Abstract
Objective: It is unknown whether muscle aponeurosis area is exaggerated in pennate muscle that has undergone extreme hypertrophy as a result of exercise. We compared the morphological characteristics of deep muscle aponeurosis in resistance-trained athletes with those in untrained students. Design: Cross-sectional study. Methods: Eight elite male Olympic weightlifters and 8 male college students volunteered for the study. Magnetic resonance imaging was used to obtain images from the first cervical vertebra to the ankle joint for each subject, and total and thigh skeletal muscle volumes were determined. Deep muscle aponeurosis in the vastus lateralis (VL) muscle was determined by summing the product of the length of the dark black line (aponeurosis) in each MRI slice and the slice thickness. Results: Fat-free mass and total and thigh muscle masses were greater (P<0.01) in the weightlifters than in the students. Aponeurosis length in the VL was similar in both groups, but the maximal width of the VL aponeurosis was greater (P<0.01) in the weightlifters (11.7 cm) than in the students (8.8 cm). Additionally, VL aponeurosis area in the P between quadriceps muscle mass and VL aponeurosis area (r=0.85, P<0.01). Conclusion: Muscle aponeurosis area may be increased by high-intensity resistance training, which is associated with muscle mass accumulation and muscle fiber geometry in hypertrophied muscle.
