In ACL sprain rehabilitation, which type of exercises should be started first?

• A. Plyometric exercises
• B. Isometric exercises
• C. Full resistance training
• D. Cardio-only training

Answer: (B)

Early rehab after an ACL injury focuses on protecting the healing tissue while reactivating the muscles around the knee. Isometric exercises fit this window because you can contract the thigh muscles without moving the knee joint, so you don’t place bending or shear forces on the ACL. This helps maintain quadriceps and hamstring activation, supports joint stability, and can reduce swelling without risking further injury. Classic moves like quad sets and hamstring sets activate the muscles safely, often with the knee in a protected position.

Plyometric work, full resistance training, and cardio-only routines are better saved for later phases when swelling is controlled, ROM is restored, and you have enough strength and neuromuscular control to handle higher forces. Isometrics provide the necessary foundation so the knee can tolerate progressive loading without compromising healing.