How is the knee joint poorly protected and thus especially vulnerable to injuries?

Question

the full question is:Compared to the shoulder and hip joints, in what way is the knee joint poorly protected and thus especially vulnerable to injuries?

Answer 1

The knee is particularly unstable because it bears so much weight with relatively little support.

Think about the structure of the joint. The very large femur sits precariously atop the significantly smaller tibia. The two bones slide back and forth on each other, even in non-stressful conditions.

A hard knock to the knee can easily take advantage of this weakness and cause injury, whereas a similar blow to the shoulder or hip will cause little, if any damage.

Fortunately the instability of the knee's bony structure is partially compensated for by strong ligaments and muscles. However, these ligaments are very prone to injury themselves when they are pushed beyond their limits.

Answer 2

The knee is a joint that has very flat articular surfaces. This works well for the motion of the knee like flexing the leg, and the knee also has the ability to rotate and have forward and backward glide action. This is at the expense of stability. In order to stabilize this very flat joint a meniscus is employed. And some intracapsular ligaments like the cruciate ligaments. These ligaments prevent over rotation of the knee and with all of ones body mass it is rather easy to over come the strength of the ligaments and tear them. A torn cruciate ligament is common. The meniscus is a cushion and helps stabilize the joint. With age it will become more brittle and is prone to small tears. Or it can tear from an injury or pounding from running. So you have a rather unstable joint holding up all your body mass now you can see how easy it is to damage your knee.

Answer 3

The knee has no bone structure holding it together or adding stability. It has soft tissue (ligaments) providing this support.

The shoulder and the hip have (in important orientations) bone to bone mechanics in the form of a ball-and-socket joint (plus ligaments).

So the knee is vulnerable to dislocation from many directions - usually leading to damaged ligaments, whereas the shoulder and hip are only vulnerable to dislocation from specific orientations of stress, or stress at much higher force levels.

Answer 4

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Answer 5

The knee is very vulnerable to medial and lateral forces that can damage the lateral collateral ligament and medial collateral ligament, respectively.

Best wishes.