A comparison of lower limb muscle activation pattern using voluntary response index between pronated and normal foot structures during forward jump landing

• Published in: Journal of bodywork and movement therapies 2018-04, Vol.22 (2), p.379-384
• Main Authors: Kouhzad Mohammadi, Hosein, Mehravar, Mohammad, Khademi Kalantari, Khosro, Naimi, Sedighe Sadat, Akbarzadeh Baghban, Alireza, Okhovatian, Farshad, Rezasoltani, Asghar, Mohseni Bandpei, Mohammad Ali, Taheri, Navid
• Format: Article
• Language: English
• Subjects: Adult; Biomechanical Phenomena; Cross-Sectional Studies; Electromyography; Female; Foot - physiology; Humans; Jump landing; Lower Extremity - physiology; Male; Muscle Contraction - physiology; Muscle, Skeletal - physiology; Pronated foot; Pronation - physiology; Voluntary response index; Young Adult
• ISSN: 1360-8592; 1532-9283
• DOI: 10.1016/j.jbmt.2017.07.004

Pronated of the foot is one of the important factors contributing to musculoskeletal problems affecting the lower extremities. It is known that in a pronated foot, excessive mechanical load is applied to the lower limb structures which may result in altered biomechanics and muscle activation patterns. The aim of this study was to determine changes in the muscle activation pattern of the lower extremities in individuals with pronated, compared to normal, feet, using the voluntary response index (VRI). In this cross sectional study, 15 asymptomatic pronated foot individuals (mean age 23.27 ± 3.28 years) and 15 normal subjects (mean age 23.40 ± 3.11 years) were recruited by simple non-random sampling. Electrical activities of gluteus medius (GM), vastus lateralis (VL), vastus medialis (VM), biceps femoris, semitendinosus (ST), and medial gastrocnemius (MG) muscles were recorded during a forward jump landing task. Voluntary response index (VRI) variables, included similarity index (SI) and magnitude (Mag) were also evaluated. Muscle activity of VM (p