To test for "Normal" muscle strength in the Tibialis Posterior, what position should the patient be in?

To assess the strength of the Tibialis Posterior muscle, the patient should indeed be positioned in side lying on the test side with the foot off the table. This position effectively isolates the muscle and allows for optimal resistance testing.

When the patient is lying on their side, the Tibialis Posterior can be evaluated as it is most commonly involved in foot inversion and provides support for the medial arch. This position enables the examiner to apply resistance to the foot while the muscle is active in its primary function, allowing for an accurate assessment of muscle strength.

In contrast, other positions tend to engage other muscle groups or do not adequately isolate the Tibialis Posterior for strength testing. For example, sitting with legs extended may allow for compensatory movements, while standing places weight on other leg structures, which can alter the dynamic during the test. Therefore, side-lying on the test side provides the best position for evaluating the Tibialis Posterior's strength effectively.