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Background and Objective: Proprioceptors of the plantar surfaces of the foot have less efficiency and the stimulation and reinforcement of them may be lead to reduction of falling risk. One of the methods to reinforce proprioceptor receptors in these individuals is using textured foot orthoses. The aim of this study was to evaluate the effect of textured foot orthoses on frequency spectrum of lower extremity muscles, stance time and comfort in individuals over age of 55 years during walking.
Methods: This quasi-experimental study was done on the 14 females and 14 males age ranged of 56-70 years with the ability to walk independently and with physical and mental health status. Subjects were compared during five conditions including without foot orthoses and using four foot orthoses (including small and large foot orthoses with two types of flexible and rigid), flexible and rigid large textured foot orthoses. The 8 electrodes were located on tibialis anterior, medial gastrocnemius, vastus medialis, vastus lateralis, biceps femoris, semitendinisus, gluteus, and erector spinae in 3 lumbar vertebrae region muscles.
Results: Frequency content of tibialis anterior and vastus medialis was significantly increased in males than female (P<0.05). Vastus medialis frequency during walking with large foot orthoses was more than walking without foot orthoses (P<0.05). The comfort level was different during flexible large textured foot orthoses condition compared with flexible small textured foot orthoses condition (P<0.05). The stance time was not significant between all conditions.
Conclusion: Increased frequency content of the vastus medialis muscle can increase the absorption and decrease the vertical loading rate imposed on the foot, which in turn reduces the risk of injury of the lower limb in older adults.

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Background and Objective: Anterior cruciate ligament rupture is among the most common sports injuries and has substantial consequences for function, return to sport, and knee-joint health. This study aimed to determine the effect of a fatigue protocol on the frequency spectrum of ground reaction forces during running in men with pronated feet following anterior cruciate ligament reconstruction.
Methods: This clinical trial was conducted at the University of Mohaghegh Ardabili and included 15 men with pronated feet who had undergone anterior cruciate ligament reconstruction and 15 healthy men. Participants in the intervention group had undergone unilateral anterior cruciate ligament reconstruction using a hamstring autograft 4-8 months before the study. Participants first ran along an 18-m track while ground reaction forces were recorded using a force plate positioned at the midpoint. After completing the fatigue protocol, ground reaction force data were recorded again during running.
Results: Changes in the 99.5% power frequency of the mediolateral (2.72±2.31) and anteroposterior (2.35±1.11) ground reaction force components were greater in the intervention group than in the healthy group (-1.24±2.96 and -1.42±4.17, respectively; P<0.05). Within-group analysis showed that the 99.5% power frequency values for the mediolateral ground reaction force component after fatigue in the anterior cruciate ligament reconstruction group with pronated feet (16.16±1.75 and 12.00±1.98, respectively) were higher than the corresponding values before fatigue (13.85±2.36 and 10.16±2.26, respectively) (P<0.05).
Conclusion: Fatigue may affect balance control, particularly in individuals who have undergone anterior cruciate ligament reconstruction. Reduced balance may also decrease running speed.