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Trunk-thigh coordination pattern in ataxic patients
S18
Abstracts / Gait & Posture 42S (2015) S1–S27
Discussion: The results of posturographic analysis suggested that the posture control showed by children with blindness is not due to a balance deficit but is compatible with that of normal sighted children when they close their eyes. These results, in association with reduced thorax anterior-flexion, reduced pelvic anterior tilt, reduced ground reaction force and ankle maximum angle, moment and power in late stance, previously described [3] support the hypothesis of a reduced forward dynamic projection of the body. Overall our findings did not prove the presence of balance deficit in blind children but can be explained by the lack of visually driven anticipatory control mechanisms. References [1] Nakamura T. Disabil Rehabil 1997;19:194–7. [2] Hallemans A, et al. Gait Posture 2010;32:547–51. [3] Gazzellini S, et al. The impact of vision on the dynamic characteristics of the gait: strategies in children with congenital blindness. In: 1st clinical movement analysis world conference. 2014.
http://dx.doi.org/10.1016/j.gaitpost.2015.07.040
the ten CRP curves of each subject. ND and the CMC values were used to describe differences of coordination between groups. Results: Gait speed was matched between the groups, the mean speed values were 0.62 ± 0.11 m/s in the controls and 0.53 ± 0.25 m/s in patients (p > 0.05). We found that one and two discontinuities were more frequent in the control group (respectively p: 0.017 and p < 0.001) than in ataxic patients. Three or more discontinuities were more frequent in the ataxic group (p: 0.015). CMC analysis revealed a higher within-subject variability in the patient sample (CMC: 0.48 ± 0.24) than in control group (CMC: 0.87 ± 0.12) (p: 0.001). Discussion: Our data assessed an impaired coordination between trunk and thigh in ataxia. In fact, in the sample of patients, we found an increased dissimilarity between the phase-plots of trunk and thigh than healthy subjects. Moreover, the variability in coordination was much more evident in patients. These findings suggest a dual mode loss of coordination which appears distorted and extremely variable. We think that these patterns should be taken into account in planning an effective rehabilitative program in these patients.
O27 Trunk-thigh coordination pattern in ataxic patients Chiara Iacovelli 1,2,∗ , Carmela Conte 1 , Mariano Serrao 3 , Luca Padua 1,2 , Gabriella Silvestri 1 , Carlo Casali 3 , Giuseppe Reale 2 , Chiara Simbolotti 1 , Paolo Maria Rossini 2,4 , Pietro Caliandro 1,2 1
Don Carlo Gnocchi Onlus Foundation, Milan, Italy 2 Institute of Neurology, Department Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy 3 Department of Medical and Surgical Sciences and Biotechnologies, University of Rome Polo Pontino, Latina, Italy 4 IRCSS S. Raffaele Pisana Roma, Rome, Italy
References [1] Serrao M, et al. Cerebellum 2012;11:194–211. [2] Conte C, et al. Cerebellum 2014;13:689–97. [3] Haddad JM, et al. Gait Posture 2006;23:429–34.
http://dx.doi.org/10.1016/j.gaitpost.2015.07.041 O28 Ergonomic assessment of an active pelvis orthosis Nicolò d’Elia 1,∗ , Federica Vannetti 3 , Marco Cempini 1 , Guido Pasquini 3 , Marco Rabuffetti 2 , Maurizio Ferrarin 2 , Raffaele Molino Lova 3 , Nicola Vitiello 1,3 1
Introduction: Cerebellar ataxia is characterized by abnormal oscillation of the upper body trunk, impaired lower limb coordination and marked variability of kinematic and spatio-temporal gait parameters [1]. Coordination between the different segments of the body is pivotal in maintaining the efficiency of gait and in this regard the control of trunk may have a significant role [2]. Nowadays no data are available on the coordination between trunk and thigh in ataxia. We hypothesized an impaired relationship between upper and lower body segments in ataxic patients during gait and to verify our hypothesis we estimated the trunk-thigh coordination in ataxic gait and its variability during different gait trials. Methods: We enrolled 16 patients with primary degenerative cerebellar ataxia (9 M, 7 F; mean age, 52.8 ± 11.3 years; range, 31–70 years) and sixteen age-and sex-matched healthy subjects (10 M, 6 F; mean age, 52.5 ± 15.4 years, range 29–76 years). In this experimental procedure, subjects were required to walk barefoot along 6 meters walkway. Gait was analyzed by an optoelectronic system with 8 infrared cameras. We used the Davis model that includes 22 markers. We calculated the position-velocity phase plot of trunk and thigh and evaluated the coordination between the two segments on the sagittal plane by the continuous relative phase (CRP). CRP is defined as the difference between phase angles of the two segments in each instant and allows to describe, continuously during a gait cycle, the relationship between trunk and thigh. We used the number of discontinuity (ND) in ten CRP curves of each subject to describe the pattern of coordination [3]. Furthermore, in order to determine the within-subjects variability of coordination we calculated the coefficient of multiple correlation (CMC) between
The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy 2 Fondazione Don Carlo Gnocchi IRCCS, Milan, Italy 3 Fondazione Don Carlo Gnocchi IRCCS, Florence, Italy Introduction: Safety, comfort and ergonomics are critical features in the design of robotic exoskeletons, since they inherently interact with the user. These devices are designed to transfer mechanical power at the joint level, thus requiring an optimal kinematic coupling between robot and wearer rotational joint axes. Axes misalignments may cause undesired overloads on the articulations, pressure sores at the human-robot interface and unreliable torque transmission [1]. Usually, passive degrees of freedom (DoFs) are added in parallel to human limbs in order to avoid both axes misalignments and instability at the human–robot interface [2]. As a consequence, relevant to the development process of a robotic exoskeleton is the assessment of its kinematic compatibility with the end-user biomechanics. In this abstract we investigate the effects of an active pelvis orthosis (APO) onto the human kinematics under different modalities of use. The APO was designed to assist the hip flexion/extension (f/e), and is endowed with a chain of passive DoFs for a free abduction/adduction (a/a) and internal/external rotation (i/e). Methods: Five healthy subjects walked on a treadmill at three different speeds (V1, V2, V3) and under five modalities, namely: without the APO (NE), wearing the APO in zero-torque control mode, i.e. transparent mode (TM), and in assistive mode with three different levels of assistance (AM1, AM2, AM3). APO sensors
Abstracts / Gait & Posture 42S (2015) S1–S27
Discussion: The results of posturographic analysis suggested that the posture control showed by children with blindness is not due to a balance deficit but is compatible with that of normal sighted children when they close their eyes. These results, in association with reduced thorax anterior-flexion, reduced pelvic anterior tilt, reduced ground reaction force and ankle maximum angle, moment and power in late stance, previously described [3] support the hypothesis of a reduced forward dynamic projection of the body. Overall our findings did not prove the presence of balance deficit in blind children but can be explained by the lack of visually driven anticipatory control mechanisms. References [1] Nakamura T. Disabil Rehabil 1997;19:194–7. [2] Hallemans A, et al. Gait Posture 2010;32:547–51. [3] Gazzellini S, et al. The impact of vision on the dynamic characteristics of the gait: strategies in children with congenital blindness. In: 1st clinical movement analysis world conference. 2014.
http://dx.doi.org/10.1016/j.gaitpost.2015.07.040
the ten CRP curves of each subject. ND and the CMC values were used to describe differences of coordination between groups. Results: Gait speed was matched between the groups, the mean speed values were 0.62 ± 0.11 m/s in the controls and 0.53 ± 0.25 m/s in patients (p > 0.05). We found that one and two discontinuities were more frequent in the control group (respectively p: 0.017 and p < 0.001) than in ataxic patients. Three or more discontinuities were more frequent in the ataxic group (p: 0.015). CMC analysis revealed a higher within-subject variability in the patient sample (CMC: 0.48 ± 0.24) than in control group (CMC: 0.87 ± 0.12) (p: 0.001). Discussion: Our data assessed an impaired coordination between trunk and thigh in ataxia. In fact, in the sample of patients, we found an increased dissimilarity between the phase-plots of trunk and thigh than healthy subjects. Moreover, the variability in coordination was much more evident in patients. These findings suggest a dual mode loss of coordination which appears distorted and extremely variable. We think that these patterns should be taken into account in planning an effective rehabilitative program in these patients.
O27 Trunk-thigh coordination pattern in ataxic patients Chiara Iacovelli 1,2,∗ , Carmela Conte 1 , Mariano Serrao 3 , Luca Padua 1,2 , Gabriella Silvestri 1 , Carlo Casali 3 , Giuseppe Reale 2 , Chiara Simbolotti 1 , Paolo Maria Rossini 2,4 , Pietro Caliandro 1,2 1
Don Carlo Gnocchi Onlus Foundation, Milan, Italy 2 Institute of Neurology, Department Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy 3 Department of Medical and Surgical Sciences and Biotechnologies, University of Rome Polo Pontino, Latina, Italy 4 IRCSS S. Raffaele Pisana Roma, Rome, Italy
References [1] Serrao M, et al. Cerebellum 2012;11:194–211. [2] Conte C, et al. Cerebellum 2014;13:689–97. [3] Haddad JM, et al. Gait Posture 2006;23:429–34.
http://dx.doi.org/10.1016/j.gaitpost.2015.07.041 O28 Ergonomic assessment of an active pelvis orthosis Nicolò d’Elia 1,∗ , Federica Vannetti 3 , Marco Cempini 1 , Guido Pasquini 3 , Marco Rabuffetti 2 , Maurizio Ferrarin 2 , Raffaele Molino Lova 3 , Nicola Vitiello 1,3 1
Introduction: Cerebellar ataxia is characterized by abnormal oscillation of the upper body trunk, impaired lower limb coordination and marked variability of kinematic and spatio-temporal gait parameters [1]. Coordination between the different segments of the body is pivotal in maintaining the efficiency of gait and in this regard the control of trunk may have a significant role [2]. Nowadays no data are available on the coordination between trunk and thigh in ataxia. We hypothesized an impaired relationship between upper and lower body segments in ataxic patients during gait and to verify our hypothesis we estimated the trunk-thigh coordination in ataxic gait and its variability during different gait trials. Methods: We enrolled 16 patients with primary degenerative cerebellar ataxia (9 M, 7 F; mean age, 52.8 ± 11.3 years; range, 31–70 years) and sixteen age-and sex-matched healthy subjects (10 M, 6 F; mean age, 52.5 ± 15.4 years, range 29–76 years). In this experimental procedure, subjects were required to walk barefoot along 6 meters walkway. Gait was analyzed by an optoelectronic system with 8 infrared cameras. We used the Davis model that includes 22 markers. We calculated the position-velocity phase plot of trunk and thigh and evaluated the coordination between the two segments on the sagittal plane by the continuous relative phase (CRP). CRP is defined as the difference between phase angles of the two segments in each instant and allows to describe, continuously during a gait cycle, the relationship between trunk and thigh. We used the number of discontinuity (ND) in ten CRP curves of each subject to describe the pattern of coordination [3]. Furthermore, in order to determine the within-subjects variability of coordination we calculated the coefficient of multiple correlation (CMC) between
The BioRobotics Institute, Scuola Superiore Sant’Anna, Pisa, Italy 2 Fondazione Don Carlo Gnocchi IRCCS, Milan, Italy 3 Fondazione Don Carlo Gnocchi IRCCS, Florence, Italy Introduction: Safety, comfort and ergonomics are critical features in the design of robotic exoskeletons, since they inherently interact with the user. These devices are designed to transfer mechanical power at the joint level, thus requiring an optimal kinematic coupling between robot and wearer rotational joint axes. Axes misalignments may cause undesired overloads on the articulations, pressure sores at the human-robot interface and unreliable torque transmission [1]. Usually, passive degrees of freedom (DoFs) are added in parallel to human limbs in order to avoid both axes misalignments and instability at the human–robot interface [2]. As a consequence, relevant to the development process of a robotic exoskeleton is the assessment of its kinematic compatibility with the end-user biomechanics. In this abstract we investigate the effects of an active pelvis orthosis (APO) onto the human kinematics under different modalities of use. The APO was designed to assist the hip flexion/extension (f/e), and is endowed with a chain of passive DoFs for a free abduction/adduction (a/a) and internal/external rotation (i/e). Methods: Five healthy subjects walked on a treadmill at three different speeds (V1, V2, V3) and under five modalities, namely: without the APO (NE), wearing the APO in zero-torque control mode, i.e. transparent mode (TM), and in assistive mode with three different levels of assistance (AM1, AM2, AM3). APO sensors