Changes in abdominal muscle thickness measured by ultrasound are not associated with recovery in athletes with longstanding groin pain associated with resisted hip adduction.
METHODS
Longitudinal single-cohort study.


BACKGROUND
Athletes with longstanding groin pain associated with resisted hip adduction have been shown to have abnormal activation of the transversus abdominis (TA). Therefore, exercises targeting the TA to help stabilize the lumbopelvic area are generally used in the rehabilitation of these athletes.


OBJECTIVE
To investigate if (1) changes in abdominal muscle resting thickness and changes in relative thickness during lower extremity tasks after 14 weeks of intervention are related to changes in clinical status and (2) the changes in abdominal muscle resting/relative thickness are significant postintervention.


METHODS
In 21 athletes with longstanding groin pain associated with resisted hip adduction, ultrasound imaging of the abdominal musculature on the right side was performed at rest, during the active straight-leg raise (left and right), and during bilateral isometric hip adduction. Athletes then followed a 14-week rehabilitation protocol. Clinical outcome measured by self-reported sports restriction and change in abdominal muscle resting and relative thickness during lower extremity tasks were evaluated.


RESULTS
There was an overall significant decrease in self-reported sports restriction after intervention for this group of athletes. Apart from a significant negative correlation for changes in TA resting thickness, no significant association between changes in abdominal muscle thickness and change in self-reported sports restriction were found. Postintervention, TA resting thickness was significantly increased but relative thickness during the lower extremity tasks was found not to be statistically different for all muscles, except for a decreased relative thickness of obliquus externus abdominus (OE) during the active straight-leg raise for the left lower extremity.


CONCLUSIONS
There was no association between changes in abdominal muscle resting thickness and relative thickness during lower extremity tasks, and change in self-reported sports restriction after a period of physical therapy in athletes with longstanding groin pain associated with resisted hip adduction. Although this study was designed as a single-cohort longitudinal study, the data suggest that the intervention described can change TA resting thickness. The intervention did not influence abdominal muscle relative thickness during lower extremity tasks.
University Medical Center Utrecht, Department of Rehabilitation and Sport Medicine, Rotterdam, The Netherlands; Erasmus Medical Centre, Department of Rehabilitation Medicine, Rotterdam, The Netherlands. jjansen4@umcutrecht.nl
J A C G
JA
Jansen
J M A
JM
Mens
Frank J G
FJ
Backx
Henk J
HJ
Stam
D000009:Abdominal Muscles / Q000000981:diagnostic imaging*; D000328:Adult; D015331:Cohort Studies; D005260:Female; D006119:Groin / Q000503:physiopathology*; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008137:Longitudinal Studies; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology / Q000534:rehabilitation*; D013177:Sports / Q000502:physiology; D014463:Ultrasonography