Metabolic and Physiological Differences Between Knee Crutch Ambulation and Normal Gait: A Case Study

The knee crutch was originally developed in 1999 by the company iWalkFree as an assistive aid for individuals with below-the-knee injuries (iWALKFree). Although it has been over 20 years since the knee crutch was first commercialized, there have been very few studies published on how it affects the user. In addition, most studies concerning the knee crutch only describe the biomechanical and EMG data, instead of physiological and metabolic data. This two-participant case study research employed a portable gas analysis instrument to understand the minute ventilation (VE), oxygen (O2) consumption, and heart rate differences between walking with a knee crutch and walking with no assistive device. Upon comparing the results of this study to previous research, it was determined that the knee crutch allows greater efficiency than using other assistive devices such as traditional crutches and the knee scooter, indicated by lesser metabolic and physiologic stress.