Variable SIDE_KICK_ANIMATIONConst

Side Kick - 옆차기 (Yeop Chagi)

Powerful lateral thrusting kick - the "push kick" of Taekwondo. Heel (뒤꿈치 - Dwikkumchi) drives through target in straight line like piston.

Korean Martial Arts Biomechanics (한국 무술 생체역학):

Stance & Weight Distribution (자세와 체중 분배):

• Start: 겨루기 자세 (Fighting stance), 60/40
• Chamber: 100% weight on supporting leg, body turns SIDEWAYS
• Extension: 100% weight, body perpendicular to target
• Key: Body turns 90° from target for maximum hip drive

Chamber Phase - 준비 (Junbi) [120ms]:

• Body rotation: Turns SIDEWAYS 90° - shoulder faces target
• Kicking leg: Knee lifts to torso height, pulls ACROSS body
• Hip: Deeply COILED - kicking leg knee points toward ground initially
• Knee: Bent ~45° (0.79 rad), shin vertical but TILTED inward
• Ankle: DORSIFLEXED (발목 굽히기) - heel ready, toes pulled back
• Foot position: Blade of foot (발날 - Balnal) or heel (뒤꿈치) ready
• Supporting leg: Nearly straight 170° (0.18 rad) for stability
• Hips: Turned 90° - SIDEWAYS to target (critical for power!)
• Torso: Side-facing, shoulder points at target
• Arms: 상단막기 (High guard) - exposed side, must protect
• Head: Looks over LEAD shoulder at target
• Breathing: Deep inhale (들이마시기)
• Balance: Weight centered over supporting leg

Extension/Thrust Phase - 차기 (Chagi) [200ms]:

• Hip: Drives FORWARD and SIDEWAYS - powerful piston motion
• Knee: Extends from 45° → 170° (0.18 rad) - nearly straight
• Leg trajectory: STRAIGHT LINEAR PATH - like spear thrust
• Striking surface: 뒤꿈치 (heel) or 발날 (blade of foot)
• Ankle: Maintains dorsiflexion - rigid heel platform
• Hip thrust: Drives hip FORWARD ~15-20cm for penetration
• Supporting leg: Stays stable, may lift heel slightly
• Body: Leans AWAY ~15-20° to counterbalance (like capital "T")
• Torso: Remains perpendicular - no forward rotation
• Head: Continues looking over shoulder at target
• Arms: High guard protects exposed face
• Power: Linear thrust, not rotational - PUSHING power

Peak Impact - 정점 (Jeongjeom) [80ms]:

• Maximum extension: Leg nearly straight 170° (0.18 rad)
• Impact: 뒤꿈치 (heel) drives THROUGH target
• Target zones:
  • 늑골 (ribs) - rib fracture potential
  • 명치 (solar plexus) - wind knockout
  • 무릎 (knee) - joint destruction
  • 얼굴 (face) - if flexible enough for high side kick
• Hip position: Fully extended forward
• Body lean: Maximum ~20° away from kick
• Breathing: Explosive exhale "이야!" (Iya!) or "터억!" (Teok!)
• Power delivery: ALL body mass drives linearly through heel
• Penetration: Kick goes THROUGH target, not just touches
• Supporting leg: Solid base, no wobble

Retraction Phase - 회수 (Hoisu) [150ms]:

• Leg: Returns through CHAMBER position - knee high, across body
• Hip: Pulls back to coiled position
• Supporting leg: Maintains balance
• Body: Stays sideways throughout retraction
• Speed: Fast retraction prevents grab

Recovery Phase - 복귀 (Bokgwi) [200ms]:

• Body rotation: Turns back to face target (90° rotation back)
• Leg: Lowers from chamber to floor
• Foot: Places forward or returns to original position
• Weight: Shifts from 100% → 60/40 distribution
• Hips: Square back to target (정면 - Jeongmyeon)
• Arms: Return to 중단막기 (middle guard)
• Stance: Reset to 겨루기 자세 (fighting ready)
• Breathing: Controlled recovery
• Balance: Smooth transition

Combat Applications (전투 응용):

• Knee destruction (무릎 파괴): Side kick to knee joint = fight over
• Rib breaking (늑골 파괴): Heel to ribs = internal damage
• Distance control: Push opponent away (밀어차기)
• Defense: Stop charging opponent - best defensive kick
• Combinations:
  • 잽-옆차기 (Jab-Side kick) - hand sets up foot
  • 옆차기-뒤차기 (Side-Back kick) - rotation combo
  • 앞차기-옆차기 (Front-Side kick) - level change

Biomechanical Keys (생체역학 핵심):

1. Sideways turn = Enables hip thrust (90° turn mandatory!)
2. Hip drive = 75% of power (forward hip thrust)
3. Linear trajectory = Maximum force on target
4. Heel strike = Hardest part of foot, best penetration
5. Body lean = Counterbalance enables full extension
6. High chamber = Protects knee, enables power

Physics Principle: "직선이 가장 강하다" (Straight line is strongest)

• Linear force > Rotational force for penetration
• Heel = Smallest contact area = Maximum PSI
• Body weight + hip thrust = Maximum forward momentum
• 90° turn = Full hip power alignment

Taekwondo Principle: "옆차기는 태권도의 힘이다" (Side kick is the power of Taekwondo)

• Most powerful kick: Linear thrust beats angular rotation
• Most defensive: Stops opponent's advance instantly
• Most destructive: Heel to knee = joint destruction
• Best range: Maximum reach with maximum power

Common Mistakes (흔한 실수):

• ❌ Not turning sideways (옆으로 안 돌기) - Hip can't thrust!
• ❌ Circular motion (원형 움직임) - Not a roundhouse!
• ❌ Pointed toes (발끝 펴기) - Wrong striking surface
• ❌ Forward lean (앞으로 기울기) - Loss of balance
• ❌ Low chamber (낮은 준비) - Telegraphed and weak
• ❌ Bent leg at impact (구부린 다리) - Power leak
• ✅ Correct: 90° turn + high chamber + linear thrust + heel strike

Training Points (훈련 포인트):

• Practice turn separately: Body must go fully sideways
• Chamber position: Knee across body, not out to side
• Thrust motion: Like pushing door with foot
• Heel ready: Dorsiflexion critical for proper surface
• Balance: Supporting leg stability determines power

Self-Defense Application (호신술 응용):

• Knee kick: Most effective self-defense - destroys mobility
• Rib kick: Incapacitates attacker without lethal force
• Push kick: Creates distance, ends engagement
• Works in confined space: Can kick while backed against wall

Total duration: 750ms (MEDIUM_HEAVY technique)