Usually for sciatica the recommended progression includes nerve gliding exercises, back unloading exercises ( e.g. alternate knee to chest ) along with extension exercises ( e.g. McKenzie extension  protocol for centralizing the symptoms). I went through all the videos and they seems to be useful depending upon the stages of sciatica. For example, sitting position increases the intra-discal pressure and

1st Video: http://youtu.be/QKbAkFqRaBU : explains rounded/ protracted shoulder which is quite common posture in most of us (especially desk job) or an individual’s general tendency of adopting such posture after an injury (protected position).   This posture over time decreases the subacromial space and thereby can contribute to impingement syndrome. To prevent this; focus should be on : a) appropriate stretching

1. http://www.youtube.com/watch?v=XlrFc0BYv3U&feature=youtu.be : I personally don’t think that someone with knee pain ( meniscal tear, ACL or any other ligament injury) would be able to activate Quads effectively, especially during initial phases when done with full weight bearing or unsupported. Firstly, patient may not be able to distribute weight equally on both the limbs due to pain and secondly, there