Walking Poster

800

600 heelstrike

heeloff

midstance

foot flat

toe-off

deceleration

acceleration

heelstrike

GAS (13-50) RF (47-70) HAM (85-10)

RF (92-11)

loading response 0-10%

terminal stance 30-50%

mid stance 10-30%

GMAX (95-15) IL ( 57-80) VAS (88-25) BFsh (80-05) SOL (11-47) TA (56-15)

pre swing 50-60%

400 initial swing 60-73%

mid swing 73-87%

terminal swing 87-100%

200

swing

stance

0 -200

Maximum joint moments during walking, running, and concentric isokinetic testing

mm

0

200

400

600

800

1000

1200

1400

______________________________________________________________________________ Joint

Muscle Group

Walking

Running

Isokinetic

______________________________________________________________________________ Hip

Extensors Flexors

15-140 [100] 40-120 [70]

40-80

Knee

Extensors

5-140 [80]

125-273

Flexors

15-50 [30]

Plantarflexors

85-165 [130]

Ankle

180-240

300 170 235 (50 °/s), 166 (60 °/s), 154 (180 °/s), 120 (400 °/s) 93 (60 °/s), 70 (180 °/s) 89 (30 °/s), 50 (90 °/s), 21 (180 °/s)

______________________________________________________________________________ Note: Moments given in Nm; average peak values in brackets; angular velocities in parentheses. For walking, knee angular velocity is ~100 °/s, and ankle angular velocity is ~50 °/s at the time when peak moment occurs.

Maximum joint powers generated during walking, running, and concentric isokinetic testing

Summary of Walking Metabolic Studies hip flexor hip flex/medial rot hip flex/abd/ext rot knee flex

unweighting force VO2 monitor

50% antigravity 25% reduction

hip add/med rot knee flex hip flex knee ext hip add hip add

Farley & McMahon, 1992

______________________________________________________________________________ Joint

Muscle Group

Walking

Running

Isokinetic

______________________________________________________________________________ Hip

Extensors

0-175

160-660

Knee

Extensors Flexors

10-235 10-50

210-1050

Plantarflexors

180-790

550-1580

Ankle

200 (100 °/s) 205 (50 °/s), 840 (400 °/s) 97 (60 °/s), 220 (180 °/s) 47 (30 °/s), 79 (90 °/s), 66 (180 °/s)

hip add knee ext knee ext knee ext

forward assist force

drag force

10% BW assist 47% reduction

10% BW impeding 150% increase

Gottschall & Kram, 2003

Gottschall & Kram, 2003

______________________________________________________________________________ Note: Powers given in watts; angular velocities in parentheses. For walking, ankle angular velocity is 200 deg/s @ peak. peak power occurs.

additional mass

hip ext/ext rot hip ext knee flex hip ext knee flex hip add/med rot hip add/med rot hip ext knee flex

10% BM addition 15% increase

body interface joints/structure passives/actives

hip flex/abd/int rot

Griffin et al, 2003

knee flex ankle dorsi

major muscle groups GMAX

toes toes

treadmill

IL

GMAX - hip extensor IL - hip flexor RF VAS - knee extensor BFSH - knee flexor HA BF SOL - ankle plantarflexor SH M TA - ankle dorsiflexor RF - hip flex/knee ext HAM - hip ext/knee flex GAS - knee flex/ankle plantarflex ACH - ankle plantarflex tendon

clutch / brake / return spring

toes

actuator positive and negative work metabolic cost [Abbott et al 1952] negative 1/3 to 1/7 as costly [DeLooze et al 1994] neg work 0.3 to 0.5 as costly

TA

inversion/add foot eversion/abd foot eversion/abd

VAS cam lever transmission linkage brake

GAS

SOL ACH

ankle plantar/knee flex ankle plantar unlocks knee/rotates toes

biarticular monoarticular tendon

cam lever dorsi stop brake

return spring clutch brake?

elastic

tension only? push-pull?

cam lever transmission linkage brake

Peak kinetic values during one cycle of normal walking ______________________________________________________________________________ Variable Plane Action Hip Knee Ankle ______________________________________________________________________________ Moment Extensor 1.15 0.46 1.73 (Nm/kg) Sagittal (0.30) (0.35) (0.22) Flexor 1.10 0.43 0.20 (0.30) (0.18) (0.10) Abductor 1.20 1.10 0.13 Frontal (0.25) (0.20) (0.10) Adductor 0.10 * 0.04 (0.10) (0.04) Inversion 0.20 0.11 * Transverse (0.04) (0.03) Eversion 0.20 0.09 0.10 (0.06) (0.05) (0.04) Power Generation 1.80 0.60 4.40 (W/kg) Sagittal (0.50) (0.50) (1.10) Absorption 1.0 1.50 0.50 (0.55) (0.50) (0.30) Generation 0.55 0.18 0.07 Frontal (0.15) (0.13) (0.06) Absorption 0.90 0.18 0.12 (0.60) (0.12) (0.08) Generation 0.02 0.04 0.01 Transverse (0.06) (0.02) (0.03) Absorption 0.17 0.15 0.02 (0.16) (0.10) (0.02) ______________________________________________________________________________ Note: Values in parentheses are +/- one standard deviation *Indicates value ~ 0.