What is a significant physical finding in a patient undergoing the Phalen test?

In the context of diagnosing carpal tunnel syndrome, the Phalen test is specifically designed to assess the function of the median nerve as it passes through the carpal tunnel in the wrist. A significant physical finding in a patient who undergoes the Phalen test is the presence of numbness or tingling in the distribution of the median nerve, which typically affects the first three digits of the hand (the thumb, index, and middle fingers) and sometimes the radial half of the fourth digit.

When the wrists are held in flexion for a duration of time during the test, if there is an existing entrapment or irritation of the median nerve, this position can exacerbate symptoms, leading to numbness or tingling sensations. This reflects the impaired conduction of the median nerve due to compression or other pathology within the carpal tunnel, providing valuable diagnostic information.

The other options presented do not directly correlate with the specific objective of the Phalen test. While joint discomfort might occur in various wrist conditions, it does not have the same diagnostic specificity for median nerve involvement. Overall loss of range of motion and swelling in the wrist may indicate different issues such as arthritis or tendonitis, but they are not findings that validate the diagnostic purpose of the Phalen test