Does size matter? The impact of calf muscle volume on venous return in patients with venous leg ulcers

Objectives: The calf muscle pump is recognized as an integral component of effective venous return from the lower limbs. The aim of this study was to determine if there is a correlation between calf muscle volume and venous blood flow among patients with venous leg ulcers. Methods: Nine patients with venous leg ulceration were recruited for this study. These patients underwent haemodynamic testing using duplex ultrasound to measure peak venous velocities in response to voluntary maximum plantar flexion, with and without compression bandaging. Each patient then had magnetic resonance imaging (MRI) of the lower limbs. Calf muscle volume was calculated from the MRI images using a specially designed Matlab computer program to identify and count muscle pixels. Analyses applied Pearson's correlation coefficient to determine correlation between calf muscle volume and mean peak venous velocities in response to voluntary contraction. Results: No correlation was seen between calf muscle volume and haemodynamic venous return in response to voluntary contraction, with or without compression bandaging. Conclusion: The volume of calf muscle available for promoting venous return alone may not be an accurate indicator of muscle functioning capability.