Anterior cruciate ligament (ACL) reconstruction is the major treatment option for ACL injuries. Despite this, recurrence rates are high. Half of all recurrences occur within 8 months of reconstruction, and 70% within the first 6 months after return to sport (RTS). The decision to RTS is therefore a critical one, as returning too early can increase the risk of recurrence, whilst a delayed return delays a return to pre-injury performance levels.

To guide this decision-making process, objective data is required to determine fitness for RTS. This is why the K-STARTS (Knee Safety Athletic Return to Sport) was developed. It is a composite test comprising functional and psychological assessments that enable the calculation of an overall score used to determine the functional recovery of the knee six months after ACL reconstruction.

Currently, functional tests are limited to measuring physical performance, whereas athletes often manage complex visuospatial processing whilst performing physically. It is therefore necessary to develop clinical tests that integrate neurocognitive and physical functions in order to better simulate the sporting challenges that lead to injury and thus improve preparation for RTS NEURO-K-STARTS is a battery of functional tests based on three standard horizontal jump tests from the K-STARTS, supplemented by four neurofunctional tests.

No evaluation of the NEURO-K-STARTS in patients undergoing primary ACL reconstruction has been published. This is why this research is set up.

Anterior cruciate ligament (ACL) injuries are debilitating for both professional and amateur athletes, with long-term implications for performance and return to sport (RTS).

ACL reconstruction is the primary treatment option. Despite this, recurrence rates are high. Half of all recurrences occur within 8 months of reconstruction, and 70% within the first 6 months after RTS. The decision to return to sport is therefore a critical one, as returning too early can increase the risk of recurrence, whilst a delayed return delays a return to pre-injury performance levels.

To guide this decision-making process, objective data is required to determine fitness for RTS. It is with this in mind that the K-STARTS (Knee Safety Athletic Return to Sport) was developed. It is a composite test comprising scored functional and psychological assessments that enable the calculation of an overall score used to determine the functional recovery of the knee six months after ACL reconstruction. It consists of 7 tests scored out of 100 points:

• A psychological test: the ACL-RSI.
• Six athletic tests: Single Leg Landing (landing on one leg: dynamic valgus), Single Hop Test (single jump), Triple Hop Test (triple jump), Side Hop Test (side jumps), Crossover Hop Test (crossover jumps), Modified Illinois Test

Currently, functional tests are limited to measuring physical performance, yet athletes often multitask, divide their attention and manage complex visuospatial processing whilst performing physically. It is therefore necessary to develop clinical tests that integrate neurocognitive and physical functions in order to better simulate the sporting challenges that lead to injury and thus improve preparation for a return to sport. NEURO-K-STARTS is a battery of functional tests based on three standard horizontal jump tests from the K-STARTS, supplemented by four neurofunctional tests.

The four individual neurofunctional tests that make up the NEURO-K-STARTS have been shown to be reliable in healthy subjects, but no evaluation of the NEURO-K-STARTS in patients undergoing primary ACL reconstruction has been published. This is why this research is set up.

Inclusion Criteria (patients):

• Patient who has undergone primary ACL reconstruction at least 6 months ago
• Patient who has undergone an isokinetic strength test, the results of which do not indicate any contraindications to performing a functional test
• Patient who has resumed performing horizontal jumps under the supervision of a healthcare professional
• Patient with no history of surgery on the joints of the contralateral leg
• Patient enrolled in or covered by a social security scheme
• French-speaking patient who has signed an informed consent form

Exclusion Criteria (patients):

• Patient with a history of ligament surgery on the affected or contralateral knee
• Patient with a BMI < 18.5 or > 30
• Patient who is professional athlete
• Patient with severe associated conditions (neurological, connective tissue disorders, congenital diseases)
• Patient with colour blindness
• Patient with multi-ligament injury or associated osteotomy
• Patient enrolled in another study whose procedures may interfere with this study
• Protected patient: adults under guardianship, curatorship or other legal protection, or deprived of their liberty by judicial or administrative decision

Inclusion Criteria (healthy volunteers):

• Subject with no history of surgery on the joints of either leg
• Subject who is member of or beneficiary of a social security scheme
• French-speaking subject who has signed an informed consent form

Exclusion Criteria (healthy volunteers):

• Subject with a BMI < 18.5 or > 30
• Subject who is professional athlete
• Subject with severe associated conditions (neurological, connective tissue disorders, congenital diseases)
• Subject with colour blindness
• Subject with multi-ligament deficiency or associated osteotomy
• Subject enrolled in another study whose procedures may interfere with this study
• Subject under legal protection: adults under guardianship, curatorship or other legal protection, or deprived of their liberty by judicial or administrative decision