William H. Harris, Harvard Medical School, Orthopaedic Biomechanics and Biomaterials Laboratory
Henrik Malchau, Harvard Medical School, Orthopaedic Biomechanics and Biomaterials Laboratory
The arrival of copious and cheap flash memory, as well as micromanufacturing techniques, permitted us to generate a pager-sized whole-body activity and knee range of motion monitor-and record these kinematics continuously at 32 Hz for two days on a single AA battery. Thus, we report here data from a healthy convenience sample of 5 males and 5 females, and 3 women and 7 men who had total knee replacements (TKR) 25+4 mo previously. Prior to our project, TKRs, artificial (transfemoral) limbs, airline seats, and other ergonomic knee-motion based designs were based on simulated motion lab studies. These latter indicated that \le 105^o knee flexion was sufficient to accommodate most activities; recently, however, TKR manufacturers began supplying "high flexion" knees that permit \ge 150^o knee flexion. Our data show that healthy Caucasian health care workers rarely employ \ge 120^o knee flexion, nor do Caucasians even with high flexion TKRs-even outside the lab environment.
Citation:
David E. Krebs, James I. Huddleston, Dov Goldvasser, Donna M. Scarborough, William H. Harris, Henrik Malchau, "Biomotion Community-Wearable Human Activity Monitor: Total Knee Replacement and Healthy Control Subjects," bsn, pp.109-112, International Workshop on Wearable and Implantable Body Sensor Networks (BSN'06), 2006