 There is a higher proportion of larger diameter fibrils of collagen, but the cross-sectional area of whole mutant tendons was also significantly less than that of the wild-type tendons causing joint laxity and stiffness, easy tiring and weakness.This study is important because those diseases are often mistaken for neurological problems, since the doctor can detect a muscle weakness.This includes many painful and useless clinical neurological examination before the correct diagnosis.