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

Reactive Turning Behavior in Older Adults: Age-Related Decrease is Evident under Increased Task Demand

A sudden turn initiated at an unpredictable moment is referred to as reactive turning. This study was designed to seek an age-related decrease in reactive turning when the task demand for turning was increased using a task-switching paradigm. Twenty healthy older adults and 14 younger adults were instructed to walk and execute a 90-degree turn under two conditions. In the "reactive turning condition," participants were asked to turn abruptly when the initially presented travel direction (e.g. right) switched to the opposite direction (e.g. left) while walking. This switch occurred in only one-fifth of 40 trials. In the "pre-planned turning condition," participants were informed of the direction beforehand. The onset of the center of mass (COM) shift in older participants failed to reach significance compared to younger participants. However, correlation analyses showed impaired turning performance in older participants, as those with delayed COM shift exhibited larger pelvic rotations over a short period during reactive turning. This suggests that, owing to increased task demand, older adults had difficulty quickly responding and sufficiently rotating their bodies in the new direction. We conclude that reactive turning with increased task demand, using a task-switching paradigm, is a key factor in detecting age-related performance decline.

Reframing Whole-Body Angular Momentum: Exploring the Impact of Low-Pass Filtered Dynamic Local Reference Frames During Straight-Line and Turning Gaits

Accurately estimating whole-body angular momentum (WBAM) during daily activities may benefit from choosing a locally-defined reference frame aligned with anatomical axes, particularly during activities involving body turns. Local reference frames, potentially defined by pelvis heading angles, horizontal center of mass velocity (vCoM), or average angular velocity ( Aω ), can be utilized. To minimize the impact of inherent mediolateral oscillations of these frames, such as those caused by pelvis or vCoM rotation in the transverse plane, a low-pass filter is recommended. This study investigates how differences among global, local reference frames pre- and post-filtering affect WBAM component distribution across anatomical axes during straight-line walking and various turning tasks, which is lacking in the literature. Results highlighted significant effects of reference frame choice on WBAM distribution in the anteroposterior (AP) and mediolateral (ML) axes in all tasks. Specifically, expressing WBAM in the vCoM-oriented local reference frame yielded significantly lower (or higher) WBAM in the AP (or ML) axes compared to pelvis-oriented and Aω -oriented frames. However, these significant differences disappeared after employing a low-pass filter to local reference frames. Therefore, employing low-pass filtered local reference frames is crucial to enhance their applicability in both straight-line and turning tasks, ensuring more precise WBAM estimates. In applications that require expressing anatomical axes-dependent biomechanical parameters in a local reference frame, pelvis- and vCoM-oriented frames are more practical compared to the A ω -oriented frame, as they can be determined by a reduced optical marker set or inertial sensors in future applications when the whole-body kinematics is not available.

The psychometric properties of the figure-of-eight walk test in people with Parkinson's disease

PURPOSE

To investigate: (1) the interrater, and test-retest reliability of the figure-of-eight walk test (F8WT) in people with Parkinson's disease (PwPD); (2) the minimum detectable change in the F8WT times; (3) the concurrent and known-groups validity of the F8WT times; and (4) the cut-off times that best discriminate PwPD from healthy people and fallers from non-fallers with PD.

METHODS

This was a cross-sectional study. Forty-three PwPD and 34 healthy people were recruited. The F8WT was performed along with the timed up and go test, 10 m walk test, Berg Balance Scale, Activities-Specific Balance Confidence Scale, Unified Parkinson's disease Rating Scale, and Hoehn and Yahr Scale.

RESULTS

The F8WT showed good interrater and test-retest reliability (ICC = 0.964-0.978 and ICC = 0.905-0.920, respectively). The MDC was 2.77 s. The F8WT was correlated with other outcome measures. Significant differences in the F8WT times were found between PwPD and healthy people and between fallers and non-fallers with PD (p < 0.001 and p < 0.001, respectively). The cut-off times of 8.43 s best discriminated PwPD from healthy people, while 11.19 s best discriminated fallers from non-fallers with PD.

CONCLUSIONS

The F8WT is a reliable, valid, and easy-to-administer tool in assessing the walking skill of PwPD.Implications for rehabilitationThe figure-of-eight walk test (F8WT) is a reliable, valid, and clinically available tool for assessing walking skill in Parkinson's disease (PD).The minimal detectable change of the F8WT is 2.77 s, which may help to determine any real change in walking skill after any intervention.The F8WT correlated with functional mobility, gait speed, balance, balance confidence, and severity and stage of PD.The F8WT times may detect impaired walking skill between people with PD and healthy people, and between fallers and non-fallers with PD.

TURN-IT: a novel turning intervention program to improve quality of turning in daily life in people with Parkinson's disease

BACKGROUND

People with Parkinson's disease (PD) have a high fall rate and many falls are associated with turns. Despite this, there is minimal research on effects of rehabilitation on the quality of turns. Further, quantifying turns in the home may have broader implications since rehabilitation of turns would ideally improve turning in real world mobility.

METHODS

Sixty people with PD and a history of falls will be randomized to receive either a novel TURNing InTervention (TURN-IT) or no intervention (control group). The TURN-IT group will be seen for 6 weeks (18 visits) for an individualized, progressive program that is based on the specific constraints of turning in PD. Wearable sensors will be used to measure 7 days of mobility, including turns, before and after intervention or control period. In addition, blinded assessments of gait, mobility and turns will occur before and after intervention for both groups and falls will be monitored for twelve months post intervention with bimonthly email questionnaires.

DISCUSSION

This study has the potential to change how we rehabilitate and assess turning in people with PD and falls. There are several novel aspects to our study including a comprehensive turning-focused intervention that is tailored to the underlying constraints that impair turning in people with PD. Further, our outcome measure of turning quality during 7 days of daily life is novel and has implications for determining real-life changes after rehabilitation. The ultimate goal of this rehabilitation intervention is to improve how patients turn in daily life and to reduce falls.

TRIALS REGISTRATION

This protocol is registered at clinicaltrials.gov; #NCT04897256; https://clinicaltrials.gov/ct2/show/NCT04897256?term=Horak&cond=Parkinson+Disease&draw=2&rank=4 .

Frontal plane balance during pre-planned and late-cued 90 degree turns while walking

This study evaluated frontal-plane dynamic balance control during 90° left turns while walking. Ten healthy young adults performed straight-line gait, pre-planned turns, and turns cued visually (late-cued turns). We quantified rotational balance control via the range of frontal-plane angular momentum (Hf) about the center of mass (COM), and the relative positioning of the COM and the feet using the horizontal distance from the COM to the lateral edge of the base of support (lateral distance) and the mediolateral margin of stability (MOSml). We hypothesized that the Hf range would increase and the lateral distance and MOSml minima would decrease during each turn type vs. straight-line gait and during late-cued vs. pre-planned turns. We found that the range of Hf was significantly greater during each turn type vs. straight-line gait and during late-cued vs. pre-planned turns. Also, the lateral distance minima were significantly smaller during turns vs. straight-line gait, and during pre-planned vs. late-cued turns. Our hypotheses about MOSml were partially supported because the MOSml minima patterns were specific to right or left steps and were not significantly different between straight-line gait and pre-planned turns overall, but the right step's MOSml minima were more negative during late-cued vs. pre-planned turns and between either turn and straight-line gait. Finally, we observed slower gait speeds, fewer footfalls, shorter turn phase duration, and different turn strategies used during late-cued vs. pre-planned turns. Overall, these findings reveal multifaceted control of frontal-plane balance during turns encountered during everyday mobility.

Stereoscopic visual stimuli for examining biological motion perception and unanticipated steering manoeuvres in people with Parkinson's disease

Community falls in people with Parkinson's disease (PwPD) are common, costly, and often unanticipated. Aside from static obstacles, it has been reported that oncoming people in community settings pose problems for PwPD when navigating. This suggests that PwPD may have difficulty (i) perceiving biological motion and action possibilities, and (ii) steering out of the way of oncoming persons. To date, laboratory research that investigated unanticipated steering manoeuvres in PwPD have only incorporated light- or arrow-based visual stimuli to simulate the spatiotemporal demands of these movements. However, such simple stimuli are not ecologically valid for examining biological motion perception and unanticipated steering manoeuvres used in avoiding oncoming people. To improve the generalisability of laboratory research in this field, a set of stereoscopic visual stimuli that feature an oncoming person initiating a sudden change in direction was developed for PwPD to engage with. Specifically, we modified and improved existing cinematographic techniques, software, and stereoscopic display technology to bring about:•Ambulatory scenarios that were quasi-immersed with the laboratory environment.•Enhanced realism.•Better temporal consistency in video playback.

Walking Along Curved Trajectories. Changes With Age and Parkinson's Disease. Hints to Rehabilitation

In this review, we briefly recall the fundamental processes allowing us to change locomotion trajectory and keep walking along a curved path and provide a review of contemporary literature on turning in older adults and people with Parkinson's Disease (PD). The first part briefly summarizes the way the body exploits the physical laws to produce a curved walking trajectory. Then, the changes in muscle and brain activation underpinning this task, and the promoting role of proprioception, are briefly considered. Another section is devoted to the gait changes occurring in curved walking and steering with aging. Further, freezing during turning and rehabilitation of curved walking in patients with PD is mentioned in the last part. Obviously, as the research on body steering while walking or turning has boomed in the last 10 years, the relevant critical issues have been tackled and ways to improve this locomotor task proposed. Rationale and evidences for successful training procedures are available, to potentially reduce the risk of falling in both older adults and patients with PD. A better understanding of the pathophysiology of steering, of the subtle but vital interaction between posture, balance, and progression along non-linear trajectories, and of the residual motor learning capacities in these cohorts may provide solid bases for new rehabilitative approaches.

Mobility improves after high intensity aerobic exercise in individuals with Parkinson's disease

Emerging literature indicates aerobic exercise improves the motor symptoms associated with Parkinson's disease (PD). However, the impact of aerobic exercise on functional locomotor performance has not been evaluated systematically. The aim of this project was to determine the impact of an 8-week high intensity aerobic exercise intervention on Timed Up and Go (TUG) performance in PD. Fifty-nine participants with idiopathic PD completed 24 aerobic exercise sessions over 8 weeks. Two modes of exercise were utilized: forced (FE) and voluntary (VE). A mobile application was used to gather biomechanical data for the characterization of the TUG subtasks: Sit-Stand, Gait, Turning, and Stand-Sit. Participants were assessed in an off medication state at: 1) baseline, prior to any exercise intervention, and 2) after completion of exercise treatment. At baseline, the VE group completed the TUG in 9.41 s, while the FE group completed the TUG significantly faster in 8.0 s. Following the exercise intervention, the VE group decreased TUG time to 8.9 s (p < .01). Both exercise groups demonstrated significant improvements in Turning Velocity, time of Gait phase and Stand-Sit duration. Overall mobility in participants with PD was significantly improved after high intensity aerobic exercise training. Improvements in turning and gait speed, and in Stand-Sit times indicate exercise is effective in improving functional aspects of mobility that are often associated with falls and quality of life measures. These results support the use of high intensity aerobic exercise for improvements in functional lower extremity performance in a PD population.

Three-Dimensional Balance Training Using Visual Feedback on Balance and Walking Ability in Subacute Stroke Patients: A Single-Blinded Randomized Controlled Pilot Trial

BACKGROUND

Trunk-activating exercises for balance are important because trunk weakness is relevant to the functional performance of individuals with stroke. This study aimed to explore the effects of three-dimensional balance training using visual feedback on balance and walking ability in subacute stroke patients.

METHODS

Twenty-four participants with subacute stroke were randomly assigned to the experimental or control group. Each group underwent twenty sessions (30 min/day, 5 days/week for 4 weeks). Patients were assessed using the Berg balance scale, gait parameters (gait speed, cadence, step length, and double-limb support period) using GAITRite, and activity-specific balance confidence score, before and after the intervention.

RESULTS

The three-dimensional balance training using visual feedback exhibited greater changes in the Berg balance scale, gait speed, cadence, step length, double-limb support period, and activity-specific balance confidence compared with the control group. Statistical analyses showed significant differences in Berg balance scale (P = .012; 95% CI, 2.585-6.415), gait speed (P = .001; 95% CI, .079-.155), cadence (P = .001; 95% CI, 1.622-4.392), step length (P = .003; 95% CI, 1.864-3.908), double-limb support period (P = .003; 95% CI, -3.259 to -0.761) and activity-specific confidence (P = .008; 95% CI, 6.964-14.036) between groups.

CONCLUSION

Three-dimensional balance training using visual feedback may be more effective than conventional training in improving balance, walking ability, and activity-specific balance confidence in patients with subacute stroke.

Technology-based assessment of motor and nonmotor phenomena in Parkinson disease

INTRODUCTION

The increasing development and availability of portable and wearable technologies is rapidly expanding the field of technology-based objective measures (TOMs) in neurological disorders, including Parkinson disease (PD). Substantial challenges remain in the recognition of disease phenomena relevant to patients and clinicians, as well as in the identification of the most appropriate devices to carry out these measurements. Areas covered: The authors systematically reviewed PubMed for studies employing technology as outcome measures in the assessment of PD-associated motor and nonmotor abnormalities. Expert commentary: TOMs minimize intra- and inter-rater variability in clinical assessments of motor and nonmotor phenomena in PD, improving the accuracy of clinical endpoints. Critical unmet needs for the integration of TOMs into clinical and research practice are the identification and validation of relevant endpoints for individual patients, the capture of motor and nonmotor activities from an ecologically valid environment, the integration of various sensor data into an open-access, common-language platforms, and the definition of a regulatory pathway for approval of TOMs. The current lack of multidomain, multisensor, smart technologies to measure in real time a wide scope of relevant changes remain a significant limitation for the integration of technology into the assessment of PD motor and nonmotor functional disability.

Dynamic stability and spatiotemporal parameters during turning in healthy young adults

BACKGROUND AND PURPOSE

Turning while walking has a frequent occurrence in daily life. Evaluation of its dynamic stability will facilitate fall prevention and rehabilitation scheme. This knowledge is so limited that we set it as the first aim of this study. Another aim was to investigate spatiotemporal parameters during turning.

METHODS

Fifteen healthy young adults were instructed to perform straight walking, 45° step turn to the left and 45° spin turn to the right at natural speed. Dynamic stability was measured by margin of stability (MoS) in anterior, posterior, left and right direction at each data point where significant differences were detected using 95% bootstrap confidence band. Common spatiotemporal parameters were computed in each condition subdivided into approach, turn and depart phases.

RESULTS

Results showed that minimum anterior MoS appeared at middle of swing while minimum lateral MoS at contralateral heel strike in all conditions. Posterior MoS decreased before middle of turn phase in spin whereas after middle of turn phase in step. Lateral MoS and stride width declined in turn phase of spin while in depart of step. Spin had a long step and stride length. Long swing phases were observed in turns.

CONCLUSIONS

These data help explain that people are most likely to fall forward at middle of swing and to fall toward the back and the support side at heel strike. Our findings demonstrate that instability mainly exist in turn phase of spin and depart phase of step turn.

Medio-lateral stability during walking turns in older adults

Introduction

Medio-lateral stability during walking turns relies on the interaction between precise weight shifts of the body and changes in base of support by regulating step width. Although older adults and clinical populations often slow down while turning in order to compensate for balance impairments, little is known about the influence of walking speed on stability during turning.

Objective

To compare medio-lateral stability between walking turns and straight walking and to investigate whether walking speed affects medio-lateral stability during turning in healthy older adults.

Methods

Nineteen older adults walked straight or walked and turned 180° to the right and left at their comfortable speed and at a slow pace. The walking direction was visually cued before they started to walk (preplanned) or while walking straight (unplanned). As a proxy for medio-lateral stability, we calculated the absolute difference between pelvis lateral displacement and the lateral edge of the base of support during straight walking and turning.

Results

Overall, irrespective of turning condition, medio-lateral stability was enhanced during turning as the pelvis was further away from the boundary of the base of support resulting in a greater margin of stability compared to straight walking. Turning at a slow pace hampered medio-lateral stability as demonstrated by pelvis lateral displacement closer to the boundaries of the base of support resulting in reduced margins of stability. The reduction in stability was caused by a narrower step width during slow walking whereas pelvis lateral displacement was unaffected by turning speed.

Conclusion

In older adults, medio-lateral stability was augmented during turning compared to straight walking, whereas turning at a slow pace hampered medio-lateral stability. These findings provide insights into the postural strategies used by older adults in order to adapt to the postural challenges of turning and straight walking.