Comprehensive quantitative investigation of arm swing during walking at various speed and surface slope conditions

Previous studies have shown that inclusion of arm swing in gait rehabilitation leads to more effective walking recovery in patients with walking impairments. However, little is known about the correct arm-swing trajectories to be used in gait rehabilitation given the fact that changes in walking conditions affect arm-swing patterns. In this paper we present a comprehensive look at the effects of a variety of conditions on arm-swing patterns during walking. The results describe the effects of surface slope, walking speed, and physical characteristics on arm-swing patterns in healthy individuals. We propose data-driven mathematical models to describe arm-swing trajectories. Thirty individuals (fifteen females and fifteen males) with a wide range of height (1.58–1.91 m) and body mass (49–98 kg), participated in our study. Based on their self-selected walking speed, each participant performed walking trials with four speeds on five surface slopes while their whole-body kinematics were recorded. Statistical analysis showed that walking speed, surface slope, and height were the major factors influencing arm swing during locomotion. The results demonstrate that data-driven models can successfully describe arm-swing trajectories for normal gait under varying walking conditions. The findings also provide insight into the behavior of the elbow during walking.     

Musical pleasure beneficially alters stride and arm swing amplitude during rhythmically-cued walking in people with Parkinson's disease

Entrainment of walking to rhythmic auditory cues (e.g., metronome and/or music) improves gait in people with Parkinson's disease (PD). Studies on healthy individuals indicate that entrainment to pleasant musical rhythm can be more beneficial for gait facilitation than entrainment to isochronous rhythm, potentially as a function of emotional/motivational responses to music and their associated influence on motor function. Here, we sought to investigate how emotional attributes of music and isochronous cues influence stride and arm swing amplitude in people with PD. A within-subjects experimental trial was completed with persons with PD serving as their own controls. Twenty-three individuals with PD walked to the cue of self-chosen pleasant music cue, pitch-distorted unpleasant music, and an emotionally neutral isochronous drumbeat. All music cues were tempo-matched to individual walking pace at baseline. Greater gait velocity, stride length, arm swing peak velocity and arm swing range of motion (RoM) were found when patients walked to pleasant music cues compared to baseline, walking to unpleasant music, and walking to isochronous cues. Cued walking in general marginally increased variability of stride-to-stride time and length compared with uncued walking. Enhanced stride and arm swing amplitude were most strongly associated with increases in perceived enjoyment and pleasant musical emotions such as power, tenderness, and joyful activation. Musical pleasure contributes to improvement of stride and arm swing amplitude in people with PD, independent of perceived familiarity with music, cognitive demands of music listening, and beat salience. Our findings aid in understanding the role of musical pleasure in invigorating gait in PD, and inform novel approaches for restoring or compensating impaired motor circuits.     

Alterations in stride-to-stride variability during walking in individuals with chronic ankle instability

The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P = .04). No significant group differences were observed for SampEn values of other kinematics (P > .05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function.     

Changes in interlimb coordination during walking and grasping task in older adult fallers and non-fallers

The aim of this study was to investigate interlimb coordination in young and older adults with and without a history of falls during the combined task of walking and prehension with different levels of manual task difficulty. Participants walked on a pathway and grasped a dowel. A vector coding technique evaluated coordination patterns. The coordination pattern was not affected by the difficulty level of the manual task. Older adults seemed to prioritize the movement of the right shoulder to grasp the dowel and then ‘froze’ the movement of the other joint (left shoulder) not directly involved in the grasping task. The preference to pick up the dowel in the double support phase and the increase in right shoulder phase made by older adults with a history of falls suggests an even greater decoupling between walking and prehension.     

Using choice to increase on-task behavior in individuals with traumatic brain injury

An ABA'B design was used to evaluate the effects of choice on task engagement for 3 adults who had been diagnosed with traumatic brain injury. A yoked-control condition, in which tasks that were selected by each participant were assigned subsequently to that participant by a trainer, was implemented to help distinguish between the effects of task preference and choice. The results for all 3 participants indicated that permitting individuals to choose from a list of tasks increased on-task behavior.     

Comparison of the trunk-pelvis and lower extremities sagittal plane inter-segmental coordination and variability during walking in persons with and without chronic low back pain

Inter-segmental coordination can be influenced by chronic low back pain (CLBP). The sagittal plane lower extremities inter-segmental coordination pattern and variability, in conjunction with the pelvis and trunk, were assessed in subjects with and without non-specific CLBP during free-speed walking. Kinematic data were collected from 10 non-specific CLBP and 10 non-CLBP control volunteers while the subjects were walking at their preferred speed. Sagittal plane time-normalized segmental angles and velocities were used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify the trunk-pelvis and bilateral pelvis-thigh, thigh-shank and shank-foot coordination pattern and variability over the stance and swing phases of gait. Mann-Whitney U test was employed to compare the means of DP and MARP values between two groups (same side comparison). Statistical analysis revealed more in-phase/less variable trunk-pelvis coordination in the CLBP group (P < 0.05). CLBP group demonstrated less variable right or left pelvis-thigh coordination pattern (P < 0.05). Moreover, the left thigh-shank and left shank-foot MARP values in the CLBP group, were more in-phase than left MARP values in the non-CLBP control group during the swing phase (P < 0.05). In conclusion, the sagittal plane lower extremities, pelvis and trunk coordination pattern and variability could be generally affected by CLBP during walking. These changes can be possible compensatory strategies of the motor control system which can be considered in the CLBP subjects.     

Hemispheric visual atentional imbalance in patients with traumatic brain injury

We find a spatially asymmetric allocation of attention in patients with traumatic brain injury (TBI) despite the lack of obvious asymmetry in neurological indicators. Identification performance was measured for simple spatial patterns presented briefly to a locus 5 degrees into the left or right hemifield, after precuing attention to the same (ipsilateral) or opposite (cross-hemifield) side. Though the cue was non-predictive of target location overall, performance was significantly slower for cross than for ipsilateral trials in both patients and controls. We tested 21 TBI patients without overt focal brain damage and nine control subjects. Only patients demonstrated significantly worse performance for left side presentation in the ipsilateral condition. Furthermore, in the cross-hemifield condition, the left-right difference seen in TBI patients was significantly larger-reflecting a failure in producing a leftward attention shift. Again no significant difference was found in controls. These hemifield effects suggest an asymmetry in the ability of TBI patients in shifting attention to the left hemifield, whether from central fixation or from a cue in the contra-lateral hemifield. The results support basic hypotheses regarding visual attention: Attentional control may be asymmetric and attention may be a distributed, rather than localized cortical function.     

Disfluency clusters in speakers with and without neurogenic stuttering following traumatic brain injury

PurposeAnalyze the characteristics and rate of disfluency clusters in adults with and without neurogenic stuttering after traumatic brain injury (TBI).MethodTwenty adults with TBI participated in this study, including 10 with neurogenic stuttering (Group B) and 10 without -stuttering (Group A). Disfluency clusters in speech samples were classified into three types: Stuttering-like (SLD), other (OD), and mixed (MIX).ResultsSpeakers with and without neurogenic stuttering produced the same mean number of disfluency clusters. In addition, the mean length of clusters did not differ between these speaker groups although the longest clusters did. The most frequently occurring cluster type for people with neurogenic stuttering was MIX and OD for people without stuttering. Although the speakers in Group A produced stuttering-like disfluencies, these never occurred together to form a SLD type cluster. For Group B, the starter units of the clusters were usually stuttering-like disfluencies, while for Group A, the starter units were mostly interruptions.ConclusionsCompared to non-stuttering speakers, stuttering after TBI did not increase the number of clusters, but rather lengthened them. In speakers with neurogenic stuttering, the number and length of clusters were related to the manifestation of other communication deficits, not to the frequency of stuttering-like disfluencies. Still, SLD clusters occurred only in those people with neurogenic stuttering. These findings raise questions about the nature of both neurogenic stuttering and the dynamics of disfluency clustering.     

Differences in postural control and movement performance during goal directed reaching in children with developmental coordination disorder

Poor upper-limb coordination is a common difficulty for children with developmental coordination disorder (DCD). One hypothesis is that deviant muscle timing in proximal muscle groups results in poor postural and movement control. The relationship between muscle timing, arm motion and children's upper-limb coordination deficits has not previously been studied. The aim of this study was to investigate the relationship between functional difficulties with upper-limb motor skills and neuromuscular components of postural stability and coordination. Sixty-four children aged 8-10 years, 32 with DCD and 32 without DCD, participated in the study. The study investigated timing of muscle activity and resultant arm movement during a rapid, voluntary, goal-directed arm movement. Results showed that compared to children without DCD, children with DCD took significantly longer to respond to visual signals and longer to complete the goal-directed movement. Children with DCD also demonstrated altered activity in postural muscles. In particular, shoulder muscles, except for serratus anterior, and posterior trunk muscles demonstrated early activation. Further, anterior trunk muscles demonstrated delayed activation. In children with DCD, anticipatory function was not present in three of the four anterior trunk muscles. These differences support the hypothesis that in children with DCD, altered postural muscle activity may contribute to poor proximal stability and consequently poor arm movement control when performing goal-directed movement. These results have educational and functional implications for children at school and during activities of daily living and leisure activities and for clinicians assessing and treating children with DCD.     

Generalizability of WISC-IV index and subtest score profiles in children with traumatic brain injury

The Wechsler Intelligence Scale for Children, 4th edition (WISC-IV) is often used to assess children with traumatic brain injury (TBI); although limited information is available regarding its psychometric properties in these children. Two recent reports suggest that the Perceptual Reasoning Index is not uniquely sensitive to TBI, which differs from the Perceptual Organization Index of the WISC-III. The current study examined WISC-IV profiles in two independently gathered samples of children with TBI. Examination of profiles indicated similarities between the current findings and those reported in other studies, in that the greatest deficits were present on the Processing Speed Index and its component subtests of Coding and Symbol Search, while the Perceptual Reasoning index score was comparable to the Verbal Comprehension Index. Also, no significant index or subtest score differences were present when the current sample was compared to the children with TBI reported by Allen, Thaler, Donohue and Mayfield (2010 Allen, D. N., Thaler, N. S., Donohue, B. and Mayfield, J. 2010. WISC-IV profiles in children with traumatic brain injury: Similarities to and differences from the WISC-III. Psychological Assessment, 22(1): 57–64. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). The present findings are consistent with two prior studies of the WISC-IV in children with TBI, providing additional evidence for profile differences between the WISC-III and WISC-IV. The results also suggest that WISC-IV profiles reported in prior studies are generalizable across TBI samples and study sites.     

Working memory outcomes following traumatic brain injury in children: A systematic review with meta-analysis

The aim of this review is to systematically examine the literature concerning multicomponent working memory (WM)—comprising a central executive (CE), two storage components (phonological loop, PL and visuo-spatial sketchpad, VSSP), and episodic buffer (EB)—in pediatric traumatic brain injury (TBI). Electronic searches were conducted of MEDLINE, PsychINFO and EMBASE up to October 2014 with the inclusion criteria of children and adolescents with TBI, and quantitative methods to assess at least one component of WM. Meta-analytic procedures calculated pooled effect sizes for WM outcomes. Of the studies examined, 27 met the inclusion criteria. Children with TBI exhibited deficits in the CE and PL, but not in the VSSP, and no study could be found which examined the EB. Qualitative analysis found that greater TBI severity was associated with poorer CE functioning in five out of nine studies. Differences in patterns of brain activation were evident in four out of five fMRI studies that examined WM in TBI children and controls. Deficits in CE were associated with poorer mathematical skills in the only study that examined relations between WM and academic deficits. Notwithstanding the heterogeneity of the studies reviewed, TBI places children at risk of WM deficits. Moreover, this meta-analysis suggests that various components of WM have differential vulnerability to pediatric TBI, with significant deficits found in the CE and PL, but not in the VSSP (although the VSSP has rarely been examined to date). Future studies should be theoretically driven, employ tasks assessing all components of the WM model and examine the functional ramifications (including academic outcomes) of WM deficits in this population.     

Spatial and temporal characteristics of the spine muscles activation during walking in patients with lumbar instability due to degenerative lumbar disk disease: Evaluation in pre-surgical setting

Our purpose was to investigate the spatial and temporal profile of the paraspinal muscle activation during gait in a group of 13 patients with lumbar instability (LI) in a pre-surgical setting compared to the results with those from both 13 healthy controls (HC) and a sample of 7 patients with failed back surgery syndrome (FBSS), which represents a chronic untreatable condition, in which the spine muscles function is expected to be widely impaired.Spatiotemporal gait parameters, trunk kinematics, and muscle activation were measured through a motion analysis system integrated with a surface EMG device. The bilateral paraspinal muscles (longissimus) at L3-L4, L4-L5, and L5-S1 levels and lumbar iliocostalis muscles were evaluated.Statistical analysis revealed significant differences between groups in the step length, step width, and trunk bending and rotation. As regard the EMG analysis, significant differences were found in the cross-correlation, full-width percentage and center of activation values between groups, for all muscles investigated.Patients with LI, showed preserved trunk movements compared to HC but a series of EMG abnormalities of the spinal muscles, in terms of left-right symmetry, top-down synchronization, and spatiotemporal activation and modulation compared to the HC group. In patients with LI some of such EMG abnormalities regarded mainly the segment involved by the instability and were strictly correlated to the pain perception. Conversely, in patients with FBSS the EMG abnormalities regarded all the spinal muscles, irrespective to the segment involved, and were correlated to the disease’s severity. Furthermore, patients with FBSS showed reduced lateral bending and rotation of the trunk and a reduced gait performance and balance.Our methodological approach to analyze the functional status of patients with LI due to spine disease with surgical indications, even in more complex conditions such as deformities, could allow to evaluate the biomechanics of the spine in the preoperative conditions and, in the future, to verify whether and which surgical procedure may either preserve or improve the spine muscle function during gait.     

Expressions of emotional distress in active duty military personnel with mild traumatic brain injury: A qualitative content analysis

Service members (SMs) who sustain traumatic brain injury (TBI) during deployment have increased risk for mental health issues. Mental health treatment can be challenging in military settings where treatment seeking is often stigmatized. Adequate care relies on accurate interpretations of SMs’ verbal accounts of distress, but little is known about how SMs, embedded in a culture that values resilience and self-reliance, relay emotional distress. We performed qualitative analyses of recordings from a telephone-based intervention with 25 SMs who sustained deployment-related mild TBI (mTBI) to elucidate thematic and dialectal patterns. Consistent with our expectations, SMs rarely used explicit depressive terms while discussing their emotional distress. More prevalent was language suggestive of an overarching theme of loss of control, whereby SMs’ stress, anxiety, and anger were often attributable to SMs’ perceptions that they had incomplete jurisdiction over their own lives. This study may help mental health providers improve engagements with SMs and Veterans, preventing misunderstandings and even improper diagnoses or referrals that could result from a strict reliance on the more customary expressions of distress.     

Evaluating anxiety and depression symptoms in children and adolescents with prior mild traumatic brain injury: Agreement between methods and respondents

Psychological functioning can be adversely impacted after a mild traumatic brain injury (mTBI) and may be a potential target for intervention. Despite the use of symptom ratings or structured diagnostic interview to assess long-term anxiety and depression symptoms in children and adolescents post-injury, no known studies have considered the agreement between different assessment methods and between respondents. The objectives of this study were to investigate the agreement between symptom ratings and structured diagnostic interview and between children and parents’ symptom reporting. Participants (N = 33; 9–18 years old) were recruited from the Emergency Department and assessed on average 22.8 months (SD = 5.6) after their mTBI. Anxiety and depression symptoms were evaluated via subscales of a questionnaire (Behavior Assessment System for Children) and parts of a computerized structured diagnostic interview (generalized anxiety disorder and major depressive episode; Diagnostic Interview Schedule for Children – C-DISC-IV) administered individually to children and their parents. Results showed that the inter-method agreement to identify high levels of anxiety and depression was moderate to perfect in children while it was lower in parents. Although a similar percentage of participants with elevated anxiety or depression were identified by both children and parents, the agreement between youth and parents was variable, ranging from poor to good for anxiety and poor to moderate for depression. These results highlight the importance of collecting youth and parents’ reports of anxiety and depression symptoms and considering potential discrepancies between informants’ answers.     

Development of an eight-subtest short form of the WISC-IV and evaluation of its clinical utility in children with traumatic brain injury

This study evaluated the degree to which an 8-subtest short form of the Wechsler Intelligence Scale for Children—Fourth Edition would yield acceptable estimates of the long-form Full-Scale IQ index while clarifying the underlying factor structure in a sample of 100 children and adolescents with traumatic brain injury. The short-form Full-Scale IQ had sufficient (i.e., at least two thirds) nonerror covariance with its full-length counterpart. In addition, a sufficient proportion (i.e., > 80%) of these short-form estimates fell within the 90% confidence interval of the respective full-length scores. Importantly, the elimination of 2 subtests, and in particular the Picture Concepts subtest, resulted in a factor structure where each remaining subtest was fairly specifically associated with its intended scale. It is concluded that this short form can be used clinically in children with traumatic brain injury without sacrificing reliability and with more straightforward interpretability at the level of the factor index scores.