Contribuições relativas dos momentos articulares no controle postural dinâmico de indivíduos com instabilidade crônica de tornozelo

Abstract

Lateral ankle sprains are one of the most frequent injuries in the general population, increasing their incidence in physically active populations and sports practitioners. That injury can be considered the most common in sports and is related to several functional and mechanical alterations. Subjects who have undergone a ankle sprain can develop chronic ankle instability (CAI), dynamic postural control deficits, and biomechanical changes of the lower limb that may cause joint overload due to mechanical and sensory-motor failures. The knowlegde of these modifications may be crucial for the rehabilitation and prevention of other lower extremity injuries. Our research is a case-control study based on the STROBE guidelines for controlled studies and its execution was approved by the UFSM Ethics and Research Committee, CAAE 51543815.7.0000.5346. Twenty physically active subjects (14 women and 6 men) participated in the study, with 10 individuals (7 women and 3 men) aged 24.7 ± 3.3 years, 68.8 ± 15.5 kg and 1.66 ± 00 meters in the control group and 10 individuals (7 women and 3 men) age 23.3 ± 3.3 years, mass 68.7 ± 11.2 kg and height 1.66 ± 00 meters in the self reported ankle chronic instability group (CAI). In order to include the individuals in the study, the International Ankle Consortium criteria were used. Subjects were evaluated by the FAAM-BRASIL and CAIT questionnaires to understand the functional capacity of the subjects and classify as CAI, respectively. We measured the maximum dorsiflexion range of motion by the Weight Bearing Lunge Test (WBLT), since it is an important variable in the population with CAI. . The functional task selected for evaluation was the anterior reach of the Star Excursion Balance Test (SEBTa) concomitantly with the assessment of kinetic and 3D kinematics. The outcome variables were the relative contributions (RC’s) of the ankle, knee and hip joint moments in the sagittal, frontal and transverse planes. Significant modifications were found in ankle, knee and hip RC´s s in individuals with CAI. In the sagittal plane there is a reduction of the RC´s of ankle and knee, and a substantial increase of the RC of the hip in most part of the movement. For the frontal plane the ankle RC´s s are reduced during the forward and return phase of the movement. Conclusion: In individuals with CAI there are evident changes in the strategy in the absorption of the total flexor momentum of the lower limbs, with a substantial increase in the participation of the hip in the sagittal plane and reduction of the use of the ankle in the sagittal and frontal plane. These findings corroborate with the theory of neuromuscular pattern modifications in the population with CAI in order to perform functional tasks.