When it comes to injections, do you think of “injection in the butt” or “injection in the arm”? For older friends, what may come to mind is a shot in the butt. Nowadays, spanking shots seem to be rare. Recently, the question "Why did butt needles disappear?" has aroused widespread attention and discussion on Weibo.

Do the butt injections you got when you were a kid really disappear? This starts with what a butt needle is.

What is a butt needle?

What we call butt injection is actually a method of intramuscular injection, which refers to injecting drugs into muscle tissue. In addition to intramuscular injection, common injections include intravenous injection, subcutaneous injection, and intradermal injection. These injection methods are suitable for different types of scenarios.

1. Intradermal injection

Generally we use this injection method when doing "skin tests". The doctor will place the needle close to the surface of the skin and inject the medication. This is because the injection point is very close to the surface of the body, making it easier to see if the body reacts.

2. Subcutaneous injection

The most common is to inject insulin. Macromolecular proteins such as insulin are not suitable for oral administration and need to be administered by injection. Compared with intravenous injection and intramuscular injection, subcutaneous injection is simpler and can be performed without professional medical staff. For insulin that requires long-term injection, this injection method is very suitable.

3. Intravenous injection

Intravenous injection, as the name suggests, is the direct injection of drugs into a vein. What we call intravenous injections and intravenous drips. The advantage of this injection method is that the drug is injected directly into the blood. The drug is not easily metabolized by organs such as the liver and can be delivered throughout the body as quickly as possible. Doctors will choose this method when they need the medicine to work quickly.

4. Intramuscular injection

Like intravenous injection, intramuscular injection also prevents the drug from being metabolized by the liver. Compared with intravenous injection, intramuscular injection of drugs takes effect more slowly. This injection method is often used when injecting many types of vaccines and drugs that may cause vascular irritation.

The muscles in the butt area are very "thick", so they naturally become one of the "excellent candidate areas" for intramuscular injection.

In addition, the outer thigh (rectus femoris) and the deltoid muscle on the arm are also "candidate areas" for intramuscular injection.

However, many people may still have some "childhood shadows" about butt needles. It seems that an injection in the butt hurts more than an injection in the arm. Why is this?

Why do spanking needles hurt so much?

First of all, this may be related to our lower pain tolerance and psychological fear of injections when we were young. But apart from that, there are indeed several objective factors that make butt needles particularly painful.

1. Blunt needles

For people born in their 50s and 60s, pain may come from reused “blunt needles.”

When medical conditions were not yet developed, hospitals and outpatient clinics in many places did not use disposable needles, but reused needles that had been sterilized. For example, the following "needle sterilizer" is used to sterilize needles.

Although it stands to reason that the needle needs to be smoothed after repeated use for a period of time, there will inevitably be some "small burrs" on the needle after repeated use. You don't have to experience it yourself. Just imagining such a needle being inserted into the flesh will already start to hurt.

2. "Deep deep"

After medical conditions improved, although the problem of "blunt needles" was solved, in order to avoid the thick fat layer on the buttocks, the buttock needles often penetrated very deeply, often needing to penetrate 2 to 3 centimeters into the flesh. Deep wounds caused by needles can also increase pain.

3. "Suck"

In the past when spanking injections were given, medical staff might follow a procedure to aspirate before injecting to make sure the needle did not hit a blood vessel (otherwise it would become an intravenous injection).

A 2015 review found that aspiration causes more pain than direct injection.

At present, the US Centers for Disease Control and Prevention, the Public Health Agency of Canada and other institutions also believe that there are no large blood vessels in the area of ​​intramuscular injection, and there is no need to aspirate during injection. But regardless, suctioning may also be one of the culprits why when we were kids, we found butt needles “hurting like hell.”

Are butt needles gone?

So why are there fewer and fewer butt needles now? Are butt needles really gone?

Let’s talk about the answer first:In fact, butt needles have not disappeared, but there are fewer scenes where they need to be used.

The most important reason is that with the development of modern drugs, there are more drugs that can be taken orally, such as various penicillin derivatives, etc. Now that the problem can be solved by taking drugs, who is willing to take an injection?

And for adults, most vaccines that are not particularly large in dosage can also be completed through arm injection (deltoid muscle injection), so there is no need to take off your pants to get the injection.

In addition, a 2006 study also showed that spanking injections may not be as effective as imagined. As the obesity problem becomes more and more serious, the thickness of people's subcutaneous fat layer increases, which brings trouble to the spanking needle. The study counted the effectiveness of spanking injections in 50 patients and found that only 16 people received actual intramuscular injections, and the other 34 people received actual subcutaneous injections (injected into the fat layer), which may make the vaccine that requires intramuscular injection ineffective.

In addition, irregular butt injections may cause sciatic nerve damage. For these reasons, butt needles are becoming less and less common.

But for some intramuscular injection drugs that are administered in large doses, you may have to rely on butt injections to make them effective.

References

[1]Usach,I.,Martinez,R.,Festini,T.,&Peris,J.E.(2019).SubcutaneousInjectionofDrugs:LiteratureReviewofFactorsInflue ncingPainSensationattheInjectionSite.Advancesintherapy,36(11),2986–2996.https://doi.org/10.1007/s12325-019-01101-6

[2]WrightJC,BurgessDJ(29January2012).Longactinginjectionsandimplants.Springer.p.114.ISBN978-1-4614-0554-2.

[3]SissonH.Aspiratingduringtheintramuscularinjectionprocedure:asystematicliteraturereview.JClinNurs.2015Sep;24(17-18):2368-75.doi:10.1111/jocn.12824.Epub2015Apr14.PMID:25871949.