Over the course of our lives, it is extremely likely that at one point we are going to break a bone. For some of us that comes when we are young, perhaps 18 or younger. For others, we may break a bone later in life, perhaps at the age of 60 or older. One thing is for certain, the recovery process is significantly different from when you break a bone at 18 versus when you break a bone at 60. For my steam project, I will be looking into my favorite bone in the body, and by far my favorite course objective over this semester, which is the knee joint. For my steam project in this essay, I will be discussing the anatomy of the knee which will explain why the rate of recovery is longer for a 60-year-old versus an 18-year-old. In addition to the essay, my steam project will consist of two videos showing the rate of recovery for an 18-year-old versus a 60-year-old. In the video you will see the rehabilitation process of both ages and a noticeable difference in the speed. The video is meant to only show rate of recovery, whereas this paper is meant to show you the why and the anatomy of the knee behind the rate of recovery.  

Before talking about the recovery process of breaking a knee, it is critical that we first discuss the muscles involved in the knee. The three main things we use our knees for are flexing, stabilizing, and extending. All the muscles in our knee work closely together perform everyday things like running, walking, squatting down, landing safely when jumping, and standing still in place. When it comes to extending the knee, the quadriceps femoris is the muscle we have to thank. Broken down the quadriceps femoris consists of the rectus femoris, vastus lateralis, vastus medialis, and the vastus intermedius. The rectus femoris is found across the hip and the knee, the vastus medialis is found on the outside of the knee, the vastus medialis is found on the inside of the thigh, and the vastus intermedius is found just below the rectus femoris. Regarding flexibility and knee flexing, the muscles we owe thanks to is the hamstring group. According to peer reviewed study done by Ibrahim Moustafa, Flexibility is defined as “the range of movement or motion of a single or multiple joints.” Its limits decline significantly with age, reaching maximum flexibility in the mid-to-late twenties for males and females. The hamstring group consists of the bicep femoris, semimembranosus, and the semitendinosus. The bicep femoris has a long head and a short head and is the main muscle responsible for flexing of the knee. The Semitendinosus and the semimembranosus are both on the inner part of the bicep femoris. All the hamstring group muscles work together to flex the knee. When talking about knee stabilization, according to a peer reviewed study done by Helder Lopes, the hamstrings act as antagonist to the quadriceps to provide knee stability as well as to counteract anterior and rotational tibial shear forces during weight bearing exercises. This is important to know because during the rehab process, a lot of exercises include rebuilding the strength of the knee by doing exercises that test the stability of the knee.  

Now that we know what muscles are involved in the knee, let us look at why the recovery time would be faster in an 18-year-old versus a 60-year-old. The main reason for the 18-year-old recovering faster is due to bone density. When you are young, your bones are more dense and less brittle, so they are typically the strongest that they will ever be. The older you get the less dense your bones become you are more prone to osteoporosis; this causes the recovery time to become longer. Another reason that the 18-year-old will recover quicker is due to the muscle mass. Unfortunately, as we get older our muscle mass decreases, look at everybody builder at the peak of their career, then look at them when they are 60, the most common difference is that they look noticeably smaller. Muscle mass plays a part in recovery time because the more muscle mass that you have, the more help your bones have during recovery.  

Now that we have discussed the anatomy of the knee, let us begin breaking down the recovery time of a broken knee. According to a John’s Hopkins study, the average recovery time of a broken knee in an 18-year-old is 3 to 6 months versus 6 to 12 months in a 60-year-old. We know that the recovery time is due to bone density, muscle mass, and brittleness of bone as you get older.  

Works Cited 

  • Lopes, H. S., Waiteman, M. C., Priore, L. B., Glaviano, N. R., Bazett-Jones, D. M., Briani, R. V., & Azevedo, F. M. (2024). There is more to the knee joint than just the quadriceps: A systematic review with meta-analysis and evidence gap map of hamstring strength, flexibility, and morphology in individuals with gradual-onset knee disorders. Journal of sport and health science, 13(4), 521–536. https://doi.org/10.1016/j.jshs.2023.08.004 
  • Moustafa, I. M., Ahbouch, A., Palakkottuparambil, F., & Walton, L. M. (2021). Optimal duration of stretching of the hamstring muscle group in older adults: a randomized controlled trial. European journal of physical and rehabilitation medicine, 57(6), 931–939. https://doi.org/10.23736/S1973-9087.21.06731-9Johns Hopkins Medicine. “Kneecap Fractures.” Johns Hopkins Medicine, 2024, https://www.hopkinsmedicine.org/ health/conditions-and-diseases/. kneecap-fractures#:~:text=Depending%20on%2Oyour%20age%20and, patellar%20in-juries%20may%20take%20longer. 

VIDEO FILES LINK FOR 60 YEAR OLD RECOVERY RATE: https://media.uaf.edu/media/t/1_3rgauct9

VIDEO FILES LINK FOR 18 YEAR OLD RECOVERY RATE: https://media.uaf.edu/media/t/1_8zf4qb1q