The knee joint supports most of the body’s weight and allows movements that are essential to many everyday activities, such as walking, running, sitting and standing. The knee joint is the largest joint in the body and it relies on a variety of ligaments, tendons, and soft tissue structures to maintain flexibility, stability, and strength. The knee joint is formed by articulations between the patella, femur and tibia. The knee joint is a hinge synovial joint. Like all synovial joints, the knee is surrounded by soft tissue structures and ligaments that support the joint and help facilitate a wide range of movement. The knee joint requires these multiple ligaments to keep the bones in place and maintain its ability to flex and bend. The bones …show more content…
Fibroblasts are the most numerous cells in this dense connective tissue. Fibroblast is responsible for the synthesis of collagen and extracellular matrix. Bands of such connective tissue are used to compose ligaments and tendons. Most tendons and ligaments require strength and inelasticity. Within tendons the collagen bundles are thick and parallel with flat nuclei of fibrocytes aligned with fiber bundles. Ligaments and tendons resist linear forces along their lengths. Ligaments are ropy, fibrous bands of tissue that connect bones to other bones. Ligaments surround joints in order to provide support to the joints and prevent dislocation and injury. The stability of the knee is due to four ligaments: The anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), lateral collateral ligament (LCL), and medial collateral ligament (MCL). Ligament tares are common injuries in athletes; a torn anterior cruciate ligament often results from a one-time trauma, such as sudden twisting or an impact to the knee resulting in unable to continue to compete (Oliveria 2017). LCL tears are most commonly injures in sports that involve many quick stops, such as soccer and basketball, and …show more content…
The outer layer, or subintima, is a thicker and fibrous protecting the single cell initma layer which is composed of synoviocytes. A very thin layer of slippery, viscous joint fluid, called synovial fluid, separates and lubricates the two cartilage-covered bone surfaces. A healthy knee joint has up to 4 mL of synovial fluid (Fox 2012). Oily synovial fluid is produced by the synovial membrane that lines the joint capsule and fills the hollow space between the bones, while lubricating the knee to reduce friction and wear. At the surface contacting the synovial fluid the tissue is well-vacuolated, with many porous capillaries, and contains two specialized cells. Surface of synovium may be flat or may be covered with finger-like projections (villi), to allow the soft tissue to change shape as the joint surfaces move on one another. Lining cells are modified connective cells called synoviocytes rounded synoviocytes are phagocytes derived from blood monocytes and fibroblastic synoviocytes specialized to produce the long, nonsulfated glycosaminoglycan (GAG) hyaluronic acid and secrete other components of ground substance (Mescher
The elbow is a hinge joint, moving in only one dimension (flex or extend), making it relatively simple from an architectural and functional standpoint. The humerus bone in the upper arm connects to the two bones of the forearm by means of various connective tissues. For a pitcher, one of the most important of these connections is the unlar collaterial ligament (UCL). The UCL offers much of the stability that is necessary for the elbow to withstand the extreme stresses created by throwing a baseball at high velocity. Its function is to stabilize against lateral forces and to keep the arm connected across the joint space.
Nisell R. (1985) Mechanics of the knee: A study of joint and muscle load with clinical applications. Acta Orthop Scand 216; 1-42.
The anterior cruciate ligament (ACL) is one of the most important of your four major knee ligaments. The function of the ACL is to provide stability to the knee and minimize stress across the knee joint. It restrains excessive forward movement of the lower leg bone (the tibia) in relation to the thigh bone (the femur). It also limits rotational movements of the knee. “Greater external knee valgus and internal rotation moments have been shown to increase loading on the ACL in vitro and are thought to be associated with the increased risk of noncontact ACL injury” (Effects 2011). A tear to the anterior cruciate ligament results from overstretching of this ligament within the knee. It’s usually due to a sudden stop and twisting motion of the knee, or a “...
In order for athletes to save their active lifestyles they need understand the ACL. The ACL is the most important ligament in the knee because it provides stability to the knee. Athletes have to be aware of the importance of the ACL and know its functions in order to preserve the ligament. The ACL otherwise know as the anterior cruciate ligament is the ligament in the knee that connects the upper leg bone which is the femur to the lower leg bone which is the tibia. The anterior cruciate ligament crosses with the posterior cruciate ligament inside the center of the knee joint to stabilize to the knee in movement.
The most common knee injury in sports is damage to the anterior cruciate ligament (ACL) through tears or sprains. “They occur in high demand sports that involve planting and cutting, jumping with a poor landing, and stopping immediately or changing directions” (University of Colorado Hospital). The ACL is a ligament that runs diagonally in the middle of the knee and found at the front of the patellar bone. Its function involves controlling the back and forth motion of the knee, preventing the tibia from sliding out in front of the femur, and providing rational stability to the knee. Interestingly, women are more prone to ACL injuries than men. The occurrence is four to six times greater in female athletes.
To understand the importance of the ACL, the knee as a whole must be examined. The knee is formed by the femur, the tibia, and the patella. Several muscles and ligaments control the motion of the knee and protect it from damage at the same time. Ligaments are dense structures of connective tissue that fasten bone to bone and stabilize the knee. Two ligaments on either side of the knee, called the medial and lateral collateral ligaments, stabilize the knee from side-to-side. The ACL along with the posterior cruciate ligament are of a pair of ligaments in the center of the knee joint that form a cross. T...
The surfaces of the joint are organised to allow only back and forth motion such as bending and straightening. This type of joint can be found between your upper arm and your lower arm, in the elbow. This type of joint is incredibly important as it allows an up and down movement, without this type of joint, we wouldn’t be able to move our arm up and down. Muscles are attached to this type of joint by tendons to allow it to contract and relax and be able to move the bone within this joint. Ligaments attach the bones in a hinge joint together, for example, the humerus and the tibia are joined by ligaments but they also have antagonist muscle pairs attached to them by tendons which allow the bone to move by contraction and relaxation of the muscles. This type of joint mainly includes long bones as it’s necessary for movement in the skeletal
Ligaments are tough, non-stretchable fibers that hold bones together. Damage to cruciate ligaments, which crisscross the knee to give it stability, is one of the most common sports injuries. The “tear” occurs from changing direction rapidly, slowing down from running, or landing from a jump improperly. The A.C.L tear is one injury that worries athletes in all sports at all levels because of its devastating effects. People ages 15-25 that participate in basketball and other sports that require pivoting are especially at risk.
Have you ever been injured? By sports? If so, what injury did you have? Did you do active rehabilitation? Do you try to prevent injury when exercising? These are some questions that you might need to ask yourself when exercising or participating in sports. You also must know that there are many sports injuries as well as many ways to prevent them.
In order to understand how the menisci can be injured, you must understand the basic anatomy of the menisci and why they are important. The menisci are two oval (semilunar) fibrocartilages that deepen the articular facets of the tibia and cushion any stresses placed on the knee joint. They enhance the total stability of the knee, assist in the control of normal knee motion, and provide shock absorption against compression forces between the tibia and the femur (Booher, 2000). Articular cartilage covers the ends of the bones that make up the joint. The articular cartilage surface is a tough, very slick material that allows the surfaces to slide against one another without damage to either surface. This ability of the meniscus to spread out the force on the joint surfaces as we walk is important because it protects the articular cartilage from excessive forces occurring in any one area on the joint surface, leading to degeneration over time (Sutton, 1999).
The knee joint is extended when in the standing position, to stabilize this joint the biceps femoris, semi-mebranosus, semi-tendonosus (hamstrings) and the rectus femoris, vastus lateralis, vastus intermedius and vastus medialis (quadriceps) co-contract isometrically.
The bundles of collagen fibrils are wrapped in endotenon, which in turn is enveloped by an epitenon, forming the actual tendon. A real synovial sheath is present only in some tendons, such as tibialis posterior, peroneal, and extensor and flexor tendons of the wrist and the hand; other tendons do not have a proper sheath, with the epitenon instead surrounded by a paratenon, a layer of thin tissue(Abate et al. 2009). The space between these two layers contains fluids rich in mucopolysaccharides that provide lubrication, prevent
As submitted by Yan et al., (2011), meniscus tears, a condition prevalent among the old and young patients in equal measures are common predisposing factors for knee pain. Magnetic resonance imaging (MRI) is done on the knee section and has incidentally found meniscal tears to be a typical case in regards to the general population. The prevalence of the condition was also determined to increase with the advancement of age. The purpose of the study is to conduct a prediction of the probability of the condition (meniscus tears) using a comparison of patient’s test history and MRI with physical examination (McMurray’s test).
An ankle fracture is a break in one or more of the three bones that make up the ankle joint. The ankle joint is made up by the lower (distal) sections of your lower leg bones (tibia and fibula) along with a bone in your foot (talus). Depending on how bad the break is and if more than one ankle joint bone is broken, a cast or splint is used to protect and keep your injured bone from moving while it heals. Sometimes, surgery is required to help the fracture heal properly.
The purpose of the squat is to train the muscles around the knees and hip joints, as well as to develop strength in the lower back, for execution of basic skills required in many sporting events and activities of daily living. Because a strong and stable knee is extremely important to an athlete or patient’s success, an understanding of knee biomechanics while performing the squat is helpful to therapists, trainers, and athletes alike (11). Because most activities of daily living require the coordinated contraction of several muscle groups at once, and squatting (a multi-joint movement) is one of the few strength training exercises that is able to effectively recruit multiple muscle groups in a single movement, squats are considered one of the most functional and efficient weight-bearing exercises whether an individual’s goals are sport specific or are for an increased quality of life