The following three bad squatting habits will hurt the knee: 1, deep squatting before the habit of not doing warm-up exercises, muscle ligaments in a tense state, poor flexibility, can not be standard to complete the squatting action, it will hurt the knee. 2, do deep squatting, squatting down leg muscles relaxed, so that the ligaments and cartilage under pressure increased, thus damaging the knee. 3, arch back bending, so that the hips, back, back of the thighs The weight is completely pressed at the knee joint, increasing the burden on the knee joint, most likely to damage the knee.