چكيده به لاتين
Background and purpose: Lateral ankle sprain is one of the most common sports injuries that has high reversibility and chronicity symptoms; simultaneous investigation of the sensory-motor and skeletal-muscular system in order to better identify the effective mechanisms in causing instability and consequently Designing rehabilitation protocols that lead to an increase in athletes' performance after recovery is one of the reasons for choosing this subject for research.
Materials and methods: In this semi-experimental study, 10 healthy athletes with chronic ankle sprains aged 19-27 years in 1401 were randomly selected, as well as 10 healthy athletes who had no musculoskeletal or neurological disorders; were tested. In order to check the stability, a wooden balance board was used to evaluate the subjects' performance. Balance tests in the movement analysis laboratory on the force plate, along with 10 cameras and 10 electromyography electrodes that recorded information simultaneously; was taken According to the previous studies, parameters under the title of balance indices and also the amount of muscle activity were calculated using MATLAB software. And two groups were compared using independent t-test at the significance level of P<0.05.
Findings: There was a significant difference in the parameters of the balance indicators related to the center of pressure, in the medial-lateral direction, the variables of average displacement and distances of the center of pressure, in the group with chronic ankle instability compared to the healthy group (both p=0.02). Also, the area of the circle of 95% of the pressure center data, which was calculated in both directions. In the affected group, there was a significant difference compared to the control group (p=0.01).
Also, in the anterior-posterior direction, in the peroneus longus (PL) and lateral (GC-L) muscles, we see a higher mean frequency in the group with chronic ankle instability compared to the control group (respectively, p=0.03 p =0.003). In the medial-lateral direction, in the gastrolateral (GC-L), semitendinosus (SEMT), biceps femoris (BF), rectus femoris (RF) muscles, a higher significant difference was found in the RMS parameter in the group with chronic ankle instability. We see the ratio of the control group (respectively, p=0.02, p=0.03, p=0.01 and in RF-p=0.01).
Conclusion: Affected people experience a more challenging position in order to maintain control of their position during balance in the medial-lateral direction due to chronic instability and involvement of collateral ligaments. They use the compensatory strategy of thigh muscle activity. Therefore, it is recommended that therapists pay attention to identifying these strategies.
