The ACL is a strong band of tissue that helps stabilize the knee joint. It's one of two ligaments that cross the middle of the knee, connecting the thighbone (femur) to the shin bone (tibia). And it's commonly ruptured during sports such as soccer, basketball, football, and downhill skiing that involve sudden stops, jumping, landing and direction changes.

According to a 2019 study, in the US alone, 250,000 individuals suffer an ACL rupture each year. Most undergo surgical reconstruction (ACLR) early or choose to have surgery after a period of non-surgical rehabilitation. Either way, surgery carries a risk of post-op complications, including pain, stiffness and decreased range of motion in the knee joint, joint instability, and stretching or rupturing of the graft used in the reconstruction.