Anatomical and Neuromuscular Factors Associated to Non-Contact Anterior Cruciate Ligament Injury

Abstract

The majority of anterior cruciate ligament (ACL) injuries occur during non-contact mechanisms. Knowledge of the risk factors would be relevant to help prevent athletes’ injuries. We aimed to study risk factors associated with non-contact ACL injuries in a population of athletes after ACL reconstruction. From a cohort of 307 athletes, two populations were compared according to the non-contact or contact mechanism of ACL injury. Gender, age and body mass index (BMI) were reported. Passive knee alignment (valgus and extension), knee laxity (KT-1000 test), and isokinetic knee strength were measured on the non-injured limb. The relationship between these factors and the non-contact sport mechanism was established with models using logistic regression analysis for the population and after selection of gender and cut-offs of age, BMI and knee laxity calculated from Receiver Operating Characteristics curve area and Youden index. Age, BMI, antero-posterior laxity, isokinetic knee strength, passive knee valgus and passive knee extension were associated with non-contact ACL injury. According to the multivariate model, a non-contact ACL injury was associated with non-modifiable factors, age (OR: 1.05; p = 0.001), passive knee extension (OR: 1.14; p = 0.001), and with one modifiable factor (Hamstring strength: OR: 0.27; p = 0.01). For women, only passive knee valgus was reported (OR: 1.27; p = 0.01). Age, passive knee extension and weak Hamstring strength were associated with a non-contact ACL injury. Hamstring strengthening could be proposed to prevent ACL injury in young male athletes or in case of knee laxity.

Post-traumatic knee osteoarthritis; the role of inflammation and hemarthrosis on disease progression

“…Several risk factors have been identified to explain non-contact ACL injuries. These risk factors can be divided into different risk categories: extrinsic factors, such as weather condition, playing surface, level of competition, and intrinsic factors such as anatomical, neuromuscular, biomechanical, physiological, psychological, and genetic factors ( 80 ). Body weight, fatigue, and neuromuscular deficits such as hamstring strength deficit are modifiable risk factors ( 80 – 82 ).…”

“…These risk factors can be divided into different risk categories: extrinsic factors, such as weather condition, playing surface, level of competition, and intrinsic factors such as anatomical, neuromuscular, biomechanical, physiological, psychological, and genetic factors ( 80 ). Body weight, fatigue, and neuromuscular deficits such as hamstring strength deficit are modifiable risk factors ( 80 – 82 ). Female gender, age and anatomical features such as decreased femoral intercondylar notch width, increased medial and lateral tibial slopes and ligamentous laxity are non-modifiable factors ( 67 , 80 ).…”

“…Body weight, fatigue, and neuromuscular deficits such as hamstring strength deficit are modifiable risk factors ( 80 – 82 ). Female gender, age and anatomical features such as decreased femoral intercondylar notch width, increased medial and lateral tibial slopes and ligamentous laxity are non-modifiable factors ( 67 , 80 ). Failure to correct modifiable factors, such as neuromuscular control and landing biomechanics, increases the risk of injury and recurrence ( 74 ) (as summarized in Table 1 ).…”

Effectiveness of Warm-Up Exercises with Tissue Flossing in Increasing Muscle Strength

“…There are several factors, that increase the risk of injury, including non-modifiable factors like age, anatomical knee structure, congenital ligaments laxity, and previous injuries, as well as modifiable factors like environment, technique, body weight, muscle laxity, and muscle strength [ 15 , 16 , 17 , 18 ]. The relationship between injury rate and muscle strength is visible, especially in the knee joint, which transfers high forces and is stabilized both by ligaments and muscles.…”

“…The relationship between injury rate and muscle strength is visible, especially in the knee joint, which transfers high forces and is stabilized both by ligaments and muscles. Insufficiency of the knee flexors and extensor strength can cause dynamic knee valgus being one of the main knee injury risk factors [ 15 , 19 , 20 ]. Other researchers showed a relationship between muscle strength and the hamstring strain injury risk [ 16 ], meniscus damage progression [ 21 ], or re-injury following ACL reconstruction [ 22 , 23 ].…”