extending between its proximal end and distal end relative to the amputated limb by providing one of the invented side located u201c proximally located u201d attachment systems such rotation is limited or prevented this is because strap extends from a fixed anchor location on the side of the liner limb to a fixed anchor location on the side of the socket thus connecting those two fixed locations together at substantially a fixed distance apart thereby not allowing the anchor location on the socket to rotate any significant distance away from the anchor location on the liner although one of the invented attachment systems is preferred more than one may possibly be used for example at two positions around the side of the limb socket as described below in the especially preferred embodiment section other benefits of the attachment system include comfort and ease of use the preferred attachment system is simple to use each to reach and requires a minimum of dexterity the externally mounted lock mechanism eliminates the jamming of conventional distal locks often caused by a sock worn over the roll on liner while a ratchet style buckle and strap combination is preferred other releasable attachments and fasteners may be used for example extension members other than a flat strap with detents may be used such as a cord s loop s tab s or other rigid or flexible extension members latch mechanisms other than a.