Effects of Shoes and a Prefabricated Medial Arch Support on Medial Gastrocnemius and Tibialis Anterior Activity while doing Leg Press Exercise in Normal Feet Athletes

• Published in: International journal of kinesiology and sports science Vol. 5; no. 2; p. 31
• Main Authors: Sheikhi, Maryam, Piroozi, Soraya, Mirzaie Khoshalani, Mohsen, Motiallah, Tahere, Zolanvar, Seyed Hasan
• Format: Journal Article
• Language: English
• Published: Footscray Australian International Academic Centre PTY. Ltd (AIAC) 30.04.2017
• Subjects: Arches; Athletes; Body mass; Body mass index; Electromyography; Feet; Functional anatomy; Injuries; Inserts; Knee; Leg; Loads (forces); Mean square values; Men; Misalignment; Muscles; Phase transitions; Physical training; Prefabrication; Recreation; Rehabilitation; Repetition; Skeletal muscle; Sporting goods; Statistical analysis
• ISSN: 2202-946X; 2202-946X
• DOI: 10.7575/aiac.ijkss.v.5n.2p.31

Background: Nowadays, different types of exercise machines are being used in the field of athletic training, recreation, post-injury and post-operation rehabilitation. Leg press is a commonly-used one that retrains muscles and simulates natural functional activities. In this activity, feet are in contact with a footrest to exert muscular forces. In addition, the footrest inserts reactive forces to feet and from the feet load would transfer to structures that are more proximal. Any misalignment in foot structure may interfere its function. Objective: The aim of this study was to assess the effect of shoes and using a prefabricated medial arch support on the activity of Tibialis anterior and medial gastrocnemius muscles while doing leg press exercise in normal feet subjects. Method: 14 men with normal Medial Longitudinal Arch and normal Body Mass Index aged between 18-35 years old, with at least 6 months experience of doing leg press volunteered to participate in this study.  Medial gastrocnemius and Tibialis anterior activity were measured by surface electromyography while doing leg press with 70% of subjects 1 Repetition Maximum.  To increase accuracy, motion was divided into knee flexion and knee extension phases. Peak Amplitude, Time to Peak Amplitude and Root Mean Square variables were used for analysis. Wilcoxon nonparametric test was used to compare the results. Results: No statistically significant difference was found in the electromyographic parameters of Medial gastrocnemius nor Tibialis anterior in any phases of motion, except for an increase in Tibialis anterior time to peak amplitude in shod condition compared with barefoot in knee extension phase of motion (p-value=0.008) and Tibialis anterior RMS in knee flexion phase in orthotic condition compared to shod (p-value=0.03). Conclusion: It seems that in high loads shoes or medial arch supports cannot change electromyographic parameters in Medial gastrocnemius nor Tibialis anterior in any phase of motion while working with leg press device.