ACL Tears Are Brain Injury's

Not literally a traumatic brain injury, but an ACL tear has a long-term impact on the brain's wiring and firing. If this is not addressed in ACL rehab early and often, it can result in long-term compensation and increase the chances of re-injury.

What Happens?

The ACL is full of mechanoreceptors — they tell the brain where the knee is in space unconsciously. Before an ACL injury, you don't think about where your knee is in space because those mechanoreceptors constantly relay that information to the brain without any conscious control from you.

After an ACL tear, your brain essentially shuts down the quadriceps muscle to protect you. What was once unconscious now requires high degrees of conscious control and focus — and this is a dangerous pattern to get into.

Compensations

• ✓Internal Focus: Your body now requires conscious control to fire muscles and stabilize the knee
• ✓Visual Dominance: The body loses its sensory supply and now relies on vision to pick up the slack — creating an over-reliance on the visual system
• ✓Cognitive Load: Attention resources are now divided, leaving less 'room' for sport demands like reacting to a defender or catching a ball

Is That Bad?

Sports are incredibly chaotic — they require processing hundreds of decisions within milliseconds. If you still require conscious control of your knee, you won't be prepared. Your attention can only be subdivided so many times before you break down.

How Do We Fix It?

• ✓Down-regulate vision: Perform tasks with eyes closed to force the body to rely on the sensory system
• ✓Up-regulate sensory: Challenge the sensory system on solid ground (NOT unstable surfaces — that increases visual and vestibular reliance)
• ✓Dual task: Bring focus out into the external environment rather than being solely focused on the knee