Abstract
The purpose of this study was to assess the effects of bed rest for 2 to 3 weeks on the musculoskeletal and cardiovascular systems. Subjects were seven female patients between the ages of 54 and 65 years with unilateral coxarthrosis deformans who were admitted for the total hip replacement. Biographical and physical data on each subject were considered to be the same. The changes before and after bed rest were measured as follows:
1) The maximum isometric muscle strength on flexion and extension of the uninvolved knee joint and the left elbow joint,
2) The thickness of the uninvolved quadriceps femoris and the left biceps brachii muscle using the ultrasound technique,
3) The responses to ergometric exercise in blood pressure, heart rate and oxygen consumption.
The maximum muscle strength loss after bed rest was greater in the leg muscles than in the arm muscles, and the decrease of knee extensors was greater than that of knee flexors in the leg muscles. The reduction of muscle thickness demonstrated in the rectus femoris was most pronounced in the quadriceps group. In the cardiovascular responses to ergometric exercise, there were significant increases in heart rate and oxygen consumption after bed rest.
