Concentric contractions: A concentric contraction is a type of muscle contraction where the length of the muscles shorten while undergoing tension. For example, when you pick up a curl bar and perform a biceps curl, the length of your biceps muscles shorten.
Blood in Baby's Stool. Babies can sometimes have blood in their stool that is caused by food allergies, a small anal tear or fissure, or even a temporary case of lactose intolerance. It might even be a drop of blood that came from a cracked nipple, which the baby then passed through his system.
Infant â Baby and Toddler. Some of the causes of abnormal vaginal bleeding in babies may include : Hormones. Vaginal bleeding in an infant, usually within the first 2 weeks of life, may occur as a result of hormones from the mother.