Author response: Nintendo Wii remote controllers for head posture measurement--accuracy, validity, and reliability of the infrared optical head tracker letters.

we reported that the newlydeveloped IOHT showed strong concordance with the CROM,which is considered a gold standard for head posturemeasurement, and has relatively a good test–retest reliability,thereby proving its validity and reliability as a head posture–measuring device.First of all, in their letter Sabour and Ghassemi questionedwhy we did not use the seven well-known statistical tests(sensitivity, specificity, positive predictive value, negativepredictive value, likelihood ratio positive and negative, andodds ratio) for evaluating the validity of the infrared opticalhead tracker (IOHT) compared to cervical range of motion(CROM). In our article,