I've had this problem since 9 days ago. 4 days prior to that, I did a part time job as a promoter in an event for kids which required me to stand and squat (to play with kids) for 10 hours without sitting, and one day prior to the problem, I did a lot of prolonged squatting which caused me much more pain in my thighs and soles. In the morning of the incidence, I realized that I can flex downwards, but not extend upwards. I also have a tingling sensation on my big toe when bending my knee.