Contributions of Intrinsic and Extrinsic Foot Muscles during Functional Standing Postures

Abstract

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.

Injury of flexor halluics longus tendon in amateur marathon runners results in abnormal plantar pressure distribution: observational study

“…The results showed that only the forefoot pressure data of the sole of the dominant limb were different, while the rest of the static plantar data were not significantly different, which was similar to the results of our study. Our results showed no difference in the static data between the two groups, but we believe that this is related to the weaker FHL tendon function in the static condition [22]. A systematic review study addressed the relationship between static plantar posture and plantar pressure [23].…”

Vertical ground reaction force oscillation during standing on hard and compliant surfaces: The “postural rhythm”

“…Whereas, the much larger peak amplitude of the spectrum for compliant than hard support surface would be explained by the strong and rhythmic activity of the muscles involved in the balance correcting reactions (131), in turn connected with the need for more vigorous contractions. On compliant surface, the feedback would recruit several body muscles (20,75,118,(132)(133)(134) and operate together with anticipatory activations (135,136). This interaction would be modulated by the sensory inputs and efference copies connected with the continuous body sway and muscle actions, respectively (137).…”

Interaction between Feet and Gaze in Postural Control

“…When moving at moderate speed from the base of support, the muscles of the feet stabilize the head [ 32 ]. Intrinsic feet muscle activity increases with postural activity and contributes significantly to the maintenance of postural balance [ 33 ].…”