human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 
    Output:
    
agent
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 .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 
    Output:
    