushes) work by trapping the opponent's arm over a fulcrum — typically the attacker's wrist, forearm, or shin — and forcing the arm to fold, crushing the biceps or forearm muscle against the underlying bone. The biceps slicer is the most common arm compression, applied by placing a forearm or shin in the crook of the opponent's elbow and pulling the wrist to close the angle, compressing the biceps against the radius and ulna.
Where does the Arm Compression come from?
Arm compression techniques appear in multiple grappling traditions. In sambo, the biceps crush has been a recognized competition technique since the sport's early development, consistent with sambo's emphasis on practical finishing techniques.
Is the Arm Compression legal in competition?
IBJJF: restricted — Brown and black belt only; IJF: banned — Only elbow joint locks permitted in judo — compression locks prohibited; ADCC: legal — Legal; Unified MMA: legal — Legal; FIAS Sport Sambo: legal — Legal; FIAS Combat Sambo: legal — Legal
How dangerous is the Arm Compression?
Danger rating 6/10. Bicep and forearm compression locks crush muscle against bone, causing intense pain
How do I set up the Arm Compression?
The standard setup chain: Control the Arm → Position the Hips → Pinch Knees → Extend for the Finish.
How do I defend against the Arm Compression?
Standard counters include: Clasp Hands — grip own wrist to prevent arm extension / Stack — drive forward to compress the attacker and relieve elbow pressure / Hitchhiker Escape — rotate the thumb toward the mat and roll to extract the arm.
What are the variants of the Arm Compression?
Common variants: Standard armbar (hips drive upward against the extended arm with legs clam…); Belly-down armbar (rolling to face the mat to prevent the opponent from stac…); S-mount armbar (transitioned from S-mount position for tighter control be…); Spinning armbar (rapid pivot from guard or side to catch the arm during tr…).
How effective is the Arm Compression in competition?
Arm compressions are legal at brown/black belt in IBJJF and fully legal in ADCC and MMA.
What are common mistakes when doing the Arm Compression?
Top errors to watch for: Applying without a secure fulcrum — the forearm or shin must be firmly positioned behind the elbow; a loose fulcrum s… / Not controlling the opponent's shoulder — if the opponent can rotate or pull the arm free, the compression releases / Cranking rapidly — the arm compression causes sudden intense pain; apply gradually to give the partner time to tap / Attempting without the armbar threat — the compression works best when the opponent is defending the armbar; without ….
What are other names for the Arm Compression?
The Arm Compression is also known as Ude Appaku, Biceps Slicer, Biceps Crush, Arm Muscle Crush.