Static Balance Tasks Research Articles

Strength Proxies Explain Balance Task Performance by Proximity to Peak Height Velocity in Young Acrobatic Gymnasts.

Background: Balance tasks are critical for performance in acrobatic gymnastics, where athletes often train and compete in mixed-age groups with varying maturational stages. To improve individualized training, in this cross-sectional study, the relationship was examined between strength capacity and balance task performance in female gymnasts at two maturational stages based on peak height velocity (PHV). Methods: Circa-PHV (n = 17, 11.92 ± 1.7 years) and post-PHV (n = 17, 16.47 ± 1.8 years) participants performed static balance tasks (standing on blocks, tandem stance, headstand) while center of pressure (CoP) excursion was recorded, and a proactive balance task (time to stabilization after landing, TTS). Strength assessments included isometric mid-thigh pull, handgrip, countermovement jump (CMJ), and push-up tests. Results: Correlational, regression, and inter-group analyses highlighted differences in strength-balance relationships across groups. Maximal isometric strength and CMJ power were the strongest predictors of static standing balance, with greater predictive strength in the circa-PHV group, underscoring the role of maturation in strength-balance interactions. The results also revealed that strength parameters influenced balance differently depending on the task, suggesting that specific balance types (static-proactive) and tasks (standing-inverted) require distinct strength capacities. Conclusions: Strength's influence on balance varies by maturational stage, emphasizing the need for tailored training programs to enhance balance and optimize performance in young gymnasts.

Changes in Motor Strategy and Neuromuscular Control During Balance Tasks in People with a Bimalleolar Ankle Fracture: A Preliminary and Exploratory Study.

Ankle fractures can lead to issues such as limited dorsiflexion, strength deficits, swelling, stiffness, balance disorders, and functional limitations, which complicate daily activities. This study aimed to describe neuromuscular adaptations at 6 and 12 months post-surgery during static and dynamic balance tasks, specifically using the Y-Balance Test (YBT). Additionally, the relationship between neuromuscular patterns, balance, and musculoskeletal deficits was evaluated. In 21 participants (14 at 6 months and 21 at 12 months) with bimalleolar fractures, hip strength, ankle dorsiflexion, ankle functionality, and static and dynamic balance were assessed using electromyography of five lower limb muscles (tibialis anterior, peroneus longus, lateral gastrocnemius, biceps femoris, and gluteus medius). A significant interaction effect (limb × proximal [hip]-distal [ankle] muscle) (F = 30.806, p < 0.001) was observed in the anterior direction of the Y-Balance Test (YBTA) at 6 months post-surgery. During the YBTA and YBT posteromedial (YBTPM), it was found that a lower dorsiflexion range of movement was associated specifically at 6 months with greater activation of the lateral gastrocnemius. However, these differences tended to diminish by 12 months. These findings suggest that neuromuscular patterns differ between operated and non-operated limbs during the YBTA at 6 months post-surgery. The Y-Balance Test, particularly its anterior direction, effectively highlighted these neuromuscular changes. This is a preliminary study; further research is needed to explore these findings in depth.

Reliability and validity of the ratings of perceived stability scale as a measure of balance exercise intensity in persons with multiple sclerosis

Purpose The study aimed to determine the test-retest reliability and concurrent validity of the Ratings of Perceived Stability (RPS) scale as a measure of balance exercise intensity in persons with multiple sclerosis (MS). Methods Twenty participants with MS (mean age: 58.1 ± 15.29; 60% female) performed 14 balance tasks on two separate occasions wearing body-worn inertial sensors and rated their perceived stability for each task. Sensor data included sway velocity and angle, gait speed, turn velocity, and lean angle. Intraclass correlation coefficients (ICC) and Spearman rank correlations (r s) were employed to assess reliability and validity, respectively. Results The RPS showed good to excellent test-retest reliability (ICC> 0.75) on 12 out of the 14 tasks. The stability ratings revealed moderate relationships with postural sway outcomes in static balance tasks (r s: 0.49 to 0.77) and weak to moderate associations with gait speed (r s: −0.69 to −0.14). Ratings of stability were also strongly related to turn velocity (r s= −0.77) and moderately related to lean angle (r s= 0.58). Conclusions The RPS scale offers a promising clinical tool to measure balance exercise intensity for persons with MS. This standardized scale allows for tailored balance training with a novel means for exercise monitoring and progression in this population.

Smartphone-based evaluation of static balance and mobility in type 2 Diabetes.

It was compared smartphone-based measurements of static balance control and mobility of elderly population with and without type 2 diabetes mellitus (DM2). The present cross-sectional study investigated 73 participants grouped in a control group (n = 36) and a DM2 group (n = 37). Smartphone's built in inertial sensors were used to record inertial changes of the participants during static balance and mobility (Timed Up and Go test - TUG) tasks. The inertial variations as a function of the time were analyzed and compared between groups. Both groups were matched in age, body mass index, male-female proportion, but DM2 group had significant larger fasting glucose than control group. Additionally, DM2 group had worst static balance control with open and closed eyes than the controls (p < 0.05) as well as they also had longer duration to execute the different events of the mobility test than the controls (p < 0.05). DM2 patients had decline of motor functions compared to controls and the use of bult-in sensors of smartphones was feasible to identify these functional impairments. The easy access of smartphones could be improving the screening of functional impairments in DM2 patients.

Use of Reactive Balance Assessments With Clinical Baseline Concussion Assessments in Collegiate Athletes.

Current clinical concussion evaluations assess balance deficits using static or dynamic balance tasks while largely ignoring reactive balance. Including a reactive balance assessment might provide a more comprehensive concussion evaluation. To identify redundancy in current clinical baseline assessments of concussion and determine whether reactive balance adds unique information to these evaluations. Cross-sectional study. Clinical assessment. A total of 279 healthy National Collegiate Athletic Association Division I athletes. Two cohorts of data were collected at the beginning of the athletic season. For cohort 1 (n = 191), the Immediate Post-Concussion Assessment and Cognitive Tool, instrumented modified push and release (I-mP&R), and Balance Error Scoring System (BESS) were administered. For cohort 2 (n = 88), the I-mP&R, BESS, timed tandem gait, walking with eyes closed, and clinical reaction time were administered. The strengths of the relationships between the Immediate Post-Concussion Assessment and Cognitive Tool cognitive indices, mP&R clinical score, instrumented measures (BESS sway; I-mP&R time to stability, latency, and step length), BESS score, timed tandem gait, walking time to completion, and clinical reaction time were characterized. The strongest interinstrument correlation value was between single-task time to stability from the I-mP&R and clinical reaction time but was considered weak (r = 0.35, P = .001). The mP&R and I-mP&R clinical scores were weakly associated with the other assessments. Weak correlations between interassessment variables indicated that little redundancy was present in the current clinical evaluations. Furthermore, reactive balance represents a unique domain of function that may improve the comprehensiveness of clinical assessments.

Smartphone-based evaluation of static balance and mobility in long-lasting COVID-19 patients.

SARS-CoV-2 infection can lead to a variety of persistent sequelae, collectively known as long COVID-19. Deficits in postural balance have been reported in patients several months after COVID-19 infection. The purpose of this study was to evaluate the static balance and balance of individuals with long COVID-19 using inertial sensors in smartphones. A total of 73 participants were included in this study, of which 41 had long COVID-19 and 32 served as controls. All participants in the long COVID-19 group reported physical complaints for at least 7 months after SARS-CoV-2 infection. Participants were evaluated using a built-in inertial sensor of a smartphone attached to the low back, which recorded inertial signals during a static balance and mobility task (timed up and go test). The parameters of static balance and mobility obtained from both groups were compared. The groups were matched for age and BMI. Of the 41 participants in the long COVID-19 group, 22 reported balance impairment and 33 had impaired balance in the Sharpened Romberg test. Static balance assessment revealed that the long COVID-19 group had greater postural instability with both eyes open and closed than the control group. In the TUG test, the long COVID-19 group showed greater acceleration during the sit-to-stand transition compared to the control group. The smartphone was feasible to identify losses in the balance motor control and mobility of patients with long-lasting symptomatic COVID-19 even after several months or years. Attention to the balance impairment experienced by these patients could help prevent falls and improve their quality of life, and the use of the smartphone can expand this monitoring for a broader population.

The Relationship between Balance Confidence and Center of Pressure in Lower-Limb Prosthesis Users

Background: Agreement between the activities-specific balance confidence scale (ABC) and center of pressure (CoP) in prosthesis users is still very much unknown. The purpose of this study was to investigate the agreement between ABC and CoP in lower-limb prosthesis users. Methods: Twenty-one individuals with lower-limb prostheses were recruited. Participants were provided with the ABC scale and performed static balance tasks during eyes opened (EO) and eyes closed (EC) conditions whilst standing on a force platform. Pearson product moment coefficients between CoP displacements and ABC scores were performed. Participants were also stratified by those who had better (≥80 on ABC scale) and less (&lt;80 on ABC scale) perceived balance confidence. Displacement was compared using an independent t-test with Cohen’s d to estimate effect size with alpha set at 0.05 for these tests. Results: There was a significant inverse moderate relationship between eyes opened displacement (EOD) (18.3 ± 12.5 cm) and ABC (75.1 ± 18.3%), r = (19)−0.58, p = 0.006, as well as eyes closed displacement (ECD) (37.7 ± 22.1 cm) and ABC, r = (19)−0.56, p = 0.008. No significant difference in EOD (t(19) = 1.36, p = 0.189, d = 0.61) and ECD (t(19) = 1.47, p = 0.156, d = 0.66) was seen between those with greater and less balance confidence. Conclusions: Self-report and performance-based balance outcome measures are recommended when assessing lower-limb prostheses users.

Perceived cognitive fatigue has only marginal effects on static balance control in healthy young adults.

We examined the influence of perceived cognitive fatigue on static balance control in healthy young adults to gain greater clarity about this issue than provided in previous research. Based on the prevailing assumption in pertinent literature, we hypothesized that the influence of cognitive fatigue on balance control depends on the attentional effort required by the balance tasks being performed. To test this hypothesis, 44 young adults (24 women and 20 men) were alternately assigned to either the experimental group that was cognitively fatigued (using the 16-min TloadDback-task with individualized settings) or the control group (who watched a documentary). Before and after the intervention, the participants performed six balance tasks that differed in (attentional) control requirements, while recording the center of pressure (COP). From these time series, sway variability, mean speed, and sample entropy were calculated and analyzed statistically. Additionally, perceived cognitive fatigue was assessed using VAS scales. Statistical analyses confirmed that the balance tasks differed in control characteristics and that cognitive fatigue was elevated in the experimental group, but not in the control group. Nevertheless, no significant main effects of cognitive fatigue were found on any of the COP measures of interest, except for some non-robust interaction effects related primarily tosample entropy. These results suggest that, in young adults, postural control in static balance tasks is largely automatic and unaffected by task-induced state fatigue.

Postural control measured before and after simulated ankle inversion landings among individuals with chronic ankle instability, copers, and controls

BackgroundPostural control measured during single-leg stance and single-leg hop stabilization has been used to estimate sensorimotor function in CAI individuals and copers. To date, studies have not used postural control tasks as a way of measuring responses to sudden changes in sensory information after simulated ankle inversion landings. Research questionA cross-sectional study was performed to identify any differences in static and dynamic postural control before and after simulated ankle inversion landings among individuals with chronic ankle instability (CAI), copers, and healthy controls. MethodsNineteen CAI individuals, 19 copers, and 19 controls participated in this study. Participants performed 3 static and dynamic balance tasks before and after simulated ankle inversion landings onto a 25° tilted platform from a height of 30 cm. The main outcome measures were the center of pressure (COP) velocity and range from the single-leg stance, as well as the dynamic postural stability index from the single-leg hop stabilization. The Wilcoxon signed-rank test was used to compare posttest and pretest differences in static and dynamic postural control between groups. ResultsIn the static postural control measures, the CAI group had a higher difference in COP velocity and COP range in the frontal plane (p < 0.05 and p < 0.05, respectively) than the coper group. In the dynamic postural control measures, the CAI group demonstrated a higher difference in the vertical stability index (p < 0.05) than the healthy control group. SignificanceCAI individuals have persistent worse postural control after somatosensory modulation due to their inability to adapt to sudden somatosensory modulation. Relative to CAI individuals, copers may have different abilities not only the integration of somatosensory input about ankle inversion modulation, but also the adaptation of the entire motor control system, preventing recurrent ankle sprains after an initial LAS. Therefore, somatosensory modulation may be the indicator of understanding CAI and coper.

Different neuromuscular control mechanisms regulate static and dynamic balance: A center-of-pressure analysis in young adults

The analysis of the center of pressure (CoP) trajectory, derived from force platforms, is a widely accepted measure to investigate postural balance control. The CoP trajectory could be analyzed as a physiological time-series through a general stochastic modeling framework (i.e., Stabilogram Diffusion Analysis (SDA)). Critical point divides short-term from long-term regions and diffusion coefficients reflect the level of stochastic activity of the CoP. Sample Entropy (SampEn) allows quantifying the CoP complexity in terms of regularity. Thus, this study aimed to understand whether SDA and SampEn could discriminate the neuromuscular control mechanisms underpinning static and dynamic postural tasks. Static balance control and its relationship with dynamic balance control were investigated through the CoP velocity (Mean Velocity) and the area of the 95th percentile ellipse (Area95). Balance was assessed in 15 subjects (age: 23.13 ± 0.99 years; M = 9) over a force platform under two conditions: static (ST) and dynamic, both in anterior-posterior (DAP) and medio-lateral (DML) directions. During the DAP and DML, subjects stood on an unstable board positioned over a force platform. Short-term SDA diffusion coefficients and critical points were lower in ST than in DAP and DML (p < 0.05). SampEn values resulted greater in ST than in DAP and DML (p < 0.001). As expected, lower values of Area95 (p < 0.001) and Mean Velocity (p < 0.001) were detected in the easiest condition, the ST, compared to DAP and DML. No significant correlations between static and dynamic balance performances were detected. Moreover, differences in the diffusion coefficients were detected comparing DAP and DML (p < 0.05). In the anterior-posterior direction, the critical point occurred at relatively small intervals in DML compared to DAP (p < 0.001) and ST (p < 0.001). In the medio-lateral direction, the critical point differed only between DAP and DML (p < 0.05). Overall, SDA analysis pointed out a less tightly regulated neuromuscular control system in the dynamic tasks, with closed-loop corrective feedback mechanisms called into play at different time intervals in the three conditions. SampEn results reflected more attention and, thus, less automatic control mechanisms in the dynamic conditions, particularly in the medio-lateral task. The different neuromuscular control mechanisms that emerged in the static and dynamic balance tasks encourage using both static and dynamic tests for a more comprehensive balance performance assessment.

Principal component analysis of whole-body kinematics using markerless motion capture during static balance tasks

Balance tests have clinical utility in identifying balance deficits and supporting recommendations for appropriate treatments. Motion capture technology can be used to measure whole-body kinematics during balance tasks, but to date the high technical and financial costs have limited uptake of traditional marker-based motion capture systems for clinical applications. Markerless motion capture technology using standard video cameras has the potential to provide whole-body kinematic assessments with clinically accessible technology. Our aim was to quantify poses and movement strategies during static balance tasks (tandem stance, single limb stance, standing hip abduction, and quiet standing on foam with eyes closed) using video-based markerless motion capture software (Theia3D) and principal component analysis to examine the associations with age, body mass index (BMI) and sex. In 30 healthy adults, the mean poses for all balance tasks had at least one principal component (PC) that differed significantly by sex. Age was significantly associated with the PC describing leg height for the hip abduction task and erect posture for the quiet standing task. BMI was significantly associated with the PC capturing knee flexion in the single leg stance task. The movement strategies used to maintain balance showed significant differences by sex for the tandem stance pose. BMI was correlated with PCs for movement strategies for hip abduction and quiet standing tasks. Results from this study demonstrate how markerless motion capture technology could be used to augment analyses of balance both in the clinic and in the field.

Motivating Instructions Provoke Large Increases In Volitional Postural Sway

Postural sway generally is assessed using static balance tasks. Dynamic “limits of stability” (LoS) tasks have been used, though these typically provide a visual target to inform the direction and amplitude of sway for the participant. Recently, a new version of this task has been developed to better assess volitional sway control. It is unclear what external motivation may do to affect performance on this task. PURPOSE: To explore the effects of verbal encouragement on volitional sway during the LoS protocol on a Balance Tracking System (BTrackS) Balance Plate. METHODS: Forty healthy college students (age 20.1 ± .9 y) performed three trials of LoS, each lasting one minute in duration with five minutes between each trial. Prior to trials 1 and 2, a researcher stated the following instructions: “During this task, I want you to lean in all directions and make the largest blue box possible on the computer screen. The further you lean, the larger the box will get. During this test, please keep your feet completely flat on the board.” Participants were allowed to look at their performance (i.e., total area covered) but were not given any verbal feedback from the researcher. For the 3rd trial, similar instructions were given to each participant except with more emphasis on overall performance: “For this final trial, I want you to lean in all directions as far as you absolutely can. The goal for this trial is to beat your first two attempts. The further you lean, the larger the box will get. Please remember to keep your feet completely flat.” Values for total area covered during each trial were provided by the software and recorded for analysis. RESULTS: Image Here CONCLUSION: Our data show a significant and large increase in volitional sway area after verbal encouragement. This highlights the importance of following the verbal prompt provided by the LoS protocol. Further, it supports the emerging value of volitional sway tasks to fully understand the underlying mechanisms of dynamic postural control.

Postural balance in frequent lucid dreamers: a replication attempt.

Early research suggests that the vestibular system is implicated in lucid dreaming, e.g. frequent lucid dreamers outperform others on static balance tasks. Furthermore, gravity-themed dreams, such as flying dreams, frequently accompany lucid dreaming. Nonetheless, studies are scarce. We attempted to: (1) replicate previous findings using more sensitive static balance measures and (2) extend these findings by examining relationships with dreamed gravity imagery more generally. 131 participants (80 F; Mage=24.1 ± 4.1 yrs) estimated lucid dreaming frequency then completed a 5-day home log with ratings for dream lucidity awareness, control, and gravity sensations (flying, falling). They then performed balance tasks on a sensitive force plate, i.e. standing on one or both feet, with eyes open or closed. Center of pressure (CoP) Displacement and CoP Velocity on each trial measured postural stability. Findings partially support the claim of a vestibular contribution to lucid dreaming. Frequent lucid dreamers displayed better balance (lower CoP Velocity) than did other participants on some trials and lucid dreaming frequency was globally correlated with better balance (lower CoP Velocity). Lower CoP Velocity was related to flying sensations in men's dreams and with more dream control in women's dreams. However, body height-possibly due to its relationship to sex-and levels of sleepiness confound some of these effects. While findings only provide a partial replication of previous work, they nonetheless support an emerging view that the vestibular system underlies basic attributes of bodily self-consciousness, such as feelings of self-agency and self-location, whether such consciousness occurs during wakefulness or dreaming.

Principal Component Analysis of Whole-Body Kinematics Using Markerless Motion Capture During Static Balance Tasks

Principal Component Analysis of Whole-Body Kinematics Using Markerless Motion Capture During Static Balance Tasks

Does instructing attentional focus direction affect static single leg balance performance?

Balance and postural control exercises are generally included as a part of exercise programs, during which movement practitioners can provide instructions to facilitate the performance of motor skills. Instructions can be used as cues to direct attentional focus, which has been found to affect the performance of motor skills, including balance and postural control tasks. However, no known studies to date have investigated the effect of both internal and external attentional focus instructions on static single leg balance performance, and it seems unclear whether effects of such instructions are related specifically to the direction of attention. The purpose of this study was to investigate the effect of instructing the direction of attentional focus on single leg static balance performance as reflected by the complexity of the center of pressure (COP) profile. Participants (N = 46) between the ages of 19–28 years old were randomly assigned to one of three group conditions: internal focus (INTn=15), external focus (EXTn=16) and control (CONn=15). Participants performed a thirty-five second static single leg balance task. Outcome measures were the scaling exponent determined from a detrended fluctuation analysis (DFA) to infer complexity of the COP profile in the anterior-posterior (AP) and medial-lateral (ML) directions, and root mean square error (RMSE) of the COP profile in AP and ML directions. A one-way analysis of variance (ANOVA) determined there were no statistically significant differences in the measured variables among groups. The results do not support the claim that manipulating the direction of attentional focus affects static single leg balance performance.

The effects of leg preference and leg dominance on static and dynamic balance performance in highly-trained tennis players.

In this study, 90 (51 males, 39 females) tennis players performed single-leg quiet stance and single-leg landing tasks. For the static standing task, center-of pressure (CoP) velocities, amplitudes, frequency and area were calculated. For the landing tasks, time to stabilization as well as dynamic postural stability index were considered. The analysis of differences between the legs was done based on two methods for a priori determination of leg preference, one based on the preference of kicking a ball and one based on the preference for single-leg jumping. An additional analysis was done based on the leg dominance (determined post hoc), based on the observed performance of the tasks. In case of the classification based on kicking a ball, there was a statistically significantly lower CoP anterior-posterior velocity and anterior-posterior amplitude in static balance task (p ≤ 0.017; 0.17 ≤ d ≤ 0.28) for the preferred leg. The CoP frequency was higher in the preferred leg for both directions (p ≤ 0.002; 0.10 ≤ d ≤ 0.22). For the landing task, CoP medial-lateral time to stabilization was statistically significantly shorter for the preferred leg (0.28 ± 0.38 s) compared to the non-preferred leg (0.47 ± 0.60 s) (p = 0.012; d = 0.38). There were no differences between the legs for the landing task. Moreover, there were no differences between the legs when we used the preference based on jumping for either of the tasks (d ≤ 0.14). The differences between legs in terms of observed dominance were larger than the differences based on the preference, which stresses the need for clear distinction of limb preference and limb dominance in research and practice. Regarding the effect of leg preference, small differences in static balance may exist between the legs (when the preference is based on kicking a ball).

Impact of strength and balance on Functional Gait Assessment performance in older adults

BackgroundThe Functional Gait Assessment (FGA) evaluates postural stability in gait and predicts fall risk in older adults. Individual tasks within the FGA consider aspects of mobility assumed to require strength and/or balance to complete. Identifying how quantitative measures of strength and balance relate to FGA performance would allow for more targeted interventions based on one’s pattern of performance on different tasks. Research QuestionIs performance on the FGA (total score and individual task scores) related to measures of strength and balance in healthy older adults? MethodsIn a cross-sectional study, healthy older adults (N = 46) were evaluated with the FGA, measures of knee extensor strength, and balance (static stance and weight shifting) (N = 46). Correlational analyses were performed between FGA scores (total and individual) and measures of strength and balance. ResultsTotal FGA performance was positively correlated with knee extensor strength (maximum torque and rate of torque development). Individual FGA tasks of walking backwards (task 9) and stair climbing (task 10) had the highest correlations with strength measures. Total FGA performance was correlated with reduced postural sway in static balance tasks, but not with balance performance on the weight shifting tasks. The individual FGA task that challenged proprioceptive (task 7) inputs for balance was associated with static balance. SignificanceThe total FGA score is related to domains of strength and static balance. The results indicate that the FGA can be influenced by reduced strength and balance. The pattern of performance on individual FGA tasks may indicate whether reduced postural stability in gait is related to deficits in strength or balance domains in this older population.

Postural balance problems in people with intellectual disabilities: Do not forget the sensory input systems.

This pilot study aimed to explore the impact of visual, auditory and vestibular dysfunctions on the postural balance performance in adults with intellectual disabilities. Additionally, a comparison was made between the subjects with intellectual disabilities and a control group concerning static and dynamic balance tasks. Thirty adults with intellectual disabilities and 25 control subjects received a postural balance assessment. Additionally, the experimental group was subjected to a visual, auditory and vestibular screening. The experimental group performed significantly worse and/or showed more sway compared to the control group for all balance tasks (p < .01) except the timed up and go test. Within the experimental group, a significant positive correlation (rs (24)=0.513, p=.007) was observed between the number of failed sensory screening items and the number of failed balance tasks. These findings suggest significant involvement of peripheral sensorial deficits in the balance problems that people with intellectual disabilities often experience.

Balance is impaired in symptomatic ankle osteoarthritis: A cross-sectional study

Ankle osteoarthritis (OA) is associated with several physical impairments but investigations into balance impairments in this population are limited. Understanding balance impairments in ankle OA may help inform the management of this condition. Does balance overall performance differ between individuals with symptomatic radiographic ankle OA, asymptomatic radiographic ankle OA and healthy controls? Are there any differences in mediolateral or anteroposterior balance, or confidence to perform balance tasks between these groups? Ninety-six volunteers (31 symptomatic radiographic ankle OA, 41 asymptomatic radiographic ankle OA and 24 healthy controls) completed six static balance tasks: bilateral stance on a firm surface, bilateral stance on foam, and tandem stance, all performed with eyes open and closed. Centre of pressure (COP) data were collected using force plates. Confidence to perform each balance task was collected using an 11-point numerical rating scale. Compared to controls, participants with symptomatic radiographic ankle OA had greater COP area when standing on a firm surface, foam and in tandem with eyes closed (all p < 0.05) and greater total COP sway in both firm surface and tandem stance conditions (p < 0.04). Participants with symptomatic ankle OA had greater COP area (p < 0.04) and total COP sway (p = 0.01) than those with asymptomatic ankle OA during tandem stance. Total COP sway and area were similar between asymptomatic ankle OA and control participants. Some differences in mediolateral and anteroposterior balance were identified between groups. Individuals with symptomatic ankle OA had lower confidence to perform the tandem stance eyes closed task compared to controls. Balance impairments and decreased balance confidence were identified in those with symptomatic radiographic ankle OA compared to asymptomatic individuals with and without radiographic ankle OA. This suggests that balance deficits in ankle OA may be related to symptoms, rather than radiographic evidence of disease.

The Effects of Firefighter Equipment and Gear on the Static and Dynamic Postural Stability of Fire Cadets.

Slips, trips, falls, and jumps were the second leading cause of injuries at the fireground. The purpose of this study was to explore the effects of firefighter equipment and gear (EQG) on postural stability and determine if load per kg of body mass (L/BM) is associated with postural stability. 26 male fire cadets (26.15 ± 4.16 yr., 178.92 ± 6.92 cm, 86.61 ± 9.09 kg) were included in the analyses. Participants performed 3 single-leg landings (SLL) with and without EQG. The first 3 seconds of ground reaction forces following initial ground contact were used to calculate dynamic postural stability index (DPSI). Participants completed 2 static balance tasks (normal stability and limits of stability (LoS)) with and without EQG. Main outcome measures were overall LoS score (LoSS), direction-specific LoSS, and LoS distance (cm) of COP excursion (LoSD) in the anterior, posterior, right, and left directions. Separate paired-samples t-tests were run to determine the differences between load conditions for DPSI, overall LoSS, direction-specific LoSS, and LoSD in all directions. Bivariate correlations were conducted to determine the relationship of L/BM to DPSI, overall LoSS, and LoSS and LoSD in the anterior, posterior, right and left directions. Due to the use of multiple statistical tests, a Bonferroni correction was used, and the alpha level of .05 was adjusted to .005. DPSI was significantly higher loaded than unloaded, t(25) = -13.965, p < .001, d = 7.032, 95% CI, -0.133 to -0.099. No other comparisons were significant. A significant strong positive correlation (r(24) = .665, p < .001) was observed between L/BM and DPSI. No other correlations were significant. This study demonstrates that firefighter EQG may significantly impact a cadet's ability to maintain postural stability while performing their duties.