# The Impact of Excessive Muscle Co‐Contraction on Sit‐To‐Stand Performance in High‐Heeled Footwear

## TL;DR

Wearing high-heeled shoes increases muscle co-contraction, which affects balance and performance during sit-to-stand tasks in women.

## Contribution

This study quantifies how high-heeled footwear influences muscle co-contraction and compensatory mechanisms during sit-to-stand movements.

## Key findings

- Increased heel height correlates with higher co-contraction in quadriceps and hamstring muscles.
- Compensatory mechanisms in these muscles may lead to imbalance and fatigue with regular high-heel use.
- Maintaining normal movement during high-heel use requires greater external work from lower limb muscles.

## Abstract

This study aimed to analyse the effects of co‐contraction on quadriceps and hamstring muscles during sit‐to‐stand (STS) tasks for females wearing shoes with different heel heights. The study aimed to identify compensatory strategies during the STS tasks in response to excessive muscle co‐contraction during high‐heeled gait. Sixteen healthy young women (age: 24.4 ± 1.7 years, body mass index: 18.4 ± 1 kg/m2, weight: 50.2 ± 5.2 kg, height: 1.63 ± 4.4 m) participated in this study. Electromyography signals were recorded from three quadriceps (vastus medialis, vastus lateralis, and rectus femoris) and one hamstring (semitendinosus) muscles. The participants wore shoes with different heights, including 4, 6, 8, and 10 cm. For each heel height, the co‐contraction index is computed to measure postural balance using the quadriceps to hamstring muscle pairs. The results that were obtained and quantified with statistical measures show that for elevated shoes, if co‐contraction increases, both quadriceps and hamstring muscles tend to compensate. This suggests that the capacity of the quadriceps and hamstring muscles to compensate is essential to retain normal walking and STS tasks in co‐contracted persons. However, the compensation mechanisms may induce imbalance, muscle stiffness, and fatigue for women who regularly use high‐heeled shoes during sit‐to‐stand tasks.

This exploratory study aimed to quantify the effect of co‐contraction for high heeled shoes (HHS). The results support the hypothesis that quadriceps to hamstring co‐contraction increases for elevated HHS. Our study findings indicated that capacity of the quadriceps and hamstring muscles to compensate is fundamental for retaining normal sit to stand (STS) tasks with muscle co‐contraction. From the results, it could be expected that elevated HHS exerts more external work to maintain the same quadriceps‐to‐hamstring ratio compared to lower HHS. Hence, the compensation mechanisms used by lower limb muscles may induce imbalance, muscle stiffness, and fatigue with regular usage of high heel shoes in women during the STS task.