After reconstruction of the anterior cruciate ligament, the aim for the vast majority of sportspeople is to return to the field. To date, 65% of patients who have undergone ACL rehabilitation return to their previous level, and 55% return to competition. To achieve this, physiotherapy sessions need to prepare the return to sport as well as possible, by simulating the cognitive demands (reading the game, double task, etc.) that might be encountered on the pitch. Tests to assess the athlete's performance do exist, in order to optimise this return to sport, but they do not include the cognitive tasks that are present in sport. The high cognitive demands of the sporting environment therefore justify the inclusion of cognitive tasks in these return to sport tests. The aim of this research is to assess the impact of the cognitive task on the performance of a return to sport test following ACL reconstruction. Patients who have undergone ACL reconstruction and healthy subjects will therefore be given a return to sport test called the 'Single Leg Hop for Distance' with and without a cognitive task in order to observe the influence of the cognitive task on the results of the hop.

Including healthy subjects in this study will make it possible to study the impact of the cognitive task in these subjects, who have no neurophysiological dysfunction linked to ACL reconstruction.

The aim of this study is therefore to try to develop the return to sport tests currently described in the literature by proposing a new, improved test that takes account of the cognitive dimension, which is omnipresent in the sporting environment.

The inclusion criteria for the test group (patients with ACL reconstruction) were as follows :

• Patients with an isolated, unilateral ACL rupture, corresponding to a first injury occurring without contact,
• Patients who have undergone surgical reconstruction using an autograft of the semitendinosus tendon alone, or an autograft of the semitendinosus tendon and gracilis, or BTB surgery,
• Patients at 6 +/- 1 months post-operative management,
• Patients aged between 16 and 40 included,
• Patients whose level of physical activity, assessed using the Tegner scale, is greater than or equal to 5.

Patients meeting all these inclusion criteria will be included in the study.

Thus, for the test group, the non-inclusion criteria to be taken into account are as follows:

• Patients with injuries associated with ACL rupture,
• Patients who have received conservative treatment or who have benefited from another surgical technique,
• Patients less than 5 months or more than 7 months post-operatively,
• Patients aged under 16 or over 40,
• Patients with a Tegner score of less than 5,
• Patients with recurrent homolateral or controlateral ACL rupture,
• Patients with an ACL rupture resulting from a direct or indirect impact injury mechanism.

Finally, for the test group, the exclusion criteria to be taken into account are as follows:

• Refusal to take part in the study,
• Withdrawal of the participant during the study,
• Loss of sight of the participant between the two weeks.

For the control group (healthy persons), the inclusion criteria are similar to those for the test group. They correspond to :

• Persons with no knee trauma in the six months prior to the start of the study,
• Persons between 16 and 40 years of age included,
• Persons whose level of physical activity, assessed using the Tegner scale, was greater than or equal to 5.

Persons meeting all these inclusion criteria will be included in the study.

Thus, for the control group, the non-inclusion criteria are as follows:

• Persons with knee lesions in the six months preceding the start of the study,
• Persons aged under 16 or over 40,
• Persons with a Tegner score strictly below 5.

Finally, the exclusion criteria for this group correspond to :

• Refusal to take part in the study,
• Retraction of the participant during the study,
• Loss of vision between the two weeks,
• Knee trauma between the two weeks.