Simbios Talk by Jeffrey Reinbolt, Stanford University, January 31, 2007

Title: Neuromuscular DBP Science: Investigating Stiff-Knee Gait

Stiff-knee gait is a symptom of spastic cerebral palsy characterized by diminished knee flexion during the swing phase of gait. This diminished knee flexion has traditionally been attributed to excessive activity of the rectus femoris, a knee extensor, during swing. It has more recently been observed that many stiff-knee patients exhibit excessive knee extension moments prior to swing. Rectus femoris transfer surgery, a common treatment for stiff-knee gait, reattaches the distal tendon to a new site, such as the sartorius muscle. Some patients show dramatic improvements after this surgery while others suffer further impairment.

In this talk, I will describe the use of subject-specific simulations to identify biomechanical causes of stiff-knee gait and potentially improve treatment planning. I will summarize whether abnormal rectus femoris activity prior to swing or during swing has a greater influence on knee flexion. I will show the simulated potential efficacy of rectus femoris transfer surgery. I will end with a description of ongoing efforts to predict outcomes of rectus femoris transfer surgery through the use of supervised learning techniques.