The Adaptation Of The Opposable Thumb

Trigger finger, sometimes called trigger thumb, is a condition that locks a person’s finger into a bent position. Sometimes the finger will then snap straight out, similar to the way a trigger is pulled and released. It happens when inflammation causes the space around the sheath that protects the tendon to narrow. In severe cases, the finger cannot be straightened out.

Thus, the study concluded by Schmalzl, Kalckert, Ragnö, and Ehrsson (2013) provide evidence that “even years after the amputation, a few seconds of synchronous visuotactile stimulation are sufficient to activate hand-centered multisensory integration mechanisms” (p.11). That is, people could feel their amputated hands during The Rubber Hand Illusion when the stump of the hand was synchronously stroked with the brush stroking the rubber hand. That knowledge can eventually lead to the creation of advanced prosthetic limbs. Moreover, such limbs would theoretically be able to “trigger an immediate tactile stimulation on the stump, which in turn would trigger ownership sensations of the hand provided that the user would look at the hand at the same time” (Schmalzl, Kalckert, Ragnö, & Ehrsson, 2013 p. 12). Such implementation of the theoretical knowledge can create an entirely different reality for millions of people who lost their limbs at this or that stage of their lives, and therefore the further study of this topic is

These involve the small muscles of the body used for hand –eye co-ordination, writing and grasping of small objects.

Chapter 2, Getting a Grip, talks about the connections between the human and other creatures’ limbs. It also talks about Shubin’s fossil, Tiktaalik, and the unique specialized limbs it had.

Extensor Pollicis Longus - It's major attachment is the mid ulna shaft. When it contracts it causes Extension in the thumb. And, is also one of the tendons of anatomical snuff box.

Chimps for example, have similar hands to humans, however, when using a hammer stone, they frequently use a power grip where all fingers are used to control nut-cracking (Wong, 2004). Here, their finger proportions inhibit easy coordination between the index finger and thumb (Wong, 2004). This is significantly different to that of hominids who have hands and thumbs which are very effective and allow for precise knapping and control over hammer stones. This illustrates that their differences in physical characteristics lead to distinctly different behaviors that cannot be considered the

All primates are descended from tree-dwellers, showing adaptations which permit for tree climbing which include: a moving shoulder joint, divided big toes as well as the thumb for gripping, and also stereoscopic eyesight.

A major impetus to improving artificial limbs started when the United States encouraged companies to improve prosthetics instead of munitions (Norton, 2007). The combination of lighter materials and robotics assist has created huge advancements in functionality and has dramatically improved quality of life and potential for independent living. Even with the advancement of these limbs, the basic mechanical principals are still the same. Modern times allow for many different types of limbs to be created. Limbs can be created to match skin tone, freckles and fingerprints. There are three many ways a limb can be made to move. The first is attaching the limb to a moving body part to act as a gear shifter. Another variation is a motor attached and the person can switch modes by a mechanical toggle shift. The most advanced movement is the myoelectric capability. This is when electrodes are placed on the muscles of the residual limb. When contracted the arm will move according to which electrode fired. A microprocessor can also be attached to learn exactly how the person walks (Clements, 2008). Modern prosthetics offer valuable life skills, yet are very

The hand is a very important extremity attached to the human body and is used in everyday life. Humans use it doing almost everything. The major systems the body uses to be able to move the hands are the skeletal, muscular and nerves systems. The skeletal system of the hand involves the bones, such as, eight carpal bones, five metacarpal and fourteen finger bones (Istitute for Quality & Efficiency in Health Care, 2013). All connected by joints and ligaments. The muscles include two parts, the thenar eminence and the hypothenar eminence (Istitute for Quality & Efficiency in Health Care, 2013). The thenar eminence moves the base of the thumb, also lets the thumb touch the four fingers; the hypothenar eminence allows the little finger to bend

Most of the coordination of the primates especially the movement from place to place are aided by the sight. The primates can only have the sense of smell when the source of the smell is very close to them. Another important general characteristic of primates is the possession of the four limbs (Srivastava 2009). All the primates have four limbs but in some like the humans, the forelimbs are specialized to be hands. The forelimbs provide the strength of the primates. All the activities revolving around their daily activities including movement, work, jumping, eating, etc. are all aided by the use of the limbs that is the legs and the

Within the world of primates, the family Hominidae includes the primates known as the great apes. These primates, are then broken down into two subfamilies. One subfamily contains the primates chimpanzees, bonobos, gorillas and humans, while the other subfamily, Ponginae, only contains the species Pongo, commonly known as the orangutan. Orangutans, although closely related to the other great apes, represent a lot of extremes in biological parameters (Campbell, C. J., 2011). One of the most drastic extremes is that orangutans are the largest primary arboreal mammal in the world. This is a result of special evolutionary adaptations that allow these primates to mechanically function in an arboreal lifestyle. Unlike the other great apes,

As a result of this omnivore diet, this had led to retention of the generalized dentition that we could now see in present day expressed in primates. This adaptive process is also quite evident in the large extend to which the primates rely on vision. For instance, in a three-dimensional environment with a tendency of easily misplacing your steps (not knowing where to walk) and especially, while climbing for primates, colour vision and depth perception are two key assets to acquire. In addition, grasping hands and feet are reflective of the adaptation to living in the trees. Even though, grasping hands are needed to in order to climb which is shown by many animals (cats, squirrels and raccoons). However, the majority of primates have adopted a mechanism of grasping branches with prehensile hands and feet and for some species, tails and the ability to grasp has significantly improved with the appearance of flattened nails in replacement for

Why haven’t primates evolved like humans? This question that some may be asking. Humans and primates walked along each other for thousands of years, but then humans began using tools while the others were still picking fruit and eating it. Why did humans and not primates evolve? This paper will answer this question.

pinky bone, and it would require surgery to put it back into place otherwise I

to be able to have any sense of touch. Dynamic prosthesis, the more popular choice, uses