7%

of clinicians rate their return-to-sport testing as excellent

Most know their current protocols fall short.

80%

of lower-limb injuries are non-contact

How an athlete moves is the missing link.

SYS/EV · THE ARGUMENT

Four steps from problem to product

Every step is carried by peer-reviewed work. Follow the line.

Step 01

Nobody agrees what recovered means.

Return-to-sport testing has no shared standard. Ask 1,154 clinicians in 78 countries how they clear an athlete and you get 157 different combinations of tests. Almost everyone uses multiple devices, averaging 3.6 of them. Fewer than half test against defined criteria at all.

So what should we be measuring?
Step 02

The core is where the answer lives.

Core stability is not a posture. It is the ability to control the trunk over the pelvis while force transfers out to the limbs, which means it has to be judged dynamically, in three planes. And it is not academic: core capacity measured before a season predicts who gets injured during it.

How much does the trunk actually matter?
Step 03

Where the trunk goes, the knee pays.

Constrain the trunk during a cut and knee energy absorption jumps by roughly a quarter. Train an athlete to cut faster and the same braking mechanics that buy the speed also drive the knee abduction moment. Performance and risk share a mechanism, so watching one without the other is guesswork. Trunk control is also trainable, which is what makes measuring it useful rather than merely interesting.

Can a machine see it better than an eye?
Step 04

Objective movement data makes the call.

Return to performance demands sport-specific, criteria-based decisions across multiple domains, not a date on a calendar. And movement data reaches further than the eye does: fused kinematics and muscle activation classify fear of re-injury at 86% accuracy, with trunk tilt among the strongest predictors. That is a readiness signal a questionnaire cannot reach.

This is the tool that closes the loop.

Papers are provided for reference and remain the copyright of their respective publishers. Links open the full PDF.