Objective: To develop a classification scale for manometry of pelvic floor muscles (PFM) in Brazilian women, according to the modified Oxford scale.
Methods: A cross sectional study, with 288 women enrolled in the Maternity, Natal, Brazil. Manometry and PFM strength data were collected and classified according to the modified Oxford scale. A simple linear regression was performed to determine the classification scale of manometry using the modified Oxford scale as the explanatory variable and the arithmetic mean of the manometry measurements as the response variable.
Results: The average age was 52.80 (±8.78; CI: 51.67-53.93) years. Manometry showed an average of 35.1 (±22.7; CI: 32.1-38.0) cmH2O and most women (29.7%) scored grade 3 on the modified Oxford scale. According to the proposed scale, values between 7.5 to 14.5 cmH2O correspond to very weak pressure; 14.6 to 26.5 cmH2O represent weak pressure; 26.6 to 41.5 cmH2O represent moderate pressure; 41.6 to 60.5 cmH2O represent good pressure, and values above 60.6 cmH2O correspond to strong pressure.
Conclusion: Manometry values were rated on a five-point scale. It is possible to rank the pressure levels performed by voluntary contraction of PFM with this new scale.