Influence of Exercise-Induced Injury on Knee Extension Torque in the Presence of Long-Standing Quadriceps Atrophy: Case Report

Abstract

Purpose: The purposes of this case report were (1) to describe muscle volume and torque-generating capacity of the quadriceps muscle in a 46-year-old woman 16 years following tibial plateau fracture and (2) to compare the decline and recovery of quadriceps torque following exerciseinduced muscle damage between the affected and unaffected lower extremity (LE). Methods: Magnetic resonance imaging was used to determine quadriceps volume. Repeated measures of concentric, eccentric, and isometric torque and muscle soreness were acquired for quadriceps bilaterally during four baseline tests, as well as 2 hours and 1, 2, 11, 12, and 13 days after exerciseinduced muscle damage (eccentric exercise). Results: At baseline, the affected quadriceps showed profound atrophy (74% of unaffected quadriceps volume) and deficits in all torque measures. Exercise-induced muscle damage resulted in slight delayed-onset muscle soreness and a decrease in all torque measures bilaterally. In the affected LE at 13 days after exercise, eccentric torque did not recover and isometric torque on the affected side recovered only partially. Conclusions: Quadriceps atrophy and torque deficit can be substantial long after tibial plateau fracture. Eccentric torque was the most sensitive measure of torque deficit, showing only partial recovery after exercise-induced muscle damage.