In the X-ray diffraction pattern from skeletal muscle the 3rd order myosin-based meridional M3 reflection originates from the axial repeat of myosin cross-bridges along the thick filament. Changes in the intensity (I_M3), spacing (S_M3), and fine structure (R_M3) of the M3 reflection in contracting muscle have been measured in many different protocols (Linari et al. PNAS97:7226, 2000; Piazzesi et al. Nature415:659, 2002; Reconditi et al. Nature428:578, 2004; Huxley et al. J. Mol. Biol.363:743, 2006). The results are explained with model simulations based on (1) the crystallographic structure of the myosin head (subfragment-1, S1), integrated with the tilting lever arm hypothesis (Rayment et al. Science261:50, 1993), (2) the presence of a fixed periodic mass attributed to detached myosin heads and (3) the assumption that all the compliance of the cross-bridges resides in S1 (Seebohm et al. Biophys. J.97:806, 2009). Here the possibility that a substantial proportion of the cross-bridge compliance is provided by the subfragment-2 (S2) link between the head and the thick filament (Knupp et al. J. Mol. Biol.390:168, 2009) is analysed by adding a variable compliance in S2 and testing the resulting model in the different protocols mentioned above and, moreover, against I_M3 changes induced by rapid length changes imposed on the muscle fibre in rigor (Dobbie et al. Nature396:383, 1998). The results show that S2 does not significantly contribute to the cross-bridge compliance.