Effects of Ankle Plantar Flexion Position During Squatting on Tibialis Anterior and Triceps Surae Muscle Activity in Healthy Adults: A Systematic Review and Meta-Analysis

Abstract

Background: Squatting is a fundamental movement in which ankle position is frequently modified with external tools such as shoes, insoles, or wedges. However, the effects of these modifications on shank muscle electromyographic (EMG) activity remain unclear. This systematic review and meta-analysis aimed to examine how changes in sagittal ankle position influence shank muscle EMG activity during squatting.
Material and Methods: A systematic search of six databases was conducted from inception until August 2026. Included studies reported EMG activity of the tibialis anterior (TA), gastrocnemius (GA), or soleus (SOL) during squats performed in plantar flexion or dorsiflexion, compared with a neutral ankle position.
Results: Analysis of eleven studies (141 participants) revealed that the plantar flexion position significantly decreased dorsiflexor (TA) activity (Hedges' g = -1.048; P < 0.001) but had no significant effect on plantar flexor (GA, SOL) activity (Hedges' g = 0.069; P = 0.672). High heterogeneity (I² > 75%) was observed for both meta-analyses. Limited evidence also suggested that dorsiflexed positions may reduce plantar flexor activity.
Conclusions: Ankle plantar flexion during squatting significantly reduces dorsiflexor activity without systematically altering plantar flexor activation. These findings provide preliminary support for the clinical use of heel lifts to offload the TA but question their efficacy for modifying calf muscle recruitment. Future research should prioritize standardizing EMG methodologies and investigating these effects in clinical populations.