Growth spurts are rough - it’s amazing that practically overnight a student can lose so much of what they’ve gained in strength and flexibility. Rest assured that he/she can get it back pretty much the same way you’d normally improve extension — core strengthening, iliopsoas strengthening (don’t forget to lengthen too), gentle stretching, and muscle release techniques (with balls and rollers and such).
But please be patient (this part won’t happen overnight) but if the student had it at one time, chances are it won’t take that long to get it back. It’s just that the student suddenly has a new body — longer limbs to leverage, etc. — and there’s a learning curve for operating it. This is a frustrating time for the student so as a parent or a teacher, the number one priority is to help him/her stay free of injury!
Stretching and strengthening too aggressively can be damaging during this time.
Also, please check out this article by Lisa Howell - some excellent ideas to take action after a growth spurt.
