Cross Acid
Elite one-wheeled crossed-leg pivot – demands extreme core tension and micro-adjustment precision. The pinnacle of balance combos in WSSF competition.
Classification & Prerequisites
Non-Negotiable Prerequisites
1. Toe One Wheel (A):
- 8 revolutions without deceleration
- 5/5 blind entries
2. Core Certification:
- 90s plank with 5kg back load
- Rotary stability test: 8/8 reps
Technical Execution
1. Entry & Lock (0.4s)
- Feet: Lead foot crossed over the trail foot, both on a single wheel
- Weight: 70% on the ball of the lead foot, 30% on the heel of the trail foot
Kinetic Rationale: Tibialis anterior isometric contraction stabilizes the ankle (↓ wobble amplitude 65%)
2. Pivot Revolution (0.8s/rev)
- Core Mechanics: Transverse abdominis rotation → drives 15° hip rotation/rev
- Upper Body: Arms in "opposition guard" (45° front, 30° rear)
Kinetic Rationale: Oblique fascia stores elastic energy for continuous rotation
3. Exit Transition (0.3s)
- Weight Shift: Trail heel press → uncross → toe snap to Nelson/Volt
Kinetic Rationale: Gluteus medius eccentric loading enables explosive decoupling
Gear Requirements
Biomechanical Tolerances
Injury Biomechanics: Core disengagement → lumbar shear force >800N (disc herniation risk)
Mastery Metrics
Competition Utility (WSSF)
Pro Tip
> "Squeeze a lemon between your crossed ankles" – elite skaters maintain 30% inter-foot pressure to prevent decoupling. Pre-tensioning transverse abdominis 0.2s pre-entry cuts wobble by 40%
Safety Protocol
- Mandatory Gear:
- Lumbar brace (20mmHg compression)
- Smart insoles with real-time pressure mapping
- Ban: Attempts without a certified core score >85%