[R] doubly multivariate analysis in R

[Ludo Max]

20 subjects were measured in 5 conditions (thus repeated measures) and
for each subject in each condition there are 4 response measures (thus
multivariate as it is a combined score that needs to be compared across
the conditions).
 
So, using a multivariate approach to repeated measures this is a doubly
multivariate analysis.
 
I would appreciate any suggestions as to the best way to do such a
doubly multivariate analysis in R (I have done it in SPSS and SAS but
would like to see what it takes to do the same in R).
 
Thank you in advance for any help.
 
Ludo