Postural control and cognitive task performance in healthy participants while balancing on different support-surface configurations

Postural control during normal upright stance in humans is a well-learned task. Hence, it has often been argued that it requires very little attention. However, many studies have recently shown that postural control is modified when a cognitive task is executed simultaneously especially in the elderly and in the presence of pathology. This study examined postural control modifications when a cognitive task of varying difficulty levels is added. Postural stance difficulty was also varied. Results from this study suggest that a generalized capacity interference may occur due to the larger interference found with the addition of a cognitive task in the more novel and difficult postural task. Because the performance of the cognitive task was tapered by a speed-difficulty trade-off, it was not possible to determine whether a change in the level of difficulty of the cognitive task occurred and if it would produce larger dual-task interference.     

Noon is the best time to perform a dual task while cognitive performance may be boosted by concurrent performance of a physical task

BackgroundDual-task is the concurrent performance of two independent single tasks (ST) that have distinct goals. Daily variations in performance of singular cognitive or motor tasks are reported in the literature.Research questionTo investigate whether performance of a dual-task (DT) varies based on the time of day and whether there is interference between the motor and cognitive aspect of DT.MethodsParticipants performed a 10 Meter Walk Test (10MWT) for motor and a Stroop Test for cognitive task. The DT activity combined both STs. All participants performed three trials for all three conditions at three different times of the day (morning, noon, afternoon), on separate testing days.ResultsData were collected on 42 participants. Most participants were female (28/42), average age of 27.95 ± 9.28 years, and BMI of 25.58 ± 4.49 Kg/m2. Walking velocities in ST were consistently faster than in DT, p < .0005. In DT conditions, the participants walked faster at noon (1.21 ± 0.13 m/s) compared to the morning (1.16 ± 0.15 m/s, p = 0.01) or the afternoon (1.16 ± 0.18 m/s, p = 0.04). The participants’ score on the DT-Stroop test were only different at noon (11.43 ± 2.28) when compared to morning (10.67 ± 1.34, p = 0.006). The percentage DT-Cognitive interference effect was 26.1 % in the morning, 11.8 % at noon and 13.4 % in the afternoon. The Motor interference was −14.6 % in the morning, −12.2 % at noon and −13.8 % in the afternoon.SignificanceNoon is the best time to perform a dual task condition. Noon consistently exhibited the least motor or cognitive interference. Conversely, the maximum boost in cognitive performance was observed in the mornings.     

Novice vs expert inter-rater reliability of the balance error scoring system in children between the ages of 5 and 14

BackgroundThe Balance Error Scoring System (BESS) is a tool to measure balance, however, no studies have shown its reliability between novice and expert raters.Research QuestionWhat is the inter-rater reliability of BESS measurements when performed by novice raters compared to experts, and does completion of a focused, online training module increase the inter-rater reliability among novice raters?MethodsIn this reliability study, 5 novice volunteers were asked to independently rate BESS tests from 50 random prerecorded BESS videos of normal healthy subjects aged 5–14. Novice raters regraded the same 50 videos after receiving a formal training. The novices’ scores before and after the formal training were compared to one another and then the scores were compared to 4 expert scores. Intraclass correlation (ICC) with 95 % confidence intervals or percent agreements were calculated and compared across groups.ResultsFor the total BESS score, novice raters showed good reliability (ICC 0.845) which did not change with a formal training (ICC 0.846). Expert raters showed excellent reliability (ICC 0.929). Poor to moderate reliability was noted in the foam stance-single leg in the untrained novice and trained novice group (ICCs 0.452 and 0.64 L respectively).SignificanceBESS testing by novice raters with only written instruction and no formal training yields good inter-rater reliability. In contrast, BESS testing by expert raters yields excellent reliability. A focused training for novice raters conferred a small improvement in the reliability of the scoring of the single leg stance on foam condition but not a significant difference to the overall BESS score. While novices demonstrated promising reliability for overall BESS scores, optimizing clinical research using the BESS with expert raters show the highest reliability.     

Motor adaptation to cognitive challenges and walking perturbations in healthy young adults

BackgroundCognitive-walking interference is manifested when simultaneously performing a cognitive task while walking. However, majority of the dual-task walking paradigms incorporated relatively short testing trials and were focused on posing a cognitive challenge by adding a secondary cognitive task but not introducing walking perturbations.Research questionHow do healthy young adults adapt to concurrent cognitive challenges and walking perturbations in terms of task prioritization and adaptation strategies to control walking stability?MethodsEighteen healthy young participants walked with and without (1) continuous treadmill platform sways (Perturbed and Unperturbed walking), and (2) performing one of the cognitive tasks: visual and auditory Stroop tasks, Clock task, Paced Auditory Serial Addition Test (PASAT), and walk only. Primary outcome measures included cognitive task performance, mediolateral dynamic margins of stability (MOS_ML), M-L local dynamic stability, stride time variability and the dual-task interference (DTI) on these measures.ResultsGait adjustments made during Perturbed walking did not improve walking stability but instead, showing more local instability and greater gait variability (all p < 0.001) than Unperturbed walking. Participants increased average MOS_ML during Clock and PASAT compared to Walk Only for both Perturbed and Unperturbed walking (THSD, p < 0.05). Participants had significantly less DTI on stride time variability during Unperturbed walking than during Perturbed walking (p < 0.001). Participants also had significantly greater DTI on PASAT performance during Perturbed than during Unperturbed walking (THSD, p < 0.05)SignificanceParticipants prioritized the walking task under a more challenging walking condition although the adjustments made during Perturbed walking were not sufficient to maintain a similar level of walking stability as Unperturbed walking. Adjustments to the cognitive-walking challenges were differed by the type of cognitive tasks. The current findings suggest that cognitive tasks involving both working memory and information processing or visuospatial recognition or attention have greater impact on gait especially during the perturbed walking condition.     

Consistency and cost of dual-task gait balance measure in healthy adolescents and young adults

Matched control data are commonly used to examine recovery from concussion. Limited data exist, however, examining dual-task gait data consistency collected over time in healthy individuals. The study purposes were to: 1) assess the consistency of single-task and dual-task gait balance control measures, 2) determine the minimal detectable change (MDC) of gait balance control measures, and 3) examine the extent to which age and task complexity affect dual-task walking costs in healthy adolescents and young adults. Twenty-four adolescent (mean age = 15.5 ± 1.1 years) and 21 young adult (mean age = 21.2 ± 4.5 years) healthy participants completed 5 testing sessions across a two-month period, which involved analyses of gait balance control and temporal-distance variables during single-task and dual-task walking conditions in a motion analysis laboratory. Cronbach’s α and MDCs were used to determine the consistency of the gait balance control variables and the smallest amount of change required to distinguish true performance from change due to the performance/measurement variability, respectively. Dual-task costs were evaluated to determine the effect of task complexity and age across time using 3-way ANOVAs. Good to excellent test-retest consistency was found for all single-task and dual-task walking (Cronbach’s α range: 0.764–0.970), with a center-of-mass medial-lateral displacement MDC range of 0.835–0.948 cm. Greater frontal plane dual-task costs were observed during more complex secondary tasks (p < 0.001). The results revealed good-excellent consistency across testing sessions for all variables and indicated dual-task costs are affected by task complexity. Thus, healthy controls can be effective comparators when assessing injured subjects.     

Single session of repetitive transcranial magnetic stimulation to left dorsolateral prefrontal cortex increased dual-task gait speed in chronic stroke: A pilot study

BackgroundIndividuals with stroke often experience difficulty in dual-task walking and are prone to falling when walking and talking. Previous studies in other populations have suggested that non-invasive brain stimulation could enhance dual-task gait performance by stimulating dorsolateral prefrontal cortex (DLPFC) or supplementary motor area (SMA). It was unclear if the benefits of brain stimulation would be observed in individuals with stroke.Research QuestionWould single-session 5 Hz rTMS applied to DLPFC or SMA improve dual-task gait performance in individuals with stroke?MethodsThis single group repeated measure study included fifteen individuals with left chronic stroke (mean age = 58 years). Participants received 5 Hz rTMS to either DLPFC, SMA, or M1 of the left lesioned hemisphere across three different sessions. Single- and dual-task gait speed was assessed before and after rTMS with the dualtask gait being walking and counting backward by 3 s.ResultsWe observed that rTMS to left DLPFC resulted in a greater increase in dual-task gait speed, but not single-task gait speed, compared to the other two stimulation sites (M1 and SMA) but the difference was not statistically significant (p = 0.06). Five out of fifteen participants demonstrated a clinically significant improvement in dual-task gait speed (> 0.1 m/s) after rTMS to DLPFC.SignificancesThe results suggest that DLPFC could be a potential treatment target to improve dual-task gait performance in persons with chronic stroke.     

Attentional prioritization in dual-task walking: Effects of stroke,environment, and instructed focus

BackgroundThe impact of high distraction, real-world environments on dual-task interference and flexibility of attentional prioritization during dual-task walking in people with stroke is unknown.Research questionHow does a real-world environment affect dual-task performance and flexible task prioritization during dual-task walking in adults with and without stroke?MethodsAdults with stroke (n = 29) as well as age-, gender-, and education-matched adults without stroke (n = 23) participated. Single and dual-task walking were examined in two different environments (lab hallway, hospital lobby). Two different dual-task combinations were assessed (Stroop-gait, speech-gait). Each dual-task was performed first without explicit instruction about task prioritization (no-priority) and then with gait-priority instruction and Stroop/speech-priority instruction in randomized order.ResultsPeople with stroke had significantly slower dual-task gait speed (Stroop only) in the lobby than the lab, but the effect was not clinically meaningful. Stroop reaction time for all participants was also slower in the lobby than the lab. All participants slowed their walking speed while generating spontaneous speech, but this effect was not influenced by environment. The dual-task attention allocation strategy was generally inflexible to instructed prioritization in adults with and without stroke in both environments, however, the volitional attention allocation strategy differed for the two dual-task conditions such that speech was prioritized in the speech-gait dual-task and gait appeared to be prioritized in the Stroop-gait dual-task.SignificanceAlthough dual-tasking slows walking speed and verbal responses to auditory stimuli in people with stroke, the effects are not considerably impacted by a more complex, distracting environment. Adults with and without stroke may have difficulty overriding the preferred attention allocation strategy during dual-task walking, especially for habitual dual-tasks such as walking while speaking. It may also be that the cognitive control strategy governing task prioritization is influenced by degree of cognitive engagement.     

Haptic information provided by anchors and the presence of cognitive tasks contribute separately to reducing postural sway in young adults

BackgroundHaptic information provided by the anchors reduces postural sway while standing upright. It is unclear whether this benefit would remain in the presence of cognitive tasks combined with a more challenging postural task.Research questionOur aim was to investigate the effects of the anchors and visual and auditory cognitive tasks on postural control in young adults in a challenging balancing task.MethodsTwenty young adults stood upright on a balance beam with the central portion of each foot placed over the beam and feet at shoulder width without and with the use of the anchors in three cognitive conditions: control, visual Stroop task, and auditory digit-monitoring task. Each anchor consisted of a flexible cable with a light load (125 g) attached at one end of the cable. With the anchors, the participants held the flexible cable in each hand with the light load resting on the ground while keeping tension in the cable.ResultsBoth visual and auditory cognitive tasks reduced the center of pressure (COP) ellipse area, the root mean square of the margin of dynamic stability (based on the extrapolated center of mass, COM) and increased the COM time-to-contact relative to the boundaries of the base of support in the AP direction. The anchors reduced the COP ellipse area.SignificanceThere is a functional integration between postural control and cognitive tasks, such that postural sway was reduced to facilitate the execution of the cognitive tasks. Anchors were effective in reducing postural sway, suggesting that haptic information was able to benefit postural control in a challenging balancing task regardless of the cognitive task.     

Lower Quarter Y Balance Test performance: Reference values for healthy youth aged 10 to 17 years

BackgroundThe Lower Quarter Y Balance Test (YBT-LQ) has been widely used to register dynamic balance performance in children and adolescents. However, studies evaluating age- and sex-specific normative data to assess and classify YBT-LQ performance for these age-cohorts are missing.ObjectiveThus, we investigated YBT-LQ performance in healthy youth to provide age- and sex-specific reference values.MethodsSix-hundred and sixty-nine individuals (286 female, 383 male) aged 10–17 years performed the YBT-LQ with their left and right leg. Normalized maximal reach distances (% leg length) for all three directions (i.e., anterior, posterolateral, posteromedial) and the composite score were calculated. Further, age- and sex-specific percentile values (i.e., 10th to 90th percentile) were computed and plotted.ResultsIn boys, the oldest age group (16−17 years) performed better than the younger ones (14−15, 12−13, and 10−11 years). In girls, the youngest age group (10−11 years) often achieved better values compared to the 12−13-year olds. Further, 16−17-year old boys compared to the same aged girls showed better YBT-LQ performance in all but one measure (except left leg reach in posterolateral direction). For both sexes, curvilinear shaped curves were detected for percentile values across the reach directions.ConclusionsThe generated age- and sex-specific reference values for the YBT-LQ can be used by practitioners to evaluate dynamic balance performance in healthy youth aged 10–17 years.     

Continuous and difficult discrete cognitive tasks promote improved stability in older adults

Directing attention away from postural control and onto a cognitive task affords the emergence of automatic control processes. Perhaps the continuous withdrawal of attention from the postural task facilitates an automatization of posture as opposed to only intermittent withdrawal; however this is unknown in the aging population. Twenty older adults (69.9 ± 3.5 years) stood with feet together on a force platform for 60 s while performing randomly assigned discrete and continuous cognitive tasks. Participants were instructed to stand comfortably with their arms by their sides while verbally responding to the auditory stimuli as fast as possible during the discrete tasks, or mentally performing the continuous cognitive tasks. Participants also performed single-task standing. Results demonstrate significant reductions in sway amplitude and sway variability for the difficult discrete task as well as the continuous tasks relative to single-task standing. The continuous cognitive tasks also prompted greater frequency of sway in the anterior-posterior direction compared to single-standing and discrete tasks, and greater velocity in both directions compared to single-task standing, which could suggest ankle stiffening. No differences in the simple discrete condition were shown compared to single-task standing, perhaps due to the simplicity of the task. Therefore, we propose that the level of difficulty of the task, the specific neuropsychological process engaged during the cognitive task, and the type of task (discrete vs. continuous) influence postural control in older adults. Dual-tasking is a common activity of daily living; this work provides insight into the age-related changes in postural stability and attention demand.     

The feasibility and efficacy of a serial reaction time task that measures motor learning of anticipatory stepping

BackgroundMotor learning has been investigated using various paradigms, including serial reaction time tasks (SRTT) that examine upper extremity reaching and pointing while seated. Few studies have used a stepping SRTT, which could offer additional insights into motor learning involving postural demands. For a task to measure motor learning, naïve participants must demonstrate a) improved performance with task practice, and b) a dose-response relationship to learning the task.Research questionIs a stepping SRTT feasible and efficacious for measuring motor learning?MethodsIn this prospective study, 20 participants stood on an instrumented mat and were presented with stimuli on a computer screen. They stepped to the corresponding positions on the mat as quickly as possible. Presented stimuli included random sequences and a blinded imbedded repeating sequence. Three days after completing the randomly assigned practice dose [high dose group (n = 10) performed 4320 steps; low dose group (n = 10) performed 144 steps], a retention test of 72 steps was performed. Feasibility was measured as the proportion of participants who completed the assigned practice dose without adverse events. Efficacy was measured as within-group performance improvement on the random sequences and on the repeating sequence (paired t-tests), as well as a dose-response relationship to learning both types of sequences (independent t-tests).ResultsAll participants (mean age 26.8 years) completed all practice sessions without adverse events, indicating feasibility. High dose practice resulted in performance improvement while low dose did not; a dose-response relationship was found, with high dose practice resulting in greater learning of the task than low dose practice, indicating efficacy.SignificanceThis stepping SRTT is a feasible and efficacious way to measure motor learning, which could provide critical insights into anticipatory stepping, postural control, and fall risk. Future research is needed to determine feasibility, efficacy, and optimal practice dosages for older and impaired populations.     

Effects of balance exercises during daily tooth brushing on balance performance in healthy children

BackgroundIt has been shown that supervised balance training is effective in improving balance performance in children but relatively costly in terms of personnel, materials, and time. Integrating balance exercises into daily routines such as tooth brushing reduces these needs, but its effectiveness is unknown.ObjectiveThis study investigated the impact of balance exercises performed during daily tooth brushing on measures of static and dynamic balance in healthy children.MethodsFifty-five healthy children were assigned to either an intervention (n = 32, age: 9.5 ± 0.7 years) or a control (n = 23, age: 9.2 ± 0.5 years) group. Participants of the intervention group performed progressive balance exercises while tooth brushing on a daily basis (2 sessions per day × 3 min per session) for eight weeks. Static (i.e., timed one-legged stance test [OLS]) and dynamic (i.e., Lower Quarter Y Balance test [YBT-LQ]) balance were tested before and after the intervention period.ResultsThe adherence rate to exercise was 98% for the participants of the intervention group. Significant test × group interactions in favor of the intervention group were detected in three out of four OLS stance conditions and for all YBT-LQ reach directions.ConclusionsEight weeks of balance exercises while tooth brushing proved to be feasible (i.e., high adherence rate) and effective (i.e., enhanced static and dynamic balance performance) and is thus recommended to improve postural control in healthy children.     

Using functional movement tests to investigate the presence of sensorimotor impairment in amateur athletes following sport-related concussion: A prospective,longitudinal study

ObjectiveTo longitudinally investigate the presence of sensorimotor impairments in amateur athletes following sport-related concussion using two functional movement tests.DesignProspective, longitudinal study.SettingHuman movement analysis laboratory.ParticipantsAthletes who presented to a hospital emergency department and were diagnosed with sport-related concussion, and sex-, age-, and activity-matched non-concussed, control athletes. Concussed participants were assessed within one-week following sport-related concussion, upon clearance to return-to-sporting activity (RTA), and two weeks after RTA. Control participants were assessed at an initial time-point and approximately two and four weeks following their initial study assessment.Main outcomes measuresAt each laboratory assessment, participants completed two functional movement tests: the Star Excursion Balance Test to evaluate anterior reach distance (normalised for leg length) and fractal dimension (centre of pressure path complexity), and the Multiple Hop Test to evaluate corrective postural strategies and time-to-stabilisation.ResultsFifty concussed athletes and 50 control athletes completed the study. There were no significant differences at any study assessment between the concussion and control group on the Star Excursion Balance Test anterior reach distance or fractal dimension (centre of pressure path complexity). During the Multiple Hop Test, the concussion group used a significantly greater number of corrective postural strategies than the control group one-week following sport-related concussion and upon clearance to RTA, but not two weeks following RTA.ConclusionRecently concussed athletes made a greater number of corrective postural strategies than control participants during the Multiple Hop Test upon clearance to RTA but not two weeks after RTA. The Multiple Hop Test may offer a clinically useful tool for practitioners to examine the recovery of subtle sensorimotor impairments and related RTA readiness.     

Balance and cognitive performance during a dual-task: Preliminary implications for use in concussion assessment

ObjectivesTo determine the reliability and effects of a dual-task paradigm on balance and cognitive function compared to a single-task paradigm.DesignRepeated measures.MethodsHealthy participants (n = 23) completed a variation of the Sensory Organization Test and the incongruent Stroop test individually (single-task) and concurrently (dual-task) during two testing sessions.ResultsThe Sensory Organization Test and incongruent Stroop test had moderate to high reliability (1.00 > ICC_2,k > 0.60) under the dual-task conditions. Reaction time was significantly longer (t₂₁ = ?2.54, p = 0.019) under the dual-task conditions, while balance scores under one of the four conditions of the Sensory Organization Test (sway floor/fixed wall) were statistically better (t₂₂ = ?3.03, p = 0.006) under the dual-task conditions. However, this difference in balance scores may not be clinically meaningful.ConclusionsThese findings illustrate that the Sensory Organization Test and incongruent Stroop task can be reliably incorporated into a dual-task assessment paradigm. The slowed reaction time under the dual-task paradigm indicates that the dual-task provided an additional cost to cognitive function. Dual-task concussion assessment paradigms involving these two tasks are psychometrically appropriate as well as more representative of actual sporting situations. However, more research should be conducted in a concussed population to further validate this claim.     

Postural stability and physical performance in social dancers

This cross-sectional study examined the benefits of social dancing on postural stability and physical performance in dancers aged 50 years or more. Walking speed, lower limb reaction time and low back flexibility were measured in 202 social dancers and 202 community-dwelling comparison subjects aged 50–87 years. The results showed that dancers who were older than 60 years had better postural stability and faster leg reaction times, whilst dancers aged 50–59 showed only better flexibility, when compared with the controls. Male dancers had greater low back flexibility and leg reaction time compared to controls. In contrast, female dancers had superior performance only for leg reaction time when compared with controls. The results indicate that social dancing is associated with enhanced postural stability and physical performance in older adults.     

Comparable walking gait performance during executive and non-executive cognitive dual-tasks in chronic stroke: A pilot study

BackgroundFalls are a serious problem among stroke survivors due to subsequent injuries, recovery setbacks, dependence, and mortality. A growing body of dual-task (DT) studies suggests a role of executive functions in gait control and falls, particularly in subacute stroke. However, few studies have compared distinct executive and non-executive tasks, nor their effects on chronic stroke gait. Research question: The purpose of this cross-sectional study was to compare the effects of distinct working memory (2-back) and inhibition (Stroop) tasks on walking gait performance in chronic stroke survivors.MethodsA pilot sample of chronic stroke survivors (n = 11, 8 males, mean age = 70.91, 6-12months post-stroke event) and age-matched healthy controls (n = 13, 4 male; mean age = 68.46) were tested. Gait performance (speed, stride time, stride time variability, stride length and stride length variability) was measured using 2 wireless inertial measurement sensors under 4 walking conditions: 1) preferred walking (single-task: ST), 2) walking with a 2-back DT, 3) walking with a Stroop DT, and 4) walking with a non-executive motor response DT. The secondary tasks were also carried out in both ST (seated) and DT conditions, to examine bidirectional effects.ResultsWhile the stroke survivor sample had a slower gait speed across conditions and tasks, there were no significant differences between the groups [F(1, 22) = 1.13, p =.299, η²p = .049] on the spatial or temporal gait characteristics recorded: gait performance was maintained during executive and non-executive DTs. In addition, we did not find a significant effect of group on cognitive task performance (all p > .052). However, we observed a cost in accuracy on the 2-back DT for both groups, suggesting resource overlap and greater cognitive load (all t > 19.72, all p < .001).SignificanceOur gait data contradict previous studies evidencing impaired gait post-stroke, suggesting functional recovery in this chronic stroke sample.     

Development of a limits of stability protocol for use in transtibial prosthesis users: Learning effects and reliability of outcome variables

The aims of this study were to empirically quantify reliability and learning effects of a Limits of Stability protocol for transtibial prosthesis users. Outcome variables from center of pressure and center of mass were tested on: 1) multiple test repetitions within a single test occasion; and 2) between multiple test occasions. Trantibial prosthesis users (n = 7) and matched controls (n = 7) executed five trials of the Limits of Stability protocol on two occasions per day, on two consecutive days. Inter-trial learning effects and reliability of outcomes extracted via center of mass and center of pressure were evaluated utilizing standard biomechanics laboratory equipment. Reliability was good to excellent except the reaction time variable which was poor (Pooled 95%CI of ICC = 0.248–0.484). An inter-trial learning effect was present in directional control for prosthesis users when the first trial was included in analysis (center of mass: 95%CI of r = 0.065–0.239; center of pressure: 95%CI of r = 0.076–0.249). The use of standard biomechanics lab equipment can produce reliable results for the Limits of Stability protocol. Researchers should be aware of low reliability of reaction time variable in the protocol assessed and should execute at least one practice trial prior to that which is used in subsequent analysis.     

Association of trunk control with mobility performance and accelerometry-based gait characteristics in hemiparetic patients with subacute stroke

Trunk control plays an important role in movement control and postural balance during functional activities. The purpose of this study was to investigate the association of trunk control early after stroke with mobility performance and quantitative gait characteristics derived from trunk accelerations. Fifteen patients with hemiparesis following stroke (median age, 61 years [range, 56–78 years]; median time since stroke, 9 days [range, 7–15 days]) participated in this cross-sectional observational study. Subjects were evaluated using the Trunk Impairment Scale (TIS), the short-form of the Berg Balance Scale (SF-BBS), an isometric knee extension strength test, the Timed Up and Go test (TUG), and a timed walking test. The linear acceleration of the lower trunk was recorded along the 3 axes during walking and quantified using the autocorrelation coefficient and harmonic ratio to assess the variability and smoothness of upper-body movement. The TIS total score had a significant correlation with TUG time. The coordination subscale score of the TIS was significantly correlated with TUG time, walking speed, and accelerometry variables in univariate analysis. The TIS coordination subscale score was significantly related to accelerometry variables in the partial correlation analysis adjusted for SF-BBS score and knee extension strength on the paretic and nonparetic side. These results indicate that trunk motor impairment after stroke is closely associated with poor mobility performance and trunk instability in gait. These findings support intensive rehabilitation treatment targeting trunk control to regain better mobility and stable gait in patients early after stroke.     

Changes in exertion-related symptoms in adults and youth who have sustained a sport-related concussion

ObjectivesTo identify the symptoms responsible for cessation of exercise testing and evaluate changes in post-concussion symptom scores on the Post-Concussion Symptom Scale (PCSS) from the Sport-Concussion Assessment Tool (SCAT5) immediately, 1–4 h, and 6–12 h following completion of the Buffalo Concussion Treadmill Test (BCTT) in youth and adults who have sustained a sport-related concussion.DesignProspective case-series.MethodsIndividuals who were diagnosed with a sport-related concussion and self-reported difficulties with exertion were referred to perform an exertional treadmill test. Individuals were recruited from a university sports medicine clinic. Change in PCSS symptom severity scores were operationally defined as a change ≥4 points.ResultsForty-five individuals aged 13–57 years consented to participate. A total of 14/24 (58.3%) female and 13/21 (61.9%) male participants reported an increase in symptom severity scores immediately following the BCTT. At 1–4 h, 5/10 (50.0%) males and 5/14 (35.7%) females who completed the PCSS had elevated symptom severity scores compared to pre-exertion. Only 24.2% (3/17 males and 5/16 females) of participants completing the PCSS at 6–12 h reported increased symptom severity scores.ConclusionExertional testing is an important component of a multifaceted assessment following concussion; however, previous research evaluating symptom responses to exertion is limited. This study provides evidence to suggest individuals who experience an exacerbation of concussion-associated symptoms after exertion are likely to return to pre-exertion levels within the same day. Future research monitoring symptoms following exertion and throughout recovery should be performed in tandem with physiological measures to better understand the source of symptoms.