Parkinson's Disease and Segmental Coordination during Turning: I. Standing Turns

Abstract

ABSTRACT:Objective: Many of the falls among people with Parkinson's disease (PD) occur during sudden, on-the-spot turning which requires systematic reorientation of axial segments towards the new direction. We examined whether a disturbance in the coordination of segmental reorientation is an important cause of turning difficulty in individuals with PD and is altered by dopaminergic medication. Methods: the sequence and timing of segmental reorientation during 45° and 90° on-the-spot turns was examined in fourteen individuals with PD while "off" and "on" medication and nineteen healthy controls (HC). Results: Regardless of the magnitude of the turn, HC reoriented their head, shoulder, and pelvis simultaneously followed by mediolateral foot displacement. PD patients displayed temporal coordination patterns similar to the HC. PD however, reduced the velocity and early magnitude of reorientation of each body segment which were both slightly improved by dopaminergic medication. Conclusion: Our finding that the HC and PD patients turn en bloc when the turn is predictable and there are no time constraints shows that the strategy of en bloc turning is not wrong if the movement parameters are unconstrained. However, in real life situations, which usually require quick and unpredictable turns, the en bloc strategy may be unsafe and more likely to result in falls. While in such situations HC are able to change the strategy from en bloc to sequential segmental turning, PD patients may not be able to do so and continue to turn en bloc. RÉSUMÉ: Maladie de Parkinson et coordination segmentaire au cours des changements de direction : I. les changements de direction sur place.Objectif : Plusieurs chutes chez les parkinsoniens surviennent pendant un changement de direction subit, sur place, qui requiert une réorientation systématique des segments axiaux vers une nouvelle direction. nous avons examiné si une perturbation de la coordination de la réorientation segmentaire est une cause importante des difficultés éprouvées par les parkinsoniens quand ils changent de direction et si la médication dopaminergique les modifient. Méthode : La séquence et la chronologie de la réorientation segmentaire au cours de changements de direction sur place à 45° et à 90°o nt été examinées chez 14 parkinsoniens sous médication en phase « off » et en phase « on » et chez 19 sujets témoins en bonne santé. Résultats : Quelle que soit l'ampleur du changement de direction, les sujets témoins réorientaient leur tête, leurs épaules et leur bassin simultanément et ceci était suivi d'un déplacement médio-latéral des pieds. Chez les parkinsoniens, la séquence temporelle de la coordination était semblable à celle des témoins. Cependant, au début du mouvement, la vitesse et l'ampleur de la réorientation de chaque segment corporel étaient diminuées chez les parkinsoniens. Ceci était amélioré légèrement par la médication dopaminergique. Conclusion : notre observation que les sujets témoins et les parkinsoniens tournent en bloc quand le changement de direction e...

A narrative review of turning deficits in people with Parkinson’s disease

“…The axial deficits include segment rigidity [4,13,24,25,38], altered trunk segment co-ordination [6,8,18,22,27,29,38,39] and timing [6,8,9,14,19,25,26,32,33], reduced segment rotation [9,14,22,27] and altered posture [2,5,7] (Table 2). Each deficit, alongside their interactions and clinical implications, will be discussed in this review.…”

“…(ii) Axial deficit -Segment coordination and timing When turning, people with PD have consistently shown linked movement of the head, trunk and pelvis in a characteristic ''enbloc'' appearance [6,8,17,22,27,29,45]. In comparison, healthy young controls demonstrate a reciprocal oscillating pattern of movement, with movement of one segment resulting in co-ordinated counterbalancing in the next [16,20], also retained in healthy older adults during walking turns [17,22].…”

“…Such motor deficits commonly lead to poor performance in measures of balance and functional tasks, and have been associated with generalised deficits of attention and falls [3]. Difficulties with turning around the longitudinal axis are a common and early feature of PD, and can be present while lying recumbent [4], seated [5], standing [6][7][8][9][10][11][12][13][14][15] or walking [9][10][11][12][13][14][15][16][17][18][19].…”

“…Healthy young and older adults engage in cranio-caudal sequences of movement to turn while walking, with head rotation leading, then trunk and then pelvis rotation to re-orientate the body towards the new direction [9,20] resulting in inter-segmental reciprocal movements [16]. This is not the case in people with PD, who demonstrate a loss of axial rotation of the spine [21], with little dissociation between the head, trunk and lower limbs [8], which results in a decreased inter-segmental coordination producing an ''enbloc'' turn [8,22], i.e. a turn which has been described as ''nearly simultaneous rotation of head and trunk and decreased relative head excursion after the second turning step'' [22].…”

“…a turn which has been described as ''nearly simultaneous rotation of head and trunk and decreased relative head excursion after the second turning step'' [22]. Whilst some studies have also found the presence of an ''enbloc'' turn in the healthy elderly [8], kinematic analysis of body segment movements during turning reveals clear abnormalities within the ''enbloc'' turn in people with PD, including head-on-trunk turning [9,23,24], trunk-on-hip turning [5,6], whole body turning [19,25], stepping of the feet [9,10,12,15,16,22,[25][26][27][28][29], turning step strategy [10,16,28,30,31] and timing of the turn [14,17,19,25,26,32,33]. Globally, the characteristic Parkinsonian turn from a standing start involves at least four steps over two seconds prior to forward gait, the quality is poor with reference to independence, continuity, ground clearance, stability and posture, and differences between turning directions are marked [34].…”