Greatest Muscle in the Animal Kingdom

Hello there, James, your favorite physical therapist here coming to you live from Rapid City SoDak with a blog post that will blow your friggen mind. When I was an undergrad and graduate student I would ask the question to my peers or teachers: “what is your favorite skeletal muscle in the human body?” It was a nice question that would fill quiet space and provide some insight into how someone thinks. I had one professor respond: “well ya know, I’ve never thought of that before, that is a good question.”

I think a lot about skeletal muscles. I might see a new referral walking into the clinic with complaints of hip pain. When they are walking in, I notice the hip is dropping excessively. I think: “I should check that gluteus medius/minimus muscle during examination. Probably take note of the glute max while I’m there.”

I get a new referral for neck pain and I notice that they have a forward head posture. I tell myself, “you should really check that upper trapezius muscle length. Maybe check rhomboid and lower trap strength as well.

I think about muscles all day every day and I love them in every way. So, I am going to tell you what I think is the greatest skeletal muscle in the animal kingdom. That’s right, the whole kingdom of animals. While I specialize almost exclusively in humans, I do like to think into other domains. I was gifted a book once: “Principles of Animal Locomotion” by McNeil Alexander. Life changing book that opens up the mind to the glory of God’s creation.

The pectoralis major and supracoracoideus in birds. An unbelievable piece of anatomy. This muscle group contracts with such power and force that it allows the animal to be propelled upwards. The

animal is essentially a skeleton built around the pectoral muscles affixed to the wing system. Look at the size of the “breast” muscles in relation to everything else on this bald eagle. That bird is meant to generate lift and hopefully snipe a few of those rabbits digging holes in my lawn. I don’t care how much bench presses the local body builder does, they will never be able to strap some wings to their arms and generate lift like the bald eagle or any bird.

Alas, this is the one chance I have been given to talk about one of my favorite fields of study – the biomechanics of a cheetah. The cheetah goes 0-60 mph in three strides. It’s acceleration is faster than even a Ferrari. I don’t know what is man made that can accelerate faster than a cheetah. Probably only a bullet out of a gun or a light switch connected to a light bulb. What’s especially unique about the

cheetah is the amount of lumbar flexibility. When you watch the cheetah run at full speed, it’s hind legs come into extreme flexion during the flight phase, the spine contorts – but the head is steady with the eyes purely fixed on it’s prey – in anticipation of an explosive hip and knee extension moment. If I had to answer the question: “what’s your favorite muscle in the sprinting cheetah?” I’d assume the psoas muscle group – or hip flexors. How can the hip get so much flexion so fast? I’d also like to know more about how it’s head can stay so stationary when literally every other joint is moving. Check out this video to have your mind blown.

Though one might make the case for the hamstring muscle group in horses. Perhaps the most powerful muscle in the animal kingdom. Don’t agree with me. Go stand behind a really pissed off horse. The forceful hip and knee extension – or double barrel kick – has sent many people to the Horsepital over the years. I don’t want to bore the reader with animal locomotion, though I do think about it on occasion. I do have a favorite skeletal muscle and I’m going to touch on it once I get done thinking about the biomechanics of the pistol shrimps bubble bullet and maybe what makes a squirrel jump and climb so well.

Ok, I’m done now. Everyone is really pissed off these days. People angry about all kinds of things. One doesn’t have to peruse the news very long to realize that people are really pissed off. Everyone shakes their fist at one another. But I won't be going into the biomechanics of a fist - to blah.

My personal favorite muscle in skeletal anatomy used to be the intercostals – they are so inspiring. But without further ado, my favorite muscle in the animal kingdom is the zygomaticus major muscle in humans.

The zygomaticus major muscle allows one to smile. I think this is what sets humans apart from any other species on the planet. Humans use a ton of facial muscles for facial expression. The ability to communicate and make friends is what sets us apart from other animals in the animal kingdom. Our ability to smile is really cool. In the last few years there has been a lot of atrophy of this muscle nationwide. While I specialize in rehabbing weak muscles, I did not get any formal training on making a person laugh – thanks USD and UMary for selling me short. Seriously, it’s the greatest muscle on planet earth because when you engage it, someone might engage theirs back.

Physical Therapy tip of the day.

Don’t let your Zygomaticus Major muscle atrophy and do your best to get others to smile as well. Frankly, I’m on a mission to Make Zygomaticus Major Muscles Great Again. What's your favorite muscle in the animal kingdom? Cheers, James

DPT