“Any defect, i.e. any physical defect, confronts the body with the task of overcoming this defect, making up for the deficiency, compensating for the damage caused by it. Thus, the influence of a defect is always dual and contradictory: on the one hand, it weakens the body, undermines its activity, and is a disadvantage; on the other hand, precisely because it complicates and disrupts the activity of the body, it serves as a stimulus for the increased development of other functions of the body, it pushes and encourages the body to intensified activity, which could compensate for the deficiency, overcome difficulties...”