Calf raises are sometimes done with a flexed knee, usually roughly 90 degrees. This lessens the stretch in the gastrocnemius (a knee flexor), so the movement is done to emphasize the soleus.
Seated Bent-knee calf raises are frequently done in a seated position for comfort. Since the weight of the upper body is rested on the seat, resistance is frequently added. Using bodyweight, one leg could be draped across the other (through external rotation) to exercise unilaterally and double the weight lifted. It can also be executed by using a weight, such as a
barbell, to provide resistance to the action of the calf muscles. The exercise is performed from a seated position while the weight rests on the upper leg, just above the knee. The person engaged in this exercise lifts the weight by pushing down on the balls of the feet. Due to the discomfort of higher weights on a bar, barbells used for seated calf raises are frequently padded or wrapped in a towel. There are also seated calf raise machines designed using levers that have pads built into them to protect the patella, quadriceps and tendons. This exercise is more commonly used for the soleus since the gastrocnemius does not work as much in a bent knee position.
Bridging Bridging exercises are done with a flexed knee to lessen the stretch on the hamstring (a knee flexor) and focus the hip extension work on the gluteus maximus. In that same respect, the reduced knee flexion makes plantar flexion work comparable to a seated calf raise, due to the lessened stretch on the gastrocnemius (like the hamstring, also a knee flexor). Since the pelvis is in the air, its weight can be shifted onto the feet allowing greater resistance. This is an awkward exercise due to the reduced stability and difficulty in adding resistance. If one were to raise a leg, the use of the arms to avoid falling sideways would often be necessary. If one were to place a padded barbell on the upper quadriceps to add resistance, this would make the arms less able to stabilize, requiring core stabilization. ==Straight-knee==