Sensory and Motor Homunculii -- attributed to Wilder Penfield show the disproportionate regions of the motor cortex associated with the hands.

Role of motor cortex versus cerebellum for learning skilled movements.

http://en.wikipedia.org/wiki/Sensory_homunculus

Good tutorial: http://thebrain.mcgill.ca/flash/i/i_06/i_06_cr/i_06_cr_mou/i_06_cr_mou.html

Twitchell, T.E., The Automatic Grasping Responses of Infants, Neuropsychologia 1965 Vol. 3, p 247-259, Pergamon Press. -- grasping, avoiding, orienting responses used for monitor normal development in infants. especially apparent ~4 months. May reappear much later during recovery from hemiplegia.

Johansson, R.S., How is Grasping Modified by Somatosensory Input?, Dahlem Workshop Life Science Research Reports. ~80ms responses to incipient slippage

Manual dexterity takes a long time to be fully developed. For example, children 6-7 are considerably more skilled with chopsticks than children 4-5 years of age, although all of these children grasp and manipulate simple objects without obvious difficulty. HK J Paediatr (new series) 2006;11:103-109 Validation of a Chopsticks Manipulation Test for Screening Chinese Children with Fine Motor Dysfunction CWP LI-TSANG, HCY LEE, LK HUNG http://www.hkjpaed.org/details.asp?id=554&show=1234

The 6-7 years group completed the task faster than their younger counterparts. The boys required longer time (mean difference=22.8 sec) to complete the task than girls.

This study showed that the attainment of the chopstick manipulation skill emerges at the age 4, then quickly progresses to the mastery of the skill at age 5. As the child moves to 6-7 years of age, the skill appears more mature in terms of the quality of grasp and also the speed of transfer of objects.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B7CPJ-4GP1D2P-9&_user=145269&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000012078&_version=1&_urlVersion=0&_userid=145269&md5=220c6dcbe3600d7a57faf6f3152a1587

Janet L. Poole, Patricia A. Burtner, Theresa A. Torres, Cheryl Kirk McMullen? , Amy Markham, Michelle Lee Marcum, Jennifer Bradley Anderson, Clifford Qualls, Measuring Dexterity in Children Using the Nine-hole Peg Test, Journal of Hand TherapyVolume? 18, Issue 3, , July-September 2005, Pages 348-351. (http://www.sciencedirect.com/science/article/B7CPJ-4GP1D2P-9/1/15d0d8bfb24edf1d40f88cd15c22d8c3) Abstract: The purpose of this study was to measure dexterity in children aged 4-19 years using the Nine-hole Peg Test. Four hundred and six children were tested with their dominant hand and then their nondominant hand. A commercial version of the Nine-hole Peg Test was used. An analysis of variance showed a main effect for age, gender, and hand dominance. Speed of dexterity improved with age. In all age groups, females performed faster than males. Participants performed faster with the dominant hand than the nondominant hand. The normative data collected provide information for comparing scores to children with different diagnostic categories to screen for fine motor difficulties.

For the dominant hand (Table 3), times for children 4–9 years old were significantly slower than each other and slower than children older than 10 years of age. Times for the 10–11-year-old children were similar to the 12–13 and 14–15 year olds, but were significantly slower than children aged 16 years and older.

Evolution of forelimb movement patterns for prey manipulation in anurans Lucie A. Gray, James C. O'Reilly, Kiisa C. Nishikawa, Journal of Experimental Zoology Part A: Comparative Experimental Biology, Volume 277 Issue 6, Pages 417 - 424, Published Online: 7 Dec 1998.

http://dx.doi.org/10.1002/(SICI)1097-010X(19970415)277:6<417::AID-JEZ1>3.0.CO;2-R

A classic "funnel" in Koditschek terminology:

Five distinct behavior patterns were identified: scooping entails using the back of the hand to push prey into the mouth; wiping involves the use of the palm of the hand to push prey, protruding laterally from the mouth, toward the midline; during prey stretching, one end of the prey is held in a stationary position by the hands while the other end is pulled upward by the jaws; in grasping, the palms face the midline or the substrate as the fingers are wrapped around the prey; grasping with wrist rotation is similar to grasping, but the wrists rotate inward as the hands grasp the prey so that the palms face the mouth.