The average person can bend their feet back (dorsiflexion) about 10 to 15 degrees using only their leg muscles (no external force). While barefoot, standing perfectly straight, and holding on to something to keep from falling down, try to raise the ball of your feet off the ground. If you can't, then you DEFINATELY need to be stretching.
The next picture shows the fascia under strain when walking.
Below is a picture showing how a heel pad can help relieve the strain. If a heel pad gives immediate relief, then it is a good indication that stretching the calf muscles is needed. Heel pads usually should be only a temporary solution. They should be used in both feet.
Below is a picture showing how stretching the calf muscles can relieve the strain in the fascia and Achilles tendon.
Running and longer strides also cause the angle to be greater. Running shoes have a raised heel for this purpose.
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