Increase In Postural Sway Research Articles

Reduction In Support Leg Active Range Of Motion And Increase In Postural Sway On People With Chronic Low Back Pain During Y-balance Test

Reduction In Support Leg Active Range Of Motion And Increase In Postural Sway On People With Chronic Low Back Pain During Y-balance Test

Postural Control and Muscle Activity during Dual-Task in Young Adults.

In everyday life, we recurrently perform two tasks simultaneously, which is called dual-tasking. A common dual task is smartphone use while standing or walking. According to previous studies, this task can compromise postural stability. However, few studies have analyzed lower limb muscle activity during dual-tasking using smartphones. This study aimed to assess the postural sway and muscle activity during dual-tasking in young adults. Thirty-six healthy young adults (23.08 ± 3.92 years) participated in this study. They performed a single task (ST: keeping a quiet standing posture) and a dual task (DT: keeping the ST while simultaneously performing a cognitive task on their smartphone). Postural sway was assessed through the center of pressure (CoP) analysis using a force platform: total CoP displacement, CoP displacement in the anterior-posterior and medial-lateral directions, mean total velocity of the CoP, mean velocity of the CoP in the anterior-posterior and medial-lateral directions, and 95% confidence ellipse sway area. A surface electromyography system recorded the muscle activity of the lumbar spinal erector and five muscles of the lower limb (bilaterally). The results showed an increase in postural sway from the ST to the DT in all CoP variables (p < 0.05), and muscle activity in most muscles analyzed decreased from the ST to the DT (p < 0.05). In conclusion, our results reflect a decentralization of attention from motor performance once postural sway increased and muscle activity decreased in dual-task conditions.

Quantifying unsupported sitting posture impairments in humans with cervical spinal cord injury using a head-mounted IMU sensor.

Cross-sectional study. To evaluate unsupported sitting posture impairments and identify postural regulatory strategies in cervical spinal cord injury (cSCI) participants via a head-mounted IMU sensor. A research lab in the United States of America. cSCI participants and controls maintained postural stability during unsupported sitting with eyes either open or closed. The head-mounted IMU sensor recorded accelerometer data to calculate cumulative sway motion. The postural regulatory strategy was analyzed by assessing the normalized power spectral density (PSD) in four frequency bands: 0-0.1 Hz (visual regulation), 0.1-0.5 Hz (vestibular regulation), 0.5-1 Hz (cerebellar regulation), and >1 Hz (proprioception and muscle control). Significant increases in postural sway were observed in cSCI participants compared to controls during unsupported sitting. For cSCI participants, normalized PSD significantly increased in the low-frequency bands (0-0.1 Hz and 0.1-0.5 Hz) but decreased in the high-frequency band (>1 Hz) compared to controls. cSCI participants were more reliant on visual and vestibular systems for sitting balance, while depending less on proprioception and muscle control compared to controls. These findings suggest that the altered postural regulatory strategy is ineffective in maintaining postural stability during unsupported sitting, emphasizing the importance of proprioception and muscle control for seated postural stability in cSCI participants.

A preliminary investigation into the impact of shock wave therapy and sonotherapy on postural control of stepping tasks in patients with Achilles tendinopathy.

The outcomes of physical therapy are commonly assessed with subjective scales and questionnaires. Hence, a continuous search to identify diagnostic tests that would facilitate objective assessment of symptom reduction in those patients with Achilles tendinopathy who undergo mechanotherapy. The main aim of this study was to evaluate and compare the effectiveness of shock wave and ultrasound treatments, using objective posturographic assessment during step-up and step-down initiation. The patients with non-insertional Achilles tendinopathy and pain lasting for more than 3 months were randomly assigned to one of the experimental groups, i.e., radial shock wave therapy (RSWT), ultrasound therapy, or placebo ultrasound. All groups also received deep friction massage as the primary therapy. The transitional locomotor task was performed with the affected and unaffected limb in random order, on two force platforms under two conditions (step-up and step-down). The recording of center of foot pressure displacements was divided into three phases: quiet standing before step-up/step-down, transit, and quiet standing until measurement completion. Pre-intervention measurements were performed and then short-term follow-ups at weeks 1 and 6 post-therapy. The three-way repeated measures ANOVA showed few statistically significant two-factor interactions between therapy type, time point of measurement and the type of the locomotor task. Significant increases in postural sway were observed in the entire study population throughout the follow-up period. Three-way ANOVAs revealed a group effect (shock wave vs. ultrasound) on almost all variables of the quiet standing phase prior to step-up/step-down initiation. Overall, postural stability before the step-up and step-down tasks appeared to be more efficient in patients who had undergone RSWT compared to the ultrasound group. Objective posturographic assessment during step-up and step-down initiation did not demonstrate therapeutic superiority of any of the three therapeutic interventions used in patients with non-insertional Achilles tendinopathy.Clinical Trial Registration: The trial was prospectively registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12617000860369; registration date: 9.06.2017).

The effects of optic flow on postural stability: Influence of age and fall risk

BackgroundOptic flow provides dynamic information relating to body position and motion with respect to visual frames of reference. This study investigated the effects of optic flow stimuli presented in four directions on postural stability in young and older adults. MethodsTwenty-five young (20–40 years) and 51 older (≥65 years) people participated in this study, with the older group classified into low fall risk (n = 27), and high fall risk (n = 24) sub-groups. While standing in a dark room, participants viewed static scattered white dots for 30 s, followed by 30 s periods of optic flow consisting of white dots “moving” in one of four flow directions, randomised: radial expansion and contraction, circular anti-clockwise and clockwise. Centre of pressure (CoP) position, postural sway in anteroposterior (AP) and mediolateral (ML) axes, and muscle activity of tibialis anterior (TA), gastrocnemius medialis (GM) and tensor fascia latae (TFL) were recorded. ResultsAcross groups, the four optic flow stimuli induced increased AP sway and three of the four optic flow stimuli induced increased ML sway, with concomitant increases in muscle activity, indicating optic flow stimuli induced a generalised destabilising, rather than a direction-specific, effect. Only one optic flow condition (radial contraction) induced a change in average CoP position, and this may reflect the adoption of a protective stance position to avoid a backward fall. Optic flow destabilised postural control more in older people compared with younger people, and radial expansion stimuli destabilised ML postural control more in the older high fall risk group compared with the older low fall risk group. ConclusionOptic flow stimuli have a generalised destabilising effect on postural control across groups as shown by non-directional specific increases in postural sway and muscular activity. Optic flow stimuli have a greater impact on postural stability in older compared with younger adults and this is more pronounced in the ML plane for older people at increased risk of falls.

The effects of acute normobaric hypoxia on vestibular-evoked balance responses in humans.

Hypoxia influences standing balance and vestibular function. The purpose here was to investigate the effect of hypoxia on the vestibular control of balance. Twenty participants (10 males; 10 females) were tested over two days (normobaric hypoxia and normoxia). Participants stood on a force plate (head rotated leftward) and experienced random, continuous electrical vestibular stimulation (EVS) during trials of eyes open (EO) and closed (EC) at baseline (BL), after 5 (H1), 30 (H2) and 55-min (H3) of hypoxia, and 10-min into normoxic recovery (NR). Vestibular-evoked balance responses were quantified using cumulant density, coherence, and gain functions between EVS and anteroposterior forces. Oxyhemoglobin saturation, end-tidal oxygen and carbon dioxide decreased for H1-3 compared to BL; however, end-tidal carbon dioxide remained reduced at NR with EC (p≤0.003). EVS-AP force peak-to-peak amplitude was lower at H3 and NR than at BL (p≤0.01). At multiple frequencies, EVS-AP force coherence and gain estimates were lower at H3 and NR than BL for females; however, this was only observed for coherence for males. Overall, vestibular-evoked balance responses are blunted following normobaric hypoxia >30 min, which persists into NR and may contribute to the reported increases in postural sway.

Evaluation of Static and Dynamic Balance During Menstrual Cycle (Day 1 And Day 14) And Its Correlation with Primary Dysmenorrhea in Physiotherapy Students (18-25 Year) - A Correlational Study

The purpose of study was to evaluate static and dynamic balance during menstrual cycle (Day 1 and Day 14) and its co relation with primary dysmenorrhea in physiotherapy study (18-25 year). [Subject and Methods] 45 subjects (mean age 21.75 year) weight 21.57kg; height 154.5cm) participated in the study. The balance assessment was done for static balance, single leg stance test (rt and lt leg) and dynamic balance using star excursion balance test ( rt and lt leg)..[Results ] The study was done, the study showed that there was an impairment in balance and significant increase in postural sway at day 14 compared to day 1 [p &lt;0.05 ].The moderate negative correlation exist between dynamic balance (rt) and (lt) day 14 WaLIDD Score,(primary dysmenorrhea).This implies that as WaLIDD score increases the dynamic balance i.e. STAR EXCURSION BALANCE TEST score decreases on day 14.[Conclusion] The study concludes that balance is affected at 14th day of menstrual cycle as compared to 1 st day. There is moderate negative correlation exist between primary dysmenorrhea and dynamic balance. Keywords: [Menstrual cycle, static balance, dynamic balance, WaLIDD score balance impairment]

Postural sway and weight distribution in diabetic neuropathy patients: narrative Review.

Background: Type 2 Diabetes mellitus is a common metabolic condition increasing in the elderly population which leads to various disabilities and in longtime can cause chronic complications like diabetic neuropathy, diabetic nephropathy, diabetic retinopathy and diabetic cardiopathy. Objective: The aim of this narrative review is to identify the sway in posture and distribution of weight in bilateral stance in diabetic neuropathy patients. Methods: The articles are taken from Google Scholar, PUBMED, and EMBASE MEDLINE. Results: Increased anterior displacement than medial, lateral and posterior displacement in postural sway both in eye closed and eyes open, center of pressure and center of mass also changes in postural stability which will aid to identify risk of fall. In weight distribution there is an increased plantar pressure in anterior direction and higher plantar pressures were obtained in long standing phase. Discussion and Conclusion: Early detection of postural sway in diabetic patients may decrease in risk of fall, identifying the muscle strengthening and balance impairment. Even early detection of improper weight distribution over the lower limbs mainly over the foot can reduced the presence of plantar pressure sores, risk of falls and balance instability, or diabetic foot. Postural sway and weight distribution is measured in stance phase than dynamic phase, increase in postural sway can cause to risk of fall and increase in weight distribution on limb can cause wear and tear of the structure. Keyword: Postural Sway, Diabetic Neuropathy and Diabetic Nephropathy, weight distribution, plantar pressure, diabetes mellitus, diabetic foot.

Influence of serial subtraction tasks on transient characteristics of postural control.

We sought to better understand the influence of cognitive perturbations on transient aspects of postural control. Twenty healthy, younger adults had their postural control assessed during eyes open quiet stance. Participants completed three different conditions that either had no cognitive perturbation present, an easy cognitive perturbation (i.e., serial subtraction by ones), or a more difficult cognitive perturbation (i.e., serial subtraction by sevens). All trials finished with 60s of undisturbed eyes open quiet stance, which was the focus of the balance assessment. 95% confidence ellipse area (EA) was calculated for 5-s epochs throughout the trial. The difference in EA from the first epoch after participants started (onset) or stopped (offset) the cognitive task to the last epoch of the trial (i.e., 55-60s after perturbation) was used to characterize transient postural control behavior. Functional near-infrared spectroscopy was also used to quantify changes in prefrontal cortex activation during the counting tasks to support interpretation of the transient balance findings. There was a significant effect of condition for transient balance characteristics following a cognitive perturbation (P<0.001), with greater transient increases in postural sway for both difficult (Cohen's d=0.40, P<0.001) and easier (Cohen's d=0.29, P=0.013) cognitive perturbations relative to no cognitive perturbation. The onset of cognitive tasks was also associated with greater transient increases in postural sway than the offset of the cognitive tasks (Cohen's d=0.24, P=0.019). The functional near-infrared spectroscopy data indicated that a significant decrease in deoxygenated hemoglobin was observed for left Brodmann area 46 for both the subtraction by ones (T=-3.97; Benjamini-Hochberg significance value (q)=0.008) and subtraction by sevens (T=-3.11; q=0.036) conditions relative to the baseline condition. The subtraction by sevens condition was also associated with a relative increase in deoxygenated hemoglobin for the right Brodmann area 9 (T=3.36; q=0.026) compared to the subtraction by ones condition. In conclusion, serial subtraction can elicit transient increases in postural sway, with more difficult tasks and the onset of the cognitive-motor challenge exhibiting magnified effects. Additionally, even the cessation of a cognitive task (i.e., serial subtraction) can be associated with lingering perturbing effects on balance control.

Stationary auditory white noise improves postural control in healthy adults: A novel study on head-shaking.

Auditory cues might play a role in postural control. The primary aim of this study was to investigate the association between white noise and head-shake (HS) related changes in postural sway. Fifty healthy adults underwent Synapsys Posturography System (SPS) evaluation. The posturography (PG) evaluation consisted of two protocols: sensory organization test (SOT) and SOT with head-shake (HS) (HS-SOT). The standard SOT protocol of SPS involves a battery of six postural conditions. In the current study, participants underwent only four SOT conditions. The participants were asked to stand barefoot on the SPS platform (static platform and foam). The SOT standing conditions were as follow: (1) firm surface (force platform only) with eyes open (SOT1); (2) firm surface with eyes closed (SOT2); (3) foam surface (which was positioned on the force platform) with eyes open (SOT4); and (4) foam surface with eyes closed (SOT5). For the HS-SOT protocol, we asked the participants to move their heads left and right (i.e., yaw head rotation) in the mentioned SOT conditions. Each postural condition was 10 seconds long. Both SOT and HS-SOT postural conditions were conducted across the two hearing modes of silence and noise. To achieve our aims, comparison of sway parameters between SOT and HS-SOT, and between hearing modes were considered. White noise was associated with a reduction in postural sway. The reduction observed in sway area, sway amplitude, and sway frequency. Moreover, HS significantly increased postural sway in all HS-SOT conditions compared to their SOT equivalents (i.e., HS-SOT1 compared to SOT1, etc.). The presence of white noise was associated with a decrease in the HS-related increase in postural sway. Considering the results, this study adds to the body of literature suggesting that white noise contributes to postural control, and the implications of this for rehabilitation need to be further investigated.

Quantitative Assessment of Sensory Integration and Balance in Children with Autism Spectrum Disorders: Cross-Sectional Study.

Postural stability is dependent on the interpretation of external inputs acquired by sensory information processes, such as visual, vestibular, and proprioceptive systems, in order to accomplish neuromuscular control, balance maintenance, and appropriate motor response. A defect in any of these systems, or in the integration of information given by these systems, might threaten their capacity to maintain balance. Therefore, the purpose of this study was to investigate the sensory integration and balance using the Biodex balance system (BBS) in children with autism spectrum disorder (ASD) during the static posture. Seventy-four children from both sexes, 38 with ASD matched with 36 typically developed (TD) children as a control group, were included in the study. Using the Biodex balance system, the postural sway was evaluated through the modified Clinical Test of Sensory Integration and Balance (m-CTSIB) during quiet standing. In this test, four different situations were considered from standing position: eyes open/firm surface, eyes closed/firm surface, eyes open/foam surface, and eyes closed/foam surface. ASD children showed a significant increase in postural sway under all tested conditions when compared to the TD children group, especially for the conditions in which visual and somatosensory inputs were disrupted (p-value < 0.05). These results provide evidence that postural stability decreased in ASD children. Under static postural challenges, the current study’s findings imply that children diagnosed with ASD have postural control deficiencies, especially for the conditions in which visual and somatosensory input was disrupted. Further research must be conducted to find the best balance training program for ASD cases using the Biodex balance system and considering its impact on motor skills.

Does an Externally Focused Dual-task Mitigate Real-time Conscious Postural Control in Older Adults?

ABSTRACT Objectives This study first examined whether real-time conscious postural control (reinvestment) and postural sway increase with different postural difficulties on a compliant surface among older adults. The second objective was to investigate the effect of an externally focused dual-task on real-time reinvestment and postural sway under a relatively challenging standing position. Method Thirty-two community-dwelling older adults (mean age = 72.09, SD = 4.18 years) were recruited. Participants performed balance tasks in four standing positions in a randomized order on a balance foam pad. The four positions included wide-based standing on foam (WBF), narrow-based standing on foam (NBF), tandem-based standing on foam (TBF) and tandem-based standing on foam with an externally focused dual-task (TBFE). Throughout all the balance tasks, participants’ real-time reinvestment and body sway were indicated by the Alpha2 T3-Fz Electroencephalogram (EEG) coherence and the total sway length (TSL), respectively. Results and Discussion Our results revealed no significant difference in real-time reinvestment among different standing positions while postural sway increased from WBF to NBF and reduced from NBF to TBF. We also demonstrated that when performing a relatively challenging standing task on a compliant surface, an externally focused dual-task (TBFE), compared to a baseline single task (TBF), can neither mitigate real-time reinvestment nor improve balance performance in community-dwelling older adults with good balance capability. Potential explanations and implications are discussed.

Smaller Cortisol Awakening Responses Are Associated with Greater Visual Dependence in Postural Control.

There are known links between the hypothalamic–pituitary–adrenal (HPA) axis and systems responsible for regulating posture. Our aim was to explore directly, for the first time, whether an aspect of circadian HPA axis activity (the cortisol awakening response: CAR) was associated with greater visual dependency in postural control. For measurement of the CAR, electronically monitored saliva samples were collected by participants following morning awakening in their home environment. On the afternoons of the same days, postural sway was measured in the laboratory by exposing participants to static (control) and moving visual stimuli whilst standing still and upright on a force platform. Visual dependence was assessed as the increase in postural sway (path length) during exposure to the moving compared with the static condition. The 44 measurement days were derived from four days for each of eleven healthy participants (mean ± SD age: 51.18 ± 3.3 years). As expected, postural sway was greater when exposed to moving versus static cues. Mixed regression modelling showed that participants with smaller four day average CARs had greater deterioration in postural sway when presented with moving stimuli. These data are the first to document associations between the CAR and visual dependency in postural sway.

Occlusal support and postural stability in children: An observational study.

The relationship between uneven occlusal contact and fall risk has been described in elderly participants; however, multiple confounding factors, such as systemic disease or deterioration in vestibular function, have not been well considered. This study aimed to investigate this relationship in pediatric participants at the age of approximately 9-12, where these confounding factors are absent and the replacement of primary molars by permanent ones generally occurs and transiently results in uneven occlusal contact. Sixty-five children (36 boys and 29 girls, mean age: 9.5 ± 1.5years) were enrolled in this study. Participants were asked whether they had experienced at least two falls within the past 1year. The occlusal contact area ratio was calculated by dividing the greater half (right or left dental arch) by the smaller half (the other half) with U-shaped pressure sensor sheet. The total length and rectangular area of the center of pressure while standing upright for 10s were measured with a stabilometer and used as postural sway parameters. The occlusal contact area ratio significantly correlated with the postural sway parameters. Comparison between those who had experienced the fall incidences and those who had not after propensity score matching that adjusts their overall physical function revealed that there were no significant differences in the postural sway parameters and occlusal contact area ratio regardless of the history of fall incidence. Uneven occlusal contact leads to an increase in postural sway in children; however, this may not be associated with fall incidence.

The influence of cognitive tasks on sensory organization test performance

IntroductionMany static postural tasks requiring vestibular contributions are completed while dual- tasking. ObjectiveWe investigated the influence of dual-tasks on sensory integration for postural control and cognitive performance during the sensory organization test and examined the relationship between cognitive function and dual-task cost during the sensory organization test. MethodsTwenty adults completed single and dual-task versions of the six conditions of the sensory organization test were completed during two visits separated by one week. A subset of 13 participants completed three National Institute of Health (NIH)-toolbox cognitive tests including the Flanker inhibitory control and attention test, dimensional change card sort test and pattern comparison processing speed test. Wilcoxon signed rank tests were used to compare postural sway during single and dual-task sensory organization test. Friedman’s test, with pairwise comparison post-hoc tests, was used to compare single task serial subtraction performance to the 6 dual-task sensory organization test conditions. Spearman’s correlation coefficients were used to assess the relationship between cognitive performance on NIH-toolbox test and postural and cognitive dual-task cost during the sensory organization test. ResultsPerforming a cognitive dual-task during the sensory organization test resulted in a significant increase in postural sway during condition 1 (Z=−3.26, p=0.001, ES=0.73), condition 3 (Z=−2.53, p=0.012, ES=0.56), and condition 6 (Z=−2.02, p=0.044, ES=0.45). Subtraction performance significantly decreased in during condition 6 (Z=−2.479, p=0.011, ES=0.55) compared to single-task. The dimensional change card sort test demonstrated moderate correlations with dual-task cost of serial subtraction performance in condition 5 (dimensional change card sort test: r=−0.62, p=0.02) and condition 6 (dimensional change card sort test: r=−0.56, p=0.04). Pattern comparison processing speed test scores were significantly correlated with dual-task cost of postural control during condition 2. ConclusionPerforming a cognitive task during the sensory organization test resulted in significantly increased postural sway during three conditions, particularly during visual environment manipulation oppose to vestibular and somatosensory manipulation. Cognitive performance decreased during the most complex sensory organization test condition. Additionally, we found participants with poorer executive function had greater dual-task cost during more complex sensory integration demands.

Effect of fatigue on postural sway in sport-specific positions of young rhythmic gymnasts

In rhythmic gymnastics, balance represents a key element in achieving optimal performance. However, there is a lack of data on the modalities with which postural control is impaired by fatigue originated by actual competitive performance. This study aims to analyze the effect of fatigue consequent to a competitive performance on static balance of rhythmic gymnasts (quantitatively assessed by means of postural sway analysis) for several sport-specific positions. Fifteen rhythmic gymnasts (mean age 12.7 years) who compete at national and regional levels participated in the study. Their balance was assessed before and after a 90 s performance for 4 unipedal positions (i.e., “ring with hand support”, “back split without hand support”, “arabesque”, and “split with hand support”) using a pressure platform. Center-of-pressure (COP) time series acquired for 10 s was processed to calculate sway area, COP path length, and COP displacements in the antero-posterior and medio-lateral directions. After the performance, a generalized increase in postural sway was detected for all the positions tested, with the exception of “arabesque”. Sway area doubled for most positions after the performance, while fatigue appears to have a reduced effect on COP displacements in the ML direction, which were found significantly increased only for the “split with hand support” position. The physical effort associated with the performance influences the effectiveness of the postural control system. Coaches could include specific balance exercises even when gymnasts are fatigued to improve their adaptations to competitive conditions and reduce the risk of injuries.

Evaluation of Self-reported Symptoms in 1,457 Dizzy Patients and Associations With Caloric Testing and Posturography.

To determine if symptoms regarding timing and triggers of dizziness are useful for categorizing patients with dizziness, and to evaluate how patient-reported symptoms predict vestibular asymmetry, postural sway, and vestibular diagnoses. Retrospective chart review. Tertiary referral center. Patients referred for suspected vestibular disease. Patients completed a symptom questionnaire before laboratory testing with static posturography and bithermal caloric tests. Evaluate whether responses from a symptom questionnaire predict caloric asymmetry, postural balance, and diagnoses. One thousand four hundred fifty seven patients, 60.1% women, mean age 49.9 (±16.6) years were included. Vomiting was the strongest predictor for caloric asymmetry in adjusted analysis, odds ratio (OR): 1.60 (95% confidence interval [CI]: 1.24-2.06), followed by chronic hearing loss OR: 1.59 (1.19-2.13). Patients who reported constant dizziness had impaired postural balance, quantified as 15% increase in postural sway in adjusted analyses (7.25-24.6%). We found no association between caloric asymmetry and postural instability with eyes closed. Most patients were able to describe the timing of their symptoms and a categorization based on timing seems feasible. There seemed to be an over-reporting of triggers and confirmatory testing of triggers is therefore advocated. Vomiting, but not nausea, was a strong indicator of vestibular disease in this primarily outpatient population. Caloric asymmetry and postural balance were not associated, and assessment of fall risk may be warranted in patients who reports constant dizziness, visual disturbances or dizziness triggered by light, darkness or sounds.

Effects of Increasing Balance Task Difficulty on Postural Sway and Muscle Activity in Healthy Adolescents.

Evidence-based prescriptions for balance training in youth have recently been established. However, there is currently no standardized means available to assess and quantify balance task difficulty (BTD). Therefore, the objectives of this study were to examine the effects of graded BTD on postural sway, lower limb muscle activity and coactivation in adolescents. Thirteen healthy high-school students aged 16 to 17 volunteered to participate in this cross-sectional study. Testing involved participants to stand on a commercially available balance board with an adjustable pivot that allowed six levels of increasing task difficulty. Postural sway [i.e., total center of pressure (CoP) displacements] and lower limb muscle activity were recorded simultaneously during each trial. Surface electromyography (EMG) was applied in muscles encompassing the ankle (m. tibialis anterior, medial gastrocnemius, peroneus longus) and knee joint (m. vastus medialis, biceps femoris). The coactivation index (CAI) was calculated for ankle and thigh muscles. Repeated measures analyses of variance revealed a significant main effect of BTD with increasing task difficulty for postural sway (p < 0.001; d = 6.36), muscle activity (p < 0.001; 2.19 < d < 4.88), and CAI (p < 0.001; 1.32 < d < 1.41). Multiple regression analyses showed that m. tibialis anterior activity best explained overall CoP displacements with 32.5% explained variance (p < 0.001). The observed increases in postural sway, lower limb muscle activity, and coactivation indicate increasing postural demands while standing on the balance board. Thus, the examined board can be implemented in balance training to progressively increase BTD in healthy adolescents.

Postural balance and rifle stability in a standing shooting position after specific physical effort in biathletes

ABSTRACTThe aim of the study was to evaluate the effect of maximal specific physical effort on postural balance and rifle stability in biathletes in a standing shooting position. The study included 10 junior elite biathletes. The measurements were taken with the Vicon system and AMTI force platform. Postural balance and rifle stability characteristics were determined at rest as well as 1 and 5 min post maximal specific physical effort which was performed on a ski ergometer and continued until exhaustion. Maximal physical effort exerted a significant effect on all examined postural sway and rifle sway characteristics. The duration of the post-exercise changes was longer than 5 minutes. Higher post-effort rifle sway was observed in the vertical direction than in the across the shooting line direction. Post-effort postural balance impairment in the shooting line was much greater than in the across the shooting line direction. Moreover, a strong correlation was found between postural balance and rifle stability. Maximal physical effort influenced postural balance and rifle stability during aiming. Rifle sway during aiming in a standing shooting position seems to be coordinated with the postural sway of the biathlete’s body. Thus, an increase in postural sway contributes to greater sway and lesser stability of the rifle.

The Effect of Sensory Stimulation versus Motor Control Cueing of the Foot on Balance in Elderly Females: Single Group Pretest-Posttest Study

Study Design: A Quasi Experimental Single Group Pre-Test Post-Test. Objectives: The aim of this study was to determine the effects of sensory stimulation and motor control cueing of the foot on balance in females over the age of 65. Background: Balance deficits in the elderly population have shown to have detrimental consequences. Evidence suggests that sensory stimulation and motor control of the foot improve postural sway, however, studies have yet to compare the effects of both interventions on balance. Method and Measures: A total of 40 participants were contacted to complete the study with 32 participants meeting inclusion criteria for data collection and completing the research study. Two data collection days were utilized to perform pre and post-test outcome measures using the Functional Reach Test and Overall Sway Index (collected using the Biodex Medical System Inc., Biodex Biosway Portable Balance System). The interventions were 2-minute sensory stimulation to the sole of each foot on day one, and the “short foot” motor control cue on day two. Four related sample T-tests were conducted with the interventions as the dependent variable and the time of observation (pre and post) as the independent variable. Results: The results revealed sensory stimulation significantly improved balance as indicated by a decline in postural sway from pretest (5.92 ± 3.05) to posttest (5.00 ± 2.92) (p = 0.045) and a significant increase in Functional Reach from pretest (8.01 ± 2.55) to posttest (8.70 ± 2.66) (p < 0.001). Motor control cueing demonstrated mixed results on balance with an increase in postural sway from pretest (5.52 ± 3.50) to posttest (6.66 ± 4.06) (p = 0.015), and an increase in Functional Reach from pretest (8.47 ± 2.34) to posttest (9.01 ± 2.37) (p = 0.004). Conclusion: Based on the results, researchers concluded that sensory stimulation is a viable intervention to utilize in order to improve balance in the elderly population. Further research to identify the appropriate prescription of sensory stimulation to maximize effects should be completed.