[THE INFLUENCE OF VARUS DEFORMITY ATMIDDLE THIRD OF FEMURON THE STRENGTH OF THE LOWER LIMB MUSCLES].

Treatment of post-traumatic deformities is a separate task of orthopedics and traumatology, because for the normalization of injured limb function requires more than realignment of bone fragments followed with their stable fixation. The analysis of post-traumatic deformities pays attention mostly to their influence on the joints. The functional state of the muscles of the damaged segment and limb, in general, is analyzed very seldom and not taken into consideration in the planning of treatment.Purpose - to study the effect of varus deformity of the femur at the level of the middle third on the strength of the muscles of the lower limb and to determine the minimal muscle strength required to perform a normal step.Gait analysis was performed in OpenSim 4.0. The modeling is based on the gait 2394 model. The original model was deformed by distorting the main isometric axis by 15°, 30° and 45° in the lateral direction.The deformity of femur at middle third initiates the failure of almost all muscles on the injured extremity. The most severe changes were revealed in the adductor muscles. Femur deformity creates varus position of knee joint, that also affects the work of the muscles responsible for knee stabilization and femur adduction while walking. The disorders in lower leg muscles are also noticed, these changes are exacerbated by the increasing of deformity severity. Foot takes a valgus stance when knee joint takes a varus stance, that creates an imbalance in the work of the foot stabilizers. Moreover, functional shortening of the limb in the conditions of severe deformities further worsens the condition of these muscles and force them to be constantly tense. The varus deformity of the femur provokes some changes in the muscles of the entire lower limb. This effect is manifested at its minimum severity (15 °) and directly depends on the severity of the deformity.