ENERGY EXPENDITURE
DURING AMBULATION WITH PROSTHETICS
AND IMPACT OF NEW TECHNOLOGY
Jeffrey M. Cohen, MD
Clinical Professor of Rehabilitation Medicine
NYU-Langone Medical Center
Energy consumption in normal gait
•Linear Relationship:
Gait speed and energy cost of walking
(O2 consumption)
(Perry, J (ed), Gait Analysis: Normal and Pathological Gait,1992)
Energy consumption in normal gait
Energy Consumption in Amputees:
Prosthetic ambulation
• Walking speed is slower (Chosen Walking Speed)
Minimizes the rate of energy used during walking
• (Duff, Kerrigan, Corcoran et al, Arch Phys Med Rehabil, 1996)
Energy Consumption in Amputees:
Chosen Walking Speed-Prosthetic ambulation
• 70 patients with unilateral traumatic and vascular amputations
40 control subjects
• Compared selected gait parameters and the energy cost of prosthetic
walking
(Waters, Perry, Antonelli et al, JBJS, 1976)
Energy Consumption in Amputees:
Chosen Walking Speed-Prosthetic ambulation
• Chosen Walking Speed declines at each higher amputation level for
both traumatic and vascular amputee groups
Transtibial (TT)
Knee disarticulation
Transfemoral (TF)
Hip Disarticulation
(71 m/min)
(61 m/min)
(52 m/min)
(47 m/min)
• In all groups of amputees performance was significantly better the lower
the level of the amputation.
Energy Consumption in Amputees:
Chosen Walking Speed-Prosthetic ambulation
•Conclusion:
•When preservation of function is the chief concern,
amputation should be performed at the lowest possible
level.
Energy Consumption in Amputees:
Gait Speed, Oxygen Cost
Energy Consumption in Amputees:
Traumatic amputees
Level of amputation
(Traumatic)
Increased energy
above normal
• TT
• TT + TT
20-25% (Short-40%)
(Long-10%)
41% (Gonzalez-1974)
• TF
60-70% (Traugh-1975)
• TF + TT
118% (Traugh-1975)
• TF + TF
260% (Huang 1979)
(Gonzalez, Corcoran, Reyes, Arch Phys Med Rehabil, 1974)
(Traugh, Corcoran, Reyes, Arch Phys Med Rehabil 1975)
(Huang, Jackson, Moore et al, Arch Phys Med Rehabil 1974)
Energy Consumption in Amputees:
Bilateral (TT) vs Unilateral (TF)
-Bilateral TT exert less effort (41%) than a Unilateral TF
(60-70%)
-Important to retain biological knee whenever possible
(Gonzalez, Corcoran, Reyes, Arch Phys Med Rehabil, 1974)
Energy Consumption in Amputees:
Hip Disarticulation Prosthesis
> 200 % increase in energy compared with unimpaired
walking
High rejection rate
(Huang, Jackson, Moore et al, Arch Phys Med Rehabil 1979)
Energy Consumption in Amputees:
Traumatic vs Vascular
• Traumatic Amputees:
-Walk faster
-Exert less oxygen cost (ml/kg/m)
• Vascular amputees:
-Older
-Cardiovascular disease
-Lower energy reserves
-Anaerobic energy
(Waters, Perry, Antonelli et al, JBJS, 1976)
Energy Consumption in Amputees:
Traumatic vs Vascular
Level of amputation
Traumatic Transtibial
Vascular Transtibial
Traumatic Transfemoral
Vascular Transfemoral
Metabolic cost
above normal
25%
40%
68%
100%
(Huang, Jackson, Moore et al, Arch Phys Med Rehabil 1974)
Energy Consumption in Amputees:
Traumatic vs Vascular
Relation between aerobic capacity and walking ability in
older adults with a lower-limb amputation
Wezenberg D, van der Woude LH, Faber WX, de Haan A, Houdik H
Arch Phys Med Rehabil; 2013 Sep; 94 (9):1714-20
Energy Consumption in Amputees:
Traumatic vs Vascular
• OBJECTIVES:
To determine the relative aerobic load, walking speed, and walking economy of older
adults with a lower-limb prosthesis
• SETTING:
Human motion laboratory at a rehabilitation center.
• PARTICIPANTS:
Sample of older adults (n=36) who underwent lower-limb amputation because of vascular
deficiency or trauma and able-bodied controls (n=21).
• MAIN OUTCOME MEASURES:
Peak aerobic capacity and oxygen consumption while walking were determined. The
relative aerobic load and walking economy were assessed as a function of walking speed
Energy Consumption in Amputees:
Traumatic vs Vascular
• RESULTS:
-People with a vascular amputation walked at a substantially higher
(45.2%) relative aerobic load than people with an amputation because of
trauma.
-The preferred walking speed in both groups of amputees was slower than that
of able-bodied controls and below their most economical walking speed.
• CONCLUSIONS:
Findings corroborate the notion that, especially in people with a vascular
amputation, the peak aerobic capacity is an important determinant for walking
ability.
Energy Consumption in Amputees:
Prosthesis vs Walker/Crutches
-The increased energy cost over baseline of walking with a
comfortably fitting prosthesis without an assistive device is
less than that expended when walking w/out prosthesis
using walker or crutches
(Waters, Perry, Antonelli et al, JBJS, 1976)
Energy Consumption in Amputees:
Prosthesis vs Walker/Crutches
Comparison of energy cost in transtibial amputees using
"prosthesis" and "crutches without prosthesis" for
walking activities.
Mohanty RK, Lenka P, Fouehal, A, Kumar, R
Ann Phys Med Rehabil 2012 May;55(4):252-62.
Energy Consumption in Amputees:
Prosthesis vs Walker/Crutches
• METHODS:
Thirty adults who had a unilateral transtibial amputation
Oxygen consumption was measured as the participants walked over level
ground for 30 meters at a self-selected speed.
• RESULTS:
Ambulation “with prosthesis”:
21% more efficiency in terms of VO(2) uptake rate
92% more efficiency in terms of energy expenditure/min
(compared to “crutches without prosthesis”)
Energy Consumption in Amputees:
Prosthesis vs Walker/Crutches
• CONCLUSIONS:
Significant difference between “prosthesis walking” and “crutches
without prosthesis” walking in terms of VO(2) uptake rate (P<0.005) and
EE/min (P<0.00001)
All below knee amputee groups walk with less effort by using prosthesis.
Energy Consumption in Amputees
Effect of New Technology
•Reduce energy cost of prosthetic gait by developing:
-Dynamic
Responsive (energy storing) feet
-Cadence Responsive Microprocessor Controlled Knee
Units
-Suspension System Modifications
Energy Consumption in Amputees:
Effect of Prosthetic Foot Design
The effects of prosthetic foot design on physiologic
measurements, self-selected walking velocity, and physical activity
in people with transtibial amputation
Hsu MJ, Nielsen DH, Lin-Chan SJ, Shurr D.
Arch Phys Med Rehabil. 2006 Jan;87(1):123-9.
Energy Consumption in Amputees:
Effect of Prosthetic Foot Design
• OBJECTIVE:
Investigate the physiologic differences during multispeed treadmill walking and physical
activity profiles for the Otto Bock C-Walk foot (C-Walk), Flex-Foot, and solid ankle cushion
heel (SACH) foot in people with transtibial amputation.
• SETTING:
Research laboratory
• PARTICIPANTS:
Eight men with unilateral transtibial amputation.
• MAIN OUTCOME MEASURES:
Physiologic responses (energy expenditure, gait efficiency, exercise intensity, rating of
perceived exertion [RPE]) during multispeed treadmill walking (53.64, 67.05, 80.46, 93.87,
107.28 m/min)
Energy Consumption in Amputees:
Effect of Prosthetic Foot Design
• RESULTS:
The C-Walk had a trend of improved physiologic responses compared with the SACH;
however, no foot-type differences were statistically significant
The Flex-Foot showed a significantly lower percentage of age-predicted maximum heart
rate and RPE values (compared with the C-Walk and SACH)
• CONCLUSIONS:
The energy storing-releasing feet appeared to have certain trends of improved gait
performance compared with the SACH; however, not many objective foot-type differences
were significantly noted. Further studies with a larger sample size are suggested.
Energy Consumption in Amputees:
Carbon Fiber vs Bionic foot
Assessment of the effects of carbon fiber and bionic foot (Proprio)
during over ground and treadmill walking in transtibial amputees
Delussu AS, Brunelli S, Paradisi F, Iosa M, Pellegrini R, Zenardi D, Traballesi
Gait Posture 2013 Sep;38(4):876-82
Energy Consumption in Amputees:
Carbon Fiber vs Bionic foot
• METHOD:
-Ten transtibial amputees
-Assess energy cost of walking and perceived mobility wearing prosthesis using
a bionic foot (Proprio-Foot®) vs a dynamic carbon fiber foot.
-Testing done on a regular floor surface and on treadmill with -5%, 0% and 12%
slopes.
-Amputees walked at their own self-selected speed. Metabolic and cardiac data
were collected using a portable gas analyzer.
Energy Consumption in Amputees:
Carbon Fiber vs Bionic foot
• PROPRIO FOOT
-for low to moderately active below-knee amputees
-mimics natural foot motion
-Motor-powered ankle motion increases ground clearance and reduces the risk of
tripping and falling. Allows users to traverse different kinds of terrain.
Energy Consumption in Amputees:
Carbon Fiber vs Bionic foot
• RESULTS:
-Energy cost of walking with the Proprio-Foot® was significantly lower than with
a dynamic carbon fiber foot (p=0.002).
-No significant improvements were observed for perceived mobility or walking
ability.
• CONCLUSIONS:
-Results suggest that use of the Proprio-Foot® can lower the energy cost of
walking for transtibial amputees in spite of its added weight
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
-21 unilateral, transfemoral amputees
-Transition from mechanical to microprocessor knee
(Otto Bock C leg)
(Hafner, Willingham, et al Arch Phys Med Rehabil 2007)
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
Results:
•Stair descent score, hill descent time improved significantly,
significant decrease in frequency of stumbles and falls
•Subject satisfaction significantly greater with
microprocessor controlled knee
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
Energy Expenditure and Activity of Transfemoral Amputees Using
Mechanical and Microprocessor-Controlled Prosthetic Knees
Kaufman KR, Levine JA, Brey RH, McCrady SK, Padgett DJ, Joyner MJ.
Arch Phys Med Rehabil. 2008 Jul;89(7):1380-5
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
• Objective
To quantify the energy efficiency of locomotion and energy expenditure of transfemoral
amputees using a mechanical and microprocessor-controlled prosthetic knee
• Methods
Subjects (N=15; 12 men, 3 women; age, 42±9y; range, 26 –57y)
Transfemoral amputees; long-term users of a mechanical prosthesis (20±10y as an
amputee; range, 3–36y). Subjects served as their own controls
Tested with a mechanical fluid-controlled knee prosthesis (11 Mauch SNS,a 2 CaTach,b 1
Black Max,c 1 Century 2000a). Then given an acclimation period (18±8 weeks) before
testing on the microprocessor-controlled knee (Otto Bock C-Legd).
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
• Results
-Increased physical activity–related energy expenditure levels (P=.04) after wearing
the microprocessor-controlled prosthetic knee joint.
-When using the microprocessor-controlled knee, the subjects expressed increased
satisfaction in their daily lives (P=.02)
-No significant difference in the energy efficiency of walking (P=.34)
• Conclusions
People ambulating with a microprocessor-controlled knee significantly increased
their physical activity during daily life, outside the laboratory setting, and
expressed an increased quality of life.
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
Safety, energy efficiency, and cost efficacy of the C-Leg for
transfemoral amputees: A review of the literature.
Highsmith MJ, Kahle JT, Bongiorni DR, Sutton BS, Groer S, Kaufman KR
Prosthet Orthot Int. 2010 34(4):362-377
Energy Consumption in Amputees:
Mechanical vs Microprocessor-controlled knee
• Purpose:
-Performed a structured literature review and provided a grade of recommendation for
patient safety, gait energy efficiency, and cost effectiveness of the C-Leg microprocessorcontrolled prosthetic knee for transfemoral amputees
-Review of Medline (Ovid) and CINAHL (EBSCO) data bases from1995-2009.
-18 articles were determined to be pertinent:
• Conclusions: .
Methodologic quality was low with a moderate risk of bias in the safety and energy
effectiveness categories.
Sufficient evidence to suggest increased efficacy of the C-Leg in the areas of
safety, energy efficiency and cost when compared with other prosthetic knees for
transfemoral amputees.
Energy Consumption in Amputees:
Effect of suspension system
A comparison between the suction suspension system and the
hypobaric Iceross Seal-In® X5 in transtibial amputees.
Brunelli S, Delussu AS, Paradisi F, Pellegrini R, Traballesi M.
Prosthet Orthot Int. 2013 Dec;37(6):436-44.
Energy Consumption in Amputees:
Effect of suspension system
• OBJECTIVES:
Compare the effect of the hypobaric Iceross Seal-In(®) liner with that of the suction
suspension system for quality of life, pistoning, and prosthesis efficiency in unilateral
transtibial amputees.
• METHODS:
Ten amputees were enrolled
Testing: wearing suction suspension system and after 2, 5,7 weeks of Seal-In® X5 use.
Pistoning test to compare vertical movement of the stump within the socket
Energy cost of walking test
Prosthesis Evaluation Questionnaire and Houghton Scale Questionnaire of
perceived mobility and quality of life with the prosthesis
Timed Up &Go Test
Locomotor Capability Index for functional mobility
Energy Consumption in Amputees:
Effect of suspension system
• RESULTS:
The hypobaric Iceross Seal-In® X5 led to significant pistoning reduction and
improvement on the Houghton Scale Questionnaire and 3 of 9 domains of the
Prosthesis Evaluation Questionnaire.
No statistical changes were observed in functional mobility or the energy cost of
walking tests.
• CONCLUSION:
Replacing the suction suspension system with the hypobaric Iceross Seal-In® X5
improves quality of life in transtibial amputees.
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