"[Break point] The point at which your hair always breaks is the point at which you may need to change your routine....Think back to the longest your hair has ever grown. Even if your hair is still at this length, if it doesn't grow any longer this is likely to be your break point."
I find this paragraph very fascinating because it is scientifically accurate (even though Chicoro was writing based on observation and not science).
Fact: Hair APPEARS not to gain length because it is breaking
In order for hair to gain length, it must grow faster than it breaks. Let me repeat that, In order for hair to gain length, it MUST grow faster than it breaks.
This break point as observed by Chicoro is known scientifically as the critical length (Journal of the Society of Cosmetic Chemists, pg 155-75, 1978). I have previously discussed the findings of this paper here
Fact: Is regular trimming necessary?
The best science points to yes being the answer. The reason why hair reaches the critical point is because the cuticle layers gradually become thinner. This leads to easier breakage and split ends. Some people CAN grow very long hair without needing to trim (Example Teri of tightly curly).
However, remember that we are all individuals. If you have experienced a break point then you are probably not in this group. Regular trimming means a snip every 3,4 or 6 months, whichever one helps you find less and less split ends.
Fact: Why does regular trimming help hair grow longer?
Remember the crucial balance - In order for hair to gain length it MUST grow faster than it breaks. Trimming does not grow hair but getting rid of thinned down or absent cuticles may help to stop or slow breakage (meaning hair can return to growing faster than it breaks) .
Fact: What else can you do to pass the break point?
Chicoro suggests changing routines and trying to strengthen the ends of the hair. (taken from SofullSista). I think this is good advice. If your hair is stuck at a certain point then the methods and skills you have are good enough to keep it at that length. If you want to move it along then you have to change what you are doing.
The main change should be along the lines of being gentle. Hair breaks because of applied force. Be conscious whenever you touch your hair, are you being as gentle as possible? Really be conscious, are you pulling your hair when styling it? When you apply styling products are you being as gentle as possible?