Teenage growth spurt

guys,
can you tell me why i have a problem with maintaining hip height after a major growth spurt. What are the physical reasons for this happening?
Confusingly, i am stil having this problem (im now 21) after the spurt has finished???
Is it possible my body has not finished growing at 21?
Any advice would be great

Thanks

Think of a specific level of output. When you grow, you use a tremendous amount of the output level you have on hand, reducing what you can do in training. Spurst tend to go in cycles and can go on to your early 20s