Free-Living Muscle Activity in Type 2 Diabetes: Sitting, Standing and Walking

AIMS: Using thigh-worn accelerometers and wearable electromyographic (EMG) shorts, we investigated muscle activity during sitting, standing and walking in adults with type 2 diabetes. METHODS: Isometric maximal voluntary contraction measures for quadriceps, hamstring, and gluteal muscle groups normalized the EMG signal to individual maximum capacity. Participants concurrently wore accelerometers and EMG shorts for 3.2 days, and average EMG amplitude (aEMG) was assessed from quadriceps, hamstring, and gluteal muscle groups within accelerometer-derived sitting, standing, walking times. RESULTS: Muscle groups examined used only 2.7–4.4% of their maximum voluntary capacity (%EMG _MVC ) and were inactive for 75-80% of the measurement time. Sitting time was significantly correlated with muscle inactivity across all three muscle groups, but inversely so for hamstring aEMG (r = -0.51). Standing (r = 0.51) and walking (r = 0.48) were correlated with daily aEMG only in hamstrings. Relative to sitting, standing aEMG was 1.3–5.6 times higher and walking aEMG was 3.1–15.2 times higher, indicating varied inter-individual responsiveness. CONCLUSIONS: Reducing daily sitting, especially in favor of walking, may benefit hamstring and gluteal muscle engagement and help to prevent high levels of muscle inactivity in type 2 diabetes. Individual variability in EMG responses highlights the potential to personalize recommendations on sitting, standing and walking.