세
세사람·Seated Knee Up·1y agoIt's fine up to 13, but starting from 14, my back hurts and I can't do it. What's the problem??ㅠㅠ
It's fine up to 13, but starting from 14, my back hurts and I can't do it. What's the problem??ㅠㅠ
Thank you! 👍
Weak core strength can cause back pain. Keep your core engaged and do not relax it.