라이브러리로시작 
끝 
운동 라이브러리
Crunch (On Stability Ball, Arms Straight)
A stability ball crunch performed with arms extended straight, adding a longer lever and pre-stretched range to standard ball crunches.
복근짐볼Trunk flexion
주동근
복직근
협응근
복사근복횡근둔근
장비
짐볼
패턴
Trunk flexion
준비 자세
- 01Sit on a stability ball and walk the feet forward until the mid-back rests on the ball.
- 02Plant the feet flat, hip width apart, with knees at about 90 degrees.
- 03Extend both arms straight toward the ceiling or overhead beside the ears.
- 04Let the torso drape slightly back over the ball for a pre-stretch.
수행
- 01Exhale and curl the ribcage toward the pelvis, keeping the arms straight.
- 02Lift the shoulder blades off the ball without the hips dropping.
- 03Pause at the top with abs fully shortened.
- 04Lower back over the curve of the ball into a gentle stretch.
체크포인트
- -Arms stay straight and travel only with the torso.
- -Hips stay level; only the upper body moves.
- -The ball stays still under the mid-back.
- -Each rep starts from the stretched position over the ball.
흔한 실수
- -Swinging the straight arms to create momentum.
- -Letting the ball roll forward and back with each rep.
- -Dropping the hips and turning it into a partial sit-up.
- -Skipping the back-extension stretch at the bottom.
프로그래밍 노트
- -Use 2 to 3 sets of 10 to 15 controlled reps.
- -Arms beside the ears is harder than arms toward the ceiling; progress in that order.
- -Add a light plate in the hands once bodyweight reps exceed 15.