Question

A sit to stand model divides the body into three segments: calves, thighs, and trunk. The first

table shows the marker coordinates at the point of maximum knee extension torque, and the second table shows the relative segment center of mass (COM) locations:

Marker x (m) y (m)

Ankle 0.234 0.075

Knee 0.455 0.457

Hip 0.072 0.677

Suprasternale 0.513 1.441

Segment COM location (proportion) Relative mass

Calf 0.418 from knee to ankle 0.108

Thigh 0.400 from hip to knee 0.258

Trunk 0.438 from suprasternale to hip 0.634

a) What is the calf segment center of mass?

A. (0.326 m, 0.235 m)

B. (0.345 m, 0.266 m)

C. (0.363 m, 0.297 m)

D. (0.547 m, 0.617 m)

b) What is the thigh segment center of mass?

A. (-0.081 m, 0.765 m)

B. (0.225 m, 0.589 m)

C. (0.264 m, 0.567 m)

D. (0.302 m, 0.545 m)

c) What is the trunk segment center of mass?

A. (0.265 m, 1.012 m)

B. (0.293 m, 1.059 m)

C. (0.320 m, 1.106 m)

D. (0.706 m, 1.776 m)

d) What is the overall body center of mass?

A. (0.281 m, 0.808 m)

B. (0.291 m, 0.846 m)

C. (0.300 m, 0.885 m)

D. (0.486 m, 1.390 m)

e) What is the angular position of this individual’s ankle joint, knee joint, and hip joint (assume the foot is flat on the ground)?

A. ankle dorsiflexion, knee flexion, hip extension

B. ankle dorsiflexion, knee flexion, hip flexion

C. ankle plantarflexion, knee flexion, hip extension

D. ankle plantarflexion, knee flexion, hip flexion

Answer 1