Foot pronation, as one of the prevalent foot abnormalities, can influence the biomechanics of the lower limbs. The use of various foot orthoses, including insoles and braces, is very common in eliminating this problem. The results obtained regarding the effect of orthoses on pain and biomechanics of individuals with foot pronation are different. The present review study was conducted to evaluate the effects of foot orthoses and shoes on the biomechanics of the lower limbs and balance in individuals with foot pronation. The articles were searched in Persian and Latin languages during 2004-22 in the databases of PubMed, Web of Science (WOS), Scopus, Islamic Science Citation (ISC), and Google Scholar search engine. Moreover, the types of the searched studies were original research, review studies, and clinical trials. Using keywords of Foot pronation, Foot orthoses, Medical soles, and Motion-control shoes, 52 relevant articles were selected, and 22 articles regarding the effects of orthoses and shoes on foot pronation were finally analyzed. Eight articles also reported that reducing forces imposed on the joints, absorbing shock, preventing pronation-related running injuries, and improving muscle activity occurred when using orthosis. Furthermore, 4 articles reported improving sports performance in athletes, reducing the ground reaction forces, and changing the frequency of muscle activity. Finally, 2 articles showed that motion-control shoes prevented intensifying the injury due to increased fatigue and subsequently increased mechanical loading during running. The results of the present study demonstrated that foot orthoses and motion-control shoes could have positive effects on balance, improving the activities of the lower limbs and reducing foot pronation and force imposed on the foot and lower limb joints.

Background and Objective: Fatigue is considered one of the factors effective in changing the electrical activity of muscles so that it is directly linked to increasing the potential of muscular injuries and functional decline in various stages of sports. The present study was conducted to evaluate the frequency of electrical activity of lower limb muscles before and after fatigue during running in individuals with a history of coronavirus disease 2019 (COVID-19) compared to healthy individuals.
Methods: This quasi-experimental research was conducted on 14 women with a history of COVID-19 over the past two months (the experimental group) and 14 women without a history of COVID-19 (the control group) with an age range of 18-30 years using the convenience sampling method in the city of Ardabil. The fatigue protocol started using a sophisticated treadmill at a speed of 6 km/h, and the treadmill speed was accelerated by 1 km/h every 2 minutes. The Borg’s Rating of Perceived Exertion (RPE) 6-20 Scale was used to determine the participants’ final moment of fatigue. A steady-state running fatigue protocol ended at a score higher than 17 on the Borg’s RPE 6-20 scale or 80% of maximum heart rate. Electromyography data were analyzed using the data LITE biometrics software before and after the fatigue protocol.
Results: There was a statistically significant increase in the frequency of the electrical activity of the vastus lateralis (VL) muscle between the post-test of the control group and the experimental group (d=0.410, P=0.035). The pretest-posttest difference of the frequency of electrical activity of the VL muscle after fatigue compared to before fatigue during the loading response phase during running had a statistically significant increase in the experimental group than in the control group (d=0.602, P=0.016). The frequency of the activity of the semitendinosus muscle increased after fatigue compared to before fatigue during the mid-stance phase of running (d=0.261, P=0.005). The impact of fatigue on the frequency of the activity of the VL muscle during the push-off phase of running was statistically significant (d=0.140, P=0.049). The frequency of the activity of the VL muscle increased after fatigue compared to before fatigue during the push-off phase of running in the experimental group.
Conclusion: The increased electrical activity of the lower limb muscles in various phases of running after fatigue in individuals with a history of COVID-19 can be attributed to decreased neuromuscular coordination.