, attention, and mobility ( Antonio & Perry, 2014 ), which leads to stair-related injuries, medical emergencies ( Blazewick, Chounthirath, Hodges, Collins, & Smith, 2017 ), or death ( Startzell, Owens, & Cavanagh, 2000 ). Meanwhile, almost 21% of older adults experienced a fall under the dual-task condition
Cui Zhang, Qipeng Song, Wei Sun and Yu Liu
Daniel Hamacher, Dennis Hamacher, Roy Müller, Lutz Schega and Astrid Zech
the variability of MTC. Dual-task costs during walking (e.g., deterioration of gait variability in a dual-task situation compared with normal walking) are often used to determine gait automaticity ( Clark, 2015 ). Although the variability of stride length or stride time increases during dual-task
David R. Howell, Thomas A. Buckley, Brant Berkstresser, Francis Wang and William P. Meehan III
systematic review articles by different authors. 5 – 8 Existing data indicate that during dual-task gait, defined as asking a patient to concurrently perform 2 separate tasks (motor and cognitive) simultaneously, those with a concussion have decreased gait stability relative to controls 6 , 7 and impaired
Maria K. Talarico, Robert C. Lynall, Timothy C. Mauntel, Erin B. Wasserman, Darin A. Padua and Jason P. Mihalik
control or injury risk identification. Single-task assessments are often implemented to evaluate dynamic postural control where a task is completed independently from other tasks, such as the single-leg squat. Rehabilitation programs may incorporate dual-task strategies to rehabilitate and rebuild
Caroline Westwood, Carolyn Killelea, Mallory Faherty and Timothy Sell
although the reason for the increased risk is not clear. The effects of concussion can last months after diagnosis, and many traditional tests do not detect persistent deficits. 3 The use of a dual-task assessment, which adds a cognitive load to a motor assessment, has the potential to be a more
Christopher J. Burcal and Erik A. Wikstrom
Dual-task interference is a phenomenon that often results in performance tradeoffs when simultaneously completing tasks. Inconsistent results in the literature suggest an individualistic response to dual-tasking among chronic ankle instability (CAI) patients. We aim to examine the relationship between dual-task balance outcomes and patient- and clinician-oriented outcomes as well as injury characteristics in CAI patients. We identified moderate correlations between a higher number of ankle rolling instances in the past 3 months and worse balance while dual-tasking. Our results highlight the potential individualistic nature of dual-task impairments that may be masked within larger group comparisons.
Lauren A. Brown, Eric E. Hall, Caroline J. Ketcham, Kirtida Patel, Thomas A. Buckley, David R. Howell and Srikant Vallabhajosula
more complex challenge to the athlete’s brain and thereby be more sensitive in detecting motor deficits. 9 Previous research has used dual-task paradigms to show that gait impairments exist postconcussion but even after self-reported symptom resolution. 6 , 10 – 14 In addition, a dual-task
James G. Wrightson, Emma Z. Ross and Nicholas J. Smeeton
In a number of studies in which a dual-task gait paradigm was used, researchers reported a relationship between cognitive function and gait. However, it is not clear to what extent these effects are dependent on the type of cognitive and walking tasks used in the dual-task paradigm. This study examined whether stride-time variability (STV) and trunk range of motion (RoM) are affected by the type of cognitive task and walking speed used during dual-task gait. Participants walked at both their preferred walking speed and at 25% of their preferred walking speed and performed a serial subtraction and a working memory task at both speeds. Although both tasks significantly reduced STV at both walking speeds, there was no difference between the two tasks. Trunk RoM was affected by the walking speed and type of cognitive task used during dual-task gait: Mediolateral trunk RoM was increased at the slow walking speed, and anterior-posterior trunk RoM was higher only when performing the serial subtraction task at the slow walking speed. The reduction of STV, regardless of cognitive-task type, suggests that healthy adults may redirect cognitive processes away from gait toward cognitive-task performance during dual-task gait.
Shahrzad Mohammadi-Rad, Mahyar Salavati, Ismail Ebrahimi-Takamjani, Behnam Akhbari, Shiva Sherafat, Hossein Negahban, Pezhman Lali and Masood Mazaheri
To compare the effect of dual tasking on postural stability between patients with anterior cruciate ligament reconstruction (ACL-R) and healthy controls.
Single-limb postural stability was assessed in 17 athletes with ACL-R and 17 healthy matched athletes while standing on a Biodex Balance System platform in 4 conditions: stability level of 8 (ie, more-stable support surface) with eyes open, stability level of 8 with eyes closed, stability level of 6 (ie, less-stable support surface) with eyes open, and stability level of 6 with eyes closed. Postural-stability tasks were performed with and without auditory Stroop task. The anteroposterior stability index (APSI), mediolateral stability index (MLSI), and overall stability index (OSI) as measures of postural performance, as well as reaction time and error ratio as measures of cognitive performance, were recorded.
Dual-tasking effect on postural stability was not significantly different between the groups in 3 postural conditions. Only in level 6 with eyes open, for APSI and OSI, patients with ACL-R showed lower postural stability under the dual-task condition. However, patients showed poorer performance on both reaction time and error ratio in all postural conditions.
The patients with ACL-R appeared to sacrifice their cognitive performance to optimize their performance on postural stability. This posture-first strategy was reflected by a more pronounced effect of dual tasking on the auditory Stroop task than the postural-stability task. In situations where maintenance of posture is challenging, giving priority to the postural task at the expense of cognitive performance can ensure safety from balance loss.
Renee Beach Sample, Kurt Jackson, Allison L. Kinney, Wiebke S. Diestelkamp, Senia Smoot Reinert and Kimberly Edginton Bigelow
Falls occur in 33% of older adults each year, some leading to moderate to severe injuries. To reduce falls and fall-related injuries, it is important to identify individuals with subtle risk factors elevating their likelihood of falling. The objective of this study was to determine how postural sway measures differed between fallers and nonfallers under standard and dual-task conditions. Quietstanding posturography measures were collected from 150 older adults during standard, cognitive, manual, and cognitive+manual tasks, and analyzed through traditional and nonlinear analyses. Of the traditional measures, M/L sway range and 95% confidence ellipse sway area showed statistically significant differences in all 4 test conditions between fallers and nonfallers. Although the manual dual task showed the most stable balance, effect sizes demonstrated larger differences between fallers and nonfallers. Nonlinear analysis revealed M/L sample entropy and M/L α-scaling exponent differentiating between fallers and nonfallers, with the cognitive task demonstrating larger differences. Based on the results, it is recommended to: (1) apply M/L sway range and 95% confidence ellipse area, (2) use the manual task to differentiate between fallers and nonfallers when using traditional analyses, and (3) use the cognitive task and M/L alpha and M/L sample entropy when using nonlinear analyses.