- Email: [email protected]
Gait dynamics in the wide spectrum of children with arthrogryposis
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
Materials and methods: The user controls a virtual ice skater on a frozen canal by shifting his bodyweight in both lateral directions, thereby regulating speed and direction of the avatar. Increasing body sway amplitude and sway frequency results in a higher skating speed, resulting in higher scores. Before, after 2 and 4 weeks of training, and after the intervention, postural control was examined, by measuring sway characteristics during 45 s of quiet standing barefoot on a Pressure Mat System (MatScan® 3150, South Boston, USA) in eyes open (EO), eyes closed (EC) and dual task (DT) conditions. The following parameters were calculated from the centre of pressure signals: summed distance in anteriorposterior and mediolateral direction, mean sway velocity, root mean square distance, sway area, the total power and the 95% power frequency. Additionally balance was evaluated using the narrow ridge balance test (NRBT). Multilevel modeling (MLwin) was applied to examine changes in balance. A two-level hierarchical model was constructed, and a separate model was built for each outcome measure. Results: Participants played on average 631 (±124) minutes over a period of 6 weeks and no subjects dropped out. Improved sway characteristics in time and frequency domain (P < 0.05) were observed in EO and EC condition after 4 and 6 weeks of training. The rate of balance improvement showed differences (P < 0.05) between participants, not related to total playtime. No effects were found in DT condition and on the NRBT. Discussion: The results of the pilot study showed that a 6-week balance training paradigm based on unsupervised home-based exergaming improves balance ability in healthy older adults. However, participants did not benefit equally from the intervention, thereby emphasizing the need for a more personalized training program. An alternative interpretation is that exergames are only beneficial for a specific target group, and not for all healthy older adults. References [1] van Diest M, et al. J Neuroeng Rehabil 2013;10:101. [2] Molina KI, et al. J Neuroeng Rehabil 2014;11:156. [3] Kosse, et al. J Cyber Ther Rehab 2011;4(3):399–407.
S87
Ten subjects were measured with the wearable exoskeleton reproducing gait at a fixed speed (0.25 m/s) and the smart robotic walker under three conditions: 30%, 50% and 70% BWS. Results: The non-parametrical Friedman test showed significant differences between the 30%, 50% and 70%BWS (p < 0.05). The stance time and the double-limb support time were decreased in 70% compared with 30%BWS. Step width and center of gravity (CG) movement in frontal plane were smaller in 30% than in 50% and 70%BWS. Knee and ankle maximum and minimum moments occurred after in 30% than in 70%BWS during the gait cycle, and showed higher flexion at heel strike in 30% than in 70%BWS. The ankle also presented higher maximum and minimum values in 30% than in 70%BWS. Discussion: As it was described in previous researches [1,2] the stance time and the double-limb support time decreased as the percentage of BWS increased. Therefore subjects were forced to support their body weight and keep the balance on a single limb for longer periods of time. Step width and side-to-side movement of CG were progressively increased from 30% to 70%BWS to maintain the dynamic balance during gait. Finch et al. [1] described, like in the present study, smaller amplitude of movement in the knee and ankle attributed to the decreased amount of weight supported, mainly at heel strike. Also, the ankle maximum and minimum events appeared early during the gait cycle as the percentage of BWS increased, as Threlkeld et al. reported [2], because ankle movement was less controlled by exoskeleton. These findings show how it should be taken into account the influence of BWS in a fixed gait pattern reproduced by an exoskeleton, because that could modify the effects and conditions of training using those devices. References [1] Finch L, Barbeau H, Arsenault B. Influence of body weight support on normal human gait: development of a gait retraining strategy. Phys Ther 1991;71(11):842–55. [2] Threlkeld AJ, Cooper LD, Monger BP, Craven AN, Haupt HG. Temporospatial and kinematic gait alterations during treadmill walking with body weight suspension. Gait Posture 2003;17:235–45.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.158 http://dx.doi.org/10.1016/j.gaitpost.2015.06.159
Session OS18 Orthotics Influence of body weight support on wearable devices reproducing normal gait M. Gomez ∗ , C. Lopez de Subijana, E. Navarro Technical University of Madrid, Madrid, Spain Research question: The aim of the present study was to describe the influence of BWS in a fixed gait pattern reproduced by an exoskeleton. Introduction: The body weight suspension (BWS) with treadmill training has been traditionally reported as a way to facilitate functional gait pattern and to recover musculoskeletal injuries. Nowadays some other wearable electronic devices appear as an alternative to treadmill training, eliminating the effects of walking on a treadmill. Materials and methods: The present study was carried out with the HYBRID system, which joins together an exoskeleton robot with hip, knee and ankle control and a robotic walker which provides BWS. An optoelectronic system captured trials with six cameras (120 Hz). Twenty-eight markers were attached to anatomical landmarks following an adapted model from Plug in Gait.
Session OS18 Orthotics Gait dynamics in the wide spectrum of children with arthrogryposis M. Eriksson 1,∗ , Å. Bartonek 1 , E. Pontén 1 , E.M. Gutierrez-Farewik 2 1 Karolinska Institutet, Dept of Women’s and Children’s Health, Stockholm, Sweden 2 Royal Institute of Technology, Dept of Mechanics, Stockholm, Sweden
Research question: Our aim was to investigate how compensatory gait in children with arthrogryposis in their habitual orthotic support affects joint moments and joint mechanical work. Introduction: Arthrogryposis Multiplex Congenita (AMC) is characterized by presence of multiple joint contractures at birth [1]. Orthoses are often used to enable or improve walking function. Greater trunk movements in frontal and transverse planes during gait have been observed in children with AMC using orthoses compared to those wearing only shoes [2]. Materials and methods: 3-D gait analysis was performed (Vicon©) in 26 children with AMC median age10.3 (5.0–17.8) years and a control group of 37 typically-developing (TD) chil-
S88
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
Fig. 1. Contributions from the hip, knee and ankle joint to total positive work (mean percent) in AMC1, AMC2 and AMC3 groups and in the control group.
dren median age 9.7 (5.1–17.6) years. Children walked at a self-selected pace along a 10-m walkway with two force plates (Kistler©). Joint angles, moments, and work (time integral of power) were computed. Children with AMC were divided into 3 groups based on the type of custom-made orthosis prescribed with respect to individual deformity and muscle weakness; AMC1 used knee–ankle–foot orthosis (KAFO) with locked knee joints (n = 5), AMC2 used KAFOs with open knee joints or anklefoot orthosis (AFO) (n = 10), and AMC3 used shoes (n = 11). Non-parametric tests were used to compare results between groups. Results: Joint work analysis showed a proximal work shift in all AMC groups wherein the hip accounted for a larger portion of lower extremity positive work than the ankle or knee, primarily in AMC1 (Fig. 1). Hip abduction moment was lower in AMC1 and AMC2 than in TD, though not significantly. Trunk lateral sway and trunk rotation were greater in AMC1 and AMC2 than in AMC3 and TD. Hip flexion moment was lower in AMC1 than in other groups. Less hip extension and greater pelvic tilt were found in all AMC groups than in TD. Knee extension moments were similar between the groups. Discussion: The gait pattern with excessive trunk lateral sway in children walking with orthoses, particularly locked KAFOs, reduces the hip abduction moments. All AMC groups showed less hip extension than TD, but hip flexion moments were reduced only in AMC1, which can be attributed to their gait strategy with bilateral locked KAFOs. Children in AMC1, with weak knee extensors, were helped by their locked KAFOs and therefore showed similar knee extension moment as other groups. The joint work analysis demonstrates AMC children’s high reliance on hip muscles and presumably trunk muscles to provide propulsion, primarily in those walking with locked KAFOs. References [1] Hall J. J Ped Orthop 1997. [2] Eriksson M, et al. J Child Orthop 2010.
with respect to knee flexion during weight bearing [1] which is important to physiologically execute many activities of daily living (ADL). Therefore, the orthotronic mobility system C-Brace was developed employing microprocessor hydraulic stance and swing control. Materials and methods: Two patients using a locked KAFO (LKAFO; one unilateral, one bilateral) and four patients using a stance control orthosis (SCO) for walking were investigated. Tests were conducted with the existing orthosis (baseline) and after a minimum of 7 weeks of C-Brace use. The tests comprised level walking, descending a slope of 10◦ grade, and a stairwell. The measuring technique consisted of two force plates for recording the ground reaction forces (Kistler, sampling rate 1080 Hz) and an optoelectronic 6 camera system for determining kinematic data (Vicon 460, sampling rate 120 Hz). Based on kinematic data and ground reaction forces, the joint moments were calculated [2]. Results: During level walking, the mean time-distanceparameters do not show any significant differences, but 5 of the 6 patients were able to use knee stance flexion (mean knee angle 11◦ ) when using the C-Brace. The mean knee swing flexion angle was 66.6◦ with the C-Brace as compared to 74.0◦ with the SCOs. With the C-Brace, the sound side external joint moments are significantly reduced compared to the LKAFO condition, but do not differ from those with the SCO. With the C-Brace all six patients were able to descend the slope and stairs step over step. Only four patients were able to reciprocally descend the slope, no patient was able to do this on the stairs when using their previous devices. All patients used continuous knee flexion during weight bearing (mean maximum flexion on the slope 65◦ , on the stairs 70◦ ) with the C-Brace. The abnormally high knee extension moments that are unavoidable at ground contact of the sound limb when descending a slope with a SCO/LKAFO were reduced with the C-Brace. Discussion: The present study confirms that the microprocessor hydraulic control of stance and swing phase in the C- Brace supports nearly natural movement patterns on the orthotic side during level walking (use of stance phase flexion, control of swing phase flexion close to the physiological value) as well as controlled knee flexion during weight bearing that offers the patient remarkably increased functional options for walking on slopes and stairs. The nearly natural movement patterns allowed for by the C-Brace suggest that the loads acting on the locomotor system are qualitatively similar to those in healthy individuals. References [1] Zacharias B, Kannenberg A. J Prosth Orthot 2012;24. [2] Bellmann M, et al. Arch Phys Med Rehabil 2010;91:3.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.160 http://dx.doi.org/10.1016/j.gaitpost.2015.06.161
Session OS18 Orthotics The microprocessor controlled C-Brace orthosis and conventional knee–ankle–foot-orthoses: Comparative biomechanical evaluation of functionality T. Schmalz ∗ , E. Pröbsting Ottobock Healthcare, Clinical Research/Biomechanics, Göttingen, Germany Research question: Conventional KAFOs are compared to the C-Brace based on biomechanical parameters measured in ADL situations. Introduction: Patients with pareses or paralysis of the lower limbs often require a knee ankle foot orthosis (KAFO) to restore walking ability. Conventional KAFOs are limited in functionality
Session OS18 Orthotics Optimizing knee kinematics in mid-stance by tuning the ankle foot orthoses-footwear combination of children with cerebral palsy: A case series B. van Beeten 1,∗ , A. Hartman 2 , H. Houdijk 1 1
Rehabilitation Centre Heliomare, Wijk aan Zee, Netherlands 2 Erasmus MC, Rotterdam, Netherlands Research question: Is it necessary and possible to optimize knee kinematics in mid-stance by tuning the ankle foot orthosesfootwear combination of children with cerebral palsy?
Materials and methods: The user controls a virtual ice skater on a frozen canal by shifting his bodyweight in both lateral directions, thereby regulating speed and direction of the avatar. Increasing body sway amplitude and sway frequency results in a higher skating speed, resulting in higher scores. Before, after 2 and 4 weeks of training, and after the intervention, postural control was examined, by measuring sway characteristics during 45 s of quiet standing barefoot on a Pressure Mat System (MatScan® 3150, South Boston, USA) in eyes open (EO), eyes closed (EC) and dual task (DT) conditions. The following parameters were calculated from the centre of pressure signals: summed distance in anteriorposterior and mediolateral direction, mean sway velocity, root mean square distance, sway area, the total power and the 95% power frequency. Additionally balance was evaluated using the narrow ridge balance test (NRBT). Multilevel modeling (MLwin) was applied to examine changes in balance. A two-level hierarchical model was constructed, and a separate model was built for each outcome measure. Results: Participants played on average 631 (±124) minutes over a period of 6 weeks and no subjects dropped out. Improved sway characteristics in time and frequency domain (P < 0.05) were observed in EO and EC condition after 4 and 6 weeks of training. The rate of balance improvement showed differences (P < 0.05) between participants, not related to total playtime. No effects were found in DT condition and on the NRBT. Discussion: The results of the pilot study showed that a 6-week balance training paradigm based on unsupervised home-based exergaming improves balance ability in healthy older adults. However, participants did not benefit equally from the intervention, thereby emphasizing the need for a more personalized training program. An alternative interpretation is that exergames are only beneficial for a specific target group, and not for all healthy older adults. References [1] van Diest M, et al. J Neuroeng Rehabil 2013;10:101. [2] Molina KI, et al. J Neuroeng Rehabil 2014;11:156. [3] Kosse, et al. J Cyber Ther Rehab 2011;4(3):399–407.
S87
Ten subjects were measured with the wearable exoskeleton reproducing gait at a fixed speed (0.25 m/s) and the smart robotic walker under three conditions: 30%, 50% and 70% BWS. Results: The non-parametrical Friedman test showed significant differences between the 30%, 50% and 70%BWS (p < 0.05). The stance time and the double-limb support time were decreased in 70% compared with 30%BWS. Step width and center of gravity (CG) movement in frontal plane were smaller in 30% than in 50% and 70%BWS. Knee and ankle maximum and minimum moments occurred after in 30% than in 70%BWS during the gait cycle, and showed higher flexion at heel strike in 30% than in 70%BWS. The ankle also presented higher maximum and minimum values in 30% than in 70%BWS. Discussion: As it was described in previous researches [1,2] the stance time and the double-limb support time decreased as the percentage of BWS increased. Therefore subjects were forced to support their body weight and keep the balance on a single limb for longer periods of time. Step width and side-to-side movement of CG were progressively increased from 30% to 70%BWS to maintain the dynamic balance during gait. Finch et al. [1] described, like in the present study, smaller amplitude of movement in the knee and ankle attributed to the decreased amount of weight supported, mainly at heel strike. Also, the ankle maximum and minimum events appeared early during the gait cycle as the percentage of BWS increased, as Threlkeld et al. reported [2], because ankle movement was less controlled by exoskeleton. These findings show how it should be taken into account the influence of BWS in a fixed gait pattern reproduced by an exoskeleton, because that could modify the effects and conditions of training using those devices. References [1] Finch L, Barbeau H, Arsenault B. Influence of body weight support on normal human gait: development of a gait retraining strategy. Phys Ther 1991;71(11):842–55. [2] Threlkeld AJ, Cooper LD, Monger BP, Craven AN, Haupt HG. Temporospatial and kinematic gait alterations during treadmill walking with body weight suspension. Gait Posture 2003;17:235–45.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.158 http://dx.doi.org/10.1016/j.gaitpost.2015.06.159
Session OS18 Orthotics Influence of body weight support on wearable devices reproducing normal gait M. Gomez ∗ , C. Lopez de Subijana, E. Navarro Technical University of Madrid, Madrid, Spain Research question: The aim of the present study was to describe the influence of BWS in a fixed gait pattern reproduced by an exoskeleton. Introduction: The body weight suspension (BWS) with treadmill training has been traditionally reported as a way to facilitate functional gait pattern and to recover musculoskeletal injuries. Nowadays some other wearable electronic devices appear as an alternative to treadmill training, eliminating the effects of walking on a treadmill. Materials and methods: The present study was carried out with the HYBRID system, which joins together an exoskeleton robot with hip, knee and ankle control and a robotic walker which provides BWS. An optoelectronic system captured trials with six cameras (120 Hz). Twenty-eight markers were attached to anatomical landmarks following an adapted model from Plug in Gait.
Session OS18 Orthotics Gait dynamics in the wide spectrum of children with arthrogryposis M. Eriksson 1,∗ , Å. Bartonek 1 , E. Pontén 1 , E.M. Gutierrez-Farewik 2 1 Karolinska Institutet, Dept of Women’s and Children’s Health, Stockholm, Sweden 2 Royal Institute of Technology, Dept of Mechanics, Stockholm, Sweden
Research question: Our aim was to investigate how compensatory gait in children with arthrogryposis in their habitual orthotic support affects joint moments and joint mechanical work. Introduction: Arthrogryposis Multiplex Congenita (AMC) is characterized by presence of multiple joint contractures at birth [1]. Orthoses are often used to enable or improve walking function. Greater trunk movements in frontal and transverse planes during gait have been observed in children with AMC using orthoses compared to those wearing only shoes [2]. Materials and methods: 3-D gait analysis was performed (Vicon©) in 26 children with AMC median age10.3 (5.0–17.8) years and a control group of 37 typically-developing (TD) chil-
S88
ESMAC Abstracts 2015 / Gait & Posture 42S (2015) S1–S101
Fig. 1. Contributions from the hip, knee and ankle joint to total positive work (mean percent) in AMC1, AMC2 and AMC3 groups and in the control group.
dren median age 9.7 (5.1–17.6) years. Children walked at a self-selected pace along a 10-m walkway with two force plates (Kistler©). Joint angles, moments, and work (time integral of power) were computed. Children with AMC were divided into 3 groups based on the type of custom-made orthosis prescribed with respect to individual deformity and muscle weakness; AMC1 used knee–ankle–foot orthosis (KAFO) with locked knee joints (n = 5), AMC2 used KAFOs with open knee joints or anklefoot orthosis (AFO) (n = 10), and AMC3 used shoes (n = 11). Non-parametric tests were used to compare results between groups. Results: Joint work analysis showed a proximal work shift in all AMC groups wherein the hip accounted for a larger portion of lower extremity positive work than the ankle or knee, primarily in AMC1 (Fig. 1). Hip abduction moment was lower in AMC1 and AMC2 than in TD, though not significantly. Trunk lateral sway and trunk rotation were greater in AMC1 and AMC2 than in AMC3 and TD. Hip flexion moment was lower in AMC1 than in other groups. Less hip extension and greater pelvic tilt were found in all AMC groups than in TD. Knee extension moments were similar between the groups. Discussion: The gait pattern with excessive trunk lateral sway in children walking with orthoses, particularly locked KAFOs, reduces the hip abduction moments. All AMC groups showed less hip extension than TD, but hip flexion moments were reduced only in AMC1, which can be attributed to their gait strategy with bilateral locked KAFOs. Children in AMC1, with weak knee extensors, were helped by their locked KAFOs and therefore showed similar knee extension moment as other groups. The joint work analysis demonstrates AMC children’s high reliance on hip muscles and presumably trunk muscles to provide propulsion, primarily in those walking with locked KAFOs. References [1] Hall J. J Ped Orthop 1997. [2] Eriksson M, et al. J Child Orthop 2010.
with respect to knee flexion during weight bearing [1] which is important to physiologically execute many activities of daily living (ADL). Therefore, the orthotronic mobility system C-Brace was developed employing microprocessor hydraulic stance and swing control. Materials and methods: Two patients using a locked KAFO (LKAFO; one unilateral, one bilateral) and four patients using a stance control orthosis (SCO) for walking were investigated. Tests were conducted with the existing orthosis (baseline) and after a minimum of 7 weeks of C-Brace use. The tests comprised level walking, descending a slope of 10◦ grade, and a stairwell. The measuring technique consisted of two force plates for recording the ground reaction forces (Kistler, sampling rate 1080 Hz) and an optoelectronic 6 camera system for determining kinematic data (Vicon 460, sampling rate 120 Hz). Based on kinematic data and ground reaction forces, the joint moments were calculated [2]. Results: During level walking, the mean time-distanceparameters do not show any significant differences, but 5 of the 6 patients were able to use knee stance flexion (mean knee angle 11◦ ) when using the C-Brace. The mean knee swing flexion angle was 66.6◦ with the C-Brace as compared to 74.0◦ with the SCOs. With the C-Brace, the sound side external joint moments are significantly reduced compared to the LKAFO condition, but do not differ from those with the SCO. With the C-Brace all six patients were able to descend the slope and stairs step over step. Only four patients were able to reciprocally descend the slope, no patient was able to do this on the stairs when using their previous devices. All patients used continuous knee flexion during weight bearing (mean maximum flexion on the slope 65◦ , on the stairs 70◦ ) with the C-Brace. The abnormally high knee extension moments that are unavoidable at ground contact of the sound limb when descending a slope with a SCO/LKAFO were reduced with the C-Brace. Discussion: The present study confirms that the microprocessor hydraulic control of stance and swing phase in the C- Brace supports nearly natural movement patterns on the orthotic side during level walking (use of stance phase flexion, control of swing phase flexion close to the physiological value) as well as controlled knee flexion during weight bearing that offers the patient remarkably increased functional options for walking on slopes and stairs. The nearly natural movement patterns allowed for by the C-Brace suggest that the loads acting on the locomotor system are qualitatively similar to those in healthy individuals. References [1] Zacharias B, Kannenberg A. J Prosth Orthot 2012;24. [2] Bellmann M, et al. Arch Phys Med Rehabil 2010;91:3.
http://dx.doi.org/10.1016/j.gaitpost.2015.06.160 http://dx.doi.org/10.1016/j.gaitpost.2015.06.161
Session OS18 Orthotics The microprocessor controlled C-Brace orthosis and conventional knee–ankle–foot-orthoses: Comparative biomechanical evaluation of functionality T. Schmalz ∗ , E. Pröbsting Ottobock Healthcare, Clinical Research/Biomechanics, Göttingen, Germany Research question: Conventional KAFOs are compared to the C-Brace based on biomechanical parameters measured in ADL situations. Introduction: Patients with pareses or paralysis of the lower limbs often require a knee ankle foot orthosis (KAFO) to restore walking ability. Conventional KAFOs are limited in functionality
Session OS18 Orthotics Optimizing knee kinematics in mid-stance by tuning the ankle foot orthoses-footwear combination of children with cerebral palsy: A case series B. van Beeten 1,∗ , A. Hartman 2 , H. Houdijk 1 1
Rehabilitation Centre Heliomare, Wijk aan Zee, Netherlands 2 Erasmus MC, Rotterdam, Netherlands Research question: Is it necessary and possible to optimize knee kinematics in mid-stance by tuning the ankle foot orthosesfootwear combination of children with cerebral palsy?