Right (black column) and left (white column) width–length ratios at 0, 8, and 24 h of mice each injected with 0.5 LD50 BoNT type A. Left EDL muscles were injected with 3 µL BoNT type A, and right EDL muscles were injected with 3 µL GBS. At 24 h, left width–length ratios were significantly (*, P < 0.05) lower than were right width–length ratios.