Due to that, the investigators designed a randomized controlled trial to compare the short-term effects in the Flexion Rotation Test (FRT) of a translatoric mobilization of C0-C1, a translatoric mobilization of C7-T1 and a control group in subjects with C1-C2 hypomobility.The primary hypothesis is that C0-C1 dorsal glide mobilization applied in the neutral cervical position can recover the C1-C2 rotational range of movement in subjects with upper cervical hypomobility.