Background: Anterior cruciate ligament (ACL) rupture is the most common knee ligament injury worldwide, and it is considered as a public health problem because of its high incidence and both short- and long-term consequences. Recently, the scientific literature has shown a trend in the study of post-injury treatments and the possible risk factors associated with the causes of these injuries to facilitate the understanding of the mechanisms of this injury and assist in the elaboration of preventive measures, especially for athletes or practitioners of physical activities. This study compared the hip range of motion (ROM) measurements of athletes depending on the presence of ipsilateral ACL injury.
Methods: Athletes diagnosed with previous ACL injury were selected for the case group, and those with other injuries were selected for the control group. Data regarding participants’ histories, ages, genders, and the sports practiced were collected. All participants underwent hip ROM measurements using a goniometer. Hip radiographs were taken to measure the Alpha (α) and Wiberg (w) angles. For the statistical analysis, the means and standard deviations were calculated for continuous variables, and frequencies (percentages) were calculated for dichotomous variables. A p-value less than 5% was defined as significant. Student's t-tests were used for continuous variables, and chi-square tests was used for categorical variables.
Results: A total of 77 participants were included: 47 athletes with ACL injuries and 30 with other musculoskeletal injuries. The mean age was 24.7 years, and 46.7% were female. No between-group differences were found with regard to the baseline characteristics. Most of the athletes played futsal (50.6%) followed by soccer (29.8%). The cases presented with significant reductions in hip internal rotation (IR; 24.1° versus 32.50°, p < 0.0005) and the internal rotation associated with external rotation (IR + ER; 69.9° versus 78.5°, p = 0.005) ROMs as well as a significant increase in the w radiographic angle (38.7° versus 32.4°, p < 0.0005).
Conclusion: ROM measurements of hip IR, IR + ER, IR values less than 30°, and the w radiographic angle might be associated with previous ipsilateral ACL injuries among athletes.
Trial registration: Registered at Brazilian Clinical Trials Registry (ReBec) as RBR-6g87mn on 04 August 2020 (retrospectively registered). http://www.ensaiosclinicos.gov.br/rg/RBR-6g87mn/