Influence of Post-Stroke Gait on Bone Density

Principal Investigator: Gary S. Beaupré, PhD and Steven A. Kautz, PhD

Project Staff: Henry L. Lew, MD, PhD; R.T. Whalen, PhD; B. Jenny Kiratli, PhD; Lise C. Worthen, MS; C.Maria Kim MSc PT; Jill S. Higginson, MS; and L. Kourtis

Project Category: Osteoporosis

The underlying hypothesis for this study is that the changes in habitual skeletal loading following stroke are in large part responsible for the observed changes in bone density. This hypothesis provides the motivation for a number of key questions, the answers to which are important for improving our understanding of stroke-related osteoporosis and for providing a theoretical basis for potential rehabilitation interventions and goals. In the proposed study we will use experimental and computational approaches to answer the following key questions:

• What are the experimentally determined relationships between measured gait parameters (such as self-selected walking speed and peak ground reaction force magnitude during the stance phase of gait) and bone mineral density at the calcaneus and hip on the affected and non-affected sides?

• What are the experimentally determined relationships between the ground reaction force time histories recorded over three consecutive days and bone mineral density at the calcaneus and hip on the affected and non-affected sides?

• Do the side-to-side asymmetries in bone density correlate with the measured asymmetries in the ground reaction forces between the affected and non-affected sides?

• What are the relationships between the hip joint reaction forces calculated from gait analysis data and measured bone mineral density for both the affected and non-affected sides?

• How well can computer models predict changes in bone density in stroke patients as a function of time post-stroke based on estimates of skeletal loading obtained from gait analysis?

Milestones:

• Gait laboratory has been reconfigured for stroke gait testing using a 5-camera system
• Subject recruitment has begun and gait testing of the first subject is scheduled
• Generic 3D finite element model of the proximal femur has been created

Funding Source: VA RR&D Merit Review

Funding Status: Funded