Arguably the most damaging submission hold across all grappling styles is the heel hook. This technique works by isolating your opponent’s femur and rotating the tibia beyond its normal range of motion.
The knee (tibiofemoral joint) has 2 degrees of freedom: sagittal plane and transverse plane motion. This means that the knee is able to not only bend and straighten but there is rotation that occurs as well.
The tibiofemoral joint can allow for up to 40-50 degrees of total axial rotation with a 2:1 ratio of external rotation to internal rotation. The primary constraints to stop excessive axial rotation are the ligaments that connect the two bones.
The ligaments most commonly involve to prevent this motion include the anterior crucial ligament (ACL), medial collateral ligament (MCL) and the lateral collateral ligament (LCL).
There are 3 reasons that makes this technique so devastating:
- Ligaments do not have the same sensory receptors that muscles/tendons have so by the time tension is felt there is a very small window of opportunity to tap.
- The structures being attacked, ligaments, do not heal as easily as other tissues in the body. Often these ligaments require surgical intervention to repair, specifically the ACL. Rehabilitation of ACL reconstruction is very long, often taking 6 to 12 months, before someone is cleared to return to sport.
- Many grapplers are ignorant of the technique and do not respond properly when being attacked by this submission. Often the ignorant grappler will tap too late or attempt to escape by spinning without control which may accidently cause excessive tibial rotation resulting in injury.
As a martial artist I think it is foolish to not be educated on such an effective technique.
As a physical therapist I feel that with proper training methods and controlled training partners this submission can be trained effectively without damaging your training partners.
Dr. Mike Piekarski, DPT
BJJ Black Belt
Former MMA Fighter