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Department of Veterans Affairs. United States of America. VA Center of Excellence. For Limb Loss Prevention & Prosthetic Engineering. How humans negotiate corners. Michael Orendurff, Glenn Klute, Greta Bernatz, Brian Glaister, Jason Schoen, Elizabeth Huff, Ava Segal
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Department of Veterans Affairs United States of America VA Center of Excellence For Limb Loss Prevention & Prosthetic Engineering How humans negotiate corners Michael Orendurff, Glenn Klute, Greta Bernatz, Brian Glaister, Jason Schoen, Elizabeth Huff, Ava Segal Motion Analysis Laboratory, Center of Excellence for Limb Loss Prevention and Prosthetic Engineering Rehabilitation Research and Development, Seattle, Washington, USA · morendurff@hotmail.com
Almost everything we know about walking is about walking straight ahead • There is more known about cockroach turning than human turning • Turning is a necessary skill • A turn every 2.6 m, ~ every 5th step
Office to Car Office to Office 252 m course 47 m course 8% Turning Steps 45% Turning Steps Cafeteria Store 82 m course 82 m course 35% Turning Steps 50% Turning Steps Brian Glaister, et al; In Press, Gait & Posture
Right Foot Contact Left Foot Contact COM 1 m 1 m 1.2 m/s 1.0 m/s 0.6 m/s Straight, 0.6 m/s Turning Orendurff, et al; Gait & Posture, 2006
Systematic limb asymmetries NS IN > ST > OUT OUT = IN < ST IN > ST p < 0.0001 OUT = IN < ST IN > OUT = ST IN = ST > OUT IN > ST = OUT OUT > ST > IN OUT >> IN >> ST Orendurff, et al; Gait & Posture, 2006
Turn Continuation Straight Turn Termination Turn Initiation Straight Straight COM Path
Y X n +1 n n -1 COM (250 Hz) Elizabeth Huff, Brian Glaister, Jason Schoen
COM PELVIC ORIGIN 8 Maximum Difference with 1ab Maximum Difference with 1ab 8 150 6 6 4 Angle (degrees) 4 Angle (degrees) 130 2 2 0 0 1a 1b 5 10 15 20 25 50 1a 1b 5 10 15 20 25 50 Finite Difference Interval Finite Difference Interval 110 Angle Between COM and Global (Degrees) 1a 1a 1b 1ab 1b 1ab 5 5 10 90 10 15 15 20 20 25 25 50 50 70 1.6 1.8 2 2.2 2.4 2.6 2.8 3 1.6 1.8 2 2.2 2.4 2.6 2.8 3 time (s) time (s) Brian Glaister, Jason Schoen, Elizabeth Huff
Y (forward) and X (medial) distance COM - Foot Y X n +1 n n -1 COM (250 Hz) Greta Bernatz
Y X n +1 n n -1 COM (250 Hz) Brian Glaister, Jason Schoen
Fore Aft “Constant” Velocity ~1.3 m/s Acceleration Acceleration ~ 0.8 m/s Deceleration Ground Reaction Impulse (N-%stance/kg) Deceleration ~ 70 Propulsive ~ 60 ~ 40 Braking “Constant” Velocity ~1.3 m/s
Medial Lateral Ground Reaction Impulse (N-%Stance/kg) ~150 ~60 ~40 Same foot ~5 Other foot
Hip rotator moments during a hallway corner 200 Turn Termination (TT) Internal Straight (S) 150 Turn Initiation (TI) 100 Turn Continuation (TC) 50 0 Hip Rotator Moment (Nmm/kg) -50 -100 -150 -200 External Stance Swing 0 20 40 60 80 100 % Gait Cycle
Hip Internal Rotator Moment 300 Hip rotator moment magnitude (Nmm/kg) ~ 200 200 * ~ 170 * p < 0.002 100 * ~ 130 Hip Rotator Moment (Nmm/kg) S TI TC TT 0 -100 * p < 0.02 -200 Hip External Rotator Moment -300 COM Path
Foot Contact Location Moment GRF Vector Translation Braking
Foot Contact Location Moment GRF Vector Translation Hip Rotator Moment Braking
Thank You This work was funded by the Department of Veterans Affairs #A2661C Rehab R&D Center of Excellence Limb Loss Prevention & Prosthetic Engineering www.seattlerehabresearch.org Department of Veterans Affairs United States of America VA Center of Excellence For Limb Loss Prevention & Prosthetic Engineering