Postural control provides insight into health concerns such as fall risk but remains relatively untapped as a vital sign of health. One understudied aspect of postural control involves transient ...responses within center of pressure (CoP) data to events such as vision occlusion. Such responses are masked by common whole-trial analyses. We hypothesized that the transient behavior of postural control would yield unique and clinically-relevant information for quiet stance compared to traditionally calculated whole-trial CoP estimates. Three experiments were conducted to test different aspects of this central hypothesis. To test whether transient, epoch-based characteristics of CoP estimates provide different information than traditional whole-trial estimates, we investigated correlations between these estimates for a population of young adults performing three 60-second trials of quiet stance with eyes closed. Next, to test if transient behavior is a result of sensory reweighting after eye closure, we compared transient characteristics between eyes closed and eyes open conditions. Finally, to test if there was an effect of age on transient behavior, we compared transient characteristics during eyes closed stance between populations of young and older adults. Negligible correlations were found between transient characteristics and whole-trial estimates (p>0.08), demonstrating limited overlap in information between them. Additionally, transient behavior was exaggerated during eyes closed stance relative to eyes open (p<0.044). Lastly, we found that transient characteristics were able to distinguish between younger and older adults, supporting their clinical relevance (p<0.029). An epoch-based approach captured unique and potentially clinically-relevant postural control information compared to whole-trial estimates. While longer trials may improve the reliability of whole-trial estimates, including a complementary assessment of the initial transient characteristics may provide a more comprehensive characterization of postural control.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background
Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting toxicity of several commonly used chemotherapy drugs including taxanes, vinca alkaloids, and platinum compounds. ...Development of CIPN is highly variable, both in self-reported symptoms and functional consequences, and can be severe enough to alter dose intensity.
Purpose
To describe the natural histories of both patient-reported symptoms of CIPN and functional impairments in breast cancer patients undergoing taxane-based chemotherapy.
Methods
Thirty-three breast cancer patients (32 female/1 male; 47.8 ± 11.2 years;
n
= 17 stage II/
n
= 16 stage III) were enrolled. Patients completed self-reports of symptoms and function (e.g., EORTC QLQ-CIPN20) and objective measures of physical function (i.e., balance and gait testing) in an outpatient oncology clinic at five timepoints: (1) baseline—prior to starting chemotherapy, (2–4) before starting subsequent chemotherapy cycles, and (5) 1–3 months after receiving their last taxane infusion.
Results
Significant negative changes in both patient-reported outcomes and objective functional measures were observed. Decreased balance was observed after the first chemotherapy cycle (28% increase in medial–lateral excursion of the center of pressure,
p
= 0.016) and progressed with cumulative exposure (43% increase,
p
< 0.001). Patients also demonstrated slower walking speeds (5% decrease,
p
= 0.003) as they progressed through treatment. These functional deficits were mirrored with increased patient-reported symptom severity for all EORTC QLQ-CIPN20 subscales (all
p
< 0.05).
Conclusion
This study longitudinally assessed patient-reported outcomes concurrently with balance and gait testing in patients undergoing taxane therapy. Taxane treatment was associated with the development of clinically relevant problems in both CIPN symptoms and patient function.
Background:
Identifying athletes at an increased risk of injury is a promising approach to improve the effect of injury prevention interventions; however, it requires first identifying the potential ...athlete-specific risk factors. Cognitive ability was recently shown to correlate with noncontact anterior cruciate ligament injury rates and lower extremity mechanics, marking an underexplored area. A better understanding of how individuals’ cognitive ability is associated with neuromuscular control during sport-specific tasks may improve injury prevention.
Hypothesis:
Athletes with lower cognitive performance on a standardized cognitive assessment would demonstrate greater increases in knee valgus angle and moment when performing a sidestep cut with soccer ball dribbling versus without. Visual-spatial memory was expected to demonstrate stronger relationships than reaction time or processing speed.
Study Design:
Descriptive laboratory study.
Methods:
Fifteen male collegiate club soccer players participated (mean ± SD: 20.7 ± 2.0 years, 1.78 ± 0.07 m, 76.5 ± 8.9 kg). Participants performed anticipated 45° run-to-cut trials with and without a dual task of dribbling a soccer ball. Peak early-stance knee valgus angle and moment for the plant limb were calculated. Participants also completed a cognitive assessment to evaluate visual memory, verbal memory, reaction time, and processing speed. These composite scores were entered as candidate predictors for a stepwise regression analysis on the dual-task change scores in lower extremity biomechanical parameters (ie, ball handling – non–ball handling).
Results:
Visual memory composite score (a measure of visual-spatial memory) was the only cognitive outcome significantly associated with the change in biomechanical parameters. Each unit decrease in the visual memory composite score was associated with an increase of 0.21°± 0.05° in peak knee valgus angle during the ball-handling task as compared with the non–ball handling task (R2 = 52%, P = .003).
Conclusion:
Visual-spatial memory was associated with neuromuscular control during a sidestep cutting task during soccer ball dribbling, with deficits in this cognitive domain being associated with increased peak knee valgus angle.
Clinical Relevance:
Assessing visual-spatial memory ability may provide useful information to better understand conditions associated with impaired neuromuscular control and to potentially identify athletes at an elevated risk for musculoskeletal injury.
Studies have revealed that physical and mental demands, psychosocial factors, and individual factors can contribute to the development of WMSDs. Yet, much is still unknown regarding the effects of ...individual characteristics on WMSDs susceptibility. Previous studies discovered people assumed more awkward body postures to perform an activity when the perception of mental workload is higher. This research study explored if individual characteristics such as age, sex, personality, and anxiety help explain changes or differences in the perception of mental workload and body postures assume when performing activities. The study provided evidence that these individual characteristics have a modifying role on perceived mental workload and body postures. The results suggest that perceived mental workload is influenced to a higher extent by individual characteristics such as anxiety, sex, and personality traits. Women have a higher (18.7%) mental workload perception than men. Likewise, NASA-TLX scores are 22% higher for feelers than thinkers. In general, higher perceptions of mental workload were observed in participants with higher anxiety levels. On the other hand, body postures seem to be influenced by different individual factors depending on the nature of the activity. RULA scores increased on average by 13.1% between baseline and time constraint conditions. Larger differences were observed in certain individuals (e.g. introverts (19.7%) and intuitors (13.8%)) across conditions.
This study looked to explore if individual factors such as age, sex, personality, and anxiety have any effect in perceived mental workload and body postures. Participants performed two physical activities under four levels of mental workload. Results indicated that personality traits (sensors/intuitors), anxiety, and sex exhibited the higher contributions.
In this Perspective article we make the case for assessing National Biomechanics Day in order to better understand and maximum its impact. We present the opportunities and benefits that exist to ...assess National Biomechanics Day, as well as suggest assessment resources and tools that can be utilized. A case study is also included that details the ways that including assessment via a pre- and post-National Biomechanics Day survey provided insight into how our event changed student perceptions related to biomechanics, as well as informed us about how we might improve our event in the future.
Individuals diagnosed with chemotherapy-induced peripheral neuropathy (CIPN) demonstrate impaired balance and carry an increased risk of falling. However, prior investigations of postural instability ...have only compared these individuals against healthy controls, limiting the understanding of impairments associated with CIPN. Therefore, the purpose of this study was to better isolate postural control impairments that are associated with CIPN. Twenty cancer survivors previously diagnosed with breast or colorectal cancer participated. Participants were separated into 3 groups: no prior chemotherapy exposure (CON, n = 6), and recent treatment with taxane- or oxaliplatin-based chemotherapy with no/mild symptoms of CIPN (−CIPN, n = 8) or moderate/severe symptoms of CIPN (+CIPN, n = 6). Postural control was assessed by measuring center of pressure during standing balance conditions that systematically interfered with somatosensory, visual, and/or vestibular information. The presence of CIPN sensory symptoms was associated with impaired postural control, particularly during eyes-closed balance conditions (P < .05). Additionally, medial-lateral postural instability was more pronounced in the +CIPN group compared with the −CIPN group and CON participants (P < .05). Greater postural instability during eyes-closed balance in individuals with CIPN is consistent with impaired peripheral sensation. Balance impairments in cancer survivors with CIPN demonstrate the unique challenges in this population and motivate the need for targeted efforts to mitigate postural control deficits that have previously been associated with fall risk.
High injury rates following anterior cruciate ligament reconstruction (ACLR) motivate the need to better understand lingering movement deficiencies following return to sport. Athletic competition ...involves various types of sensory, motor, and cognitive challenges; however, postural control deficiencies during this spectrum of conditions are not well understood following ACLR.
To what extent is postural control altered following ACLR in the presence of sensory, motor, and cognitive challenges, and does postural control correlate with patient-reported symptoms?
Fourteen individuals following ACLR (4 m/10 f, 21.2 ± 2.4 yr, 76.9 ± 19.1 kg, 1.70 ± 0.14 m) and fourteen matched healthy controls (4 m/10 f, 21.2 ± 1.4 yr, 75.4 ± 15.3 kg, 1.70 ± 0.15 m) participated in the study. Participants completed single-leg balance, ACLR limb or matched side for controls, under four conditions: 1) eyes open, 2) eyes closed, 3) visual-cognitive dual task (i.e., reverse digit span), and 4) motor dual task (i.e., catching a ball). Sample entropy (SEn) was calculated for each balance condition to characterize regularity of center of pressure control. Participants also completed patient-reported outcomes to characterize self-reported knee function, symptoms, and fear. A mixed effects model tested for differences in SEn between balance conditions, and Spearman correlations tested for relationships between SEn and patient-reported outcomes.
A significant Group-by-Condition interaction was detected (P = 0.043). While the motor dual task and eyes closed balance conditions were associated with the lowest SEn for both groups, only the visual-cognitive dual task condition demonstrated a significant difference between groups, with the ACLR group having lower SEn 95% confidence interval for ΔSEn: (0.03, 0.35). Lower KOOS-Sport scores were associated with decreased SEn for the ACLR group (ρ = 0.81, P < 0.001).
These findings are consistent with ACLR individuals using a less automatic approach to postural control compared to controls, particularly when presented with a visual-cognitive challenge. Altered neuromuscular control persists well after ACLR surgery and can be related to patient-reported outcomes.
•A motor dual task elicited the greatest balance alterations for both groups.•Altered postural control was seen at least one year following ACLR.•Differences between ACLR and controls were isolated to the cognitive dual task.•CoP regularity during cognitive dual task associated with knee function after ACLR.
Background:
Physical fatigue and cognitive performance have been suggested as risk factors for an anterior cruciate ligament (ACL) injury, and fatigue has also been demonstrated to reduce cognitive ...processing. The combined effects of fatigue and lower cognitive function during cognitive-challenging movements may increase knee mechanics associated with the ACL injury risk.
Hypotheses:
We hypothesized that (1) knee mechanics would be detrimentally affected by fatigue and associated with baseline cognitive function and (2) fatigue-induced deleterious changes in cognitive performance and knee mechanics would be correlated.
Study Design:
Descriptive laboratory study.
Methods:
A total of 22 athletes completed baseline cognitive testing. After performing maximal vertical jumps, they performed a jump-land-jump task based on unanticipated visual cues. Then, they completed a fatigue protocol including countermovement jumps, among other tasks, until the jump height decreased below 90% of their assessed maximum. Immediately after reaching the first fatigue point, they performed another set of jump-landing tasks, followed by repeating the fatigue protocol until the jump height decreased below 85% of their assessed maximum. After reaching the second fatigue point, they performed a final set of jump-landing tasks and repeated the initial cognitive assessment battery.
Results:
Mixed-effects models revealed that knee flexion decreased through the fatigue protocol (baseline: 61.8°; midpoint: 61.1°; final: 60.1°; P = .003). Stepwise regression showed that fatigue-worsened attentional control corresponded to smaller knee abduction angles (R2adjusted = 51.68%; βstandardized = 1.16; P = .001), and worse reaction time after fatigue correlated with increased knee abduction angles (βstandardized = 0.85; P = .006) after accounting for the role of attentional control.
Conclusion:
Fatigue induced incremental modifications in sagittal-plane knee mechanics during an unanticipated sports movement. In addition, fatigue induced changes in cognitive function related to ACL injury–relevant knee mechanics.
Clinical Relevance:
The novel findings regarding fatigue-dependent changes in injury-relevant biomechanics during cognitively challenging movements represent an extension of recent developments in understanding the role of cognition in the ACL injury risk.
National Biomechanics Day (NBD) is an international celebration of biomechanics that seeks to increase the awareness and appreciation of biomechanics among the high school community. Initial research ...supports the positive effects of NBD on students’ attitudes toward the field of biomechanics; however, quantitative evidence remains scarce. The purpose of this study was to quantify changes in high school students’ perceptions toward biomechanics after participating in NBD events to better understand the impact of NBD. Data were collected at two locations during the 2019 NBD season. Surveys were collected before and after NBD events for 112 high school students from Montana and North Carolina. Paired pre- versus post-NBD surveys for the aggregate sample population suggest that students perceived biomechanics as more appealing (p = 0.050), exciting (p = 0.007), and important (p = 0.018) following the NBD events. Students did not report a change in whether they could see themselves in a biomechanics-related career (p = 0.49). These findings further support the ability for NBD events to positively impact students’ perceptions toward biomechanics, although opportunities persist to increase student career interest in biomechanics. This paper presents and discusses the study’s results, interpretations, limitations, and implications for future research on biomechanics outreach activities.
Context:
Does lower baseline cognitive function predispose athletes to ACL injury risk, especially when performing unplanned or dual-task movements?
Objective:
To evaluate the association between ...cognitive function and biomechanics related to ACL injuries during cognitively challenging sports movements.
Data Sources:
PubMed (MEDLINE), Web of Science, Scopus, and SciELO databases were searched; additional hand searching was also conducted.
Study Selection:
The following inclusion criteria had to be met: participants completed (1) a neurocognitive test, (2) a cognitively challenging sport-related task involving lower limbs, and (3) a biomechanical analysis. The following criteria determined exclusion from the review: studies involving participants with (1) recent or current musculoskeletal injuries; (2) recent or current concussion; (3) ACL surgical reconstruction, reviews of the literature, commentary or opinion articles, and case studies.
Study Design:
Systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) statement and registered at the International Prospective Register of Systematic Reviews (PROSPERO).
Level of Evidence:
Level 3.
Data Extraction:
Two of authors independently extracted data and assessed the methodological quality of the articles with the Downs and Black and ROBINS-I checklists, to assess methodological quality and risk of bias, respectively.
Results:
Six studies with different methodologies and confounding factors were included in this review. Of these 6 studies, 3 were ranked as high-quality, 3 demonstrated a low risk of bias, 2 a moderate risk, and 1 a severe risk. Five studies found a cognitive-motor relationship, with worse cognitive performance associated with increased injury risk, with 1 study reporting the opposite directionality for 1 variable. One study did not identify any interaction between cognitive function and biomechanical outcomes.
Conclusion:
Worse cognitive performance is associated with an increased injury risk profile during cognitively challenging movements.
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