Muscle is one of the most frequently affected tissues in laminopathies with loss of strength with or without joint contractures. Impairments in range of motion, grip strength and walking endurance have recently been measured in Hutchinson-Gilford progeria syndrome (Malloy et al. 2023). Here, we quantify muscle strength, joint contractures and walking in adult laminopathies (LGMD1B, EDMD, isolated dilated cardiomyopathy (DCM-CD) or partial lipodystrophy (PLD)). Handgrip and elbow/knee flexion/extension maximum isometric strength was measured by specific dynamometers. Strength and distance covered during a 6-minute walk test (6MWD) were expressed as a percentage of predicted value (%pred). The median(min,max) of the %pred values are presented here. So far, 30 participants aged 53(24,76) years, 20% male, have been included. Most had an impaired elbow flexion strength with a median below 100%pred regardless of phenotype: 17(6,44) for EDMD (n=3), 19(2,90) for myopathy+PLD (n=3), 51(16,65) for LGMD1B (n=9), 75(59,112) for PLD (n=9), 68 for Myopathy+DCM-CD (n=1) and 59(41,99) for DCM-CD (n=5). Elbow extension and flexion strengths were strongly correlated (rS=0.864,P<0.001), but not with elbow contracture. Handgrip strength was impaired in all participants with EDMD (61(58,62)) or myopathy+PLD (58(48,89)) and in some individuals with other phenotypes. The 6MWD was most affected in EDMD (45(0,78)), followed by myopathy+PLD (55(0,81)), LGMD1B (67(50,93)), PLD (87(66,101)), Myopathy+DCM-CD (92), and DCM-CD (98(69,103)). For all participants, knee extension and flexion strengths were strongly correlated (rS=0.730,P<0.001). The 6MWD was correlated with knee extension (rS=0.719,P<0.001) and flexion (rS=0.717,P<0.001) strength. At this stage of inclusion, no age dependence was observed for muscle strength or 6MWD. In conclusion, skeletal muscle weakness has been observed in the major phenotypes of laminopathies. Longitudinal follow-up is underway.