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The knee, like the elbow to some extent, is a hinge joint however not a simple one. The lesser part of the thigh bone broadens into the femoral condyles and the upper shin bone similarly expands into the tibial condyles, the joint of these two enlarged areas forming the knee joint. The small bone on the exterior of the knee, referred to as the fibula, is not included in weight bearing nor is really part of the knee joint, serving just as an accessory area for the muscles regulating the ankle, foot and toes. The knee functions as a hinge dividing the leg, enabling the exertion of high levels of muscular propulsive force, the folding of the leg in flexing and the reducing of the leg in stepping to permit effective gait. knee running injury
The quadriceps muscles, the main thigh group, act to bring the knee into its locking position as the joint get closer towards full straightening or extension. The apes and monkeys are not capable of extending their knees in standing so this position takes high levels of energy, while complete extension plus locking of the knee joint enables standing without much effort. The knee joint is rotated inwards by the major quadriceps muscle as it gets near to totally straight and begins to lock. Human upright pose has actually progressed by this process to permit prolonged standing with extremely low energy expenditure due to the lack of exercise in the knee and hip muscles.
The cartilages, frameworks known as menisci, are shaped like a banked track in a crescent setup and fill in to some extend in between the rounded condyles of the femur and the flat tibial surface. Their feature has actually not precisely been shown, nonetheless they may help in relieving the knee into lock, lessening unacceptable motion of the condyles and bringing the condyles towards the joint center in movement. The 3rd component of the knee joint is the patella or kneecap, this little bone being lined with cartilage and put anterior to the knee.
The tendon of the quadriceps muscle holds the patella or kneecap within it, the muscle's major function being knee extension to raise the body from a chair or negotiate actions. The inner area of the patella, divided into two elements, is lined with joint cartilage and articulates with the major groove in between the condyles of the femur, sliding back and forth. The power of the quadriceps muscle to extend the knee against the body weight is substantially increased by the presence of the kneecap.
The flexion and extension airplane is the natural airplane of knee motion as this typical positioning makes knee discomfort problems happen less commonly. A bow-legged or knock-kneed pose allows unusual sideways stresses to be applied to the knee, obliging pressure onto one side of the joint and raising wear stresses which with time could trigger pain symptoms or arthritic changes. Patellar misalignment can additionally happen, forcing one of its elements against the side of the femoral condyle groove and triggering impingement discomfort due to raise in the friction forces.
During motion of the knee the menisci (the knee cartilages) and the kneecap undergo high mechanical forces and are the cause of a lot of usual knee problems. The motion array of the knee is typically from straight (zero degrees) to complete bend at about 140 degrees, differing with the body size and joint flexibility. As the knee undergoes the movements of extension and flexion the huge rounded condyles move and slide on the top of the tibia, with the tibial surface moving beneath them also.
