Long term use of high heels can alter the anatomy of the calf muscles along with aching feet and a variety of foot deformities.
High heels put a lot of stress on the back and knees. Squeezing into high heels with narrow toe boxes can cause a condition called Morton's neuroma, which is a painful thickening of tissue between the third and fourth toes. To investigate the association between high heels and its effect on calf muscles, researchers from Austria followed 80 women aged 20 to 50 years, who had been wearing heels of at least two inches almost daily for the last two years or more. Of those, 11 said they experienced discomfort when walking in flatter shoes.
When compared with women who did not wear heels, ultrasounds revealed the women who wore heels had calf muscle fibres that were 13 percent shorter, while MRIs showed the Achilles tendon, which attaches the heel bone to the calf muscle, was stiffer and thicker.
The incline of high heels causes the calf muscles to contract. Over time, this causes the muscle fibres to shorten and the Achilles tendon to thicken; therefore some women feel pain when they try to walk in flats or sneakers.
The above findings conclude that long-term use of high-heeled shoes induces shortening of the calf muscles and increases Achilles tendon stiffness, reducing the ankle's active range of motion.