urinary incontinence ( ui ) is well - known to profoundly affect the qol ( quality of life ) of 
 women . pelvic floor muscle exercise ( pfm ) has been reported to be from 50% to 69% effective 
 at reducing urine loss episodes in women1,2,3,4 . in our previous study , we found a 
 significant relationship between the thickness of the transverse abdominal muscle ( ta ) and 
 the iemg of the levator ani muscle ( la ) . this result suggests that changes in the thickness 
 of the ta may be used to indicate changes in the electrical activity of the pfm . in our 
 other previous study , the ta and la co - contraction exercise intervention increases the 
 thickness of the ta and may be recommended to improve sui in middle - aged women5 . the purpose of this study was to devise a new urinary incontinence exercise using 
 co - contraction of both the transverse abdominal muscle and pelvic floor muscle with 
 resistance , and examined the measurement of the thickness of the transverse abdominal muscle 
 ( ta ) in different tasks in middle - aged women . the subjects were eleven healthy adult women : age , 52.9  8.0 yrs ( mean  standard 
 deviation ) ; height , 159.3  5.7  cm ; weight , 58.9  9.8  kg . all experimental procedures in this study were 
 reviewed and approved by the ethical review committee of jilin dianli hospital 
 ( jldl2015 - 018 ) . the thickness of the ta was measured 
 in all subjects under seven conditions at random in the supine position . , the subjects were instructed to draw in the lower abdominal wall toward the spine , 
 an action that specifically activates the ta . the subjects were instructed to contract the muscles 
 around the vagina  like a drawstring  and to lift them internally . 4 ) the fourth condition was maximal co - contraction of both the ta and la . subjects were 
 instructed to draw in the lower abdominal wall toward the spine , an action that specifically 
 activates the ta . when the ta sustained isometric contraction , the subjects were instructed 
 to contract the muscles around the vagina  like a drawstring  to lift them internally and to 
 keep this position for 5 seconds . 5 ) maximal simultaneous contraction of both ta and la with 
 front side resistance added to both knee , 6 ) maximal simultaneous contraction of both ta and 
 la with diagonal resistance added to both knees , and 7 ) maximal simultaneous contraction of 
 both ta and la with lateral resistance added to both knees . under each condition , the subjects were in the supine position with the knees flexed at 90 
 and a pillow under the head . the three - chamber pressure cells were placed under the lumbar spine , and the subjects were 
 asked to keep the baseline at 40 mmhg . if the pressure of the biofeedback stabilizer 
 decreased under conditions 27 , abdominal muscle re - education was provided by a physical 
 therapist . ultrasound images of the anterolateral abdominal wall were obtained using a ultrasound 
 ( sonosite 180plus , b mode , 5  mhz linear transducer ) . the transducer was positioned adjacent to and perpendicular to the 
 abdominal wall , 25  mm anteromedial to the midpoint between the ribs and ilium on the 
 midaxillary line , and parallel to the muscle fibers of the transversus abdominis6 . the same person , a midwife , made the 
 measurements to avoid inter - rater errors . all thickness measurements were of muscle only , 
 that is , between the fascia boundaries . the resistance force during maximal simultaneous contraction of ta and la was measured by 
 two hand - held dynamometers ( anima utas mt1 , hhd ) held in both hands of the measurer , using 
 the tester function of hhd . the 
 resistance force was the maximum resistance that did nt appear as for the trunk shake of the 
 subject . the mean value of the maximum resistance force of the right and left hands was 
 assumed to be a representative value . one - way analyses of variance and multiple comparisons ( bonferroni test ) were used to test 
 for statistically significant differences , and the factor was thickness of ta . the thicknesses of ta during maximal simultaneous contraction and maximal simultaneous 
 contraction with resistance were greater than during the resting state ( table 1table 1.effect of thickness of ta for each tasktaskthicknesses of ta ( mm)resting state 2.5  0.5d > a*e > a*f > a * * , c*g > a * * , 
 b*,c*maximal contraction of ta 3.8  1.4maximal contraction of la3.5  1.1maximal simultaneous contraction of both ta and la 
 3.9  1.3maximal simultaneous contraction of both ta and la 
 with front side resistance 4.0  1.2maximal simultaneous contraction of both ta and la 
 with diagonal resistance 4.3  1.3maximal simultaneous contraction of both ta and la 
 with lateral resistance 4.8  1.6mean  sd . la : levator ani 
 muscle the resistance force during maximal simultaneous contraction with front side resistance 
 added to both knee was 7.90  2.5  kg , 7.83  1.6 kg with diagonal resistance added to both 
 knees , and 7.52  1.8  kg with lateral resistance added to both knees with no significant 
 difference . the thicknesses of ta during maximal simultaneous contraction and maximal simultaneous 
 contraction with resistance were greater than during the resting state . the maximal 
 simultaneous contraction of both ta and la with lateral resistance was greater than the 
 maximal contraction of ta and the maximal contraction of la . the muscle output during 
 simultaneous contraction and simultaneous contraction with resistance were larger than that 
 of each individual muscle not only for ta but also for la . in clinic intervention training of ta , the simultaneous contraction with resistance 
 exercise increases the thickness of the ta and may be recommended to improve ui in 
 middle - aged women . the simultaneous contraction of both ta and la may be recommended to 
 apply as a home exercise . further investigations will need to weigh the training effect for women with urine 
 incontinence in a prospective intervention study .
[ purpose ] this study examined the measurement of the thickness of the transverse 
 abdominal muscle in different tasks . [ subjects and methods ] the subjects were eleven 
 healthy adult females . 
 thicknesses of transverse abdominal muscle were measured in seven 
 tasks in the supine position . 
 the tasks were : 1 ) resting state , 2 ) maximal contraction of 
 transverse abdominal muscle , 3 ) maximal contraction of levator ani muscle , 4 ) maximal 
 simultaneous contraction of both transverse abdominal muscle and levator ani muscle , 5 ) 
 maximal simultaneous contraction of both transverse abdominal muscle and levator ani 
 muscle with front side resistance added to both knee , 6 ) maximal simultaneous contraction 
 of both transverse abdominal muscle and levator ani muscle with diagonal resistance added 
 to both knees , and 7 ) maximal simultaneous contraction of both transverse abdominal muscle 
 and levator ani muscle with lateral resistance added to both knees . 
 [ results ] the 
 thicknesses of transverse abdominal muscle during maximal simultaneous contraction and 
 maximal simultaneous contraction with resistance were greater than during the resting 
 state . 
 [ conclusion ] the muscle output during simultaneous contraction and resistance 
 movement were larger than that of each individual muscle .