Muscle tendons symptoms and conditions

33yr Male, fairly fit. South Africa.
(very cautious on any drugs or illness - thanks for the internet for research)
About 5 weeks ago I developed severe sinusitus (headaches, dry nasal paths burning like hell, irritating eyes, sore throat...) Doctor prescribed the usual Augmentin SD. this cleared the nose, pain, throat. On the last day of the course, my chest started burning, together with coughing. Diagnosis was bronchitis (not pneumonia). so the doc prescribed Avelox for 5 days.
The pharmacist took great care in explaining all the side effects to me, and warned me to rest enough, drink lost of water (as with many medicine), don't take multi-vitamins or supplements with iron, zinc, magnesium, and most important that for 6 weeks not to do any exercise, not even walking too much, as your muscle tendons can be damaged. (I even stopped working in the garden, or lifting heavy boxes)

Taking the advice, I got better, and up to today (2 weeks since last pill), I haven't had any side effects as mentioned here. I will continue to check for any in the next few weeks.