Physical function and muscle strength in sporadic inclusion body myositis

In this study, self‐reported physical function, functional capacity, and isolated muscle function were investigated in sporadic inclusion body myositis (sIBM) patients. Methods: The 36‐item Short Form (SF‐36) Health Survey and 2‐min walk test (2MWT), timed up & go test (TUG), and 30‐s chair stand performance were evaluated. In addition, patients were tested for knee extensor muscle strength (isokinetic dynamometer) and leg extension power (Nottingham power rig). Results: TUG performance was the strongest predictor of self‐reported physical function ( r 2 = 0.56, P < 0.05). Knee extension strength and between‐limb strength asymmetry were the strongest multi‐regression indicators of TUG performance ( r 2 = 0.51, P < 0.05). Strength asymmetry showed the strongest single‐factor (negative) association with 2MWT performance ( r 2 = 0.49, P < 0.05). Discussion: TUG assessment appears to sensitively predict self‐perceived physical function in sIBM patients. Notably, between‐limb asymmetry in lower limb muscle strength had a substantial negative impact on motor tasks involving gait function. Muscle Nerve 56 : E50–E58, 2017