To paraphrase the great dance kinesiologist Sally Fitt, of all the principles of conditioning, the most frequently overlooked is effective sequencing. Five teaching principles:
1. start gradually- warm-up first
2. After fatiguing a muscle group, take time to recover and loosen (the primary problem w most gym programs)
3. before stretching a major muscle group, ‘set up’ by doing a maximal contraction in the opposing muscle group if it’s equal mass
4.consider joint actions
5. listen to the body

So it’s #3 that I want to discuss, suggesting that reciprocal stretching, as I know the term, is one of the more useful types for dance students as it both strengthens the opposing muscle groups as it ‘allows’ lengthening (muscle groups should be of equal mass). I will talk in laymen’s terms:
A. seated with legs outstretched, reach for feet for a ROM ‘test’
B. lie on the floor with knees to chest
C. grab feet if possible or shins and contract the hip flexors for 60 seconds, strengthening hip flexors
D. release and come back to #1- ROM should have improved

Here’s an article FFI –  http://voices.yahoo.com/physiological-principles-pnf-stretching-483519.html However I want to go further and suggest that the manner in which I see PNF stretching used is wrong in my opinion. All successes I’ve seen, like the one above, use short levers, not long ones (see #4- joint action is more specific with short levers). Partner assisted stretches are dangerous whether with kids or adults (see #5) And most important, as movement educators, we know that without the balance between strength and flexibility, there are no lasting effects to any flexibility program and the dancer is then prone to injury. By working close to the core, the dance student strengthens AND lengthens critical muscles groups. Conversely, strong anterior trunk muscles keep posterior muscles relaxed and vice versa. Shoulders (using doorways-watch for neck tension) and hips (seated) can be strengthened and lengthened in the same manner. I will post more later. If this is more technical than you’d like, try reading http://carol-schwarzkopf.com/posts-2/

Flexibility – the Tortoise and the Hare Revisited