The lumbrical muscles do not attach to the proximal phalanx directly, but rather connect the tendons of flexor digitorum profundus (below, ie volar) to the extensor tendons (above, ie dorsal) and produce flexion by pulling on the extensor tendons as they pass over the proximal phalanx.
By the time they are 12 months old, most babies can weigh three times what they weighed at birth and gain about an inch per month in length. The average infant at one year may be between 2630 inches long. Social and Emotional Development-Infants respond when you say their name. They begin to fear strangers.
Yes | No Thank you! If this is your first child, then I suggest you speak with professionals as her doctor or nurses in his office. Three month old babies rarely are able to sit up due to muscle control. They start holding their heads up by three months but not sitting independently. Try not to rush the process, allow all good things to come in time.....in a few months down the line, she will be sitting up and crawling then ,later ...walking.....and you won't have time to sit or think.