Reduction in thigh muscle cross-sectional area and strength in a 4-year follow-up in late polio

Abstract Objective: To study changes in cross-sectional thigh muscle are and muscle strength in late polio subjects over a 4-year period. Design: Longitudinal study of a cohort of polio survivors, comparing subjects who acknowledge (unstable) with those who do not acknowledge (stable new muscle weakness. Setting: University hospital. Subjects: Eighteen subjects (6 men, 12 women) with polio-myelitis sequelae (39 to 46 years of age) were studied on two occasions 4 years apart; the first examination was 37 to 44 years after onset of polio. Subjects were recruited through hospital registers, newspaper advertisement, and a patient organization. Outcome Measurements: Thigh muscle and intermuscular and intramuscular adipose tissue (AT) cross-sectional areas were measured by computed tomography. Isometric muscle strength for knee extension and flexion was measured using a Kin-Com dynamometer. Results: Cross-sectional muscle area decreased on average 1.3 ± 3.6cm 2 (1.4%, p 2 (12.1%, p p p p r = .44, p Conclusion: The present results demonstrate not only progress of muscle weakness, but also of muscle atrophy in postpolio subjects.