Purpose The Purpose of this study was to investigate the effects of additional limitations during walking on cardiopulmonary functions. The results can be used as basic value for studying of relative on lower extremity problem. Methods Ten healthy female college students, none of whom had gait abnormality, were participated in this experiment. Subjects walked on a treadmill at comfortable walking speed(3.62km/h) under three conditions. Three conditions were First group is without a knee immobilized and crutches(N;normal gait), Second group is with a knee immobilized(C;cast), and Third with a knee immobilized and crutches(CC;cast+cruch). RER, VO2, Kcal, VE was measured by K4b2 and body composition by Inbody 570. The effect values were used mean value of that SPSS(ver. 18.0) in performance of all statistical analyses, statistical significance was set at 0.05. Results Measures increased under three conditions, but significant differences existed in VO2, Kcal. Also, Significant differences existed in CC group compared with N group and C group. Conclusion Knee immobilization and using crutches increase energy expenditure during level walking at comfortable walking speed(3.62km/h) than knee immobilization and normal. Therefore, This fact must be considered during gait training and exercise.