Magnetic Resonance Elastography (MRE) is an emerging imaging technology that measures skeletal muscle stiffness via the study of externally induced sound waves propagating through the muscle. Evidence from mainly animal studies suggests that skeletal muscle connective tissue stiffness increases with advancing age, contributing to muscle weakness. However two recent human MRE studies measuring stiffness (shear modulus) in the relaxed state showed no statistically significant association between stiffness and age in 50-70 y old women1, and no significant differences when young and middle-aged adults were compared2. There are no MRE reports in the literature of stiffness in adults >70 y. We hypothesised that muscle stiffness measured using MRE would be higher in very elderly adults compared with young. We studied the quadriceps group of n=18 healthy men and women (n=8 older median age 81 y range 69-87 y, BMI mean (SD) 23.8 (3.3); n=10 young median age 24 y range 21-35 y; BMI 25.6 (2.3)) using a 3 tesla MRI scanner (MAGNETOM Trio, Siemens AG, Erlangen, Germany). We used a modified single-shot EPI sequence sensitized to motion by the motion encoding gradient, aligned perpendicular to the image plane. Imaging parameters were TE=56ms, TR=1600ms, FOV=235mm, Matrix=128×128, slice thickness=10mm, scan duration=1min 6s Mechanical excitation was supplied to the muscle via a ring shaped plastic cuff positioned at mid-thigh level and which was affixed to the vibration source via a carbon fibre piston. The data were imported into MATLAB then temporally Fourier transformed, filtered, inverted and averaged as previously reported3. The data were interpreted over three regions of interest, the whole axial slice, the extensor muscles, and the vastus lateralis. Comparison between groups was by 1-way ANOVA. We found a significant reduction in stiffness in older muscle compared with young across all regions of interest. Mean (SD) shear modulus for young vs old were 2053.4 (115.9) vs 1783.6 (87.2), p<0.001; 2067.7 (157.2) vs 1801.9 (98.0), p = 0.003; 1929.9 (212.2) vs 1664.5 (146.5), p = 0.02 for the whole slice, extensor muscles and VL alone respectively. Contrary to our hypothesis, these preliminary data suggest that skeletal muscle stiffness may actually decline with advancing age although this may still adversely affect force transmission. Further research on larger groups, controlling for prior physical activity, muscle length and load, are needed. MRE is non-invasive and does not entail strenuous activity. It is therefore suitable for studies with older adults and may represent a non-invasive, functional biomarker of ageing muscle function.