Signature inversion in odd-odd nuclei have been found systematically in regions of mass number A 80, 130 and 160, and although several explanations have been proposed to interpret this phenomenon, it is still not well understood. The data of electromagnetic properties obtained through lifetime measurements, will be very useful to elucidate this phenomenon. In the present work, we review several lifetime studies that measured the B(M1) strengths in the mass A 80 region. The results show that the alternating pattern in the B(M1) strengths is preserved across the signature inversion region. Also is reviewed the critical angular momentum, frequency and moment of inertia at the signature inversion point for several mass regions. The correlations among these and other nuclear parameters are discussed.