EVALUATING IMPACTS OF STIFFNESS AND NEUTRAL ANGLE ON STAIR AMBULATION AND OVERGROUND WALKING PERFORMANCE IN CEREBRAL PALSY USING AN REAL-TIME VARIABLE STIFFNESS ANKLE FOOT ORTHOSIS - PROJECT SUMMARY/ABSTRACT CEREBRAL PALSY (CP) IS THE MOST COMMON CHILDHOOD NEUROMUSCULAR CONDITION. CP CAUSES GAIT DIFFICULTIES ASSOCIATED WITH DECREASED PHYSICAL ACTIVITY, INCREASED PAIN, AND LOW QUALITY OF LIFE. PEOPLE WITH CP ADOPT CROUCHED, INEFFICIENT GAIT PATTERNS THAT NEGATIVELY AFFECT THEIR MOBILITY DUE TO REDUCED MUSCLE STRENGTH AND CONTROL AT THE ANKLE. ANKLE FOOT ORTHOSES (AFOS) ARE EXTERNAL FOOT BRACE INTERVENTIONS THAT PROVIDE SUPPORT AND STABILITY BY REGULARIZING ANKLE BIOMECHANICS. AFOS CAN IMPROVE OVERGROUND WALKING SPEED WITH THE CAVEAT THAT AFOS NEED STIFFNESS AND NEUTRAL POSITION TUNING FOR EACH USER TO SEE THE GREATEST BENEFITS. THE SUPPORT AFOS APPLY COMES AT THE COST OF RANGE OF MOTION. AS A RESULT, TASKS THAT REQUIRE MORE RANGE OF MOTION THAN OVERGROUND WALKING LIKE SIT-TO-STAND TRANSITIONS, NAVIGATING STAIRS, OR GETTING IN AND OUT OF A CAR BECOME CHALLENGING AND DANGEROUS IF AN AFO IS TOO STIFF. NOVEL, EMERGING AUTO-ADJUSTABLE AFOS CAN ACTIVELY BALANCE SUPPORT AND RANGE OF MOTION BY MODULATING AFO PROPERTIES AS A CHILD WALKS. NEW KNOWLEDGE ON OPTIMAL DEVICE SETTINGS IS NEEDED TO DETERMINE HOW TO MAXIMIZE CLINICAL BENEFITS FROM THESE ADAPTIVE AFOS. THE PURPOSE OF THIS PROJECT IS TO INVESTIGATE HOW PERSONALIZED AFO STIFFNESS AND NEUTRAL ANGLE SETTINGS CAN IMPROVE STAIR AMBULATION TIME AND MUSCLE ACTIVITY COMPARED TO STANDARD-OF-CARE RIGID AFOS, AND HOW PERSONALIZATION MAY NEED TO CHANGE TO FIT DIFFERENT TASKS. AIM 1 WILL EVALUATE HOW STIFFNESS AND NEUTRAL ANGLE IMPACT TIMED-UP-AND-DOWN-STAIRS AND 10 METER WALK TESTS PERFORMANCE IN CP THROUGH A FULL-FACTORIAL DESIGN. THE HYPOTHESIS IS THAT AFO STIFFNESS WILL POSITIVELY CORRELATE WITH AMBULATION TIME BUT NEGATIVELY CORRELATE WITH MUSCLE ACTIVITY, WHILE NEUTRAL ANGLE WILL CORRELATE NEGATIVELY WITH TIME AND POSITIVELY WITH MUSCLE ACTIVITY. AIM 2 WILL COMPARE AUTO-ADJUSTING AFO PERFORMANCE TO RIGID AFOS AND A SHOES ONLY CONDITION. THE HYPOTHESIS IS THAT THE AUTO-ADJUSTING AFO WILL YIELD HIGHER MUSCLE ACTIVITY AND SHORTER DESCENT TIMES THAN RIGID AFOS. THE RESULT OF THIS RESEARCH WILL PROVIDE USEFUL INFORMATION FOR CLINICIANS TO PERSONALIZE AFOS TO MAXIMIZE OVERGROUND AND STAIR PERFORMANCE. THESE ADVANCEMENTS COULD ALLOW CHILDREN WITH CEREBRAL PALSY NAVIGATE THE WORLD WITH GREATER EASE (QUICKER, LESS DIFFICULTY). THE FELLOWSHIP TRAINING WILL PROVIDE THE APPLICANT CLINICAL TRIAL SKILLS, SUCH AS IN MANAGEMENT, STATISTICS, AND COMMUNICATION THROUGH MENTORSHIP AND EXPERIENCE. TRAINING WILL OCCUR UNDER DR. LERNER AT THE BIOMECHATRONICS LAB, THE HUB FOR BIOMEDICAL RESEARCH AT NORTHERN ARIZONA UNIVERSITY, AND WITH CO-SPONSORS DRS. ELLIOTT ROUSE (UMICH) AND KAT STEELE (UW) AND COLLABORATOR MARK FICK (HANGER CLINIC). COMPLETING THIS PROJECT WILL PROVIDE A FOUNDATION AS AN INDEPENDENT RESEARCHER TO ACHIEVE THE LONG-TERM GOAL OF IMPROVING FUNCTIONAL CAPABILITIES OF PEOPLE WITH NEUROMUSCULAR IMPAIRMENTS USING WEARABLE ROBOTICS.