Comparative analysis of lower limb muscle activity between a passive-control foot press trainer and heel raise exercises in young adult women: A preliminary study

BACKGROUND: A passive-control foot press trainer (PFPT) based on spring resistance aims to strengthen the ankle joint, similar to heel raise exercise (HRE). OBJECTIVE: To compare the muscle activity of the tibialis anterior, gastrocnemius medialis, gastrocnemius lateralis, rectus femoris, and biceps femoris between PFPT and HRE. METHODS: Eight healthy women performed four exercise conditions: PFPT forefoot (PFPT FF), PFPT rearfoot (PFPT RF), HRE at the floor level (HRE F), and HRE on the block (HRE B). During exercise, muscle activity was measured using surface electromyography and subsequently converted to percentages of maximum voluntary isometric contraction. RESULTS: Tibialis anterior showed the highest activity in PFPT FF, with significant difference from other conditions. Gastrocnemius medialis and lateralis demonstrated the highest activity in HRE B; Rectus femoris showed the highest activity in PFPT RF, showing significant differences from other conditions ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="p&lt;" display="inline" overflow="scroll"> <mml:mrow> <mml:mi>p</mml:mi> <mml:mo>&lt;</mml:mo> <mml:mi/> </mml:mrow> </mml:math> 0.05). Biceps femoris exhibited the highest activity in HRE F and a significant difference from PFPT FF and PFPT RF. CONCLUSIONS: Lower leg and thigh muscle activity between PFPT and HRE had similarities and differences. Future studies should analyze the long-term effects of PFPT, including on patients with musculoskeletal and nervous system injuries.