Comparison of hip muscle strength, dynamic valgus and functional level in athletes with and without hip adductor strain

The aim of study was to compare the knee valgus during single leg squat (SLS), the hip muscle strength and functional levels between athletes with Adductor Strain (AS) and healthy controls. Twenty-six adolescent athletes with AS and 26 healthy athletes at the same age, height, body weight and sports branch were included in the study. Frontal plane projection angle (FPPA) was calculated during SLS task with two cameras placed on frontal and sagittal plane. Knee FPPA (knee valgus), hip FPPA and trunk lateral flexion were analyzed using Kinovea Software. Isometric hip strength was measured with hand held dynamometer and relative strength values (N.m/ kg) were used for group comparisons. Stabilizer was used to evaluate the adductor squeeze strength. Hip Outcome Score (HOS) was used to determine functional levels and Visual Analog Scale for pain level. Demographic characteristics were similar between groups (p> 0.05). Adductor squeeze test results were lower in AS group when compared to controls. While hip adductor, abductor, internal and external rotator and extensor isometric muscle strengths and adductor/abductor strength ratio were lower in the AS group (p<0.05), the flexor strength was similar between groups. Athletes with AS had higher knee FPPA angle and lower hip FPPA angle during SLS when compared to controls. These differences interpreted as the AS group had insufficient proximal stabilization. The activity of daily living and sports subscales of HOS and total HOS score in AS group was lower (p<0.001). Performing corrective exercises focusing on impaired movement patterns in athletes with AS could be effective in preventing future injuries. Evaluation of hip muscle strength and two-dimensional kinematic methods in athletes with AS by physiotherapists during return to sport phase is recommended.