In the following mentioned case, unreasonable handcuffing was discussed. it appears that, Police can not handcuff just because a person was arrested.
Kumar v Minister for Immigration, Local Government & Ethnic Affairs (1991) 28 FCR 128
In interpretation, Kyrou J. stated in Slaveski v State of Victoria  VSC 441,
“Lockhart J held that the power of arrest exercised by the officer implied a power to handcuff an arrested person, but only to prevent that person from escaping or endangering the safety or property of other persons. His Honour decided that the handcuffing of the applicant was unreasonable because his conduct had not suggested that he was likely to escape or to act in a violent manner”
If you believe you have been handcuffed unreasonably, you may have legal options.