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Data collected indicates that the study wheelchair performed very well. The data also served to identify those aspects of the wheelchair that may require additional development and testing prior to further production. To gain additional information on long term wheelchair use and performance, the CIR plans to extend this study by interviewing the same subjects at nine and fifteen months from the date they originally received the study wheelchair.

Running is a very popular sport with millions of participants worldwide. As with any physical activity, injuries occur when the musculoskeletal system is overloaded. Running surfaces are often cited as a cause of injuries. The objective of this work was to determine changes in ground contact times, impulses, and shoe reaction forces while running on different surfaces. Eleven healthy adult males (22.9 ± 3.2 years, 176.9 ± 8.4 cm, 74.5 ± 8.6 kg) were recruited to run on four different surfaces: asphalt, concrete, grass, and a synthetic track. The majority of research on running surfaces has been completed in laboratory settings with force plates mounted beneath the running surfaces. Plantar pressure technology permits data collection on the actual running surfaces outside the laboratory. Therefore, data were collected at 250 Hz using a Parotec® plantar pressure measurement system. Participants ran at the same velocity on each of the surfaces. No significant differences were detected among the surfaces for shoe reaction forces, contact time, or impulse (P > 0.05). This implies that runners who choose to run on stiffer surfaces are not exposing themselves to additional risk as a result of loading but possibly because of internal compensatory mechanisms. However, these results may not apply to all runners.

Demineralized bone has had limited use as a medical implant, although, recently Jackson et al. (Am J Sports Med 1996;24(4):405-414) examined using demineralized bone as an anterior cruciate ligament (ACL) replacement and found that within 1 year the demineralized bone had remodeled from a haversian system (bone-like) into a ligament-like structure. Little research has been done to characterize the mechanical properties of demineralized bone and examine its potential as a ligament replacement. This research examined the mechanical properties of demineralized bone as a function of acid saturation time and methods of processing and sterilization using specimens from various anatomic locations. Bone specimens were manufactured from the tibia, metatarsus, femur, radius, and humerus of bovine bone. Tensile strength, strain, and modulus of elasticity were examined for various acid saturation times and sterilization treatments. Additionally, viscoelastic properties, creep and stress relaxation, and fatigue properties were examined. The findings indicate that completely demineralized bone has mechanical properties similar to the ACL and, therefore, has increased likelihood for success in ACL reconstruction surgery.