Abstract: A joint for a storable tubular extendible member comprises an input housing with sets of rollers which progressively deform the storable tubular extendible member from its tubular state to a tape-like flat state. An output housing includes rollers allowing the tape-like member to recover to its tubular state. A pivot joins the input and output housings and a plurality of confining members such as nip rollers are provided between the input and output housings to maintain the member in its flat state. The nip rollers are supported by link arms much that some of the rollers may pivot about a pivot on the input housing and others may pivot about a pivot on the output housing. A medial set of nip rollers is constrained to remain medially positioned between the input housing and output housing by having link arms extending from both the input housing pivot and the output housing pivot. A drive is provided to cause the joint to selectively bend.