Abstract
Background: Although research has documented the efficacy of maximal voluntary contraction (MVC) exercise for improved pelvic floor muscle (PFM) strength, the efficacy of submaximal voluntary contraction (SVC) exercise for treatment of genuine stress urinary incontinence (GSUI) has not been described.
Objective: To compare the training-induced changes in endurance, strength, and muscle activity recruitment, and continence control in groups of women with GSUI who exercised the PFM using either near-maximal voluntary contraction (NMVC) or SVC effort.
Methods: Training-induced changes in PFM response to exercise were tested by using a quasi-experimental design. Thirty-two women, randomly assigned to either the SVC or NMVC exercise protocol group, were tested before and after training on endurance, muscle contraction strength, muscle activity recruitment, 10-hour weighed pad test for grams of urine loss, and subject-rated severity and frequency of leakage episodes. Repeated measures of specific study variables were retrieved and analyzed from home-training device computer memory and diary records. Changes in muscle activity recruitment, measured as microvolts of electromyogram (EMG) amplitude, were correlated with changes in muscle contraction strength and endurance.
Results: Increases in muscle contraction strength (t = 1.75; p = 0.045) and decreases in grams of urine leakage (t = -1.86; p = 0.036) were significant for the SVC group. No significant differences were found between the groups for changes in endurance, muscle activity recruitment, frequency of leakage episodes, or subject-rated severity of urine loss based on a 7-point Likert scale.
Conclusions: Study findings suggest that SVC exercise designed with specificity for gain in neuromuscular control may be beneficial for strengthening the PFM and increasing endurance of contractions to attain and maintain continence in women with GSUI.