Tendon induce endothelial cell proliferation and migration, and VEGF mRNA has been shown to be expressed at the site of tendon injuries along with collagen I mRNA. Bone morphogenetic proteins (BMPs) are a subgroup of TGF-β superfamily that can induce bone and cartilage formation as well as tissue differentiation, and BMP-12 specifically has been shown to influence formation and differentiation of tendon tissue and to promote fibrogenesis. In animal models, extensive studies have been conducted to investigate the effects of mechanical strain in the form of activity level on tendon injury and healing. While stretching can disrupt healing during the initial
Quadriceps tendon Quadriceps tendon In human anatomy, the quadriceps tendon allows the quadriceps femoris muscles ("rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius") to converge on the superior aspects of the patella on the anterior of the thigh, which continues as the patellar ligament. A tendon connects muscle to bone, while a ligament connects bone to bone. The quadriceps tendon works with the quadriceps to extend the leg. Injuries are common to this tendon, with tears, either partial or complete, being the most common. If the quadriceps tendon is completely torn, surgery will be required to regain function of the knee.