In newborns and infants a variety of respiratory disorders lead to ventilatory failure. In early life the ventilatory response to loaded breathing is limited. The risk factors of ventilatory failure are related to the developing respiratory pump because of the immaturity of the chest wall, respiratory muscles and coupling between thoracic and abdominal movements. Assessment of respiratory muscl...

Berg, H. E., L. Larsson, and P. A. Tesch. Lower limb skeletal muscle function after 6 wk of bed rest. J. Appl. Physiol. 82(1): 182–188, 1997.—Force, electromyographic (EMG) activity, muscle mass, and fiber characteristics were studied in seven healthy men before and after 6 wk of bed rest. Maximum voluntary isometric and concentric knee extensor torque decreased (P , 0.05) uniformly across angu...

Skeletal muscle consists of bundles of long spindle shaped cells called muscle fibers that attach to bone by tendinous insertions. The blood vessels and nerves that nourish and control muscle function run in thin sheets of connective tissue that surround bundles of muscle fibers. Each nerve branch communicates with one muscle fiber at the motor end. The nerve and all the muscle fibers that it s...

3.1 Caution about Copying and Comparisons / 74 3.2 Common Characterizations—Partial Picture / 75 3.2.1 Maximum Isometric Force Production Depends on the Level of Neural Activation / 75 3.2.2 Rate of Force Production and Relaxation Varies Among Muscles / 75 3.2.3 Maximum Isometric Force Depends on Muscle Length / 75 3.2.4 Force Development Decreases with an Increase in Shortening Velocity / 77 3...