Acl
In short
The anterior cruciate ligament is a key piece of tissue inside the knee that keeps the joint stable.
In plain words
It acts like a strong rope inside your knee. This rope stops your shin bone from sliding too far forward and helps your knee stay steady when you turn or jump.
A simple example
A footballer might tear their ACL when they suddenly change direction or land heavily after a jump. This often requires surgery and long physiotherapy to fix.
Why it matters
An ACL injury can stop someone from playing sports for many months. Without a healthy ligament, the knee can feel loose and unstable during movement.
Easy to mix up
People often confuse an ACL tear with a meniscus tear, which involves the shock-absorbing cartilage in the knee.