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Updated: Aug 10, 2026

Physiological Recordings of High and Low Output NMJs on the Crayfish Leg Extensor Muscle
Published on: November 17, 2010
Characteristics of leg extensor muscle in a world champion masters jumper. A case study
Abstract:
To examine the characteristics of a world champion masters jumper (aged 71 yr), a study was undertaken which included a muscle biopsy and measurement of mechanical force production. Comparisons were made to biopsy data obtained from the literature and to force data on 7 active males (63-81 yrs). Cross-sectional areas of vastus lateralis muscle of the jumper's dominant thigh were 3.43 (type I), 3.32 (type IIA) and 2.34 (type IIB) microns 2 X 10(3). This is smaller than what is reported from sedentary young and old. The torque-time curve of maximal isometric knee extension indicates that the jumper had the highest value per body weight from the onset to the peak (3.48 Nm/kg; 58.2% higher than age-matched controls). These results suggest that the daily training of the jumper has a specific effect on the rate of force production despite his relatively small muscle fiber areas.
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