Which test is most likely to indicate back pain when performed as a single-leg stance with trunk extension?

• A. Stork Standing Extension Test
• B. Single Leg Stance Test
• C. Gaenslen's Test
• D. Oostegard Test

Answer: (A)

The key idea is provocative loading of the posterior lumbar elements in extension with unilateral stance. When you stand on one leg and extend the trunk, you create a combination of lumbar extension and single-leg loading that puts increased stress on the pars interarticularis and facet joints on the supported side. If there’s a stress reaction or fracture in the pars region (spondylolysis) or other posterior element irritation, this maneuver is likely to reproduce the patient’s back pain, making the test positive and highly suggestive of pars-related pathology in younger athletes.

In contrast, a general single-leg stance test mainly assesses balance and core control without specifically loading the posterior elements in extension. Gaenslen’s test targets the sacroiliac joint by hyperflexing one hip and extending the other leg to stress the SI joint, not by extending the trunk on a single leg. The Oostegard test is also used for SI joint provocation rather than extension-related stress of the pars interarticularis. Hence, the Stork Standing Extension Test best isolates the mechanism that would reproduce pain from pars issues.