Biomedical Engineering Reference
In-Depth Information
6.5
PROBLEMS BASED ON KINETIC AND KINEMATIC DATA
1. (a)
Calculate the potential, translational, and rotational kinetic energies of
the leg segment for frame 20 using appropriate kinematic data, and
check your answer with Table A.6 in Appendix A.
(b)
Repeat Problem 1
a
for the thigh segment for frame 70.
2. (a)
Plot (every second frame) the three components of energy plus total
energy of the leg over the stride period and discuss whether this seg-
ment conserves or does not conserve energy over the stride period
(frames 28 to 97).
(b)
Repeat Problem 2
a
for the thigh segment.
(c)
Repeat Problem 2
a
for the HAT segment. Using Equation (6.18), cal-
culate the approximate percentage of energy conservation in the HAT
segment over the stride period. Compare this percentage with that
calculated using the exact Equations (6.19) to (6.22).
3. (a)
Assuming symmetrical gait, calculate the total energy of the body for
frame 28. [
Hint:
For a stride period of 68 frames, data for the left side
of the body can be estimated using right side data half a stride (34
frames) later.]
(b)
Scan the total energy of all segments, and note the energy changes
over the stride period in the lower limb compared with that of the
HAT. From your observations, deduce whether the movement of the
lower limbs or that of HAT makes the major demands on the metabolic
system.
4. (a)
Using segment angular velocity data in Table A.7 in the Appendix plus
appropriate data from other tables, calculate the power generation or
absorption of the muscles at the following joints. Identify in each case
the muscle groups involved that are responsible for the generation or
absorption. Check your numerical answers with Table A.7.
(i) Ankle joint for frame 30.
(ii) Ankle joint for frame 50.
(iii) Ankle joint for frame 65.
(iv) Knee joint for frame 35.
(v) Knee joint for frame 40.
(vi) Knee joint for frame 65.
(vii) Knee joint for frame 20.
(viii) Hip joint for frame 50
(ix)
Hip joint for frame 70
(x)
Hip joint for frame 4.
(b)
(i)
Scan the listings for muscle power in Table A.7 and identify
where the major energy generation occurs during walking. When
in the gait cycle does this occur and by what muscles?
(ii)
Do the knee extensors generate any significant energy during
walking? If so, when during the walking cycle?
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