System 4 Pro™

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ACLAnterior Cruciate Ligament (ACL)


Quad strength — one of the deciding factors for return to sport (RTS) after ACL surgery
To increase the chances of successful and safe return to sport after ACL reconstruction, specific criteria have been developed.  Studies have shown that healing time and certain factors, including more symmetrical quadriceps strength prior to return to sport reduces the reinjury rate.


When can I return to sport after ACL surgery? >>

Why You Should Be Using Knee Extensions After ACL Reconstruction >>

The objective test protocols offered with the Biodex System 4  provide valuable, isolated muscle-performance data. Test results, combined with established targeted outcomes, can be used for strengthening the quadriceps and aid with the return-to-sport decision.

While professional athletes have the incentive advantage and resources to RTS after ACLR quickly, there is clear research emerging that demonstrates a safe and successful path for all.

Two recent studies review ACL reinjury rates; both demonstrating the need to fulfill performance criteria before return to sport, with moderately similar results. While healing time plays an important factor*, measuring quads strength within 10% of uninvolved leg and several other tests prove equally vital.

*For every one month delay in RTS, the reinjury rate was reduced by 51%.

Download the studies to learn more.


Simple decision rules can reduce reinjury risk by 84% after ACL

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Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture

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