2023 Volume 31 Issue 1 Pages 109-116
In this study, we investigated the association between lumbar stress fractures (LSF), the acute phase of lumbar spondylolysis, and physical characteristics of adolescent baseball players. Participants were categorized into a fracture group (18 male baseball players aged 12-15 years, diagnosed with magnetic resonance imaging) and a control group (25 asymptomatic baseball players aged 12-16 years). We evaluated the physical examination in both groups using the following tests: finger-floor distance, angle of straight leg raising test, the external and internal range of motion (ER and IR, respectively) of the hip joint, the Duncan-Ely test, the Thomas test, and Oberʼs test. Compared with the control group, the fracture group showed bilateral high positive rates in the Duncan-Ely test, bilateral increase in ER, and bilateral decrease in IR. Tightness of the anterior hip joint may increase the pelvic tilt and a decreased IR may limit pelvic motion during pitching, batting, and dashing, which may exaggerate lumbar load and result in LSF.