Mass-normalised force results for normal subjects and the "not weak" and "weak" patients with myositis. Males and females are combined in all three groups. The "weak" patients with myositis were obviously weak relative to the other groups, with a mass-normalised force result of 2.2 N/kg compared with 6.6 N/kg for normal subjects and 6.5 N/kg for the "not weak" patients with myositis. Error bars represent + 1 SD from the mean. Abbreviation: F/LBM = force per units of lean body mass.