title: A controlled clinical trial of a clinically-tuned powered ankle prosthesis in people with transtibial amputation The CAT-CAM socket and quadrilateral socket: A comparison of energy cost during ambulation Long-term clinical evaluation of the automatic stance-phase lock-controlled prosthetic knee joint in young adults with unilateral above-knee amputation Energy expenditure and walking speed in lower limb amputees: a cross sectional study. Physiological Cost Index and Comfort Walking Speed in Two Level Lower Limb Amputees Having No Vascular Disease Energy expenditure of transfemoral amputees during floor and treadmill walking with different speeds Comparison Between the C-leg® Microprocessor-Controlled Prosthetic Knee and Non-Microprocessor Control Prosthetic Knees: A Preliminary Study of Energy Expenditure, Obstacle Course Performance, and Quality of Life Survey A comparative evaluation of oxygen consumption and gait pattern in amputees using Intelligent Prostheses and conventionally damped knee swing-phase control Exercise testing as a screening measure for ability to walk with aprosthesis after transfemoral amputation due to peripheral vascular disease Assessment of aerobic capacity and walking economy of unilateral transfemoral amputees Energy expenditure and biomechanical characteristics of lower limb amputee gait: the influence of prosthetic alignment and different prosthetic components. Comparison of the Otto Bock solid ankle cushion heel foot with wooden keel to the low-cost CR-Equipements™ solid ankle cushion heel foot with polypropylene keel: A randomized prospective double-blind crossover study assessing patient satisfaction and energy expenditure
abstract: Objective : To determine whether there are changes in level walking performance for people using a powered ankle prosthesis that was tuned by an independent , manufacturer-certified prosthetist in accordance with device recommendations . Design : Intervention study with cross-over design . Setting : Laboratory . Participants : Convenience sample of 10 individuals with unilateral , transtibial amputation , and 10 age- and gender-matched control participants . Interventions : Powered ankle prosthesis ( BiOM T2 Ankle System ) . Main outcome metrics : Metabolic costs of walking , preferred walking speed . Results : There were no significant differences in oxygen consumption ( 2.9 % difference ; P = 0.606 , d = 0.26 ) , cost of transport ( ~1 % difference ; P = 0.652 , d = 0.23 ) , or preferred walking speed ( ~1 % difference ; P = 0.147 , d = 0.76 ) when using the powered ankle compared to unpowered prostheses . Secondary analyses of user characteristics revealed that participants who were classified as having the highest function ( K4 on Medicare ’s 5-point scale from K0 to K4 ) were significantly more likely to exhibit energy cost savings than those classified as having lower function ( K3 ; P = 0.014 , d = 2.36 ) . Conclusions : Participants did not demonstrate significant improvements in energetics or preferred speed when wearing a clinical ly tuned powered ankle prosthesis compared to their non-powered prostheses . Prescribers of powered devices should underst and that not all users will show an immediate reduction in energy expenditure Twenty unilateral trans-femoral amputees fitted with either the Contoured Adducted Trochanteric-Controlled Alignment Method ( CAT-CAM ) socket ( n=10 ) or the quadrilateral ( QUAD ) socket ( n=10 ) , and a  “ non-amputee ” control group ( n=10 ) participated in the study . Subjects meeting the following criteria were studied : healthy males between the ages of 18 and 55 years , amputation due to non-vascular pathology , an unaffected sound limb , at least six months use of the test prosthesis , and a minimal stump length of 15 cm . Subjects ambulated in two r and omized trials separated by 20 minutes of rest at 2 assigned speeds : a pace reflecting normal walking speed ( 97 m/min=2.5 mph ) or a slower speed ( 48.5 m/min=1.25 mph ) . Heart rate ( HR ) and Oxygen uptake ( VO2 ) measured during steady state walking were analyzed via two-way ANOVA . Differences among means were further analyzed using Tukey post hoc and simple effects tests . Significant differences were observed between the control group and CAT-CAM subjects with respect to VO2 ( p < 0.05 ) and HR ( p < 0.01 ) at the slower speed . The control group and subjects using the QUAD socket also differed with respect to VO2 ( p < 0.01 ) and HR ( p < 0.01 ) at the slower pace . Faster pace required more energy expenditure ( p < 0.01 ) and produced higher HR ( p < 0.01 ) than slower speeds . At faster pace , a significantly higher energy expenditure in the QUAD than the CAT-CAM group was observed ( p<0.01 ) . It is concluded that ambulating at normal pace using the CAT-CAM socket design uses less energy than when using a QUAD socket design Abstract Purpose : The purpose of this study was to clinical ly evaluate the automatic stance-phase lock ( ASPL ) knee mechanism against participants ’ existing weight-activated braking ( WAB ) prosthetic knee joint . Method : This prospect i ve crossover study involved 10 young adults with an above-knee amputation . Primary measurements consisted of tests of walking speeds and capacity . Heart rate was measured during the six-minute walk test and the Physiological Cost Index ( PCI ) which was calculated from heart rate estimated energy expenditure . Activity was measured with a pedometer .  User function and quality of life were assessed using the Lower Limb Function Question naire ( LLFQ ) and Prosthetic Evaluation Question naire ( PEQ ) . Long-term follow-up over 12 months were completed . Results : Walking speeds were the same for WAB and APSL knees . Energy expenditure ( PCI ) was lower for the ASPL knees ( p = 0.007 ) . Step counts were the same for both knees , and question naires indicated ASPL knee preference attributed primarily to knee stability and improved walking , while limitations included terminal impact noise . Nine of 10 participants chose to keep using the ASPL knee as part of the long-term follow-up . Conclusions : Potential benefits of the ASPL knee were identified in this study by functional measures , question naires and user feedback , but not changes in activity or the PEQ . Keywords : Amputee ; artificial knee joint ; energy expenditure ; prosthesis ; stance-phase control ; transfemoral amputation , stance-phase BACKGROUND Energy expenditure and walking speed are generally recommended for use as measures of status and outcome for walking . The objective of this study was to measure the  physiological cost index ( PCI ) and  comfort walking speed ( CWS )  at three levels of lower limb amputation : transfemoral , transtibial and Syme level , and the relationship of these physiological variables to prosthetic ambulation supported with walking aids and stump length . MATERIAL AND METHODS This study was a prospect i ve cross-sectional study .Eighty-nine individuals with lower limb amputation for reasons other than peripheral vascular disease ( PVD ) were recruited among patients at the Department of Prosthetics and Orthotics in University Clinical Center of Kosovo .  PCI  was assessed by five minutes of continuous indoor walking at CWS . RESULTS Significant differences were found in PCI ( F=29.87 , P < 0.001 ) and CWS ( F=19.33 , P < 0.001 ) among the three amputation groups . Prosthetic ambulation supported with crutches showed an important impact on PCI ( F=35.1 , P < 0.001 ) and CWS ( F=28.42 , P < 0.001 ) . Stump length was associated with significantly increased PCI ( r=0.53 , P = 0.02 ) and reduced CWS ( r=0.58 , P = 0.004 ) in transfemoral amputees . CONCLUSIONS 1 . A higher level of amputation is associated with less energy-efficient walking and with lower walking speed . 2 . Prosthetic ambulation supported with crutches has significant impact on increasing of energy expenditure and decreasing walking speed . 3 . Stump length is shown to have a major impact on PCI and CWS in transfemoral amputees Background : The Physiological Cost Index  ( PCI ) was introduced by MacGregor to estimate the energy cost in walking of healthy people , also it has been reported for persons with lower limb amputation , walking with prosthesis . Objective : To assess energy cost and walking speed in two level lower limb amputation : transfemoral and transtibial amputation  and to determine if the age and prosthetic walking supported with walking aids have impact on energy cost and walking speed . Methods : A prospect i ve cross sectional study was performed in two level lower limb amputees with no vascular disease who were rehabilitated at the Department of Prosthetics and Orthotics at the University Clinical Center of Kosovo . The  Physiological Cost Index ( PCI )  was assessed by five minutes of continuous indoor walking at Comfort Walking Speed ( CWS ) . Results : Eighty three lower limb amputees were recruited . It is shown relevant impact of level of amputation in PCI ( t=6.8 , p<0.001 ) and CWS ( T=487 , p<0.001 ) . The great influence of using crutches during prosthetic walking in  PCI  ( ANOVA F= 39.5 P < 0.001 ) and CWS ( ANOVA F=32.01 , P < 0.001 ) has been shown by One Way ANOVA test . The correlation coefficient ( R ) showed a significant correlation of age with PCI and CWS in both groups of amputation . Conclusions : Walking with transfemoral prosthesis or using walking aids during prosthetic ambulation is matched with higher cost of energy and slower walking speed . Advanced age was shown with high impact on PCI and CWS in both groups of amputees Background : Walking energy expenditure , calculated as the percent utilization of the maximal aerobic capacity , is little investigated in transfemoral amputees . Objectives : Compare the energy expenditure of  healthy participants ( control participants ) and transfemoral amputees walking with their respective  preferred walking speeds on the treadmill ( TPWS ) and floor ( FPWS ) . Study design : R and omized cross-over study . Methods : Oxygen uptake ( VO2 ) was measured when walking with the FPWS and TPWS . VO2max was measured by an incremental treadmill test . Results : Mean ± st and ard deviation VO2max of the transfemoral amputees and control participants were 30.6 ± 8.7 and 49.0 ± 14.4 mL kg−1 min−1 , respectively ( p < 0.05 ) . TPWS for the transfemoral amputees and control participants was 0.89 ± 0.2 and 1.33 ± 0.3 m s−1 , respectively ( p < 0.01 ) . FPWS for the transfemoral amputees and control participants was 1.22 ± 0.2 and 1.52 ± 0.1 m s−1 , respectively ( p < 0.01 ) . Walking on floor with the FPWS , the energy expenditure of the transfemoral amputees and control participants was 54 % and 31 % of VO2max , respectively ( p < 0.01 ) . Walking on the treadmill with the TPWS , the energy expenditure of the transfemoral amputees and control participants was 42 % and 29 % of the VO2max , respectively ( p < 0.05 ) . Conclusion : Energy expenditure is higher for the transfemoral amputees than the control participants , regardless of walking surface . There are minimal differences in energy expenditure between treadmill and floor walking for the control participants but large differences for the transfemoral amputees . Clinical relevance During walking , the transfemoral amputees expend a larger percentage of their maximal aerobic capacity than healthy participants . With a low VO2max , ordinary activities , such as walking , become physically more challenging for the transfemoral amputees than the control participants , and this may , in turn , have a negative effect on the walking range of the transfemoral amputees This study investigated energy expenditure and obstacle course negotiation between the C-leg ® and various non-microprocessor control ( NMC ) prosthetic knees and compared a quality of life survey ( SF-36v2 ™ ) of use of the C-leg ® to national norms . Thirteen subjects with unilateral limb loss ( 12 with trans-femoral and one with a knee disarticulation amputation ) participated in the study . The mean age was 46 years , range 30 – 75 . Energy expenditure using both the NMC and C-leg ® prostheses was measured at self-selected typical and fast walking paces on a motorized treadmill . Subjects were also asked to walk through a st and ardized walking obstacle course carrying a 4.5 kg ( 10 lb ) basket and with h and s free . Finally , the SF-36v2 ™ was completed for subjects while using the C-leg ® . Statistically significant differences were found in oxygen consumption between prostheses at both typical and fast paces with the C-leg ® showing decreased values . Use of the C-leg ® result ed in a statistically significant decrease in the number of steps and time to complete the obstacle course . Scores on a quality of life index for subjects using the C-leg ® were above the mean for norms for limitation in the use of an arm or leg , equal to the mean for the general United States population for the physical component score and were above this mean for the mental component score . Based on oxygen consumption and obstacle course findings , the C-leg ® when compared to the NMC prostheses may provide increased functional mobility and ease of performance in the home and community environment . Question naire results suggest a minimal quality of life impairment when using a C-leg ® for this cohort of individuals with amputation Objective : To compare the gait of amputees wearing conventionally damped pneumatic swing-phase control knees and  microchip-controlled Intelligent Prostheses .  Design : Crossover trial . Setting : An amputee rehabilitation centre in a teaching hospital . Participants : Ten established unilateral transfemoral prosthetic users were asked to participate in the trial ; all agreed . Interventions : The amputees were assessed wearing pneumatic swing-phase control knees and then with the Intelligent Prosthesis . Main outcome measures : Oxygen consumption while walking at different speeds on a treadmill , video-recording of gait assessed by a panel and temporal – spatial parameters of gait whilst walking at slow , fast or normal speeds in a gait laboratory . Results : Mean oxygen cost for all subjects at 0.69 m/s was 0.33 ml/kg.m with the conventional limb and 0.30 ml/kg.m with the Intelligent Prosthesis ( p–0.01 ) . At 1.25 m/s the mean oxygen cost for the conventional limb was 0.24 ml/kg.m and for the Intelligent Prosthesis was 0.22 ml/kg.m ( not significant ) . The ANOVA analysis showed that oxygen cost was similar at normal walking speeds but increased more at lower speeds for the pneumatic swing-phase control leg compared to the Intelligent Prosthesis ( p<0.02 ) . There were no significant differences in subjective gait evaluation or temporal and spatial gait parameters . Conclusion : At lower speeds oxygen cost was lower with the Intelligent Prosthesis . Gait analysis detected no significant changes between the two legs Abstract Purpose : To establish at which exercise-power level is the vascular response , as measured by oxygen uptake , closest to the response during the 6-min walk test ( 6 MWT ) in people after lower-limb amputation due to peripheral vascular disease ( PVD ) . Method : A prospect i ve exploratory cohort study was conducted . 6 MWT and exercise testing using a h and -wheel ergometer ( starting at 10 W and increasing the workload by 10 W ) were performed in 101 consecutively recruited participants after transfemoral amputation due to PVD . Agreement of oxygen uptake during 6 MWT and exercise testing was compared between the groups defined by the exercise-power level reached . Results : Linear regression through origin with Chow test for comparing slopes indicated that oxygen uptake at 30 W agreed more with 6 MWT than at 20 , 40 or 50 W. Analyses of observed differences ( one-way ANOVA with post-hoc tests , Jonckheere – Terpstra test ) confirmed 30 W to be the recommendable threshold . Conclusions : At the level of 30 W , the oxygen uptake during the exercise was the closest to the 6 MWT , so we estimated that to be the minimum required level for walking using a prosthesis after transfemoral amputation due to PVD . Implication s for Rehabilitation Exercise testing after transfemoral amputation . Walking with a prosthesis causes notable strain to the person ’s vascular system : after the 6-min walk test , the participants ' heart rate reached 75 % of the maximum predicted heart rate on average . The study shows that persons after transfemoral amputation due to peripheral vascular disease who reach the level of 30 W or more in exercise testing with an arm ergometer at admission to rehabilitation are likely to be able to walk in-doors using a prosthesis Background : Studies of the maximal oxygen uptake ( VO2max ) of transfemoral amputees have mostly used protocol s that activate a relatively small muscle mass . Consequently , transfemoral amputee VO2max may be systematic ally underestimated , and the validity of these test protocol s is question able . Objectives : ( 1 ) Investigate validity and reliability of a VO2max walking protocol and ( 2 ) compare the VO2max of a transfemoral amputee group with a group of matching controls . Study design : ( 1 ) R and omized crossover study : walking versus running VO2max for the control group and ( 2 ) case-control study : transfemoral amputees versus control group VO2max . Methods : Twelve transfemoral amputees and control participants performed a walking VO2max test with increasing treadmill inclinations to voluntary exhaustion . The control group also completed a running ( “ gold-st and ard ” ) VO2max test . Results : Mean ( st and ard deviation ) control group VO2max following walking and running was similar , that is , 2.99 ( 0.6 ) L min−1 and 3.09 ( 0.7 ) L min−1 , respectively . Mean ( st and ard deviation ) transfemoral amputee walking VO2max was 2.14 ( 0.8 ) L min−1 ( compared to CON ; p < 0.01 ) . Mean intraclass correlation coefficient of repeated VO2 measurements was 0.97 , and within-subjects st and ard deviation was 60 mL min−1 . Conclusions : The walk protocol is valid . Walking VO2max of transfemoral amputees was 40 % lower compared to control group . Reliability of the walking protocol is comparable to other walking protocol s. Clinical relevance The design , alignment , and material s of prostheses are important for effective ambulation . Cardio-respiratory fitness is , however , also important in this regard , and a low fitness may compromise health and independent living . Hence , transfemoral amputees with low physical fitness should engage in regular physical activity to improve health , gait capacity , and independency In this study , the influence of different prosthetic alignments and components on oxygen consumption and the important biomechanical characteristics of the normal gait pattern of leg amputees was investigated . With 15 transtibial and 12 transfemoral amputees  , the oxygen consumption during walking on a treadmill was analyzed and biomechanical parameters during walking on even ground at a self-selected speed were defined . The amputation of all patients was caused by trauma . Variations of the prosthetic alignment affect the energy consumption of transfemoral amputees more significantly than that of transtibial amputees . Comparison of different prosthetic feet worn by transtibial amputees did not show significant differences regarding metabolic parameters . Compared with conventional hydraulic knee controls , the oxygen consumption of transfemoral amputees provided with an electronically controlled hydraulic knee joint is reduced . All investigated variations can be clearly characterized by the sagittal moments acting on the joints of the prosthetic limb during gait Background : The International Committee of the Red Cross supports a worldwide program of prosthetic fitting and rehabilitation . In this context , a prosthetic foot was developed and widely distributed in least developed countries . Study design : Prospect i ve , r and omized , double-blind , controlled study . Objective : To compare patient satisfaction and energy expenditure during ambulation between a low-cost prosthetic foot design ed with a polypropylene keel ( CR-Equipements ™ solid ankle cushion heel , International Committee of the Red Cross ) to a well-recognized solid ankle cushion heel foot with a wooden keel ( solid ankle cushion heel foot , Otto Bock ) . Methods : A total of 15 participants with unilateral transtibial amputation were evaluated using the two prosthetic feet in a r and omized prospect i ve double-blind crossover study . Main outcomes were patient satisfaction question naires ( Satisfaction with Prosthesis Question naire and prosthetic foot satisfaction ) and energy expenditure ( oxygen consumption — mL/kg/min , oxygen cost — mL/kg/m , and heart rate — bpm ) . Results : There were no significant differences between the two prosthetic feet for satisfaction and energy expenditure . Conclusion : The low-cost solid ankle cushion heel foot with polypropylene keel provides comparable satisfaction and similar energy expenditure as the solid ankle cushion heel foot with wooden keel . Clinical relevance The results of this study support the application and widespread use of the CR-Equipements ™ solid ankle cushion heel foot . From a cost-effectiveness st and point , patients are well satisfied and exhibit similar outcomes at a substantially lower cost
target: During walking , oxygen consumption ( ml O2/kg/min ) and heart rate ( beats/min ) increased with a higher walking speed and a more proximal amputation .
  During walking , oxygen consumption ( ml O2/kg/min ) and heart rate ( beats/min ) increased with a higher walking speed and a more proximal amputation .
background: OBJECTIVE To systematic ally review the literature on the metabolic costs of activities of daily living ( ADL ) in persons with a lower limb amputation ( LLA ) .