Dynamic Postural Control Research Articles

Differences in lower extremity muscular coactivation during postural control between healthy and obese adults

IntroductionIt is well established that obesity is associated with deterioration in postural control that may reduce obese adults’ autonomy and increase risks of falls. However, neuromuscular mechanisms through which postural control alterations occur in obese adults remain unclear. ObjectiveTo investigate the effects of obesity on muscle coactivation at the ankle joint during static and dynamic postural control. Materials and methodsA control group (CG; n = 20; age = 32.5 ± 7.6 years; BMI = 22.4 ± 2.2 Kg/m²) and an obese group (OG; n = 20; age = 34.2 ± 5.6 years; BMI = 38.6 ± 4.1 Kg/m²) participated in this study. Static postural control was evaluated by center of pressure (CoP) displacements during quiet standing. Dynamic postural control was assessed by the maximal distance traveled by the CoP during a forward lean test. Electromyography activity data for the gastrocnemius medialis (GM), soleus (SOL) and tibialis anterior (TA) were collected during both quiet standing and forward lean tests. Muscle activities were used to calculate two separate coactivation indexes (CI) between ankle plantar and dorsal flexors (GM/TA and SOL/TA, respectively). ResultsCoP displacements were higher in the OG than in the CG for quiet standing (p < 0.05). When leaning forward, the maximal distance of the CoP was higher in the CG than in the OG (p < 0.05). Only the CI value calculated for SOL/TA was higher in the OG than in the CG for both static and dynamic tasks (p < 0.05). The SOL/TA CI value in the OG was positively correlated with CoP displacements during quiet standing (r = 0.79; p < 0.05). ConclusionObesity increases muscle coactivation of the soleus and tibialis anterior muscles at the ankle joint during both static and dynamic postural control. This adaptive neuromuscular response may represent a joint stiffening strategy for enhancing stability. Consequently, increased ankle muscle coactivation could not be considered as a good adaptation in obese adults.

Effects of two exercise programmes on joint position sense, dynamic balance and countermovement jump in male amateur football players. A randomised controlled trial

ABSTRACT Introduction: The injury prevention and warm-up exercises programmes improve physical performance and injury ratio, but it is poorly investigated in amateur football. Objectives: To assess the effects of two warm-up multi-station programmes (IAI-Programme and FIFA11+) through JPS, LSDT and CMJ. Study design: Randomised controlled trial. Methods: 36 football players were randomised into 2 groups: IAI-Programme (n = 18) and FIFA11+ (n = 18) and performed the intervention protocol for 6 weeks. JPS, LSDT and CMJ were measured at baseline, after 6, 10 and 18 weeks (from baseline). The inter-group and intra-group differences were assessed by repeated-measures analysis of variance test (ANOVA). Results: Significant differences between groups were found after 18 weeks in the absolute angular error (−2.18[−4.33,-0.047], d = 0.69, p < 0.05) of the JPS and in the CMJ (p = 0.001, ŋ2p=,0.298) in favour of IAI-Programme when compared to FIFA11 +. No significant differences between groups were found in the LSDT. There were also intra-group differences observed in the LSDT in both groups. Conclusions: IAI-Programme can provide sensitive benefits with respect to the proprioceptive ability of knee flexion and CMJ than FIFA11 +. Both IAI-Programme and FIFA11+ present improvements in the dynamic postural control measured by the LSDT.

Effects Of Stroboscopic Vision On Postural Control In Individuals With And Without Chronic Ankle Instability

Chronic ankle instability (CAI) patients have consistently displayed postural control deficits. Previous research postulated that CAI patients rely more on the utilization of visual feedback than controls to compensate for the proprioceptive deficits after lateral ankle sprains. However, little is known about how reduced visual feedback would alter dynamic postural control in CAI patients relative to controls and copers. PURPOSE: To identify the effect of visual feedback disruption via stroboscopic glasses on dynamic postural control among groups of CAI, coper, and control. METHODS: 20 CAI (10M, 10F, 23.6±3.9 yr, 174.5±11.8 cm, 76.3±17.5 kg), 20 coper (10M, 10F, 22.2±1.4 yr, 176.4±10.2 cm, 69.3±10.9 kg), and 20 control (10M, 10F, 22.6±2.7 yr, 174.4±7.2 cm, 80.0±24.4 kg) subjects were categorized according to the Foot and Ankle Ability Measure (FAAM) and Modified Ankle Instability Index (MAII) questionnaires. Each subject performed three trials of a single-leg-hop stabilization test with eyes open (EO) and stroboscopic vision (SV). Force data (200 Hz) were collected using an in-ground force plate to calculate the dynamic postural stability index (DPSI) and directional stability indices (medial/lateral, anterior/posterior, vertical). Two-way repeated ANOVAs (group × condition) were used to examine the differences between condition (EO, SV) and group (CAI, coper, control). RESULTS: Visual condition main effect was driven by differences between EO and SV during dynamic postural control (p<0.001). Only CAI patients displayed altered DPSI scores between EO and SV (p=0.005). However, no differences were observed in copers (p=0.31) and controls (p=0.99). Regardless of visual condition, CAI patients displayed dynamic postural control deficits relative to controls (p=0.003) but no differences between CAI patients and copers (p=0.45). For the directional stability indices, each group displayed no differences between visual conditions. CONCLUSION: CAI patients rely more on visual feedback during dynamic postural control than copers and controls. However, they may have decreased ability to compensate for the disrupted visual feedback during dynamic movement. Stroboscopic glasses could be effective visual-disruption devices during dynamic movement tasks regardless of lateral ankle sprain history.

Stroboscopic Vision-induced Sensory Re-weighting During Dynamic Postural Control

Three main sensory systems (somatosensory, visual, and vestibular) contribute to human postural control. These three sensory systems can compensate for each other if one of them lose their orientation information. Adjusting sensory input is referred to as sensory re-weighting. However, due to experimental limits, little is known how disrupted vision affects sensory re-weighting during dynamic postural control. PURPOSE: Therefore, this study examined the effect of impaired visual sensory input on dynamic postural control through the use of stroboscopic glasses. METHODS: Subjects were 24 physically active adults (male: 12, female: 12, height: 172.1 ± 7.8cm, weight: 67.5 ± 10.4kg) recruited from a university population, aged 18-35 years. Each subject performed the star excursion balance test (SEBT), which includes 3 trials comprised of 3 directions (anterior, posteromedial: PM, and posterolateral: PL) on each visual condition (eyes open: EO, Low Strobe frequency Vision: LSV, High Strobe frequency Vision: HSV) Each trial and visual condition was run on both firm and foam surface. Reach distance was analyzed by 2 (surface conditions) × 3 (vision conditions) ANOVAs. RESULTS: In surface condition main effects, subjects performed significantly (p<.05) shorter reach distances (anterior, PM, and PL). In vision condition main effects, subjects with EO performed significantly lower reach distances in the PM direction than HSV and LSV (p<.05, both), and subjects demonstrated shorter reach distance with EO than with LSV in PL direction (p<.05). Only with HSV, subjects performed shorter reach distance on the foam surface than the firm surface (p<.05). CONCLUSIONS: People with impaired visual sensory (strobe vision) input and/or unstable surface tend to have decreased dynamic postural control when tasked to move in a medial and lateral direction. People also demonstrated higher reliance on visual information when the somatosensory function is disturbed. The stroboscopic glasses may be used to identify the reliance of visual information in people who have an altered or reduced somatosensory system.

Comparisons of Spatiotemporal and Ground Reaction Force Components of Gait Between Individuals with Congenital Vision Loss and Sighted Individuals

Introduction: The understanding of abnormalities in biomechanical parameters of gait in individuals with vision loss (i.e., blindness or low vision) has clinical importance. The aims of this study were to compare the spatiotemporal and ground reaction force variables of sighted individuals with those with vision loss. Methods: Ten sighted males and 10 young males with congenital vision loss were recruited. A Vicon motion analysis system with four cameras and two Kistler force plates was used to quantify spatiotemporal and ground reaction force components of both groups during walking without shoes. Sighted individuals walked in eyes-open and eyes-closed conditions. Results: Results showed that the stride and step length, walking speed, the vertical and posterior–anterior reaction forces in heel contact and push-off phase, and the impulse of the control group during walking with the open- and closed-eyes conditions were significantly smaller than those in persons with vision loss ( p &lt; .05). Discussion: Vision loss is associated with decreased step and stride length, slower walking, and smaller propulsive reaction force. These kinematic and kinetics alterations suggest an adaptation to a new neuromuscular response for dynamic postural control as a result of lack of vision. These alterations in the long term may result in rigidity and muscle weakness. Implications for practitioners: A rehabilitation program to enhance mobility and strength is suggested for individuals with vision loss.

Effect of Dynamic Postural Control Activities on Balance in Amateur Indian Taekwondo Players

Background: Taekwondo is a technique of unarmed self-defense that involves skillful application of techniques which include punching, jumping, kicks, blocks and dodges. Beside speed, response to the opponent’s actions along with good balance appear to be key elements for victory. Hence a good balance is required for excellent performance with minimal injuries Method: A total of 60 players were selected based on inclusion and exclusion criteria. The aim and objectives of the study were explained to them and their written consent was taken. Balance was assessed using single legged stance test and community balance and mobility scale. The players were divided into two groups of 30 players each. A four week intervention program consisting of dynamic postural control activities was given to the players in group Athrice a week for four consecutive weeks and those in group B received conventional exercises including stretching and drilling. The pre and post values were recorded on 1st and 12th day respectively and the data obtained was statistically analyzed. Results:The average CBM scale score before intervention were 74/96 in group A and 72/96 in group B. These were improved to an average of 91.2/96 and 80.32/96 in group A and group B respectively after intervention showing a value of p&lt;0.0001. Also, significant improvement is seen in single legged stance test scores in group A as compared to group B. Conclusion: Dynamic postural control activities are effective in improving the balance thereby improving the performance in amateur Indian Taekwondo players.

BTrackS limits of stability test is a reliable assessment of volitional dynamic postural control

BackgroundUnconstrained limits of stability assessment reveals aspects of volitional postural sway control that are inaccessible by other means. Prior versions of this assessment include instructions to sway towards predefined targets, and may not capture the full capability of the individual. Research questionThis study sought to establish the test-retest reliability of a novel limits of stability protocol. MethodsVolitional sway area was determined during unconstrained trials, where participants were instructed to explore their ability to sway towards the perimeter of their base of support. Visual feedback was provided via computer monitor. Forty healthy young adults (mean age = 20.2 ± 1.3, 15 males, 25 females) participated in this study. Trials were collected in three sessions, repeated at the same time of the same day, with one week between. Reliability was assessed using IntraClass Correlation Coefficients (ICC), considering the total area of sway as well as quadrant level area. ResultsReliability was moderate between the first and second session (0.583), and much higher 0.921) between the second and third session. The quadrant level reliability was poor to excellent (0.183−0.791), with similar trends between the three sessions. SignificanceUltimately, these results indicate that the novel limits of stability test is reliable. However, it is recommended that a practice trial be conducted prior to baseline establishment.

Efficacy of Ankle Supports on Dynamic Postural Control in Patients with Chronic Ankle Instability

ABSTRACT Introduction The chronic ankle instability (CAI) that results from a lateral ankle sprain causes balance deficits during quiet standing. Dynamic postural control in patients with CAI can be improved using soft and semirigid braces. Objective This study was aimed at investigating the effects of soft and semirigid ankle supports on dynamic postural stability in subjects with CAI. Materials and Methods Fifteen subjects with unilateral CAI as the CAI group and 15 healthy control subjects as the control group were recruited for participation in the study. Stability indexes (SIs), including overall SI, anteroposterior SI, and mediolateral SI, were determined using the Biodex Balance System (BBS), and lower-limb reach was ascertained using the Star Excursion Balance Test (SEBT). These indicators were measured under three conditions: without orthosis, with soft orthosis, and with semirigid orthosis. Results Significant differences in overall SI were found between the affected and healthy feet of the CAI group (P = 0.009) and between the affected feet of the CAI group and the healthy feet of the control group (P = 0.031). The SEBT revealed significant differences between the injured and uninjured sides of the CAI group in the anterior, anterior-medial, and anterior-lateral directions. With the use of soft ankle supports, no significant differences were found between the affected and unaffected limbs of the CAI group in the overall and mediolateral SIs of BBS test and the anterior-medial (P = 0.057) and anterior-lateral (P = 0.07) directions of SEBT. Conclusions The soft ankle support has more effect on the balance of the CAI patients in comparison with the semirigid orthosis.

Directions of single-leg landing affect multi-segment foot kinematics and dynamic postural stability in male collegiate soccer athletes

BackgroundUnderstanding lower limb kinematics and postural control in different directions of single-leg landings is critical to evaluate postural control and prevent lower limb injuries. However, foot and ankle kinematics and postural control during single-leg landings in different directions are less known. Research questionDoes the difference in the direction of single-leg landing affect the foot kinematics on the frontal plane and dynamic postural stability? MethodsA cross-sectional study was conducted. Forty-nine male collegiate soccer players performed single-leg forward (FL), 45° lateral (LL), and medial (ML) direction landings. The lower limb, foot (rearfoot, midfoot, forefoot), and ankle kinematics during an impact phase were evaluated, and a curve analysis was performed using a statistical parametric mapping method to compare the three landings. The three landings were compared in terms of postural control parameters, including time to stabilization (TTS), peak of ground reaction forces (GRFs), root-mean-square of the mediolateral GRFs for 0–0.4 s (GRFML0.4), loading rate, and magnitude of horizontal GRFs from 0–0.4 s (HGRF-0.4), 0.4–2.4 s (HGRF-2.4), and 3.0–5.0 s. ResultsAnkle and rearfoot kinematics in LL exhibited smaller eversion and pronation positions than FL and ML (p < 0.01). The TTS-mediolateral (TTS-ML) was longer in the LL than in FL and ML (p < 0.001). The GRFML0.4, HGRF-0.4, and -2.4 in the LL and ML were greater than those in the FL (p < 0.001). SignificanceDirections of single-leg landing affect foot and ankle kinematics and postural stability. Specifically, the LL exhibits more inverted ankle and supinated rearfoot positions, and longer TTS-ML. Thus, the LL may induce stretching of the lateral ankle ligament. These findings can help understand foot kinematics and assess dynamic postural control.

Development of a Computerized Device for Evaluating Vestibular Function in Locomotion: A New Evaluation Tool of Vestibular Hypofunction.

To evaluate vestibular function in the clinic, current assessments are applied under static conditions, such as with the subject in a sitting or supine position. Considering the complexities of daily activities, the combination of dynamic activities, dynamic visual acuity (DVA) and postural control could produce an evaluation that better reflects vestibular function in daily activities.Objective: To develop a novel sensor-based system to investigate DVA, walking trajectory, head and trunk movements and the chest-pelvis rotation ratio during forward and backward overground walking in both healthy individuals and patients with vestibular hypofunction.Methods: Fifteen healthy subjects and 7 patients with bilateral vestibular hypofunction (BVH) were recruited for this study. Inertial measurement units were placed on each subject's head and torso. Each subject walked forward and backward for 5 m twice with 2 Hz head yaw. Our experiment comprised 2 stages. In stage 1, we measured forward (FW), backward (BW), and medial-lateral (MLW) walking trajectories; head and trunk movements; and the chest-pelvis rotation ratio. In stage 2, we measured standing and locomotion DVA (loDVA). Using Mann–Whitney U-test, we compared the abovementioned parameters between the 2 groups.Results: Patients exhibited an in-phase chest/pelvis reciprocal rotation ratio only in FW. The walking trajectory deviation, calculated by normalizing the summation of medial-lateral swaying with 1/2 body height (%), was significantly larger (FW mean ± standard deviation: 20.4 ± 7.1% (median (M)/interquartile range (IQR): 19.3/14.4–25.2)in healthy vs. 43.9 ± 27. 3% (M/IQR: 36.9/21.3–56.9) in patients, p = 0.020)/(BW mean ± standard deviation: 19.2 ± 11.5% (M/IQR: 13.6/10.4–25.3) in healthy vs. 29.3 ± 6.4% (M/IQR: 27.7/26.5–34.4) in patients, p = 0.026), and the walking DVA was also significantly higher (LogMAR score in the patient group [FW LogMAR: rightDVA: mean ± standard deviation:0.127 ± 0.081 (M/IQR: 0.127/0.036–0.159) in healthy vs. 0.243 ± 0.101 (M/IQR: 0.247/0.143–0.337) in patients (p = 0.013) and leftDVA: 0.136 ± 0.096 (M/IQR: 0.127/0.036–0.176) in healthy vs. 0.258 ± 0.092 (M/IQR: 0.247/0.176–0.301) in patients (p = 0.016); BW LogMAR: rightDVA: mean ± standard deviation: 0.162 ± 0.097 (M/IQR: 0.159/0.097–0.273) in healthy vs. 0.281 ± 0.130 (M/IQR: 0.273/0.176–0.418) in patients(p = 0.047) and leftDVA: 0.156 ± 0.101 (M/IQR: 0.159/0.097–0.198) in healthy vs. 0.298 ± 0.153 (M/IQR: 0.2730/0.159–0.484) in patients (p = 0.038)].Conclusions: Our sensor-based vestibular evaluation system provided a more functionally relevant assessment for the identification of BVH patients.

A comparative study on different surface balance training on dyanamic postural control in collegiate female athletes

Purpose: The study aims to evaluate the effectiveness of different surface balance training on dynamic posture control in collegiate female athletes. Methods: The research was experimental in nature. The subjects were selected through purposive sampling. 40 female collegiate students were selected and divided into 2 groups. Group A was given star excursion balance training on stable surface and Group B was given Star Excursion Balance Training on unstable surface. Pre and post protocol assessment was done with the help of YBT on day 1st and end of the 4th week.

Acute Effects of Increased Joint Mobilization Treatment Duration on Ankle Function and Dynamic Postural Control in Female Athletes With Chronic Ankle Instability.

Background:Chronic ankle instability (CAI) is linked to mechanical and functional insufficiencies. Joint mobilization is purported to be effective at treating these deficits.Purpose:To examine the effect of different treatment durations of a grade IV anterior-to-posterior ankle joint mobilization on weightbearing dorsiflexion range of motion (WB-DFROM), posterior talar glide (PG), and dynamic postural control in individuals with CAI.Study Design:Controlled laboratory study.Methods:A total of 48 female athletes (mean age, 22.8 ± 4.8 years) with unilateral CAI participated in this study. Participants were randomly assigned to 1 of 3 treatment conditions: 30 seconds, 60 seconds, and 120 seconds. Treatment was provided to the injured limb on 3 separate occasions 48 hours apart and consisted of a Maitland grade IV anterior-to-posterior talar joint mobilization based on the participant’s initial group assignment. WB-DFROM; PG; and the anterior (ANT), posteromedial (PM), and posterolateral (PL) reach directions of the Star Excursion Balance Test were measured bilaterally before and after each treatment. The uninjured limb acted as a control. Data were analyzed using 2-way mixed-model analyses of variance, and effect sizes were calculated through use of Hedges g.Results:Significant differences were detected after all treatment sessions for all outcome measures (P ≤ .001) and between treatment groups after sessions 1, 2, and 3 for all outcome measures (P ≤ .001). Effect sizes were very large or huge for all treatment groups for WB-DFROM, PG, and ANT reach direction. Substantial variation was found in effect sizes for PM and PL measures.Conclusion:Accessory mobilization is an effective treatment to induce acute changes in ankle motion and dynamic postural control in patients with CAI, with longer treatment durations conferring greater improvements.Clinical Relevance:This study adds clarity to the use of joint mobilization treatments and will add to the current clinical practice strategy for patients with CAI.

Robust transition control of underactuated two-wheeled self-balancing vehicle with semi-online dynamic trajectory planning

In order to increase the mobility and dynamic agility of a two-wheeled self-balancing vehicle, a dynamic posture control strategy for the initial state transition is proposed in terms of a well-planned nonlinear reference trajectory. The dynamic trajectory planning for the underactuatedmobile inverted pendulum is conducted by solving a two-point boundary value problem with the constraint equation of internal dynamics. The restriction of the offline trajectories for real-time applications is relaxed by establishing a semi-online planning method by assuming velocity-controlled missions. For the transition tasks requiring high maneuver motions including quick start and stop and quick speed change, the proposed control scheme is profitable to stabilize the initial transient motion and get over the performance limit of the conventional feedback-only control with typical step reference inputs. As a result, it enables to achieve consistent state transition to the target velocity and requires just minimal control efforts.

Acute peripheral vestibular dysfunction: diagnostics and treatment

The aim of this article is to demonstrate ENT specialists, neurologists and general practitioners how to examine and treat patients with acute vertiginous complaints. Traditional otoneurologic testing that carried out for accurate topic diagnostics of acute vestibular dysfunction is described as available «Vestibular passport». Clinical diagnosis can be achieved after thorough assessment of patient’s complaints as well as history of the present illness. Gaze tests and posture control trials are demonstrated in details. Diagnostic value of each probe is shown from the viewpoint of differential diagnostics of peripheral and central vestibular dysfunction. High diagnostic value of registration and analysis of oculogyric reactions is presented by history cases of acute labyrinthopathy and acute vestibular neuronitis. In these cases absence of saccadic and pursuit gaze disturbances rule out central vestibular system dysfunction. The salient feature of these two variants of peripheral vestibular dysfunction is spontaneous nystagmus that revealed by Frenzel glasses. This significant oculomotor symptom as well as disturbances of static and dynamic postural control confirm patient’s vestibular complaints in objective way. Revelation of decompensation signs of vestibular dysfunction needs urgent medicine vertigo therapy and spare vestibular rehabilitation. Actually, medications of choice are sedative drugs with antiemetic effect, non-loop diuretics and glucocorticoids.

Effects of in Season Multi-Directional Plyometric Training on Vertical Jump Performance, Change of Direction Speed and Dynamic Postural Control in U-21 Soccer Players.

The aim of the study was to assess the effects of multi-directional plyometric training (MPT) on vertical jump height, change of direction speed (CODS), and dynamic postural control (DPC) of soccer players under 21 year (U-21). Twenty-seven male soccer players were randomly allocated to either an experimental group (EG; n = 14; age: 19.0 ± 0.9 years) or a control group (CG; n = 13; age: 19.0 ± 0.7 years). The EG introduced 6 weeks MPT, 2 days per week into their in-season training, while CG continued training without change. Measurements of vertical jump height, CODS and DPC were completed at the beginning and end of the 6 week MPT. ANOVA demonstrated a significant group × time interaction for SJ (F = 6.03, p = 0.021), CMJ (F = 9.10, p = 0.006), and T-Test (F = 10.46, p = 0.002). The Bonferroni Post Hoc test demonstrated significant increase for the three tests in both group (EG and CG). For SJ (EG: p < 0.001; CG: p < 0.001), CMJ (EG: p < 0.001; CG: p = 0.005) and T-Test (EG: p < 0.001; CG: p = 0.02). For DPC on the dominant leg, there was a significant group × time interaction for four axes [anterior (F = 5.48, p = 0.028), antero-lateral (F = 4.82, p = 0.038), postero-lateral (F = 4.82, p = 0.038), and medial (F = 6.77, p = 0.015)]. The Bonferroni Post Hoc test demonstrated significant increase in EG (p < 0.001), but no significant change in CG in four axes (anterior, antero-lateral, postero-lateral and medial). Furthermore DPC on the non-dominant leg, there was a significant group × time interaction for three axes [lateral (F = 8.09, p = 0.009), postero-lateral (F = 11.92, p = 0.002), and medial (F = 5.84, p = 0.023)]. The Bonferroni Post Hoc test demonstrated significant increase in EG (p < 0.001), but no significant change in CG in three axes (lateral, postero-lateral, and medial). In conclusion, incorporating MPT into the in-season regimen of under 21 soccer players improved performance of various indices related to soccer activity (i.e., CMJ, CODS, and DPC). MPT has the potential to be appealing to coaches, as it requires little time while yielding valuable results in the physical preparation of soccer players.

Comparison of the Y-Balance Test and Star Excursion Balance Test: Utilization of a Discrete Event Simulation.

The Y-Balance Test (YBT) and Star Excursion Balance Test (SEBT) are commonly used to detect deficits in dynamic postural control. There is a lack of literature on the differences in reach distances and efficiency of the tests. To compare the reach distances of the YBT and SEBT. An additional aim was to compare the time necessary to administer the 2 tests and utilize a discrete event simulation to determine the number of participants who could be screened within different scenarios. Cross-sectional. Laboratory Patients: Twenty-four physically active individuals between the ages of 18-35years volunteered to participate in this study (M/F: 11/13; age 22.78 [2.63]y, height 68.22 [4.32]cm, mass 173.27 [10.96]kg). The participants reported to the laboratory on one occasion and performed the YBT and SEBT. The anterior, posteromedial, and posterolateral reach distances were recorded for each test. In addition, the time to administer each test was recorded in seconds. The average reach distances and time for each test were used for analysis. Paired t tests were utilized to compare the reach distances and time to administer the 2 tests. A discrete event simulation was used to determine how many participants could be screened using each test. The anterior reach for the SEBT (64.52% [6.07%]) was significantly greater than the YBT (61.66% [6.37%]; P < .01). The administration time for the YBT (512.42 [123.97]s) was significantly longer than the administration time for the SEBT (364.96 [69.46]s; P < .01). The discrete event simulation revealed more participants could be screened using the SEBT when compared with the YBT for every situation. Scores on the anterior reach of the SEBT are larger when compared with the YBT. The discrete event simulation can successfully be used to determine how many participants could be screened with a certain amount of resources given the use of a specific test.

Modulation of spinal cord excitability following remote limb ischemic preconditioning in healthy young men.

Remote limb ischemic preconditioning (RIPC) has shown to improve dynamic postural control in humans. However, studies on the underlying adaptations of spinal cord networks have never been performed. The present work addresses this issue by investigating parameters from the soleus H-reflex recruitment curve (RC), presynaptic mechanisms of reflex modulation (presynaptic inhibition-PSI, and post activation depression-PAD), and the excursion of the center of pressure (CP) recorded during 1min in upright stance over a compliant surface. A sham ischemic protocol (partial obstruction of blood flow) was applied to the contralateral thigh along four consecutive days. The same procedure was repeated with full obstruction (RIPC) three days after ending the sham protocol. Data were collected before and after both sham and RIPC protocols. The follow-up data were collected five days after the last ischemic intervention. Significant reduction was detected for both the fast oscillations of the CP (higher frequency components) and the parameter estimated from the RC corresponding to the high amplitude H-reflexes (p < 0.05). Even though the magnitude of effects was similar, it was washed out within three days after sham, but persisted for at least five days after RIPC. No significant differences were found for PSI and PAD levels across conditions. These findings indicate that RIPC leads to enduring changes in spinal cord excitability for the latest reflexively recruited motoneurons, along with improvement in balance control. However, these adaptations were not mediated by the presynaptic mechanisms currently assessed.

THE EFFECTS OF MULTIPLE MODALITIES OF COGNITIVE LOADING ON DYNAMIC POSTURAL CONTROL IN INDIVIDUALS WITH CHRONIC ANKLE INSTABILITY

BackgroundEvidence of neuroplasticity after joint injury has suggested that individuals with chronic ankle instability (CAI) may have degraded movement when facing cognitive demand. To date, research into these effects have been limited to static balance models, and typically only incorporate a single type of cognitive demands. Research questionWe aimed to determine the effects of multiple modalities of cognitive load (quantitative, verbal-memory, visuospatial) on dynamic postural control strategies in a sample of patients with CAI compared to uninjured controls. MethodsThirty-two participants (16 CAI, 16 healthy) performed a series of 20 hops-to-stabilization while either under no cognitive load (CON), or while performing Benton’s judgment of line orientation (JLO), the symbol digit modalities test (SDM), or a serial seven task (SVN). Dynamic postural stability indices and mean muscle activation from the lower leg muscles were extracted and assessed via analysis of variance. ResultsHealthy subjects demonstrated better vertical and dynamic postural stability indices under JLO (P ≤ 0.017) and SVN (P ≤ 0.010) conditions compared to CON. Postural stability was unaffected in CAI (P > 0.050). Peroneus longus and lateral gastrocnemius activation was lowest in SVN across all subjects (P ≤ 0.033). Lateral gastrocnemius activation was greatest in SDM (P ≤ 0.033). SignificanceThese results suggest improvements in postural stability under cognitive demand in healthy individuals that did not occur in CAI, suggesting less movement optimization. Quantitative tasks appear to impede stabilizing muscle activation in the leg, while verbal-memory tasks result in a more protective landing strategy.

Somatosensory impairments in patients with multiple sclerosis: association with dynamic postural control and upper extremity motor function

Purpose: We planned this study to bring attention to the somatosensory impairments in patients with multiple sclerosis (PwMS) and to investigate relationship of somatosensory impairments with dynamic postural stability and upper extremity motor function.Methods: Seven males and 23 females, 30 patients with mean EDSS 2.9 (SD = 1.4), aged between 18 and 65 years (mean = 41.43 ± 14.90 years) were included in this clinical study. Light touch sensorial assessment was made with Semmes Weinstein monofilament test and proprioception by distal proprioception test. Hand strength was measured by the Jamar dynamometer, fine motor skill was examined with nine-hole peg test, functional reach test in sitting and standing position was applied. Nottingham Extended Activities of Daily Living Scale (NEADLS) was used to measure everyday activities.Results: We found a negative and moderate correlation between FRT in standing and light touch of the middle of the heel (right: –0.515), metatarsal bone (right r: 0.453, left r: –0.426), and medial of the foot (right r: –0.462). There was a negative and moderate correlation between NEADLS and light touch of the metatarsal bone (right r: –0.564, left r: –0.472), medial of the foot (right r: –0.531, left r: –0.479), and lateral of the foot (right r: –0.526). We found a positive and moderate correlation between proprioception of the ankle (right r: 0.421 left r: 0.588) and NEADLS.Conclusions: We found impairment in light touch and proprioception and, associations between sensorial functions and dynamic postural stability in PwMS. Also impaired sensorial functions cause dependent patients in daily living activities. In the assessment of balance and falling risk, independency in daily living activities; foot light touch and proprioception sense should be taken into account, hence it may provide guidance in planning rehabilitation programmes.Abbreviations: MS: multiple sclerosis; PwMS: patients with multiple sclerosis; VAS: visual analogue scale; FRT: functional reach test; 9-HPT: Nine-hole peg test; EDSS: The Expanded Disability Status Scale; NEADLS: Nottingham Extended Activities of Daily Living Scale

Effectiveness of acupuncture vs. core stability training in balance and functional capacity of women with fibromyalgia: a randomized controlled trial

Objective: This study investigated the effectiveness of a core stability training physiotherapy programme vs. acupuncture for the management of balance and functional capacity impairments of women with Fibromyalgia. Design: Single-blind randomized controlled trial. Setting: Outpatients setting. Subjects: Women with Fibromyalgia and balance impairment. Interventions: Participants were randomized to a core stability physiotherapy programme group (n = 45), acupuncture treatment group (n = 45) and control group (n = 45) for 13 weeks. Main Measures: Measures were taken at baseline (week 0), postintervention (week 6) and follow-up (week 13). The primary outcome measures were static balance (posturography) and dynamic balance and functional mobility (Berg Balance Scale, timed up and go test and 10-m walk). The secondary outcome measure was functional capacity (Fibromyalgia Health Assessment Questionnaire and the physical function item from the Spanish Fibromyalgia Impact Questionnaire). Results: In all, 103 participants completed the study. The results showed statistically significant improvements in the acupuncture and physiotherapy groups vs. the control group at week 6 regarding Berg Balance Scale (P = 0.00, both groups), timed up and go test (P = 0.00 and P = 0.01, respectively) and 10-m walk test at comfortable speed (P = 0.02 and P = 0.03, respectively). The 10-m walk test at maximum speed showed significance when comparing the physiotherapy and control group (P = 0.03). However, no significant differences were found between the physiotherapy and the acupuncture groups. In relation to functional capacity, the improvements achieved after the treatments were not statistically significant. Conclusion: Core stability-based physiotherapy and acupuncture improve dynamic balance and postural control in women with Fibromyalgia.