MECHANICAL WORK, ENERGY, AND POWER - Biomechanics and Motor Control of Human Movement - page 174

(iii) What hip muscle group generates energy to assist the swinging
of the lower limb? When is this energy generated?
5. Using Equation (6.10) (see Figure 6.8), calculate the passive rate of energy
transfer across the following joints, and check your answers with Table
A.7. From what segment to what segment is the energy flowing?
(i) Ankle for frame 20.
(ii) Ankle for frame 33.
(iii) Ankle for frame 65.
(iv) Knee for frame 2.
(v) Knee for frame 20.
(vi) Knee for frame 65.
(vii) Hip for frame 2.
(viii) Hip for frame 20.
(ix) Hip for frame 67.
6. (a) Using equations in Figure 6.19 b , carry out a power balance for the
foot segment for frame 20.
(b) Repeat Problem 6 (a) for the leg segment for frame 20.
(c) Repeat Problem 6 (a) for the leg segment for frame 65.
(d) Repeat Problem 6 (a) for the thigh segment for frame 63.
7. Muscles can transfer energy between adjacent segments when they are
rotating in the same direction in space. Calculate the power transfer
between the following segments, and indicate the direction of energy
flow. Compare your answers with those listed in Table A.7.
(a) Leg/foot for frame 60.
(b) Thigh/leg for frame 7.
(c) Thigh/leg for frame 35.

6.6 REFERENCES

Abbot, B. C., Bigland, and J. M. Ritchie. “The Physiological Cost of Negative Work,”
J. Physiol. 117 :380 -390, 1952.
Bresler, B. and F. Berry. “Energy Levels during Normal Level Walking,” Rep. of
Prosthetic Devices Res. Proj., University of California, Berkeley, May 1951.
Cappozzo, A., F. Figura, and M. Marchetti. “The Interplay of Muscular and External
Forces in Human Ambulation,” J. Biomech. 9 :35 - 43, 1976.
Cavagna, G. A. and R. Margaria. “Mechanics of Walking,” J. Appl. Physiol.

21 :271 - 278, 1996.
Cotes, J. and F. Meade. “The Energy Expenditure and Mechanical Energy Demand in
Walking,” Ergonomics 3 :97 - 119, 1960.
Elftman, H. “Forces and Energy Changes in the Leg during Walking,” Am. J. Physiol.
125 :339 - 356, 1939.
Falconer, K. and D. A. Winter. “Quantitative Assessment of Cocontraction at the Ankle
Joint in Walking,” Electromyogr. & Clin. Neurophysiol. 25 :135 -148, 1985.