The viscoelastic properties of muscle have been measured for more than a century to describe muscle disease, damage, recovery and performance. Magnetic Resonance Elastography (MRE) (Muthupillai et al. Science 1995;5232:1854-7) measures viscoelastic parameters of soft tissue in vivo. New software developed by the Clinical Research Imaging Centre (CRIC), MRE-J (Barnhill et al. Proc Image J Dev Conf, Oct 2012), enables the creation of maps of skeletal muscle viscoelastic properties through the transverse plane with MRE. In the present study, thigh muscle stiffness maps were created of ten subjects in a knee extension task. MRE data were acquired for ten subjects using a Siemens Verio 3T MRI Scanner (Erlangen, Germany), in a transverse section of the thigh with the tissue vibrated at 50Hz, during knee extension. Stiffness (storage modulus) maps were created with MRE-J. Quadriceps median stiffness in the knee extension condition increased from 1317 to 1617 Pa, with sigma of 116 Pa. Additionally, the stiffness maps captured heterogeneous approaches to the knee extension task, with subjects activating either vastus lateralis (2 subjects), vastus intermedius (1 subject), or vastus medialis (7 subjects) as the stiffest muscle. Individual activation patterns differed widely compared to the mean for each subject, and for global medians for each muscle. The MRE scans captured wide individual variation in the knee extension patterns that were not captured in the individual or global mean stiffness values. With its ability to capture individual variation in these tasks, MRE offers a novel way to analyse and target therapies and training regimens based on a subject's individual movement patterns.