I have empathy for you as I've been dealing with the patellar tendonisis thing myself for a while.
Have someone watch you ski while you ski first as flexed as you can, then extended as you can, then your normal pattern. Their feedback should help you determine where you both: Travel within your overall range of flexion/extension limits and where your normal skiing puts you within that range.
If you are skiing from more flexed to partially extended, and staying flexed most of the time, this would contribute to a tendonitis aggrivation. The more flexed you are at falline the longer you will need muscular engagment for support until you can start to release (stressing tendons). This stress is compounded if you are skiing with extension (up motion) prior to and thru your edge change.
If this is the case try to move up within avaliable range so that by being more fully extended you "stack your bones" for support in each turn and reduce constant stress of support on those tendons. This should involve really trying to lengthen legs in top of turn as you move body to inside after edge change. The more extended you are in falline the sooner you can "soften" muscles while turning out of it. Try to smoothly progress from max extension at falline, to relaxion/flexion thru edge change. When the turn dynamics are building thru finish, yield to allow CM to flow across edge change, don't resist, trying to extend up as forces are at maximum (it is a battle your body can only lose). Make love, not war with gravity. [img]smile.gif[/img]
You may need to adjust forward lean, boot flex, boot ramp and/or binding ramp angle to find a new stance to support a more extended and less flexed travel range for your skiing for/aft balancing needs.
I've reduced my binding ramp angle and softened my boots and I am always working on developing a smoother pressure cycle throughout the whole arc of my turns. I'm not yet ready to back off on the energy level and give up the skiing I love to do, so I continue to pursue efficiency.