Comparison of Lower Limb Muscle Activation Patterns in Different Foot Structures using Voluntary Response Index: A Study Protocol

Abstract

Background: Structural foot disorders can widely contribute to lower limb musculoskeletal conditions. Some researchers consider them the origin of overuse injuries in lower limbs. Although their effects on electrical activities of intrinsic and extrinsic foot muscles are well-established, their impact on other lower limb muscle groups are yet to be clarified.
 Objectives: This study aims to identify the activation patterns of lower limb muscle groups in various foot structures.
 Materials and Methods: In this case control study, 45 asymptomatic male and female subjects with different foot structures (pronated, supinated, and normal) will be selected using non-random sampling. The electrical activities of the gluteus medius, vastus lateralis and medialis, biceps femoris, semitendinosus, and lateral and medial gastrocnemius muscles will be examined during a jump-landing task. Voluntary response index, including magnitude and similarity index, will be subsequently calculated.
 Discussion: While several studies have evaluated the activation of lower limb muscles in different foot structures, they have solely focused on foot muscles. In contrast, the present study will assess activation patterns of the global lower limb muscles using the voluntary response index.