The incidence of an initial medial elbow injury was 22.1%. Age, number of throws per day, thoracic kyphosis angle, and elbow extension deficit are newly discovered risk factors related to physical function. Improvement of the posture and early detection of a silent elbow extension deficit may prevent a medial elbow injury.

A prevention program aiming to improve physical function can prevent medial elbow injury in youth baseball players.

Extracts of normal mature articular cartilage contain aggrecan molecules which bear the G1 domain (the N-terminal globular domain of aggrecan) and are C-terminally truncated by proteolysis at a number of sites. A proportion of these molecules are generated by an aggrecanase and/or matrix-metalloproteinase-mediated cleavage in the IGD (interglobular domain between the G1 and G2 domains of aggrecan). However, the proteinase(s) responsible for formation of the majority of the larger G1-G2 and glycosaminoglycan-bearing truncated species is (are) unknown. N-terminal sequencing of aggrecan core fragments generated by m-calpain digestion of bovine aggrecan has identified four novel cleavage sites: one within the CS (chondroitin sulphate)-1 domain (at one or more of the bonds Ser1229-Val1230, Ser1249-Val1250, Ser1287-Val1288, Gly1307-Val1308 and Ser1346-Val1347), two within the IGD (at bonds Ala474-Ala475 and Gly365-Gly366) and one within the KS (keratan sulphate) domain (at Ala719-Ala720). A new monoclonal antibody (SK-28) to the C-terminal neoepitope at M710VTQVGPGVA719 showed that aggrecan products generated by this cleavage are present in high abundance in mature bovine articular cartilage extracts. We conclude that m-calpain, or an unidentified proteinase with the capacity to cleave at the same site, is active during aggrecan biosynthesis/secretion by mature chondrocytes or in the matrix of mature bovine articular cartilage in vivo.

In CAI, altered subtalar internal rotation occurs with increased talocrural anterior translation and reduced talocrural internal rotation during weightbearing ankle internal rotation in plantarflexion. These results suggest that altered subtalar mechanics may contribute to CAI symptoms.

These results suggest that TNF-alpha stimulates upregulation and release of m-calpain in chondrocytic HCS-2/8 cells, and that stimulation of EP2-PGE(2) receptor by produced PGE(2) is deeply involved in this process.