An extensometer structure comprising a first extension arm having a first mount configured to support a first specimen engaging member and a second extension arm having a second mount configured to support a second specimen engaging member. A cross-flexure assembly is formed between the first extension arm and the second extension arm remote from the first mount and the second mount. The cross-flexure assembly may include a first flexure and a second flexure each joined to and extending between the first extension arm and the second extension arm. The second flexure is orthogonal to the first flexure to form a pivot axis, the second flexure extending only on one lateral side of the first flexure from the first extension arm to the second extension arm and the first flexure extending only on one lateral side of the second flexure from the first extension arm to the second extension arm.