Plantar Fasciitis, end of recovery

Our user asked: "I am a 21 year old athlete, 6'4'', 210 lbs. I developed plantar fasciitis while in tryouts for a basketball team at my former college in late October. I have FINALLY gotten over most all of the symptoms. I can walk without pain all day, it rarely hurts in the morning, and is fine with a light rolling out of my foot using a FootLog. However, my big toe on my left (affected foot) has slightly less mobility than my right, and the plantar fascia that was damaged is very ridged and tight. When i pull either toe to moderate complete extension, the plantar fascia on my right foot is fairly springy and pliable, while the one on the left is much more stiff and ridged. I have my own personal FootLog, a plantar fascia brace, several exercise bands, a trigger point stick, an ankle rocker, and a personal ultrasound device. My new plan of attack is to apply pressure at different points along the plantar fascia and slowly extend the fascia through big toe stretches, move the pressure (thumb) and repeat, to perhaps losen some scar tissue. I also plan on using the ultrasound, and continuing with my stretches, and strengthening exercises. Any idea why this happened? And on a tangent, why must you keep the ultrasound head moving at all times? I see this warning, but I cannot find an answer for it online. (I am an aspiring physical therapist myself)"