My Science School

Prosthetics is the evaluation, fabrication, and custom fitting of artificial limbs, known as "prostheses." Prostheses enhance the function and lifestyle of persons with limb loss. The prosthesis must be a unique combination of appropriate materials, alignment, design, and construction.

Lower-limb prostheses might address stability in standing and walking, shock absorption, energy storage and return, cosmetic appearance, and even running, jumping, and other athletic activities. Upper-limb prostheses might address reaching and grasping, occupational challenges including hammering, painting, or weight lifting, and activities of daily living like eating, writing, and dressing.

A person's prosthesis should be designed and assembled according to the person's appearance and functional needs. For instance, a person may need a transradial prosthesis, but need to choose between an aesthetic functional device, a myoelectric device, a body-powered device, or an activity specific device. The person's future goals and economical capabilities may help them choose between one or more devices.

Craniofacial prostheses include intra-oral and extra-oral prostheses. Extra-oral prostheses are further divided into hemifacial, auricular (ear), nasal, orbital and ocular. Intra-oral prostheses include dental prostheses such as dentures, obturators, and dental implants.

Prostheses of the neck include larynx substitutes, trachea and upper esophageal replacements,

Somato prostheses of the torso include breast prostheses which may be either single or bilateral, full breast devices or nipple prostheses.

Penile prostheses are used to treat erectile dysfunction, correct penile deformity, perform phalloplasty and metoidioplasty procedures in biological men, and to build a new penis in female-to-male gender reassignment surgeries.

 

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The definition of visual impairment is “a decrease in the ability to see to a certain degree that causes problems not fixable by usual means, such as glasses.” Blindness is “the state of being unable to see due to injury, disease or genetic condition.”

There are four terms used to describe different levels of vision impairment and blindness—partially sighted, low vision, legally blind and totally blind. Partially sighted means a person has partial vision, either in one or both eyes. Low vision refers to a severe visual impairment in which visual acuity is 20/70 or poorer in the better-seeing eye and cannot improve with glasses or contacts. Legally blind means a person has a corrected vision of 20/200 in their best-seeing eye. Totally blind refers to a complete loss of sight.

Effective interventions are available for health promotion, prevention, treatment and rehabilitation to address the entire range of needs associated with eye conditions and vision impairment across the life course. Some are among the most feasible and cost-effective to implement. For example, uncorrected refractive error can be corrected with glasses while cataract surgery can restore vision. Vision rehabilitation is also effective in improving functioning for people with an irreversible vision impairment.

 

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Sign languages (also known as signed languages) are languages that use the visual-manual modality to convey meaning. Sign languages are expressed through manual articulations in combination with non-manual elements. Sign languages are full-fledged natural languages with their own grammar and lexicon. Sign languages are not universal and they are not mutually intelligible with each other, although there are also striking similarities among sign languages.

Wherever communities of deaf people exist, sign languages have developed as useful means of communication, and they form the core of local Deaf cultures. Although signing is used primarily by the deaf and hard of hearing, it is also used by hearing individuals, such as those unable to physically speak, those who have trouble with spoken language due to a disability or condition (augmentative and alternative communication), or those with deaf family members, such as children of deaf adults.

 

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Over 1 billion people are estimated to live with some form of disability. This corresponds to about 15% of the world's population, with up to 190 million (3.8%) people aged 15 years and older having significant difficulties in functioning, often requiring healthcare services. 

Disability is extremely diverse. While some health conditions associated with disability result in poor health and extensive healthcare needs, others do not. However, all people with disability have the same general healthcare needs as everyone else, and therefore need access to mainstream healthcare services. Article 25 of the UN Convention on the Rights of Persons with Disabilities (CRPD) reinforces the right of persons with disability to attain the highest standard of healthcare, without discrimination. However, the reality is that few countries provide adequate quality services for people with disability.

Also, very few countries collect data to enable disaggregation by disability in the health sector.  This became very apparent during the COVID-19 pandemic where countries failed to include disability consistently in their response to control the pandemic. This left people with disability exposed to three increased risks with devastating consequences: the risks of contracting COVID-19, developing severe symptoms from COVID-19 or dying from the disease, as well as having poorer health during and after the pandemic, whether or not they are infected with COVID-19.

 

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The general recommendation for fruit and vegetable intake is at least 400 grams per day, or five servings of 80 grams.

One 80-gram serving is equivalent to a small piece about the size of a tennis ball. For fruits and vegetables that can be measured by the cup, a serving is roughly 1 cup.

This recommendation stems from the fact that eating five servings of fruits and vegetables daily is associated with a lower risk of death from diseases like heart disease, stroke and cancer.

One large analysis of 16 scientific studies found that eating more than five servings per day provided no added benefit.

However, another systematic review of 95 scientific studies found the lowest disease risk at 800 grams, or 10 daily servings.

Keep in mind that these studies looked at both fruits and vegetables. Assuming half of these servings come from fruit, you should consume somewhere between two to five servings of fruit daily.

Recommendations from different health authorities vary slightly, but generally seem to align with the current research.

For example, United States Department of Agriculture (USDA) guidelines recommend the average adult consume two servings of fruit per day, while the American Heart Association (AHA) recommends adults eat four to five servings of fruit per day.

 

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Trans fat is considered the worst type of fat you can eat. Unlike other dietary fats, trans fat — also called trans-fatty acids — raises your "bad" cholesterol and also lowers your "good" cholesterol.

A diet laden with trans fat increases your risk of heart disease, the leading killer of adults. The more trans fat you eat, the greater your risk of heart and blood vessel disease.

Trans fat is so unhealthy that the Food and Drug Administration has recently prohibited food manufacturers from adding the major source of artificial trans fat to foods and beverages.

Most trans fat is formed through an industrial process that adds hydrogen to vegetable oil, which causes the oil to become solid at room temperature.

This partially hydrogenated oil is less likely to spoil, so foods made with it have a longer shelf life. Some restaurants use partially hydrogenated vegetable oil in their deep fryers, because it doesn't have to be changed as often as do other oils.

Some meat and dairy products have a small amount of naturally occurring trans fat. It's not clear whether this naturally occurring trans fat has any benefits or harm.

Doctors worry about added trans fat because it increases the risk for heart attacks, stroke and type 2 diabetes. Trans fat also has an unhealthy effect on your cholesterol levels. Trans fat increases your LDL cholesterol and decreases your HDL cholesterol.

If the fatty deposits within your arteries tear or rupture, a blood clot may form and block blood flow to a part of your heart, causing a heart attack; or to a part of your brain, causing a stroke.

 

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Soft drinks are carbonated beverages. They are commonly also known as soda, soda pop, pop or tonic. While occasional consumption of these types of beverages may not cause any negative effects, drinking them on a regular basis is not healthy. Cutting back on the number of soft drinks you consume -- or eliminating them from your diet altogether -- is the best way to prevent associated health problems.

Obesity and a high body mass index are risk factors for many chronic health problems such as heart disease, diabetes and some forms of cancer. While still not a healthy alternative, substituting diet soda for regular soda will at least reduce caloric intake and can help to shed unwanted pounds. However, a better solution is to replace the soda, with calorie-free water and three servings of low-fat or fat-free milk per day.

According to an article published in 2005 by "American Academy of Family Physicians," consuming soft drinks on a regular basis may also contribute to a higher risk of developing diabetes. The sweeteners and caramel coloring added to soft drinks, may decrease insulin sensitivity. Since drinking soda adds sugar and calories to the diet, it may also raise the risk of developing metabolic syndrome, which raises the risk of a heart attack or stroke. Ingesting sugar can contribute to tooth decay because acid is produced when bacteria enters the mouth and mixes with sugar. When the acid attacks the teeth for 20 minutes or more and causes plaque buildup on the teeth and gums, it leads to tooth decay. 

 

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Salt in the diet can come from processed foods, either because they are particularly high in salt (such as ready meals, processed meats like bacon, ham and salami, cheese, salty snack foods, and instant noodles, among others) or because they are consumed frequently in large amounts (such as bread and processed cereal products). Salt is also added to food during cooking (bouillon and stock cubes) or at the table (soy sauce, fish sauce and table salt).

For adults: WHO recommends that adults consume less than 5 g (just under a teaspoon) of salt per day.

For children: WHO recommends that the recommended maximum intake of salt for adults be adjusted downward for children aged two to 15 years based on their energy requirements relative to those of adults. 

All salt that is consumed should be iodized or “fortified” with iodine, which is essential for healthy brain development in the fetus and young child and optimizing people’s mental function in general.

 

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