How Does Our Musculoskeletal System Age?

Most, if not all of us, know that as we age, our bones and muscles age with us. Bones and muscles primarily compose our musculoskeletal system—a system full of bones, muscles, tendons, and ligaments. The musculoskeletal system allows us to perform movements such as walking or typing on a keyboard.

Our skeleton, a flexible “framework” that supports our body, protects internal organs and makes movement possible. The skeleton is grouped into two divisions: the axial and appendicular skeletons.

The axial skeleton contains 80 out of the 206 total bones and makes up the long axis that runs down the center of our body. It provides protection, support, and consists of the cranium (skull), vertebral column, ribs, and sternum.

The appendicular skeleton, containing the remaining 126 bones, lets us move from one place to another and to manipulate objects. It consists of the bones of the upper and lower limbs and the girdles that attach them to the axial skeleton. The pectoral girdles, made of a scapula and clavicle, attach the bones of the upper arm to the ribcage. The pelvic girdle, made up of two hip bones joined to each other and the sacrum, attaches the femurs (thighbones) to the vertebral column.

When bones meet, they form joints. Joints are flexible and allow movement. However, the range of movement of any singular joint depends on the conformation of the joint and how tightly ligaments and skeletal muscles hold it together. Each skeletal muscle has specific points to which it’s connected to bones by tendons. Muscles contract to pull bones in, creating a wider range of movement.

Additionally, another function of bones is to protect organs, such as the heart and the brain. These organs would easily be damaged without the protection offered by the rib cage and the cranium respectively. The bones of the skull also protect the inner parts of the ear and create the protective sockets that house the eyes. The rib cage protects the heart and lungs, as well as blood vessels, and offers a large degree of protection to the organs of the gastrointestinal tract.

Although important to supporting our bodies, bones are subject to two main stresses: the weight that bears down on them as a direct result of gravity, and the force of tension exerted by muscles. As a result of these stressors, multiple changes occur as bones age. Over time, they lose their density and become more vulnerable to fractures and other complications, such as osteoporosis. Osteoporosis creates a loss of calcium and other important minerals that are vital to bones. As a result of this, bones become more porous and brittle, reducing their strength and increasing the risk of damage. Our joints also stiffen, potentially leading to osteoarthritis.

On the other hand, muscles, the other core component of our musculoskeletal system, age just as much as the rest of our body does. Instead of losing density, muscles lose mass. Whereas bone density is the amount of minerals in bone tissue, muscle mass includes the total weight of your skeletal muscles and smooth muscles, along with the amount of water within them. Along with decreased muscle mass, muscles age by losing tone. Simply put, muscle tone is how much muscles resist stretching during a resting state. On a more complex level, it’s the normal state of balanced tension within the tissues of an individual’s body.

So, how can we help keep our muscles healthy? In order to help lower the risk of extensive damage in our older years, there are numerous practices individuals can participate in - the first being exercise! Exercise mitigates the loss of muscle bulk and can partially compensate for decreased flexibility of joints along with age-related arthritic symptoms. Exercises such as walking, running, dancing, or sports (when performed several times weekly) stimulate bone cells to reshape bones and strengthen them. Another way to keep our bones and muscles healthy is to maintain a constant intake of calcium, vitamin D, and water.

Our musculoskeletal system helps support our daily life. From movement to protecting organs, the musculoskeletal system is vital to maintaining our health. As we age, our musculoskeletal system ages, and it is crucial that we continue to take good care of our bones and muscles at every age!

References

• Roberts, A. (2019). The complete human body: The definitive visual guide. NY, DK Publishing.

Images

• https://i.pinimg.com/originals/bc/26/45/bc26451e3a66e32b4d68fb263e7a1db7.jpg

• https://www.spineuniverse.com/sites/default/files/imagecache/gallery-large/wysiwyg_imageupload/3998/2018/08/28/bone_normal_osteoporosis_53334713_ML_cropped.jpg

• http://il6.picdn.net/shutterstock/videos/5040104/thumb/1.jpg