The Impact of Resistance Toe-Curl Exercise on Venous Blood Flow Velocity Following Foot and Ankle Immobilisation in Below-Knee Casts

Abstract

Category: Trauma; Ankle Introduction/Purpose: Venous thromboembolism (VTE) is a serious complication associated with lower limb immobilisation due to casting, posing significant morbidity and mortality risks. Virchow's triad identifies three key components contributing to VTE risk, with blood stasis being particularly pertinent in immobilised individuals. Prophylactic anticoagulant therapy is standard practice to mitigate VTE risk in such cases, but entail’s potential complications. Exercise has emerged as a promising strategy to enhance venous velocity and mitigate stasis in immobilised patients. This study aimed to investigate the effects of exercise on venous velocity in individuals wearing lower limb casts, with a specific focus on the impact of resistance exercise. Understanding the impact of exercise on venous haemodynamics could inform novel approaches to VTE prevention and management. Methods: Ten healthy male medical students, with a mean age of 23.4 ± 1.2 years, were recruited for the study. Participants underwent below-knee casting on their non-dominant leg to simulate lower-limb immobilisation. Before the commencement of the study, participants were instructed on how to complete the toe-curl exercises. They were then laid on their side, with the non-dominant leg positioned on top and lying straight, to standardise the testing procedure. Using ultrasound imaging, blood flow velocity through the popliteal vein was assessed under three conditions: rest, toe curl exercises without resistance, and toe curl exercises against resistance using a blue TheraBand. Peak venous velocity measurements were recorded after 30 seconds of exercise in each condition. Ethical approval was obtained from the University of Leeds Medical Ethics Committee (MREC 22-058). Results: The results revealed significant enhancements in peak venous flow following both types of exercise compared to rest. At rest, the mean peak venous velocity measured 4.92 ± 1.16 cm/s. During exercise without resistance, the mean peak velocity increased to 28.73 ± 9.72 cm/s, and with resistance, it further elevated to 58.42 ± 29.52 cm/s. These increases were statistically significant when compared to rest (p = 0.019 for exercise without resistance and p < 0.001 for exercise with resistance). Importantly, venous velocity was significantly higher during resistance exercise compared to exercise without resistance (p = 0.003), highlighting the potential benefits of incorporating resistance training into rehabilitation programs for individuals with lower-limb casts. Conclusion: The study highlights the efficacy of exercise, particularly resistance exercise, in enhancing venous velocity among individuals with lower-limb immobilisation. Significant increases in venous flow during both exercise modalities compared to rest, along with the superiority of resistance exercise, show its potential in mitigating venous stasis and reducing the risk of venous thromboembolism. These findings emphasise the potential integration of resistance training into rehabilitation regimens for individuals with lower-limb casts, offering a complementary or alternative approach to pharmacological management in VTE prophylaxis. Further research is needed to determine the long-term impacts of resistance exercise interventions on VTE incidence, guiding clinical practice.