When recovering from ACL reconstruction (ACLR), most athletes focus on regaining strength and stability. But one often overlooked piece of the puzzle is reactive strength — a quality that plays a major role in returning to sport safely and effectively.
Physiotherapist Konstantinos Defteraios, from Aspetar Orthopaedic and Sports Medicine Hospital in Qatar, outlines just how important this quality is in modern ACL rehabilitation.
What Is Reactive Strength?
Reactive strength is your body’s ability to absorb and then quickly release force, much like a spring.
This ability is powered by the stretch-shortening cycle (SSC):
Stretch (Eccentric phase): The muscle lengthens under load (like when landing from a jump)
Store (Amortization phase): A brief transition where the energy is stored
Release (Concentric phase): The muscle contracts and releases that stored energy to jump or push off