Background: Delivery workers repeatedly get in and out of trucks and walk or run to deliver packages during work. Iliotibial band syndrome (ITBS) is a well-known non-traumatic overuse injury of the lateral side of the knee caused by frequent knee flexion and extension. Hip muscle strength is among the factors that prevent lower extremity injuries. Although many studies have examined the relationship between ITBS and hip muscle strengths, there was no study comparing hip muscle strength and ratio between delivery workers with and without ITBS. Objects: This study aimed to compare hip muscle strength and hip internal/external rotator and adductor/abductor strength ratios between delivery workers with and without ITBS. Methods: Fourteen delivery workers with ITBS matched inclusion criteria in the present study among 20 participants. Because total sample size was required 28 subjects by G*power program (ver. 3.1.9.4; University of Trier), 14 delivery workers without ITBS were recruited. Hip muscle strengths were measured in a side-lying position using a Smart KEMA pulling sensor (KOREATECH Co. Ltd.). An independent t-test was used to compare hip muscle strengths and hip internal/external rotator and hip adductor/abductor strength ratios between delivery workers with and without ITBS. Results: The adductor/abductor strength ratio was significantly greater in delivery workers without ITBS than in those with ITBS (p < 0.05). The strengths of the hip abductor, hip adductor, hip internal rotator, hip external rotator, and the ratio of internal/external rotator strengths were not significantly different between the delivery workers with and without ITBS (p > 0.05). Conclusion: This study’s findings showed that delivery workers with ITBS had significantly lesser adductor/abductor strength ratio, while the strengths of the hip abductor and adductor muscles did not differ significantly. These results suggest that adductor/abductor strength ratio should be considered when evaluating and treating ITBS in delivery workers.

The purpose of this study was to identify the effects of tensor fasciae latae-iliotibial band (TFL-ITB) self-stretching exercise on the lumbopelvic movement patterns during active prone hip lateral rotation (HLR) in subjects with lumbar extension rotation syndrome accompanying TFL-ITB shortness. Eleven subjects (9 male and 2 female) were recruited for the two-week study. A three dimensional ultrasonic motion analysis system was used to measure the lumbopelvic movement patterns. The TFL-ITB length was measured using the modified Ober's test and was expressed as the hip horizontal adduction angle. The subjects were instructed how to perform TFL-ITB self-stretching exercise program at home. A paired t-test was performed to determine the significant difference in the angle of lumbopelvic rotation, movement onset time of lumbopelvic rotation, TFL-ITB length, and LBP intensity before and after the two-week period of performing the TFL-ITB self-stretching exercise. The results showed that after the intervention, the lumbopelvic rotation angle decreased significantly (p<.05), the movement onset time reduced significantly (p<.05), and LBP intensity decreased slightly but not significantly (p=.07). The hip horizontal adduction angle increased significantly (p<.05) after the intervention. These findings indicate that TFL-ITB stretching exercise increased TFL-ITB length, decreased lumbopelvic rotation angle, and delayed the movement onset time of lumbopelvic rotation after two-weeks. In conclusion, the TFL-ITB self-stretching exercise performed over a period of two weeks may be an effective approach for patients with lumbar extension rotation syndrome accompanying TFL-ITB shortness.