What are some symptoms of knee injuries?

See below: This would obviously depend on the type of injury but generally speaking: pain, swelling, stiffness, locking, decreased range of motion, bruising, etc. Would be some signs.

Pain/swelling.: Pain and swelling are common. You may also encounter mechanical symptoms, such as "locking and catching" within the knee.

Knee injuries: Knee injury is accompanied by pain , swelling, bruising , feelings of weakness or buckling, at times numbness and tingling., giving out or instability, difficulty with stairs , kneeling , squatting, pivoting, crouching,running , jumping .