In the tension/bowstring test, what action is taken to assess sciatic nerve irritation?

In the tension/bowstring test, the key action performed to assess sciatic nerve irritation involves flexing the hip while passively extending the knee. This maneuver stretches the sciatic nerve and can elicit symptoms if there is irritation or involvement of the nerve. By doing this maneuver, the practitioner can evaluate the response of the nerve as it is put under tension, which may help identify any underlying pathology related to nerve compression or irritation.

The rationale behind this choice lies in the anatomical relationship of the sciatic nerve to the structures it runs through. Sciatic nerve irritation can often present with specific symptoms when subjected to different motions, particularly those that alter its length or tension, thereby revealing potential problems such as sciatica or herniated discs.

The other options do not effectively assess sciatic nerve irritation in the same way. For instance, flexing the knee until pain disappears does not apply sufficient tension to the nerve, while palpating the lumbar spine is not a direct test for nerve irritation. Lastly, assessing the foot for movement does not specifically target the sciatic nerve, making it less relevant in this context. Hence, the chosen action effectively evaluates the presence of sciatic nerve issues.