Tag Archives | skin

Muscles in the Hand and Fingers

The system of muscles in the hand and fingers of a human by far in the world of biology is the most well developed structure in the animal kingdom. The human hand can perform any possible movement and the fingers alone are capable of producing tremendous amount of strength. But for all we know, we may always use fingers every day and despite the amount of force the human finger can apply, there are actually no muscles that can be found within the fingers. Our five fingers do not have muscles, it is simply a group of bones cloaked with skin, but we are able to move them because of a number of reasons. Basically, our ability to move our fingers is not as direct as it may seem, because our fingers do not have muscles, there motion in other words is controlled by another set of muscles that are not found in the fingers themselves. In fact, the muscles that control the finger’s ability of motion are found in the hand and also on the forearm.

Muscles in the Hand and Fingers

The cloaked bones of our fingers are connected to the muscles of our hand and arm through thin strings called as tendons. Tendons are the basic structures that are responsible for the motion of our fingers, a damage tendon can result to numerous diseases like trigger finger which will lead to the inability of a finger to move, just an example of how vital the tendon’s role are. The tendons act like strings for our fingers which are controlled by the muscles in our hand and arm, as we flex, the string is pulled resulting to the motion of our fingers. The strength of our fingers in short are determined by the strength of the muscle in arms, which makes grip exercise devices just the same as working out with dumbbells. Without going to much deeper technical terms, the tendons of the fingers can be grouped into two, the intrinsic and the extrinsic. The extensors are the long muscles that are located starting from the forearm to the fingers. Their main role is to perform the straightening of the fingers, while the intrinsic muscles are shorter ones compared to the extensors. The thumb is composed of a number of tendons which gives it the ability of grasping. Other fingers do also have addition tendons which gives the ability of fingers of further movement.

Muscles in the Hand and Fingers

In order to fully understand the motor characteristics of fingers, it is necessary to learn the origin of the motion. To start off, the most complex structure of the five fingers which is the thumb is controlled by the thenar muscles. The thenar muscles are a group of intrinsic muscles that are found within the compartment of the thenar, slightly distinguished from other muscles because it is separated by a wall called the fascia. There are four different types of specific muscles under the specification of the thenar group, without going to the more technical aspects, one of the four types is the Flexor Pollicis Brevis, and this is the basic muscle that gives the thumb its ability to simply flex in its usual position, the fully straight stretch of the thumb. Second, Opponens Pollicis is the muscle that gives the thumb another mode of motion. This allows the abduction of the thumb. This is the movement done when you are trying to reach the pinky. The two other muscles are the Abductor Pollicis Brevis and Adductor Pollicis, these two muscles are highly different from one another, and they differ in structure mainly. The Abductor Pollicis Brevis is a sheath of muscle while the Adductor Pollicis has two heads basically, not going into more technical aspects, these muscles give the thumb its ability to abduct, the motion while grouping with other fingers or when the thumb comes close to the pointer finger. The thenar muscles can be seen just by looking at the base of the thumb, the large area and bulk generated are the muscles that mainly control the motions of the thumb.

The exact opposite of the thumb which is the pinky is controlled by another set of muscles which are called hypothenar muscles. These are intrinsic muscles that compose the medial side of the hand. They are controlled by the nerves of the deep branch of an ulnar nerve. Under the hypothenar muscles are two intrinsic muscles that give the pinky its different forms of motor motion. The first is the Abductor Digiti Minimi which origins at the pisiform and enters through the base of the pinky finger. It is mainly responsible for the abducting motion, followed by the Flexor Digiti Minimi. This muscle originates from the Hamate and comes close to the Abductor Digiti Minimi muscle. It is the key muscle that gives the pinky the flexing motion, the ability to straighten and stretch the pinky. The Opponens digiti Minimi originates also from the Hamate. What it does is that it pulls and rotates the fifth metacarpal which gives the pinky its ability to oppose the thumb or come in contact with the thumb.

If you are wondering whether the muscles controlling the three different enclose fingers are different, then you are slightly wrong. The muscles responsible for the motion of the ring, index and middle finger are all under in one classification. To start with, the Interosseous muscles which are then also later divided by seven even smaller sub-groups of muscles which are also controlled by the ulnar nerve. There are four dorsal muscles that are responsible for the flexing and three palmar muscles that are responsible for the abducting capabilities of the three fingers. The other type of muscle is the Lumbricals. There are actually four of these and are located between metacarpals. The first and second are controlled by the median nerve while the third and fourth by the ulnar nerve. These muscles give the ability of flexing and extending the three enclosed fingers. All the muscles that compose the hand are responsible for the motion of the fingers, while also the forearm is still partly responsible for some muscles that cause the movement of the fingers, like the long extrinsic muscles.

Comments are closed

The Risk Factors and the Cause of Dupuytren’s Contracture

Dupuytren’s contracture which is also referred to as the Dupuytren’s disease is a deformity of the hand which causes its tissues beneath the hand to contract and thicken. A prominent and initial symptom of this disease is the thickening of a person’s palm. Lumps under the palm’s skin, which often vary in number, might appear most often at the pinkie or ring finger’s base.

As this disease continues to progress, the lumps – sometimes called nodules, will develop into hard bands and cords which can extend to the fingers. The fingers’ cords will eventually contract and will make finger extension impossible to do. Household chores like washing dishes and exercises as shaking the hands will eventually become impossible or difficult.

Risk Factors

Although not too many people know about Dupuytren’s contracture, Keith Segalman – a hand surgeon has seen thousands of this disease’s cases already. While this condition is not new anymore, the disease’s origin still is a mystery. According to Dr. Segalman, “We have already studied the possible several reasons for this. However, there is still no definite cause of Dupuytren’s contracture. Here are some of the medical experts’ speculations about the cause of the disease:

Heredity

According to Taizoon Baxamusa – a surgeon and spokesperson of the Orthopedic Surgeons of America, “this disease is in bloodlines”. This does not imply that since your mother had Dupuytren’s disease, you automatically will have it too. This just means that you have a higher risk of developing the disease too.

Ancestry

Most often, Dupuytren’s disease is observed in the people of the Northern part of Europe like the French, Dutch, Irish, Scottish and English people or the Scandinavians such as the Finnish, Norwegian, Swedish and Danish people. However, this disease could be developed by just any race and ethnicity.

Age and Gender

Men are the ones which are more likely to have the disease than women and this condition most often appear when the person reaches 40. If women develop this condition, these are observed to occur in the later stage of their lives with milder symptoms.

Seizure Disorders and Diabetes

The Risk Factors and the Cause of Dupuytren’s Contracture

Actually, experts still do not know the relationship between the disease and these disorders. However, medical professionals have revealed that the symptoms and Dupuytren are less severe with patients that have Diabetes. Although excessive use of the hand, as well as, injury are not connected to the emergence of Dupuytren’s disease; however, people that have hand trauma have higher risks of developing the disease.

Almost always, patients think that hand trauma and Dupuytren’s disease are connected because they tend to experience symptoms when they are doing activities that involve the hands. Because the disease is common in male senior citizens, a few men notice nodules on both of their palms first especially with those that are playing golf.

While there are medical experts that cite tobacco and alcohol as risk factors, these are just assumptions. People with Nordic and Northern European descent still have a higher population of Dupuytren’s patients.

Comments are closed