The study focused on the comparative analysis of energy cost and gait efficiency between a below knee (BK) amputee and a reference subject (without amputation). It also attempted to indicate the specific feature responsible for a controlled gait with optimum energy cost for BK amputees. Selection criteria of the subjects were similar physical parameters and quality of life studied with WHOQOL-100 quality of life assessment. A Cosmed® k4 b2 Respiratory Analyzer system was used for the measurement of Oxygen Uptake (VO2), Energy Expenditure per minute (EE) and Heart Rate (HR). Gait efficiency (p < 0.0002) was found higher for BK amputee than normal subject. The therapeutic activities and mainly walking rhythm contributed to improve the mobility & balance. This ensures the optimum time & co-ordination of movements and hence improves the gait efficiency for the BK amputee. Comparison with control group was performed to validate the data

Biswas, Durbadal

Kumar, Ratnesh

Lenka, PK

Roy, Sukumar

English

Cognitive Sciences ePrint Archive

Original Article:
Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with Similar Physical  
Parameters & Quality of Life: A Comparative Case Study
Durbadal Biswas, National Institute for the Orthopaedically Handicapped, Under Ministry of Social Justice & Empowerment, Govt. 
of India, B-T Road, Bon Hooghly, Kolkata-700090,
Sukumar Roy, HOD of Biomedical Engineering Dept., NSEC, Garia,
PK Lenka, National Institute for the Orthopaedically Handicapped, Under Ministry of Social Justice & Empowerment, Govt. of India, 
B-T Road, Bon Hooghly, Kolkata-700090
Ratnesh Kumar, National Institute for the Orthopaedically Handicapped, Under Ministry of Social Justice & Empowerment, Govt. of 
India, B-T Road, Bon Hooghly, Kolkata-700090.
Address For Correspondence:
Durbadal Biswas,
Department of Research & Development,
National Institute for the Orthopaedically Handicapped,
Under Ministry of Social Justice & Empowerment, Govt. of India,
B.T. Road, Bon Hooghly,
Kolkata-90, India
E-mail: durbadal.bme@gmail.com
Citation: Biswas D, Roy S, Lenka PK, Kumar R. Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with  
Similar Physical Parameters & Quality of Life: A Comparative Case Study. Online J Health Allied Scs. 2010;9(3):14
URL: http://www.ojhas.org/issue35/2010-3-14.htm
Open Access Archives: http://cogprints.org/view/subjects/OJHAS.html and http://openmed.nic.in/view/subjects/ojhas.html
Submitted: Jul 16, 2010; Suggested revision: Sep 20, 2010; Resubmitted: Sep 25, 2010; Accepted: Sep29, 2010; Published: Oct 15, 2010
Abstract:
The study focused on the comparative analysis of energy cost 
and gait efficiency between a below knee (BK) amputee and a 
reference subject (without amputation). It also attempted to in-
dicate  the  specific  feature  responsible  for  a  controlled  gait 
with optimum energy cost for BK amputees. Selection criteria 
of the subjects were similar physical parameters and quality of 
life studied with WHOQOL-100 quality of life assessment. A 
Cosmed® k4 b2 Respiratory Analyzer system was used for the 
measurement  of  Oxygen  Uptake  (VO2),  Energy Expenditure 
per minute  (EE) and Heart Rate (HR). Gait efficiency (p < 
0.0002) was found higher for BK amputee than normal sub-
ject.  The  therapeutic  activities  and  mainly  walking  rhythm 
contributed to improve the mobility & balance. This ensures 
the optimum time & co-ordination of movements and hence 
improves the gait efficiency for the BK amputee. Comparison 
with control group was performed to validate the data.
Key Words:  Energy Cost; Gait Efficiency; Below knee am-
putee  
Introduction:
The lower extremity amputees have to spend huge effort & 
time to achieve their lost gait efficiency. Achieving the effi-
cient locomotion plays a major role in the individual develop-
ment. (1) Ambulation is practically difficult in trans-tibial am-
putees. Excessive energy cost may be the cause behind that. 
Earlier  studies  have  shown  elevated  relation  of  energy  ex-
penditure  & decreased gait  efficiency in  the  transtibial  am-
putees in comparison to the normal subjects with non-patholo-
gical gait. (2-9) Gait efficiency is defined as energy cost per  
distance traveled in previous research papers. (15) The lowest 
value is considered the Optimum efficiency at the self selected 
speed. (2, 7) Previous research indicates the higher energy cost 
in  amputees with  leg prosthesis  than normal  at  comparable 
walking velocities. (10-12) Ganguly et al discussed transtibial 
amputees consume 33% more energy than the normal subjects 
at 50 m/min walking speed. (3) In spite of this, most of those 
amputees achieved their normal gait within their limitation of 
disabilities. The physical parameters & Quality of life are the 
factors affecting the performance of the subjects. In this study, 
the subjects have been selected with similar physical paramet-
ers & similar Quality of life. 
The purpose of this study was to compare the energy cost, gait 
efficiency of a physically active person with conventional BK 
Prosthesis versus a normal person with similar physical para-
meters (sex, age, height, and weight) & quality of life during 
their  normal  locomotion.  The  similar  comparison  was  also 
done with reference to a control group for the data validation.
Methods:
One  right  trans-tibial  amputee  with  conventional  prosthesis 
with  patella-tendon-bearing  (PTB)  socket  &  a  solid-ankle-
cushion-heel (SACH) foot for more than five years was selec-
ted in this study with his consent to the National Institute for 
the Orthopaedically Handicapped, Bon-hooghly,  Kolkata-90, 
India. A normal subject participated as a reference with simil-
arity in age, sex, height and weight data to the trans-tibial am-
putee.(Table-1) A control group was also selected with 30 nor-
mal subjects with non pathological gait.(Table 2) All the parti-
cipants were physically active & well balanced to complete 
the protocol in full. The amputee was accustomed to wear the 
prosthesis and did not suffer from residual limb pain, swelling, 
or  pressure sores.  The fitting & alignment  of  the prosthesis 
was carried out by the resident Department of Prosthetics & 
Orthotics of the institute. The amputee was trained by thera-
peutic activities to improve the mobility with balance & to en-
sure the optimum time & co-ordination of movements. All the 
normal subjects were also examined & their fitness was certi-
fied. Subjects were asked not to ingest alcohol or caffeine for  
24 hours prior to testing. A record of the subjects’ diet was 
kept & a similar diet was maintained through out the study.
1
This work is licensed under a
Creative Commons Attribution-
No Derivative Works 2.5 India License
Online Journal of Health and Allied Sciences
Peer Reviewed, Open Access, Free Online Journal
Published Quarterly :  Mangalore, South India : ISSN 0972-5997
Volume 9, Issue 3; Jul-Sep 2010
Table 1: Physical Parameters of the amputee and refer-
ence subject
Criteria Bk(R) Amputee Reference subject
Sex Male Male
Age (yrs.) 45 46
Height (cm.) 162 163
Weight (kgs.) 61.5 62
Table 2: Physical Parameters of control group
Criteria Average value
Age (yrs.) 43±6
Height (cm.) 16.2±14.5
Weight (kgs.) 59.6±7.3
The subjects’ Quality Of Life was studied with WHOQOL-
100 quality of life assessment. The assessment would be ap-
plicable cross-culturally.(13) In this study the assessment in-
dicates the similar Quality of life for both subjects. (Table 3)
Table 3: Quality of Life Assessment
Domain
Average  Scores
Subjects with BK 
Prosthesis Reference Subject
Physical health 24.66 25
Psychological 19.18 18
Social relationship 10 11
Environment 27.7 27.5
The subjects were allowed to practice their usual gait prior to 
the  testing  until  the  normal  gait  pattern was  observed.  The 
subjects  were  instructed  to  walk  at  self  selected  speed. 
Through out this period, breath by breath analysis of the sub-
jects was carried out. A Cosmed® K4 B2 Respiratory Analyzer 
system (COSMED Srl – Italy) at National Institute for the Or-
thopaedically  Handicapped,  Bon-hooghly,  Kolkata-90,  India 
was used for the measurement of Oxygen Uptake (VO2), En-
ergy Expenditure per minute (EE), Heart Rate (HR) for both 
subjects. (Figure 1)
Figure 1: Cosmed® K4 B2 Respiratory Analyzer system
The print out giving the subjects average VO2 (ml/Min) over 
consecutive 60 seconds interval was processed by calculating 
the mean and standard deviation. A plane surface of 30 m was 
fixed for subjects’ walking. The subjects were given sufficient 
time to become accustomed to the analyzer system before the 
experiments.  Total  test  time  was  approximately  25  minutes 
consisting of  a 3-minute  warm-up period  to  ensure  that  the 
muscles did not utilize anaerobic sources of energy, 1 minute 
to prime the airways, and 1 minute of exhaled gas collection. 
The order of test configurations was maintained, and the con-
secutive information of the test was recorded at each condi-
tion. Fatigue was minimized by allowing subjects to rest dur-
ing the intervals. Difference in VO2 was determined for walk-
ing period of the subjects as follows:
Difference in VO2 =VO2 BK amputee-VO2 normal x 100 
                                           VO2 normal               (Equation-1)
Thus a negative percentage would indicate energy saving and 
positive percentage would indicate higher energy cost for the 
subject with BK amputee.(14)
A more easily determined alternative criterion measure of gait 
efficiency is the term we refer to as "distance efficiency". Gait 
(distance) efficiency was calculated simply from the ratio of 
the oxygen uptake to the walking velocity and may be ex-
pressed in milliliters of oxygen consumed per kilogram of 
body weight per meter traveled.(15)
Gait Efficiency=mlO2 /kg.min =mlO2 /kg.min
m/min
Statistics
Two-way analysis of variance (ANOVA) was used separately 
to test the level of significance of VO2, HR, EE, velocity and 
gait efficiency & a level of p < 0.05 was adopted for the de-
termination of statistical significance.
Results:
A summary of result is given in Table 4. Average Heart rate 
for  BK  amputee  &  reference  subject  was  87.92  ±  14.06  
beats/min (p < 0.002) & 103.71 ± 7.80 beats/min(p < 0.0003) 
respectively.  The  measurement  of  Heart  Rate  showed  12% 
more stability in the BK amputee. The velocity of the BK am-
putee & reference subject was 17.08 ± 1.48 m/min & 30.25 ± 
3.59 m/min. Gait efficiency (p < 0.0002) is higher for the BK 
amputee (0.98± 0.10) than the reference subject (0.30± 0.26). 
The difference in VO2 uptake for the amputee was -31.97%.
Table 4: Summary of result
Parameter BK Amputee Reference Subject
VO2 (ml/mint) 405.53± 264.99
596.096± 
366.91
HR (beats/mint) 87.92± 14.06 103.71± 7.80
EE (kcal/mint) 1.87± 1.24 2.66± 1.72
Velocity (m/min) 17.08± 1.48 30.25± 3.59
Gait Efficiency (mlO2 / 
kg . m) 0.98± 0.10 0.30± 0.26
Graph 1: Comparison of Oxygen Uptake
2
Graph 2: Comparison of Energy Expenditure
In comparison to the control  group, the VO2 uptake for BK 
were studied -16.26% whereas gait efficiency for the control 
group was found 0.29 ± 0.17 mlO2 / kg . m.
Discussion:
The focus of  the  current  study was  to  compare  the  Energy 
Cost & Gait Efficiency of BK- amputee with reference subject 
having the similar physical parameters & quality of life. Simil-
ar physical parameters allowed the subjects to be considered 
for comparison analysis. Both the subjects were found to lead 
similar Quality of Life. This indicates the nullification of any 
effect of the subjects’ life style on their comparative perform-
ances. Thus the only difference between the subjects is due to 
the  trans-tibial  prosthesis  of  the  BK amputee.  The subjects 
were certified to be physically fit. The fitment & alignment of 
the prosthesis  was checked & found perfect.  The result  ob-
tained from Cosmed® K4b2 showed consistency in heart rate 
monitoring for both the subjects. The subjects performed their 
normal gait during the test in their self selected velocity. The 
gait study advocated the normal gait pattern in both subjects 
through out the test. The energy expenditure for BK amputee 
& normal subject was 1.87 ± 1.24 Kcal/min & 2.66 ± 1.72 
Kcal/min. The Energy expenditure of BK amputee was found 
29.5% less with respect to the normal subject (p < 0.0008) & 
the difference in VO2 uptake was -31.97% (p < 0.0004)(Equa-
tion-1). The negative percentage indicates energy saving for 
the BK amputee, which was not consistent with the previous 
paper.(10-12)  The  Gait  efficiency  was  found  (p  <  0.0002) 
higher for the BK amputee (0.98 ± 0.10) than the normal sub-
ject (0.30 ± 0.26). In comparison to the control group the BK 
amputee showed negative percentage of VO2 uptake & higher 
gait efficiency. This advocated the similar trend of data & val-
idated the comparison between the amputee & the reference 
subject. This indicates that the BK amputee achieves a normal 
gait  pattern  under  the  limitation  of  disabilities.  The  result 
showed inconsistency with the previous published papers that 
the BK amputee was more  efficient in Gait performance & 
less consumer of the energy in their usual & normal gait pat-
tern. As most of the physical parameters were normalized by 
carefully selecting the test subjects after screening 50 numbers 
of patients and normal subjects, the walking rhythm played an 
important role to control the stability and increase the gait effi-
ciency.  This rhythm also contributed the  uniformity of  step 
time, step duration, cadence and stride length and helped the 
subject  to  achieve  higher  gait  efficiency.  The  amputee 
achieved the gait rhythm & balance appropriate for his body 
mechanics by therapeutic practice. Improvement in time & co-
ordination of movements  ensured the efficient gait  perform-
ance with reduced energy cost.(16) For this particular reason 
the BK amputee patient in this study was able to diminish his 
energy  consumption  compare  to  the  normal  subject  for  the 
identical performances.
The study will continue and additional research is recommen-
ded with more subjects to corroborate the findings of the cur-
rent study.
Conclusions:
Appropriate  time  & co-ordination  of  movement  resulted  in 
confident gait rhythm & balance with less energy cost for the 
amputee in this study. Higher Gait efficiency & less Energy 
Expenditure were found for the BK amputee than the refer-
ence subjects with the similar physical parameters & quality of 
life for identical performances. This advocated that therapeutic 
practice & proper training for time & co-ordination of move-
ments can help the amputee with below knee prosthesis to per-
form their ideal gait with less energy consumption.
Acknowledgements:
This  project  would  not  have  been  possible  without  the 
participation of the subjects. Their cooperation, patience, and 
genuine  interest  in  the  progress  of  research  will  be 
remembered. The research was supported by the Prosthetic & 
Orthotic  Department  of  National  Institute  for  the 
Orthopaedically Handicapped, Bon-hooghly, Kolkata-90.
References:
1. Sutherland DH, Olshen R, Cooper L et al. The De-
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2. Fisher SV, Gullickson G. Energy cost of ambula-
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Arch Phys Med Rehabil. 1978;59:124-133. 
3. Ganguli S, Datta SR, Chatterjee BB, et al. Perform-
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4. Gonzalez EG, Corcoran PJ, Reyes RL. Energy ex-
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8. Waters RL, Perry J, Antonelli D, Hislop H. Energy 
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10. James, U.: Oxygen Uptake and Heart Rate During 
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11. Traugh GH, Corcoran PJ, Reyes R.L. Energy Ex-
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12. Pagliarulo MA, Waters R, Hislop HJ. Energy Cost 
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Performance evaluation of amputee-prosthesis system in below-knee amputees.

Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with Similar Physical Parameters & Quality of Life: A Comparative Case Study

Durbadal Biswas

Sukumar Roy

PK Lenka

Ratnesh Kumar

Directory of Open Access Journals

Original Article:Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with Similar Physical Parameters & Quality of Life: A Comparative Case StudyDurbadal Biswas, National Institute for the Orthopaedically Handicapped, Under Ministry of Social Justice & Empowerment, Govt. of India, B-T Road, Bon Hooghly, Kolkata-700090,Sukumar Roy, HOD of Biomedical Engineering Dept., NSEC, Garia,PK Lenka, National Institute for the Orthopaedically Handicapped, Under Ministry of Social Justice & Empowerment, Govt. of India, B-T Road, Bon Hooghly, Kolkata-700090Ratnesh Kumar, National Institute for the Orthopaedically Handicapped, Under Ministry of Social Justice & Empowerment, Govt. of India, B-T Road, Bon Hooghly, Kolkata-700090.Address For Correspondence:Durbadal Biswas,Department of Research & Development,National Institute for the Orthopaedically Handicapped,Under Ministry of Social Justice & Empowerment, Govt. of India,B.T. Road, Bon Hooghly,Kolkata-90, IndiaE-mail: durbadal.bme@gmail.comCitation: Biswas D, Roy S, Lenka PK, Kumar R. Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with Similar Physical Parameters & Quality of Life: A Comparative Case Study. Online J Health Allied Scs. 2010;9(3):14URL: http://www.ojhas.org/issue35/2010-3-14.htmOpen Access Archives: http://cogprints.org/view/subjects/OJHAS.html and http://openmed.nic.in/view/subjects/ojhas.htmlSubmitted: Jul 16, 2010; Suggested revision: Sep 20, 2010; Resubmitted: Sep 25, 2010; Accepted: Sep29, 2010; Published: Oct 15, 2010Abstract:The study focused on the comparative analysis of energy cost and gait efficiency between a below knee (BK) amputee and a reference subject (without amputation). It also attempted to in-dicate the specific feature responsible for a controlled gait with optimum energy cost for BK amputees. Selection criteria of the subjects were similar physical parameters and quality of life studied with WHOQOL-100 quality of life assessment. A Cosmed® k4 b2 Respiratory Analyzer system was used for the measurement of Oxygen Uptake (VO2), Energy Expenditure per minute (EE) and Heart Rate (HR). Gait efficiency (p < 0.0002) was found higher for BK amputee than normal sub-ject. The therapeutic activities and mainly walking rhythm contributed to improve the mobility & balance. This ensures the optimum time & co-ordination of movements and hence improves the gait efficiency for the BK amputee. Comparison with control group was performed to validate the data.Key Words: Energy Cost; Gait Efficiency; Below knee am-putee  Introduction:The lower extremity amputees have to spend huge effort & time to achieve their lost gait efficiency. Achieving the effi-cient locomotion plays a major role in the individual develop-ment. (1) Ambulation is practically difficult in trans-tibial am-putees. Excessive energy cost may be the cause behind that. Earlier studies have shown elevated relation of energy ex-penditure & decreased gait efficiency in the transtibial am-putees in comparison to the normal subjects with non-patholo-gical gait. (2-9) Gait efficiency is defined as energy cost per distance traveled in previous research papers. (15) The lowest value is considered the Optimum efficiency at the self selected speed. (2, 7) Previous research indicates the higher energy cost in amputees with leg prosthesis than normal at comparable walking velocities. (10-12) Ganguly et al discussed transtibial amputees consume 33% more energy than the normal subjects at 50 m/min walking speed. (3) In spite of this, most of those amputees achieved their normal gait within their limitation of disabilities. The physical parameters & Quality of life are the factors affecting the performance of the subjects. In this study, the subjects have been selected with similar physical paramet-ers & similar Quality of life. The purpose of this study was to compare the energy cost, gait efficiency of a physically active person with conventional BK Prosthesis versus a normal person with similar physical para-meters (sex, age, height, and weight) & quality of life during their normal locomotion. The similar comparison was also done with reference to a control group for the data validation.Methods:One right trans-tibial amputee with conventional prosthesis with patella-tendon-bearing (PTB) socket & a solid-ankle-cushion-heel (SACH) foot for more than five years was selec-ted in this study with his consent to the National Institute for the Orthopaedically Handicapped, Bon-hooghly, Kolkata-90, India. A normal subject participated as a reference with simil-arity in age, sex, height and weight data to the trans-tibial am-putee.(Table-1) A control group was also selected with 30 nor-mal subjects with non pathological gait.(Table 2) All the parti-cipants were physically active & well balanced to complete the protocol in full. The amputee was accustomed to wear the prosthesis and did not suffer from residual limb pain, swelling, or pressure sores. The fitting & alignment of the prosthesis was carried out by the resident Department of Prosthetics & Orthotics of the institute. The amputee was trained by thera-peutic activities to improve the mobility with balance & to en-sure the optimum time & co-ordination of movements. All the normal subjects were also examined & their fitness was certi-fied. Subjects were asked not to ingest alcohol or caffeine for 24 hours prior to testing. A record of the subjects’ diet was kept & a similar diet was maintained through out the study.1This work is licensed under aCreative Commons Attribution-No Derivative Works 2.5 India LicenseOnline Journal of Health and Allied SciencesPeer Reviewed, Open Access, Free Online JournalPublished Quarterly :  Mangalore, South India : ISSN 0972-5997Volume 9, Issue 3; Jul-Sep 2010Table 1: Physical Parameters of the amputee and refer-ence subjectCriteria Bk(R) Amputee Reference subjectSex Male MaleAge (yrs.) 45 46Height (cm.) 162 163Weight (kgs.) 61.5 62Table 2: Physical Parameters of control groupCriteria Average valueAge (yrs.) 43±6Height (cm.) 16.2±14.5Weight (kgs.) 59.6±7.3The subjects’ Quality Of Life was studied with WHOQOL-100 quality of life assessment. The assessment would be ap-plicable cross-culturally.(13) In this study the assessment in-dicates the similar Quality of life for both subjects. (Table 3)Table 3: Quality of Life AssessmentDomainAverage  ScoresSubjects with BK Prosthesis Reference SubjectPhysical health 24.66 25Psychological 19.18 18Social relationship 10 11Environment 27.7 27.5The subjects were allowed to practice their usual gait prior to the testing until the normal gait pattern was observed. The subjects   were   instructed   to   walk   at   self   selected   speed. Through out this period, breath by breath analysis of the sub-jects was carried out. A Cosmed® K4 B2 Respiratory Analyzer system (COSMED Srl – Italy) at National Institute for the Or-thopaedically Handicapped, Bon-hooghly, Kolkata-90, India was used for the measurement of Oxygen Uptake (VO2), En-ergy Expenditure per minute (EE), Heart Rate (HR) for both subjects. (Figure 1)Figure 1: Cosmed® K4 B2 Respiratory Analyzer systemThe print out giving the subjects average VO2 (ml/Min) over consecutive 60 seconds interval was processed by calculating the mean and standard deviation. A plane surface of 30 m was fixed for subjects’ walking. The subjects were given sufficient time to become accustomed to the analyzer system before the experiments. Total test time was approximately 25 minutes consisting of a 3-minute warm-up period to ensure that the muscles did not utilize anaerobic sources of energy, 1 minute to prime the airways, and 1 minute of exhaled gas collection. The order of test configurations was maintained, and the con-secutive information of the test was recorded at each condi-tion. Fatigue was minimized by allowing subjects to rest dur-ing the intervals. Difference in VO2 was determined for walk-ing period of the subjects as follows:Difference in VO2 =VO2 BK amputee-VO2 normal x 100                                            VO2 normal               (Equation-1)Thus a negative percentage would indicate energy saving and positive percentage would indicate higher energy cost for the subject with BK amputee.(14)A more easily determined alternative criterion measure of gait efficiency is the term we refer to as "distance efficiency". Gait (distance) efficiency was calculated simply from the ratio of the oxygen uptake to the walking velocity and may be ex-pressed in milliliters of oxygen consumed per kilogram of body weight per meter traveled.(15)Gait Efficiency=mlO2 /kg.min =mlO2 /kg.minm/minStatisticsTwo-way analysis of variance (ANOVA) was used separately to test the level of significance of VO2, HR, EE, velocity and gait efficiency & a level of p < 0.05 was adopted for the de-termination of statistical significance.Results:A summary of result is given in Table 4. Average Heart rate for BK amputee & reference subject was 87.92 ± 14.06  beats/min (p < 0.002) & 103.71 ± 7.80 beats/min(p < 0.0003) respectively. The measurement of Heart Rate showed 12% more stability in the BK amputee. The velocity of the BK am-putee & reference subject was 17.08 ± 1.48 m/min & 30.25 ± 3.59 m/min. Gait efficiency (p < 0.0002) is higher for the BK amputee (0.98± 0.10) than the reference subject (0.30± 0.26). The difference in VO2 uptake for the amputee was -31.97%.Table 4: Summary of resultParameter BK Amputee Reference SubjectVO2 (ml/mint) 405.53± 264.99 596.096± 366.91HR (beats/mint) 87.92± 14.06 103.71± 7.80EE (kcal/mint) 1.87± 1.24 2.66± 1.72Velocity (m/min) 17.08± 1.48 30.25± 3.59Gait Efficiency (mlO2 / kg . m) 0.98± 0.10 0.30± 0.26Graph 1: Comparison of Oxygen Uptake2Graph 2: Comparison of Energy ExpenditureIn comparison to the control group, the VO2 uptake for BK were studied -16.26% whereas gait efficiency for the control group was found 0.29 ± 0.17 mlO2 / kg . m.Discussion:The focus of the current study was to compare the Energy Cost & Gait Efficiency of BK- amputee with reference subject having the similar physical parameters & quality of life. Simil-ar physical parameters allowed the subjects to be considered for comparison analysis. Both the subjects were found to lead similar Quality of Life. This indicates the nullification of any effect of the subjects’ life style on their comparative perform-ances. Thus the only difference between the subjects is due to the trans-tibial prosthesis of the BK amputee. The subjects were certified to be physically fit. The fitment & alignment of the prosthesis was checked & found perfect. The result ob-tained from Cosmed® K4b2 showed consistency in heart rate monitoring for both the subjects. The subjects performed their normal gait during the test in their self selected velocity. The gait study advocated the normal gait pattern in both subjects through out the test. The energy expenditure for BK amputee & normal subject was 1.87 ± 1.24 Kcal/min & 2.66 ± 1.72 Kcal/min. The Energy expenditure of BK amputee was found 29.5% less with respect to the normal subject (p < 0.0008) & the difference in VO2 uptake was -31.97% (p < 0.0004)(Equa-tion-1). The negative percentage indicates energy saving for the BK amputee, which was not consistent with the previous paper.(10-12) The Gait efficiency was found (p < 0.0002) higher for the BK amputee (0.98 ± 0.10) than the normal sub-ject (0.30 ± 0.26). In comparison to the control group the BK amputee showed negative percentage of VO2 uptake & higher gait efficiency. This advocated the similar trend of data & val-idated the comparison between the amputee & the reference subject. This indicates that the BK amputee achieves a normal gait pattern under the limitation of disabilities. The result showed inconsistency with the previous published papers that the BK amputee was more efficient in Gait performance & less consumer of the energy in their usual & normal gait pat-tern. As most of the physical parameters were normalized by carefully selecting the test subjects after screening 50 numbers of patients and normal subjects, the walking rhythm played an important role to control the stability and increase the gait effi-ciency. This rhythm also contributed the uniformity of step time, step duration, cadence and stride length and helped the subject   to   achieve   higher   gait   efficiency.   The   amputee achieved the gait rhythm & balance appropriate for his body mechanics by therapeutic practice. Improvement in time & co-ordination of movements ensured the efficient gait perform-ance with reduced energy cost.(16) For this particular reason the BK amputee patient in this study was able to diminish his energy consumption compare to the normal subject for the identical performances.The study will continue and additional research is recommen-ded with more subjects to corroborate the findings of the cur-rent study.Conclusions:Appropriate time & co-ordination of movement resulted in confident gait rhythm & balance with less energy cost for the amputee in this study. Higher Gait efficiency & less Energy Expenditure were found for the BK amputee than the refer-ence subjects with the similar physical parameters & quality of life for identical performances. This advocated that therapeutic practice & proper training for time & co-ordination of move-ments can help the amputee with below knee prosthesis to per-form their ideal gait with less energy consumption.Acknowledgements:This   project   would   not   have   been   possible   without   the participation of the subjects. Their cooperation, patience, and genuine   interest   in   the   progress   of   research   will   be remembered. The research was supported by the Prosthetic & Orthotic   Department   of   National   Institute   for   the Orthopaedically Handicapped, Bon-hooghly, Kolkata-90.References:1. Sutherland DH, Olshen R, Cooper L et al. The De-velopment of Mature Gait. J. Bone and Joint Surg. 1980;62:336-353.2. Fisher SV, Gullickson G. Energy cost of ambula-tion in health and disability: A literature review. Arch Phys Med Rehabil. 1978;59:124-133. 3. Ganguli S, Datta SR, Chatterjee BB, et al. Perform-ance evaluation of amputee-prosthesis system in below-knee amputees. Ergonomics. 1973;16:797. 4. Gonzalez EG, Corcoran PJ, Reyes RL. Energy ex-penditure in below-knee amputees: Correlation with stump length. Arch Phys Med Rehabil. 1974;55:111-119. 5. Huang CT, Jackson JR, Moore NB, Fine PR, Kuh-lemeier KV, Traugh GH. Amputation. Energy cost of ambulation. Arch Phys Med Rehabil. 1979;60:18-24. 6. Molen NH. Energy-speed relation of below-knee amputees walking on a motor-driven treadmill. Int Z Angrew Physiol. 1973;31:173-185. 7. Nielsen DH, Shurr DG, Golden JC, Meier K. Com-parison of energy cost and gait efficiency during ambulation in below-knee amputees using different prosthetic feet-A preliminary report. J Prosthet Or-thot. 1988;1:24-31. 8. Waters RL, Perry J, Antonelli D, Hislop H. Energy cost of walking of amputees: The influence of level of amputation. J Bone Joint Surg (Am). 1976;58:42-46. 9. Waters RL, Perry J, Chambers R. Energy expendit-ure of amputee gait. In: Moore WS, Malone JM, eds. Lower Extremity Amputation. Philadelphia, PA: WB Saunders; 1989:250-260.10. James, U.: Oxygen Uptake and Heart Rate During Prosthetic Walking in Healthy Male Unilateral Above-Knee Amputees. Scand. J Rehabil. 1973;5:71-80.11. Traugh GH, Corcoran PJ, Reyes R.L. Energy Ex-penditure of Ambulation in Patients with Above-Knee Amputations. Arch. Phys. Med. Rehabil. 1975;56:67-71.12. Pagliarulo MA, Waters R, Hislop HJ. Energy Cost of Walking of Below-Knee Amputees Having no Vascular Disease. Phys. Ther. 1979;59:538-542.13. WHOQOL-BREF Introduction, Administration, Scoring and Generic Version of the Assessment 3Orley & Kuyken, 1994; Szabo, 1996; WHOQOL Group 1994a, 1994b, 1995).14. Buckley JG, Spence WD, Solomonidis SE. Energy cost of walking: comparison of "intelligent pros-thesis" with conventional mechanism. Department of Exercise and Sport Science, Manchester Metro-politan University, Stoke-on-Trent, UK.15. Nielsen DH, Shurr DG, Golden JC, Meier K. Com-parison Of Energy Cost And Gait Efficiency Dur-ing Ambulation In Below-Knee Amputees Using Different Prosthetic Feet-A Preliminary Report. Journal of Prosthetics & Orthotics October 1988;1(1):24-3116. VanSwearingen JM, Perera S, Brach JS, Cham R, Rosano C, Studenski SA. A Randomized Trial of Two Forms of Therapeutic Activity to Improve Walking: Effect on the Energy Cost of Walking. J Gerontol A Biol Sci Med Sci 2009;64A:1190-1198.4

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Energy Cost and Gait Efficiency of Below-Knee Amputee and Normal Subject with Similar Physical Parameters & Quality of Life: A Comparative Case Study

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