One can assume that Pinan kata are derived from this kata. I have read many claims that say it is for sure even that parts from Gojushiho kata where implemented in the Pinan series. Since even our Founder Ohtsuka sensei was not sure..
from translation of his book "so much, that maybe Pin-an derived from this kata".
N. Nukina sensei performing Kushanku kata at a demonstration in Bulgaria 2007. Kushanku start at 0.52 sec.
Kushanku practise with Kaisetsu
recorded at springcamp 2010
KATA