Written Assignment for Unit 2 HS 2211 Human Anatomy and Physiology University of the People Instructor: Pankaj Mehrotra 06/26/23
Introduction The human body is made up of a complex system of joints that allow for mobility and sustain its structural strength. The knee joint is one of these joints and is essential for stability, weight- bearing, and movement. This essay will look at the skeletal structure of the knee joint and how it relates to its range of motion. Additionally, it will define and incorporate three physiological terminologies related to the functional arrangement of the joint system to show understanding of the provided information. Anatomy of the Knee Joint The knee joint is a synovial joint formed by the articulation of three bones: the femur (thigh bone), tibia (shinbone), and patella (kneecap). It is classified as a hinge joint, allowing primarily flexion and extension movements but also possessing limited rotational capabilities (OpenStax, 2018). The distal end of the femur and the proximal end of the tibia form the main components of the knee joint. The articulating surfaces of these bones are covered with a smooth layer of hyaline cartilage, which reduces friction and absorbs shock during movement. Additionally, the menisci, two C-shaped fibrocartilaginous discs located between the femoral condyles and tibial plateaus, enhance stability, and distribute forces across the joint (OpenStax, 2018). Ligaments and Tendons: Ligaments are vital structures that provide stability to the knee joint by connecting bones and limiting excessive movement. The knee joint is reinforced by several ligaments, including the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL) (OpenStax, 2018). The ACL and PCL, located inside the joint capsule, form a crossing pattern that helps prevent excessive anterior and posterior displacement of the tibia in relation to the femur. These ligaments play a crucial role in maintaining the rotational stability of the knee joint.
On the other hand, the MCL and LCL are extracapsular ligaments located on the inner and outer sides of the knee joint, respectively. They provide lateral stability by resisting excessive medial and lateral forces applied to the joint. Together, these ligaments ensure the proper alignment and functioning of the knee joint during movement (OpenStax, 2018). Muscles and Range of Motion: The knee joint's movement is facilitated by the action of the muscles surrounding the joint. The quadriceps muscles located on the front of the thigh are responsible for knee extension, while the hamstrings at the back of the thigh allow knee flexion. The muscles of the calf, such as the gastrocnemius and soleus, contribute to knee flexion and play a role in stabilizing the joint during weight-bearing activities (OpenStax, 2018). The skeletal features of the knee joint, including its hinge-like structure and the arrangement of ligaments and muscles, largely determine its range of movement. The primary movement of the knee joint is flexion, which allows bending of the leg, bringing the heel towards the buttocks. Extension, the opposite movement, straightens the leg from a