Stride length regulation in Parkinson's disease

Abstract

Results of our previous studies have shown that the slow, shuffling gait of Parkinson's disease patients is due to an inability to generate appropriate stride length and that cadence control is intact and is used as a compensatory mechanism. The reason for the reduced stride length is unclear, although deficient internal cue production or inadequate contribution to cortical motor set by the basal ganglia are two possible explanations. In this study we have examined the latter possibility by comparing the long-lasting effects of visual cues in improving stride length with that of attentional strategies. Computerized stride analysis was used to measure the spatial (distance) and temporal (timing) parameters of the walking pattern in a total of 54 subjects in three separate studies. In each study Parkinson's disease subjects were trained for 20 min by repeated 10 m walks set at control stride length (determined from control subjects matched for age, sex and height), using either visual floor markers or a mental picture of the appropriate stride size. Following training, the gait patterns were monitored (i) every 15 min for 2 h; (ii) whilst interspersing secondary tasks of increasing levels of complexity; (iii) covertly, when subjects were unaware that measurement was taking place. The results demonstrated that training with both visual cues and attentional strategies could maintain normal gait for the maximum recording time of 2 h. Secondary tasks reduced stride length towards baseline values as did covert monitoring. The findings confirm that the ability to generate a normal stepping pattern is not lost in Parkinson's disease and that gait hypokinesia reflects a difficulty in activating the motor control system. Normal stride length can be elicited in Parkinson's disease using attentional strategies and visual cues. Both strategies appear to share the same mechanism of focusing attention on the stride length. The effect of attention appears to require constant vigilance to prevent reverting to more automatic control mechanisms.

At-home training with closed-loop augmented-reality cueing device for improving gait in patients with Parkinson disease

“…He suggested that the placement of visual cues perpendicular to the direction of gait spaced one step length apart were most effective in improving gait in patients with PD. Many single-session studies have confirmed the benefit of visual cues (high-contrast transverse floor lines) [21][22][23][24]. However these open-loop feedback systems may not have long-term effects [25] unless a dedicated physical training program is established, as demonstrated in a patient trained to walk on floor cues reaching 120 percent of the uncued stride length over a 1-month period [26].…”

Effects of cognitive task on gait initiation in Parkinson disease: Evidence of motor prioritization?

“…This finding is quite surprising in the PD group, because the detrimental impact of secondary cognitive tasks on previously examined motor tasks, such as standing balance and gait, is robust [19]. It has been hypothesized that the reduction in gait performance and arrhythmicity of gait under a dualtask condition is due to individuals with PD recruiting attentional resources for gait, specifically the frontal-cortical regions, to compensate for the damaged automaticity of gait [20]. Because of limited cognitive resources and the neurodegenerative nature of the disease, the ability to recruit attentional resources is limited, particularly during a dual task and, as such, performance suffers.…”

A novel cognitive cueing approach to gait retraining in Parkinson’s disease: A pilot study

“…Despite the neuropathology of the disease, evidence suggests that individuals with PD are capable of improving their gait via motor learning strategies (Felix et al, 2012;Fok, Farrell, McMeeken, & Kuo, 2011;Pendt, Reuter, & Müller, 2011;Rochester et al, 2010;Werner & Gentile, 2010), as evidenced by the fact that exercise and movement strategy training have been found collectively to contribute to improvements in gait (Rochester, Nieuwboer, & Lord, 2011). For example, research focused on the nonpharmacological management of gait impairment in PD has found that the use of external cues is generally effective (Morris, Iansek, Matyas, & Summers, 1996;Rochester et al, 2010;Rochester et al, 2005;Spaulding et al, 2012).…”

“…A potential drawback of this approach, however, is that these strategies typically require assistive devices (e.g., a cane with laser lights or listening devices with rhythmic auditory signals) that may be expensive and impractical in certain environments. Moreover, results have predominantly shown only short-term benefits of lab-based external cueing of this nature (Morris et al, 1996;Rochester et al, 2010).…”

“…Fok, Farrel, McMeeken, and Kuo (2011) completed a systematic review of the literature that explored the effects of verbal instructions on gait among individuals with PD. In their review, Fok et al (2011) identified 13 studies that examined either independently or in combination one the following sets of verbal cues: (a) "walk fast" (Behrman, Teitelbaum, & Cauraugh, 1998;Ferrandez & Blin, 1991;Morris, Iansek, Matyas, & Summers, 1994), (b) "take big steps" (Baker, Rochester, & Nieuwboer, 2007Behrman et al, 1998;Canning, 2005;Iansek, Huxham, & McGinley, 2006;Lehman, Toole, Lofald, & Hirsch, 2005;Morris et al, 1996;Werner & Gentile, 2003), (c) "walk fast and take big steps" (Canning, Ada, & Woodhouse, 2008), (d) "swing arms while walking" (Werner & Gentile, 2003), and (e) "count rhythm while walking" (Behrman et al, 1998). While 11 of these studies examined the immediate effects of employing the instructional sets in a single laboratory-based testing session, Canning et al (2008) and Lehman et al (2005) investigated the effects of weekly training sessions.…”