Time frame: Three laboratory visits, each lasting approximately 4 hours, spanning across approximately 6-8 weeks
Stress/strain impulse at the bone-implant interface (area under time series curve) will be calculated during the stance period of the decline walk (-5 degrees). Subject-specific finite element models will be developed for each bone-anchored limb participant to calculate this outcome. This will be done by including each participant's movement patterns, muscle forces, joint forces, bone geometry and bone health. Movement patterns, muscle forces, and joint loading will be calculated from musculoskeletal modeling using whole-body motion data collected from 70 wearable reflective markers (Vicon, Centennial, CO), ground reaction forces simultaneously collected from an instrumented treadmill (Bertec, Columbus, OH). Bone geometry and healthy will be determined from quantitative computed tomography bone scans.