Posters / Parkinsonism and Related Disorders 16S1 (2010) S11–S86
combined GPI/PPN DBS. Posture was assessed by the upper body tilt angle (UBTA) in left–right body side for stance phase; to depict gait ignition, maximal rotational angle while turning on the spot (MaxRAWTOTS), mean time for turning 45° (MTT45) and the range of motion for the centre of mass while turning (ROMCOM) were measured. Results: Results are given in table 1. Table 1
PPN DBS only GPI DBS only PPN and GPI DBS
UBTA [°]
MaxRAWTOTS [°]
MTT45 [s]
ROMCOM [mm]
22.3 22.3 16.2
59 29 217
7.2 8.1 1.7
62 200 37
Conclusions: Isolated GPI and PPN DBS had a similar impact on posture, but the combination of both significantly improved the upright posture. Gait ignition was worst with isolated GPI DBS and better with isolated PPN DBS. Again the combined stimulation yielded the biggest benefit. This combined approach may be useful in treating drug-resistant features of advanced PD and encourages future studies.
Rehabilitation – Cognitive 277 RELATION BETWEEN INHIBITORY CONTROL AND IMPROVEMENT IN POSTURAL STABILITY AFTER COGNITIVE DUAL-TASK TRAINING K. Li1,2 , E. Roudaia3 , M. Lussier4,5 , L. Bherer4,5 , A. Leroux6 , P. Mckinley7 . 1 Psychology, Concordia University, 2 Centre for Research in Human Development, Montreal, QC, 3 Psychology, Neuroscience, and Behaviour, McMaster University, Hamilton, ON, 4 Psychologie, Universit´e de Qu´ebec a ` Montr´eal, 5 Institut Universitaire de G´eriatrie 6 de Montr´eal, Exercise Science, 7 Physical and Occupational Therapy, McGill University, Montreal, QC, Canada Background: The present study examined transfer effects of cognitive dual-task training to new pairings of concurrent cognitive and balance tasks. We previously reported group level trainingrelated improvements. Here, we examine the relationship between magnitude of pre–post improvements in cognition and balance and two measures of executive control: inhibition and switching. Methods: Twenty healthy older adults aged 70+ were assigned to either training or control groups. Training consisted of five sessions of computerized cognitive dual-task training spaced over 3 weeks. Subjects performed a color decision (Task A) or a letter identity decision (Task B) either alone or together. At pre- and post-training, we assessed single-leg balance with eyes open, eyes closed, alone or with a concurrent n-back cognitive load. Doublesupport balance was similarly measured. Neuropsychological tests of inhibition (Stroop interference) and task switching (Trail Making) were also assessed before and after training. Results: Pooled across groups, improvement in single-support balance with eyes closed, with 0-back cognitive load, was correlated with improvement in cognitive dual-task performance (r-values ranged from 0.48 to 0.70). Improvement in single-support balance was also positively correlated with improvement in double-support balance under 0-back and 2-back cognitive loads (rs = 0.504 and 0.515). Partialling out pre-to-post changes in inhibitory control, but not task switching, led to reductions in these correlations. Conclusions: These results are in line with current work implicating executive processes in balance control. The results suggest a more central role for inhibitory processes than for task switching in balance.
S79
278 THE THREE-DIMENSIONAL ANALYSIS OF KINEMATIC GAIT PARAMETERS OF SUBJECTS WITH GONARTHROSIS BEFORE AND AFTER TOTAL KNEE REPLACEMENT 2 K. Ogrodzka1 , T. Niedzwiedzki ´ , W. Chwała3 . 1 Department of Rehabilitation in Traumatology, Academy of Physical Education, 2 Orthopedics and Traumatology Clinic, Collegium Medicum UJ, 3 Department of Biomechanics, Academy of Physical Education, Cracow, Poland Background and Aims: The aim of the studies was an attempt to evaluate the variability of parameters of the lower limb joints of subjects before and after total knee replacement and its influence on ankle and hip joints. Angular values changes were studied in three planes of movement. Spatiotemporal parameters were also taken into consideration. Studies on the locomotion were carried out on 27 gonarthrosis subjects aged from 60 to 74. The control group consisted of 30 healthy persons aged 50–70, the so-called biomechanical norm. Methods: The gait was examined with the use of a computer system of three-dimensional movement analysis Vicon 250. Results: The limitations of extension in hip and knee joints have been observed. The varus arrangement and external rotation of knee joints has been visible. There have been no plantar flexion ankle joints at the beginning of swing phase. After total knee replacement the arrangement of hip and knee joints has improved insignificantly. The varus alignment has decreased but the external rotation has increased. There have been no changes in ankle joints function. The analysis of spatiotemporal parameters has shown diminished cadence and walking speed and shortened stride length. However the double support phase and stride time have been lengthened. After knee arthroplasty spatiotemporal parameters have been improved slightly. Conclusions: Before knee arthroplasty patients have unsettled gait pattern, which has slightly changed after operation. This is probably the result of compensatory gait mechanism which has arosen before knee arthroplasty due to pain ailments.
Rehabilitation – Physical 279 VISUAL FEEDBACK TO IMPROVE POSTURAL CONTROL DURING LOCOMOTION IN THE HEALTHY ELDERLY E. Anson, P. Agada, H. Fleming, T. Kiemel, J. Jeka. Kinesiology, University of Maryland, College Park, MD, USA Introduction: Visual biofeedback for rehabilitation of balance is well studied, with varied results depending on the outcome variable measured. Use of visual feedback for balance control during locomotion has not been reported. We developed a visual feedback system that provides center of mass position feedback while walking on a treadmill. Preliminary results indicate that in healthy young adults, visual feedback leads to reduced power at low frequencies of body sway compared to no-visual feedback conditions, suggesting that visual feedback is useful for improved control of body sway during locomotion. We demonstrate here that the same effect is not consistently preserved in healthy older adults. Methods: Unilateral kinematic data for 3 healthy older adults was collected during locomotion trials on a treadmill at their comfortable speed, determined as the average of the slowest and fastest speeds reported as comfortable by each subject. Each subject completed five repetitions of two conditions: feedback or nofeedback. Power spectral densities were computed to characterize movement at all frequencies of motion. Results: Preliminary results indicate few differences in the spectral power when comparing the feedback and no feedback conditions.