Is it permissible to pray with the hands down to one's side during theentire Naamaz like the Muslims of West Africa?

To place the hands on the side is the view of some prominent Fuqahaa,
including Imaam Maalik ibn Anas Maalik. A Maaliki (follower of the Maaliki
Madhab) only should follow the ruling of his Imaam. Followers of other
Madhaahib, for example, Hanafi, Shaaf'ee, Hanbaliy should follow the ruling
of their Imaams by tying their hands during Qiyaam (standing posture).

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai