Minors belong to people without civil capacity, and the fault caused should be borne by the guardian, but from what you said, your child is not at fault. Playing fitness equipment itself is a normal civil behavior, and the damage caused in this process is unpredictable, not a fault, and your child did not mean it. There is no causal relationship between the two, and the injury should be borne by the other parent who has not fulfilled the duty of care, but I suggest that if it is an injury, it is also beneficial to cultivate the child's sense of responsibility if it is not serious. If the other party demands a large amount of compensation, it should use legal weapons to safeguard its legitimate interests.