Swiss Ball — Jackknife
Dynamic Swiss ball exercise in plank position, drawing knees to chest while rolling the ball for intense abdominal work.
Swiss Ball — Jackknife
The Swiss Ball Jackknife is an intermediate to advanced exercise combining plank stability with dynamic hip flexion. In plank position with shins or feet on the ball, the practitioner draws knees to chest while rolling the ball, creating an intense abdominal challenge while working balance and coordination.
Targeted Anatomy
The rectus abdominis and transversus abdominis are the primary drivers of hip flexion and trunk stabilization. The hip flexors (psoas-iliacus) draw knees to chest. The obliques prevent lateral rotation. The deltoids, pectorals, and triceps maintain the high plank. The serratus anterior stabilizes scapulae. The quadriceps control ball rolling.
Step-by-Step Execution
- Starting position: High plank, hands on floor shoulder-width apart. Shins on Swiss ball. Body aligned head to toes.
- Exhale — Flexion phase: Contract deep abdominals and draw knees to chest. Ball rolls under shins toward hands. Hips rise naturally.
- Top position: Knees drawn as close as possible to chest. Hips above shoulders.
- Inhale — Return: Extend legs rolling ball backward. Return to plank with control.
Key Points
- Hands stay stable on the floor.
- Movement is fluid and controlled, no bouncing.
- Shoulders stay above wrists throughout.
- Engage core before beginning flexion.
Repetitions
10-12 reps, 2-3 sets.
Modifications
- Beginner: Ball under thighs (more stable), reduced flexion range.
- Intermediate: Standard with ball under shins.
- Advanced: Ball under feet (more unstable), add lateral plank between reps.
Contraindications
- Shoulder or wrist pathologies.
- Acute lower back pain.
- Severe balance problems.
Target Audience
Ideal for athletes seeking functional closed-chain abdominal strengthening. Used in preparation for combat sports, gymnastics, and CrossFit. In rehabilitation, represents an advanced progression exercise.