Final answer:
If an individual cannot reach the initial measure on the sit-and-reach test, they should use a modified version of the test, perform the test after warming up, or choose an alternative flexibility test if necessary.
Step-by-step explanation:
The correct course of action for an individual who cannot reach the initial measure on the sit-and-reach test is to use a modified sit-and-reach test. This allows the individual to have a means to assess their flexibility in a way that is adapted to their current level of flexibility. Modifying the test can include altering the starting position or using tools like a box or towel to reduce the distance. It is important for the individual to also repeat the test after a warm-up since muscles tend to perform better and stretch further after they have been adequately warmed up, which might improve the initial measure. If repeated attempts still do not allow for an adequate measure, the individual can also choose an alternative flexibility test that might be better suited for their condition.