Contributions of Intrinsic and Extrinsic Foot Muscles during Functional Standing Postures

• Published in: BioMed research international Vol. 2022; pp. 7708077 - 9
• Main Authors: Ridge, Sarah T., Rowley, K. Michael, Kurihara, Toshiyuki, McClung, Matthew, Tang, Jiaxi, Reischl, Steven, Kulig, Kornelia
• Format: Journal Article
• Language: English
• Published: United States Hindawi 2022; John Wiley & Sons, Inc; Hindawi Limited
• Subjects: Ankle; Balance; Center of pressure; Coordination; Electrodes; Electromyography; Equilibrium (Physiology); Feet; Flexors; Foot - physiology; Force plates; Humans; Kinematics; Muscle contraction; Muscle function; Muscle, Skeletal - physiology; Muscles; Physiological research; Posture; Posture - physiology; Standing Position; Variance analysis; Weight-Bearing - physiology; Young Adult; Young adults; United States
• DOI: 10.1155/2022/7708077
• EISSN: 2314-6141
• ISSN: 2314-6133

Purpose. Maintaining balance during static standing postures requires the coordination of many neuromuscular mechanisms. The role of the intrinsic and extrinsic foot muscles in this paradigm has yet to be clearly defined. The purpose of this study was to explore foot muscle activation during static phases on common weight-bearing tasks of varying loads and balance demands. Methods. Twenty healthy young adults performed 6 standing postures (single-limb and double-limb stand, squat, and heel raise) with one foot on a force plate. Muscle activity was recorded from the abductor hallucis, flexor hallucis longus and brevis, and tibialis posterior using intramuscular electrodes; surface electrodes were used to record activity from the peroneus longus and tibialis anterior. Two-way repeated measures ANOVA (2 loading conditions × 3 postures) were run to compare muscle activation and center of pressure velocity. Results. Intrinsic foot muscle activity increased as loading and postural demand increased; however, the specific effects varied for each of the extrinsic foot muscles. Conclusions. These results suggest that the intrinsic foot muscles play an important role in maintaining static balance. Strengthening intrinsic and extrinsic foot muscles may help increase stability in people who have weak toe flexors or who suffer from a variety of foot pathologies.