Pre- and unplanned walking turns in Parkinson’s disease – Effects of dopaminergic medication

Abstract

Although dopaminergic medication improves functional mobility in individuals with Parkinson's disease (PD), its effects on walking turns are uncertain. Our goals was to determine whether dopaminergic medication improves preplanned and unplanned walking turns in individuals with PD, compared to healthy controls. Nineteen older adults with mild-to-moderate PD and 17 healthy controls performed one of the following three tasks, presented randomly: walking straight, or walking and turning 180° to the right or left. The walking direction was visually cued before starting to walk (preplanned) or after (unplanned, i.e., 0.6m before reaching the turning point). Subjects with PD were assessed off dopaminergic medication (OFF) and on dopaminergic medication (ON) medication. Turning strategy (step and spin turns), turning performance (turning distance and body rotation) and walking pattern were analyzed for three turning steps. Irrespective of medication state and turning condition, step and spin turns followed a nearly 50:50 distribution. After intake of dopaminergic medication, subjects with PD increased their turning distance but not the amount of body rotation or their walking pattern. Compared to controls, turning impairments in subjects with PD remained while ON medication and problems regulating step width were the most prominent features of their walking pattern. Specifically, subjects with PD turned with narrower cross-over steps, i.e. when the external foot crossed over the line of progression of the internal leg. We conclude that turning impairments remained even after dopaminergic medication and problems modulating step width appears to be a critical feature for turning in PD.

Dynamic stability and spatiotemporal parameters during turning in healthy young adults

“…In contrast, spin turn phase was a great deal narrower whereas depart somewhat wider. This is in keeping with [ 8 , 12 ]. We believe that this is the two natural cooperating strategies for the bilateral lower limbs to complete the turn within only three steps.…”

“…For people with poor balance function, turning gait might expose potential problems which are undetectable in straight walking. This work could provide a valuable reference for rehabilitation evaluation and training for patients with cerebral palsy [ 9 ], post-stroke hemiparesis [ 46 , 47 ], Parkinson’s disease [ 12 , 23 ], or multiple sclerosis [ 29 ]. For example, they could be trained from straight walking to step turn and spin turn, for gradual adaptation of gait stability and spatiotemporal parameters.…”

“…Akram et al [ 11 ] found that healthy older adults (n = 19, age = 66 ± 4.2 years) preferred spin turns, whereas step turns were preferred only in 90° turns while walking fast. But Conradsson et al [ 12 ] revealed that step and spin turns followed a nearly 50:50 distribution during 90° turns both for 19 individuals with Parkinson’s disease (age = 72 ± 4 years) and for 17 age and gender matched healthy controls. Now, the reason for the turning preference is still unknown, although some studies [ 8 , 12 – 14 ] have investigated the kinematics and kinetics during turning in people of different age groups.…”

“…Based on the inverted pendulum model of balance, MoS can be used to assess gait stability for straight walking, for starting and stopping walking and for turning [ 22 ], and is much more convincing than the static method by considering both the relative position and velocity between CoM and BoS [ 18 ]. However, most studies investigating turning gait stability either assessed static stability, such as distance between the ankles [ 13 , 23 ], stride width [ 12 , 24 ] and distance between CoM and BoS [ 9 , 13 , 23 , 24 ], or did not compare dynamic stability between two turning strategies and straight walking [ 9 , 23 ]. For example, spin turns are generally considered less stable and demanding a higher biomechanical cost than step turns, mainly because Taylor et al [ 13 ] indicated that the spin turn had a narrow BoS leading to CoM outside displacement and required increased joint moments and power, compared to the step turn and straight gait.…”

Medio-lateral stability during walking turns in older adults

“…Participants walked at their self-selected comfortable speed along a 9-metre walking lane where the turning position was marked by two poles [ 19 ]. The following tasks were performed: walking and turning 180° to the right or to the left, or walking straight.…”