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.
Knowing when do babies hold their head up is not enough, it helps to know how baby's head control develops so that you can do the right thing to encourage him/her to hold up his/her head. Newborns Newborn babies totally rely on mothers to support their necks and heads in the first month of lifeâs journey.