Gastrocnemius muscle
The rectus femoris THe regular Muscle Action is hip flexion with knee extension, as in kicking a ball or doing a straight leg raise The reverse muscle action is still hip flexion with knee extension, but as in doing sit-ups while lying supine with knes straight ahead
The muscle that primarily adducts the hip and extends the knee is the adductor magnus. This large muscle is located in the inner thigh and plays a significant role in hip adduction, while its posterior fibers also assist in extending the knee. In addition to the adductor magnus, the quadriceps group can contribute to knee extension. However, the primary focus for both actions is the adductor magnus.
The primary function of the knee extension muscle is to straighten the leg by extending the knee joint.
The Gastrocnemius. There is another muscle involved in plantar flexion. The soleus and the tibialus posterior maintains the arch. The only one that does both actions, though, is the Gastrocnemius.
You can not reverse muscle tiredness, you just have to rest them.
The muscle primarily responsible for the last 10 degrees of knee extension is the popliteus muscle. It is a small muscle located at the back of the knee joint and helps to unlock the knee by internally rotating the tibia on the femur.
An agonist muscle is a muscle that plays a part in the extension of a muscle. The agonist muscles for a knee extension are the quadriceps and hamstrings.
The flexor would be the hamstring, and gastrocnemius, which bend/flex the knee. The quadriceps, are extensors, which straighten/extend the knee.
The primary muscle responsible for extending the thigh is the quadriceps femoris, specifically the rectus femoris. To flex the knee, the primary muscles involved are the hamstrings, particularly the biceps femoris, semitendinosus, and semimembranosus. These muscle actions are important for movements like running and kicking.
The muscle that contracts when the leg is extended at the knee is call the gastrocnemius muscle
Vastus medialis (a tear-shaped muscle right above your knee)
Quadriceps muscle or thigh muscle.