Activation Failure of Knee Extensors After Anterior Cruciate Ligament Rupture Depending on the Contraction Mode

Inclusion criteria

A. ACL-injured groups (surgically or conservatively treated):

• Age between 18 and 50 years
• Free, informed consent signed by the participant and the investigator.
• Session 1: Delay of 2 to 6 weeks after injury, with a quiet knee (range of motion 110- 0°, minimal effusion, maximal contraction pain ≤ 2/10)
• Session 2: Duration of 36 to 42 weeks after injury, with a quiet knee (range of motion 110-0°, minimal effusion, maximal contraction pain ≤ 2/10)
• Independent person (Unprotected: under guardianship, curatorship or other legal protection, deprived of liberty by judicial or administrative decision)

B. ControlGroup:

• Age between 18 and 50 years
• Free, informed consent signed by the participant and the investigator.
• Sport practitioners: at least once per week practicing activities like collective sports, racket sports, combat sports, skiing, or on-loading activities with changing of directions.
• Independent person (Unprotected: under guardianship, curatorship or other legal protection, deprived of liberty by judicial or administrative decision)

Exclusion criteria

• 1. Subjects fitted with an implanted electronic device such as a cardiac pacemaker 2. Professional athlete 3. Pregnant women 4. Subject with systemic pathology or treatment affecting the musculoskeletal system 5. Subject with a history of neurological pathology or traumatic pathology, or pathology that required orthopedic treatment and/or surgery of the knee, hip and/or lumbar spine 6. Contraindication to isokinetic testing: incapacitating pain, evolving pathological process, non- healed fracture, unbalanced cardiovascular pathology (angina pectoris, arterial hypertension) 7. Contralateral knee injury 8. Subject inability to follow procedures or insufficient knowledge of project language 9. Data acquisition issue or injury during testing