Recently, the problem of the high incidence of throwing injuries in young people has been gaining attention. Identifying high-risk players before the onset of the throwing injury is important for prevention. One of the most widely used screening tests for sports-related injuries is the Functional Movement Screen (FMS), which assesses the quality of movement; however, its correlation with throwing injuries has not been established. The purpose of this study was to investigate the correlation between the FMS score and throwing injuries. The FMS was used during the medical check for two hundred and thirty junior high school baseball players. We allotted those who had experienced throwing injuries multiple times to the injury group and those who had never experienced throwing injury to the control group. We then calculated the FMS cutoff value using the receiver operating characteristic curve. In addition, we investigated differences in the incidence of throwing injury between above and below the cutoff value using chi-square test. The FMS cutoff score was 17. Players who scored ≤17 had a significantly higher incidence of throwing injuries than those who scored ≥18. Conclusion: We believe that FMS score is correlated to throwing injuries. In addition, the results suggest that throwing injuries might be prevented in junior high school baseball players who scored ≤17 on the FMS if they undergo training in the correct movement patterns.

LR11, also known as SorLA or SORL1, is a type-I membrane protein from which a large extracellular part, soluble LR11 (sLR11), is released by proteolytic shedding on cleavage with a disintegrin and metalloproteinase 17 (ADAM17). A shedding mechanism is presumed to have a key role in the functions of LR11, but the evidence for this has not yet been demonstrated. Tetraspanin CD9 has been recently shown to regulate the ADAM17-mediated shedding of tumor necrosis factor-alpha and intercellular adhesion molecule-1 on the cell surface. Here, we investigated the role of CD9 on the shedding of LR11 in leukocytes. LR11 was not expressed in THP-1 monocytes, but it was expressed and released in phorbol 12-myristate 13-acetate (PMA)-induced THP-1 macrophages (PMA/THP-1). Confocal microscopy showed colocalization of LR11 and CD9 proteins on the cell surface of PMA/THP-1. Ectopic neo-expression of CD9 in CCRF-SB cells, which are LR11-positive and CD9-negative, reduced the amount of sLR11 released from the cells. In contrast, incubation of LR11-transfected THP-1 cells with neutralizing anti-CD9 monoclonal antibodies increased the amount of sLR11 released from the cells. Likewise, the PMA-stimulated release of sLR11 increased in THP-1 cells transfected with CD9-targeted shRNAs, which was negated by treatment with the metalloproteinase inhibitor GM6001. These results suggest that the tetraspanin CD9 modulates the ADAM17-mediated shedding of LR11 in various leukemia cell lines and that the association between LR11 and CD9 on the cell surface has an important role in the ADAM17-mediated shedding mechanism.
ADAM Proteins/*metabolism ; Antigens, CD9/genetics/*metabolism ; Cell Line, Tumor ; Humans ; LDL-Receptor Related Proteins/genetics/*metabolism ; Leukocytes/*metabolism ; Macrophages/metabolism ; Membrane Transport Proteins/genetics/*metabolism ; Proteolysis