Arms Akimbo

Following a straining jog or run, we tend to rest with our arms akimbo (hands on hips, with elbows facing outwards), as seen in this picture.

How does this help?

After the exercise, our body would be desperate to breathe as much as it possibly can. Standing this way actually causes a muscle in our chest to pull on our rib cage and lift it up.

As seen in the diagram, the pectoralis major muscle is attached to our clavicle (collar bone), sternum (breast bone), and to our humerus (bone of arm). Try to picture the humerus (arm) being pulled outwards and upwards. The pectoralis major muscle then creates a slight lift in our rib cage by pulling on the sternum, creating more space in our chest cavity. Our lungs can expand more fully, allowing us to breathe easier.

Effect on knuckle cracking on the joints

I greatly detest knuckle cracking, and get rather annoyed when people crack many knuckles one after another, which probably stems from a mindset that it will give you spoiled joints in time. Perhaps, it came from my personal experience where I had accidentally cracked joints and experienced pain (my pain threshold is extremely low).

From the understanding of the basis through which the sound is produced, then there will technically be no damage caused by the cracking. The sound produced has nothing to do with snapping or friction, and after all, the gas forced out would eventually redissolve.

However, there are tendons, ligaments and other structures that lie adjacent to your joints. Perhaps in serial crackers, these may be overstretched and damaged in some form. Still, many have claimed to have cracked their knuckles over many years, but have not experienced any repercussions.

The lack of research on this topic leaves it much open to debate. For now, knuckle cracking could be considered 'innocent until proven guilty'.

Cracking of fingers

Welcome back to the former NeuroChowzy blog, now known as Mediquirks. I decided to restart this blog whilst in medical school because of the exorbitant amount of interesting information we are taught in medical school. This blog will still retain its former purpose of being a layman medical blog, as well as a portal for questions. My former posts are still available for viewing and you can be a follower of this blog, by clicking on "Followers" section on the right.

Please do welcome a fellow contributor to this blog, my girlfriend Grace, who also is in the NUS Medical School.

Today's topic is one which is close to the heart of many, especially guys. It is concerned with the "cracking" of fingers. Ever pulled your finger forwards, away from your palm before? Or bent your finger and "cracked" your knuckle? You might have heard a distinct crack sound which can't be reproduced for a few minutes after that. This is why:


The joints which you normally "crack" are formed by connective tissues and ligaments which hold the two bones at the joint together in a capsule. There is fluid in the capsule, known as synovial fluid. When the bones are pulled apart, the capsule holding the both bones stretches, creating a vacuum in the capsule. Gases do not dissolve as rapidly and bubbles form in the capsule. When the bones are pulled far away from each other, the pressure drops so low that the bubbles burst, causes a "crack" sound.

It takes some time for these gases to redissolve into the joint fluids, so in the meantime, you will not be able to crack your knuckles or joints again in the same way.

Interesting eh?