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13.11 Functional evaluation of prosthetic foot kinematicsduring lower-limb amputee gait
Chapter 13. Biomechanics and orthopaedic disorders osteoarthritis and after total hip replacement. Gait and Posture 2004; 20:102 6.
[•
Joint compensation actions under different wedge conditions during single-limb stance
M. Eslami 1, P. Allard 1, C. Tanaka 2, S. Hinse 1, N. Frahpour 3.
1Department of Kinesiology, University of Montreal, Montreal, Canada and Laboratoire d'Etude du Mouvement, Research Cente~ Sainte-Justine Hospital, Montreal, Canada; 2Department of Physical Therapy, Speech Therafy and Occupational Therapy, University of S~o Paulo, Brazil," ~Department of physical education, Bouali University, Hamadan, Iran I n t r o d u c t i o n : Wedged foot orthotics are widely prescribed to promote
the mechanical alignment of foot joints. However, wedged orthoses can also affect lower limb proximal joints and axial segment as an effect of the weight-bearing closed chain. Therefore, the wedged orthoses prescription should consider the functional relationship between the foot and its proximal segments [1]. Conversely, the effect of wedged orthoses on the lower limb proximal joints and axial segment alignment is still unclear. The purpose of this study was to assess the compensation actions of the subtalar joint, ankle, knee, hip, pelvis, and upper trunk under different wedge conditions during single-limb stance. M e t h o d s : Fourteen able-bodied young male participated in this study. Participants were tested in single-limb stance under five wedge placements: no wedge (NW); anterior (AW); posterior (PW); lateral heel (LW); medial heel (MW). A Motion Analysis System using five cameras with EVaRT software was used to capture (3 trials of 60 s each) joint angle in the trunk and pelvis in horizontal plane, ankle, knee, hip in sagittal plane, and subtalar and hip joint in the frontal plane. Results: Various angular motion changes at the hip, pelvic and knee differentiate the effect of different wedge conditions. C o n c l u s i o n : Compensation actions occur at upper trunk, ankle and subtalar joint regardless the wedge conditions. This shows the participation of different planes of movement to compensate a wedge placement. Furthermore, a particular wedge condition changes differently the especial proximal joints in a weight-bearing chain. Thus, it is essential to notice the effect of different posted orthotic on proximal joints and three planes of movement.
$77
observed as a function of age, while a trend towards age-dependent decreases of W+ and Wn was detected over the whole population, which gained statistical significance only in the male group. D i s c u s s i o n a n d c o n c l u s i o n : The evidence that ankle joint stiffness and work parameters in males were different than in females, although the range of walking speed was the same, prompts for a deeper investigation about a possible gender difference in the muscle coordination at different joints.
~
Effect of obesity on standing work posture
W.L. Gilleard, T. Smith. Southern Cross University, Australia I n t r o d u c t i o n : Increased body segments' mass and diameters that
occur with obesity may alter the posture and loads on the trunk during standing tasks. The aim of the project was to investigate the hip joint moment, hip joint position relative to the bench edge and trunk segment posture during a standing working task. M e t h o d s : Obese females (BMI~>30 and waist circumference >90 cm) and age and height matched normal weight controls (BMI ~<25) with markers defining the trunk, upper limbs and thigh segments were videoed with a single camera performing three trials of a standing work task at a 90 cm bench. Hip joint moment was divided by body weight and height. Results: One way ANOVAs showed the obese group had a significantly more flexed lumbar spine, stood further back from the bench edge and had an increased hip joint moment in comparison to the normal weight control group. D i s c u s s i o n a n d C o n c l u s i o n s : The standing work task showed a significant increase in hip joint moment not accounted for by increased mass. Obese subjects, however, stood further away from the bench and their lumbar spines were more flexed in order to reach the bench, primarily due to increased thoracic segment flexion. Therefore the posture of the obese subjects was altered due to change in dimensions of the body. Measures to prevent the increased trunk load in obesity should be directed at both preventing adverse postural changes and minimizing the effective load due to altered body weight and distribution.
[1~
Functional evaluation of prosthetic foot kinematics during lower-limb amputee gait
References
H. G o u j o n 1 , X. Bonnet 1 , P. Sautreuil 2, M. Maurisset 2, D. Darmon 2,
[1] Nicolopoulos C.S, et al. Biomechanical basis of foot orthotic prescription: Foot and ankle 2000; 14:464 469.
151 bd de 1'h@ital, 75013 Paris', France," 2Centre d'appareillage d'Ile de France, Ministate de la ddfense, 10, avenue du Val-de-Fontenay, 94135 Fontenay-sous-Bois, France," 3Centre d'Etude et de Recherche sur 1'Appareillage des' Handicap&', Bellevue, Woippy, France
[•
Analysis of the moment-angle loops at the ankle joint during normal walking: effect of gender and age
C. Frigo 1, R Crenna 2. 1TBM Lab, Dept. of Bioengineering,
Polytechnic of Milan, Milan, Italy; 2L.A.M.B. Pierfranco & Luisa Mariani, Inst Human Physiology I, Universiy of Milan, Milan, Italy I n t r o d u c t i o n : A synthesis of dynamic joint stiffness and mechanical work exchange during walking can be obtained by plotting joint moments versus joint angles. The effects of walking speed have been described in previous works. Here the effect of gender and age are analysed with reference to the ankle joint. M e t h o d s : Fifty healthy subjects (25 females, 25 males, age range 6 79 years) walked barefoot on a level path at natural speed. Relative joint angles and external moments, computed by inverse dynamics, were used to generate the ankle joint moment-angle loops. The average slope was computed for each of the following phases: early and late rising phases and descending phase. The area within the loop (net mechanical work, Wn) and the ratio between the work absorbed, Wand produced, W+ were analysed as well. Results: Males exhibited a higher slope in all the three phases of the moment-angle loop and a larger mean value of W+ and Wn. No significant changes in the slopes of the three components were
R Fod~ 3, E Lavaste 1'3. 1Laboratoire de biomdcanique de I'ENSAM,
I n t r o d u c t i o n : Prosthetic foot designs are growing in complexity.
Consequently, quantitative and functional evaluation appears essential to understand foot behaviour during gait. To compare different feet, anterior studies investigate ankle, knee and hip kinematics simultaneously with ground reaction force [1,2]. M e t h o d s : An original protocol is proposed in this study. Forefoot relatively to aft-foot kinematics are measured together with body global kinematics and ground reaction forces during gait. Ten amputees (6 below-knee and 4 above-knee) and thirty-five nonamputated subjects participated in this study. This work focuses on prosthetic foot and ankle kinematics and their relation with timedistance parameters and ground reaction forces. Results: Symmetry and prosthetic propulsive force were proved to be mainly dependent on amputation level. In contrast, prosthetic forefoot flexion and several time-distance parameters are highly influenced by foot design. A correlation was observed for nonamputated subject between fore-foot flexion and propulsive force. This correlation does not exist for amputees. D i s c u s s i o n : The method proposed succeeds in quantifying accurate motions of prosthetic ankle and fore-foot. The results suggest that prosthetic foot efficiency depends simultaneously on foot design and gait style.
Chapter 13. Biomechanics and orthopaedic disorders
$78
Conclusion: Preliminary results should be confirmed through an extensive study. This functional evaluation associated to clinical exam should help to achieve the best adequacy of prosthetic foot fit to a patient.
References [1] Snyder, R.D., et al. The effect of five prosthetic feet on the gait and loading of the sound limb in dysvascular below-knee amputees. Journal of Rehabilitation Research and Development, 1995; 32(4): p.309 315. [2] Van der Linden, M.L., et al. A methodology for studying the effects of various types of prosthetic feet on the biomechanics of transfemoral amputee gait. Journal of biomechanics, 1999; 32: p.877 889.
I1~
Comparison of relative velocity of lower limbs at obese teenagers before and after loss of weight and their effects on fear performance during a vertical jump (cmj)
L. Hajri 1, P. Lacouture 1, M.L. Frelut2. 1LMS (UMR 6610); SP2ML bld Marie et Pierre CURIE, BP 30179, 86962 Futuroscope Chasseneuil C.E.D.E.X., France," eINSERM," Service de gastro-entdrologie et nutrition pddiatrique, H@ital Robert Debrd, 48 boulevard S&urie~ 75019 Paris', France Introduction: Obesity poses a large health problem throughout the word. Through this paper we want to estimate the synergy of movements; generated by obese subjects and better understand the reason by which the persons in weighty excess suffer during the execution of a sports gesture. Methods: The aim of the present study is to analyze and compare angles, inter-segmental speeds and forces on joints of lower limb of 9 severely obese adolescents before and after weight loss, with respective masses, 105.63±14.15kg and 80.83±12.30kg. Each subject realized 3 tests; the best were retained. The anthropometric modeling of the obese subjects adapted to Hanavan's model and the methods of calculation were validated in a previous study [1]. The motion is filmed by six cameras IR (50Hz) synchronized with a force- plate (1000 Hz). The validation of theses results are estimated by considering the theoretical and experimental complementary relationship of the kinematics and kinetic analyses. Results and discussion: In spite that performance it is not excesses improved, their mechanical energy expenditure decreased by half after loss weight. As regards the inter-joint speeds of the hips, knees and ankles, they are more important and hem angular speeds increased on the hips and ankles and decreased on the knees. The inter-segmental forces (x, z) increased of hips, ankles and knees safe for the forces of compression there was decrease at the level of knee. Conclusion: All these values indicate to us that a program of weight loss can be only beneficial. After weight reduction the obese teenagers, will be more economic in terms of energy expenditure and find it easier to partake the exercise. The dispersal of the results and heterogeneity displayed by the group means we cannot speak any more in term of mean values. It would be necessary to recommend the individual analysis.
References [1] Achard de Leluardi~re F., et al. Validation and influence of anthropometrical and kinematical models of obese teenagers in the vertical jump performance and the mechanical internal energy expenditure calculation, 2003. Gait & Posture (in press: on line 19 February 2005).
ll~ls
step-to-step transition of walking the source of increased energy demand using AFO's?
H. Houdijk 1'2, R.M. Hijlaard 1. 1Institute for Fundamental and
Clinical Human Movement Sciences', Vrije Universiteit Amsterdam, The Netherlands'," 2Heliomare Rehabilitation Centre, Wijk aan Zee, The Netherlands' Introduction: Walking with a rigid ankle, for instance wearing an
ankle foot orthosis (AFO), increases energy demand [1]. A model recently described by Kuo [2], could explain this. This model predicts that the mechanical energy required to redirect the centre of mass (CM) during the double support phase of walking is higher when it has to be generated around the hip, as is required when using rigid AFO's, compared to when it can be generated around the ankle. In this study we tested whether mechanical work done during double support can account for the increased energy cost of walking with an AFO. Methods: Ten healthy subjects walked at a fixed speed over a set of two force plates with and without a unilateral AFO. From the ground reaction forces under each foot, the velocity of the CM and the work done in each leg was calculated during a step. Results a n d Discussion: The negative work in the leading leg during double support was 46% higher when the AFO was worn on the trailing leg, as was suggested by the model. However, total absolute work during the step was not higher when wearing the AFO. This result might have been due to a compensatory strategy, where subjects choose not to generate positive work around the hip of the trailing leg prior to heel strike, but with the leading leg after heel strike.
References [1] Waters RL, Mulroy S. The energy expenditure of normal and pathologic gait. Gait Posture 1999; 9:207 31. [2] Kuo AD. Energetics of actively powered locomotion using the simplest walking model. J Biomech Eng 2002; 124:113 20.
I1~
Influence of knee braces on lower limb mechanics during stair locomotion after anterior cruciate ligament reconstruction
H.C. Hsu 1'2, T.W. Lu 3, H.C. Lin 2'3. 1Department of Orthopedics,
China Medical University Hospital, China; 2School of Physical Therapy, China Medical University, China," 3Institute of Biomedical Engineering, National Taiwan University, Taiwan Introduction: Use of functional knee braces is suggested after Anterior Cruciate Ligament (ACL) reconstruction. Being one of the most common daily activities, the efficacy of braces on ACLreconstructed (ACLR) subjects during stair locomotion has not been reported. Methods: Ten ACLR subjects (28.3±8.5 years) performed stair ascent and descent with and without knee braces while the kinematic and kinetic data were measured. Three-dimensional angles, moments and angular impulses at the lower limb joints were calculated and compared between bracing conditions and between limbs. Results: The affected limbs adopted significantly smaller flexion at all joints, smaller peak knee extensor moments and impulses, and larger hip extensor moments and impulses. Bracing did not affect the biomechanics of the knee during stair locomotion except minor changes at the hip and ankle. Discussion and Conclusion: Significant mechanical changes at the knee and compensations at the hip and ankle were present after ACLR, possibly due to the deficit of the quadriceps strength that may persist even at 24 months after reconstruction [1]. These mechanical changes were not affected by bracing. Therefore, muscle strengthening rather than bracing may be more important for these subjects to improve the performance of stair locomotion.
References [1] Kobayashi A., Higuchi H., Terauchi M., Kobayashi F., Kimura M. and Takagishi K. Muscle performance after anterior cruciate
[•
Joint compensation actions under different wedge conditions during single-limb stance
M. Eslami 1, P. Allard 1, C. Tanaka 2, S. Hinse 1, N. Frahpour 3.
1Department of Kinesiology, University of Montreal, Montreal, Canada and Laboratoire d'Etude du Mouvement, Research Cente~ Sainte-Justine Hospital, Montreal, Canada; 2Department of Physical Therapy, Speech Therafy and Occupational Therapy, University of S~o Paulo, Brazil," ~Department of physical education, Bouali University, Hamadan, Iran I n t r o d u c t i o n : Wedged foot orthotics are widely prescribed to promote
the mechanical alignment of foot joints. However, wedged orthoses can also affect lower limb proximal joints and axial segment as an effect of the weight-bearing closed chain. Therefore, the wedged orthoses prescription should consider the functional relationship between the foot and its proximal segments [1]. Conversely, the effect of wedged orthoses on the lower limb proximal joints and axial segment alignment is still unclear. The purpose of this study was to assess the compensation actions of the subtalar joint, ankle, knee, hip, pelvis, and upper trunk under different wedge conditions during single-limb stance. M e t h o d s : Fourteen able-bodied young male participated in this study. Participants were tested in single-limb stance under five wedge placements: no wedge (NW); anterior (AW); posterior (PW); lateral heel (LW); medial heel (MW). A Motion Analysis System using five cameras with EVaRT software was used to capture (3 trials of 60 s each) joint angle in the trunk and pelvis in horizontal plane, ankle, knee, hip in sagittal plane, and subtalar and hip joint in the frontal plane. Results: Various angular motion changes at the hip, pelvic and knee differentiate the effect of different wedge conditions. C o n c l u s i o n : Compensation actions occur at upper trunk, ankle and subtalar joint regardless the wedge conditions. This shows the participation of different planes of movement to compensate a wedge placement. Furthermore, a particular wedge condition changes differently the especial proximal joints in a weight-bearing chain. Thus, it is essential to notice the effect of different posted orthotic on proximal joints and three planes of movement.
$77
observed as a function of age, while a trend towards age-dependent decreases of W+ and Wn was detected over the whole population, which gained statistical significance only in the male group. D i s c u s s i o n a n d c o n c l u s i o n : The evidence that ankle joint stiffness and work parameters in males were different than in females, although the range of walking speed was the same, prompts for a deeper investigation about a possible gender difference in the muscle coordination at different joints.
~
Effect of obesity on standing work posture
W.L. Gilleard, T. Smith. Southern Cross University, Australia I n t r o d u c t i o n : Increased body segments' mass and diameters that
occur with obesity may alter the posture and loads on the trunk during standing tasks. The aim of the project was to investigate the hip joint moment, hip joint position relative to the bench edge and trunk segment posture during a standing working task. M e t h o d s : Obese females (BMI~>30 and waist circumference >90 cm) and age and height matched normal weight controls (BMI ~<25) with markers defining the trunk, upper limbs and thigh segments were videoed with a single camera performing three trials of a standing work task at a 90 cm bench. Hip joint moment was divided by body weight and height. Results: One way ANOVAs showed the obese group had a significantly more flexed lumbar spine, stood further back from the bench edge and had an increased hip joint moment in comparison to the normal weight control group. D i s c u s s i o n a n d C o n c l u s i o n s : The standing work task showed a significant increase in hip joint moment not accounted for by increased mass. Obese subjects, however, stood further away from the bench and their lumbar spines were more flexed in order to reach the bench, primarily due to increased thoracic segment flexion. Therefore the posture of the obese subjects was altered due to change in dimensions of the body. Measures to prevent the increased trunk load in obesity should be directed at both preventing adverse postural changes and minimizing the effective load due to altered body weight and distribution.
[1~
Functional evaluation of prosthetic foot kinematics during lower-limb amputee gait
References
H. G o u j o n 1 , X. Bonnet 1 , P. Sautreuil 2, M. Maurisset 2, D. Darmon 2,
[1] Nicolopoulos C.S, et al. Biomechanical basis of foot orthotic prescription: Foot and ankle 2000; 14:464 469.
151 bd de 1'h@ital, 75013 Paris', France," 2Centre d'appareillage d'Ile de France, Ministate de la ddfense, 10, avenue du Val-de-Fontenay, 94135 Fontenay-sous-Bois, France," 3Centre d'Etude et de Recherche sur 1'Appareillage des' Handicap&', Bellevue, Woippy, France
[•
Analysis of the moment-angle loops at the ankle joint during normal walking: effect of gender and age
C. Frigo 1, R Crenna 2. 1TBM Lab, Dept. of Bioengineering,
Polytechnic of Milan, Milan, Italy; 2L.A.M.B. Pierfranco & Luisa Mariani, Inst Human Physiology I, Universiy of Milan, Milan, Italy I n t r o d u c t i o n : A synthesis of dynamic joint stiffness and mechanical work exchange during walking can be obtained by plotting joint moments versus joint angles. The effects of walking speed have been described in previous works. Here the effect of gender and age are analysed with reference to the ankle joint. M e t h o d s : Fifty healthy subjects (25 females, 25 males, age range 6 79 years) walked barefoot on a level path at natural speed. Relative joint angles and external moments, computed by inverse dynamics, were used to generate the ankle joint moment-angle loops. The average slope was computed for each of the following phases: early and late rising phases and descending phase. The area within the loop (net mechanical work, Wn) and the ratio between the work absorbed, Wand produced, W+ were analysed as well. Results: Males exhibited a higher slope in all the three phases of the moment-angle loop and a larger mean value of W+ and Wn. No significant changes in the slopes of the three components were
R Fod~ 3, E Lavaste 1'3. 1Laboratoire de biomdcanique de I'ENSAM,
I n t r o d u c t i o n : Prosthetic foot designs are growing in complexity.
Consequently, quantitative and functional evaluation appears essential to understand foot behaviour during gait. To compare different feet, anterior studies investigate ankle, knee and hip kinematics simultaneously with ground reaction force [1,2]. M e t h o d s : An original protocol is proposed in this study. Forefoot relatively to aft-foot kinematics are measured together with body global kinematics and ground reaction forces during gait. Ten amputees (6 below-knee and 4 above-knee) and thirty-five nonamputated subjects participated in this study. This work focuses on prosthetic foot and ankle kinematics and their relation with timedistance parameters and ground reaction forces. Results: Symmetry and prosthetic propulsive force were proved to be mainly dependent on amputation level. In contrast, prosthetic forefoot flexion and several time-distance parameters are highly influenced by foot design. A correlation was observed for nonamputated subject between fore-foot flexion and propulsive force. This correlation does not exist for amputees. D i s c u s s i o n : The method proposed succeeds in quantifying accurate motions of prosthetic ankle and fore-foot. The results suggest that prosthetic foot efficiency depends simultaneously on foot design and gait style.
Chapter 13. Biomechanics and orthopaedic disorders
$78
Conclusion: Preliminary results should be confirmed through an extensive study. This functional evaluation associated to clinical exam should help to achieve the best adequacy of prosthetic foot fit to a patient.
References [1] Snyder, R.D., et al. The effect of five prosthetic feet on the gait and loading of the sound limb in dysvascular below-knee amputees. Journal of Rehabilitation Research and Development, 1995; 32(4): p.309 315. [2] Van der Linden, M.L., et al. A methodology for studying the effects of various types of prosthetic feet on the biomechanics of transfemoral amputee gait. Journal of biomechanics, 1999; 32: p.877 889.
I1~
Comparison of relative velocity of lower limbs at obese teenagers before and after loss of weight and their effects on fear performance during a vertical jump (cmj)
L. Hajri 1, P. Lacouture 1, M.L. Frelut2. 1LMS (UMR 6610); SP2ML bld Marie et Pierre CURIE, BP 30179, 86962 Futuroscope Chasseneuil C.E.D.E.X., France," eINSERM," Service de gastro-entdrologie et nutrition pddiatrique, H@ital Robert Debrd, 48 boulevard S&urie~ 75019 Paris', France Introduction: Obesity poses a large health problem throughout the word. Through this paper we want to estimate the synergy of movements; generated by obese subjects and better understand the reason by which the persons in weighty excess suffer during the execution of a sports gesture. Methods: The aim of the present study is to analyze and compare angles, inter-segmental speeds and forces on joints of lower limb of 9 severely obese adolescents before and after weight loss, with respective masses, 105.63±14.15kg and 80.83±12.30kg. Each subject realized 3 tests; the best were retained. The anthropometric modeling of the obese subjects adapted to Hanavan's model and the methods of calculation were validated in a previous study [1]. The motion is filmed by six cameras IR (50Hz) synchronized with a force- plate (1000 Hz). The validation of theses results are estimated by considering the theoretical and experimental complementary relationship of the kinematics and kinetic analyses. Results and discussion: In spite that performance it is not excesses improved, their mechanical energy expenditure decreased by half after loss weight. As regards the inter-joint speeds of the hips, knees and ankles, they are more important and hem angular speeds increased on the hips and ankles and decreased on the knees. The inter-segmental forces (x, z) increased of hips, ankles and knees safe for the forces of compression there was decrease at the level of knee. Conclusion: All these values indicate to us that a program of weight loss can be only beneficial. After weight reduction the obese teenagers, will be more economic in terms of energy expenditure and find it easier to partake the exercise. The dispersal of the results and heterogeneity displayed by the group means we cannot speak any more in term of mean values. It would be necessary to recommend the individual analysis.
References [1] Achard de Leluardi~re F., et al. Validation and influence of anthropometrical and kinematical models of obese teenagers in the vertical jump performance and the mechanical internal energy expenditure calculation, 2003. Gait & Posture (in press: on line 19 February 2005).
ll~ls
step-to-step transition of walking the source of increased energy demand using AFO's?
H. Houdijk 1'2, R.M. Hijlaard 1. 1Institute for Fundamental and
Clinical Human Movement Sciences', Vrije Universiteit Amsterdam, The Netherlands'," 2Heliomare Rehabilitation Centre, Wijk aan Zee, The Netherlands' Introduction: Walking with a rigid ankle, for instance wearing an
ankle foot orthosis (AFO), increases energy demand [1]. A model recently described by Kuo [2], could explain this. This model predicts that the mechanical energy required to redirect the centre of mass (CM) during the double support phase of walking is higher when it has to be generated around the hip, as is required when using rigid AFO's, compared to when it can be generated around the ankle. In this study we tested whether mechanical work done during double support can account for the increased energy cost of walking with an AFO. Methods: Ten healthy subjects walked at a fixed speed over a set of two force plates with and without a unilateral AFO. From the ground reaction forces under each foot, the velocity of the CM and the work done in each leg was calculated during a step. Results a n d Discussion: The negative work in the leading leg during double support was 46% higher when the AFO was worn on the trailing leg, as was suggested by the model. However, total absolute work during the step was not higher when wearing the AFO. This result might have been due to a compensatory strategy, where subjects choose not to generate positive work around the hip of the trailing leg prior to heel strike, but with the leading leg after heel strike.
References [1] Waters RL, Mulroy S. The energy expenditure of normal and pathologic gait. Gait Posture 1999; 9:207 31. [2] Kuo AD. Energetics of actively powered locomotion using the simplest walking model. J Biomech Eng 2002; 124:113 20.
I1~
Influence of knee braces on lower limb mechanics during stair locomotion after anterior cruciate ligament reconstruction
H.C. Hsu 1'2, T.W. Lu 3, H.C. Lin 2'3. 1Department of Orthopedics,
China Medical University Hospital, China; 2School of Physical Therapy, China Medical University, China," 3Institute of Biomedical Engineering, National Taiwan University, Taiwan Introduction: Use of functional knee braces is suggested after Anterior Cruciate Ligament (ACL) reconstruction. Being one of the most common daily activities, the efficacy of braces on ACLreconstructed (ACLR) subjects during stair locomotion has not been reported. Methods: Ten ACLR subjects (28.3±8.5 years) performed stair ascent and descent with and without knee braces while the kinematic and kinetic data were measured. Three-dimensional angles, moments and angular impulses at the lower limb joints were calculated and compared between bracing conditions and between limbs. Results: The affected limbs adopted significantly smaller flexion at all joints, smaller peak knee extensor moments and impulses, and larger hip extensor moments and impulses. Bracing did not affect the biomechanics of the knee during stair locomotion except minor changes at the hip and ankle. Discussion and Conclusion: Significant mechanical changes at the knee and compensations at the hip and ankle were present after ACLR, possibly due to the deficit of the quadriceps strength that may persist even at 24 months after reconstruction [1]. These mechanical changes were not affected by bracing. Therefore, muscle strengthening rather than bracing may be more important for these subjects to improve the performance of stair locomotion.
References [1] Kobayashi A., Higuchi H., Terauchi M., Kobayashi F., Kimura M. and Takagishi K. Muscle performance after anterior cruciate