@article{PalmisanoKullmannHanafietal.2022,
  author    = {Palmisano, Chiara and Kullmann, Peter and Hanafi, Ibrahem and Verrecchia, Marta and Latoschik, Marc Erich and Canessa, Andrea and Fischbach, Martin and Isaias, Ioannis Ugo},
  title     = {A fully-immersive virtual reality setup to study gait modulation},
  series = {Frontiers in Human Neuroscience},
  volume    = {16},
  journal   = {Frontiers in Human Neuroscience},
  issn      = {1662-5161},
  doi       = {10.3389/fnhum.2022.783452},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267099},
  year      = {2022},
  abstract  = {Objective: Gait adaptation to environmental challenges is fundamental for independent and safe community ambulation. The possibility of precisely studying gait modulation using standardized protocols of gait analysis closely resembling everyday life scenarios is still an unmet need. Methods: We have developed a fully-immersive virtual reality (VR) environment where subjects have to adjust their walking pattern to avoid collision with a virtual agent (VA) crossing their gait trajectory. We collected kinematic data of 12 healthy young subjects walking in real world (RW) and in the VR environment, both with (VR/A+) and without (VR/A-) the VA perturbation. The VR environment closely resembled the RW scenario of the gait laboratory. To ensure standardization of the obstacle presentation the starting time speed and trajectory of the VA were defined using the kinematics of the participant as detected online during each walking trial. Results: We did not observe kinematic differences between walking in RW and VR/A-, suggesting that our VR environment per se might not induce significant changes in the locomotor pattern. When facing the VA all subjects consistently reduced stride length and velocity while increasing stride duration. Trunk inclination and mediolateral trajectory deviation also facilitated avoidance of the obstacle. Conclusions: This proof-of-concept study shows that our VR/A+ paradigm effectively induced a timely gait modulation in a standardized immersive and realistic scenario. This protocol could be a powerful research tool to study gait modulation and its derangements in relation to aging and clinical conditions.},
  language  = {en}
}
@article{DipaolaPavanCattaneoetal.2016,
  author    = {Dipaola, Mariangela and Pavan, Esteban E. and Cattaneo, Andrea and Frazzitta, Giuseppe and Pezzoli, Gianni and Cavallari, Paolo and Frigo, Carlo A. and Isaias, Ioannis U.},
  title     = {Mechanical Energy Recovery during Walking in Patients with Parkinson Disease},
  series = {PLoS ONE},
  volume    = {11},
  journal   = {PLoS ONE},
  number    = {6},
  doi       = {10.1371/journal.pone.0156420},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-179739},
  year      = {2016},
  abstract  = {The mechanisms of mechanical energy recovery during gait have been thoroughly investigated in healthy subjects, but never described in patients with Parkinson disease (PD). The aim of this study was to investigate whether such mechanisms are preserved in PD patients despite an altered pattern of locomotion. We consecutively enrolled 23 PD patients (mean age 64±9 years) with bilateral symptoms (H\&Y ≥II) if able to walk unassisted in medication-off condition (overnight suspension of all dopaminergic drugs). Ten healthy subjects (mean age 62±3 years) walked both at their 'preferred' and 'slow' speeds, to match the whole range of PD velocities. Kinematic data were recorded by means of an optoelectronic motion analyzer. For each stride we computed spatio-temporal parameters, time-course and range of motion (ROM) of hip, knee and ankle joint angles. We also measured kinetic (Wk), potential (W\(_{p}\)), total (W\(_{totCM}\)) energy variations and the energy recovery index (ER). Along with PD progression, we found a significant correlation of W\(_{totCM}\) and W\(_{p}\) with knee ROM and in particular with knee extension in terminal stance phase. W\(_{k}\) and ER were instead mainly related to gait velocity. In PD subjects, the reduction of knee ROM significantly diminished both W\(_{p}\) and W\(_{totCM}\). Rehabilitation treatments should possibly integrate passive and active mobilization of knee to prevent a reduction of gait-related energetic components.},
  language  = {en}
}
@article{IsaiasDipaolaMichietal.2014,
  author    = {Isaias, Ioannis Ugo and Dipaola, Mariangela and Michi, Marlies and Marzegan, Alberto and Volkmann, Jens and Rodocanachi Roidi, Mariana L. and Frigo, Carlo Albino and Cavallari, Paolo},
  title     = {Gait Initiation in Children with Rett Syndrome},
  series = {PLoS ONE},
  volume    = {9},
  journal   = {PLoS ONE},
  number    = {4},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0092736},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119789},
  pages     = {e92736},
  year      = {2014},
  abstract  = {Rett syndrome is an X-linked neurodevelopmental condition mainly characterized by loss of spoken language and a regression of purposeful hand use, with the development of distinctive hand stereotypies, and gait abnormalities. Gait initiation is the transition from quiet stance to steady-state condition of walking. The associated motor program seems to be centrally mediated and includes preparatory adjustments prior to any apparent voluntary movement of the lower limbs. Anticipatory postural adjustments contribute to postural stability and to create the propulsive forces necessary to reach steady-state gait at a predefined velocity and may be indicative of the effectiveness of the feedforward control of gait. In this study, we examined anticipatory postural adjustments associated with gait initiation in eleven girls with Rett syndrome and ten healthy subjects. Muscle activity (tibialis anterior and soleus muscles), ground reaction forces and body kinematic were recorded. Children with Rett syndrome showed a distinctive impairment in temporal organization of all phases of the anticipatory postural adjustments. The lack of appropriate temporal scaling resulted in a diminished impulse to move forward, documented by an impairment in several parameters describing the efficiency of gait start: length and velocity of the first step, magnitude and orientation of centre of pressure-centre of mass vector at the instant of (swing-)toe off. These findings were related to an abnormal muscular activation pattern mainly characterized by a disruption of the synergistic activity of antagonistic pairs of postural muscles. This study showed that girls with Rett syndrome lack accurate tuning of feedforward control of gait.},
  language  = {en}
}