The triceps is a muscle in the upper arm that extends the elbow. It has no direct relationship to the knee.
extends leg; straightens knee joint
Quadriceps contracts to extend the knee joint. Rectus femoris, the part of quadriceps flex the hip joint on the thigh.
If your rectus femoris contracts, it would help to extend your knee and flex your hip joint. This muscle is involved in movements like walking, running, and jumping.
It is not a separate joint it is your hip joint, the hip joint is a ball & socket joint!!!
knee
Knee extension is a strength exercise that primarily targets the quadriceps muscle at the front of the thigh. It is commonly performed using a leg extension machine or with resistance bands. In contrast, triceps flexion and shoulder rotation are not standard strength exercises; triceps flexion typically refers to the action of bending the elbow, while shoulder rotation involves movement of the shoulder joint.
well suddenly you make a wrong movement and that's how it can happen
Two joint muscles in the upper limb is the wrist and the elbow. Two joint muscles in the lower limb is the ankle and the knee.
The muscle that contracts when the leg is extended at the knee is call the gastrocnemius muscle
It can make the joint unstable.
the muscle that is attached to the knee joint is the HINGE
knee joint