scholarly journals Ankle Bracing and the Neuromuscular Factors Influencing Joint Stiffness

2009 ◽  
Vol 44 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Steven M. Zinder ◽  
Kevin P. Granata ◽  
Sandra J. Shultz ◽  
Bruce M. Gansneder

Abstract Health care professionals commonly prescribe external stabilization to decrease the incidence and severity of ankle sprains. The mechanism for this decrease is not clearly understood. Examining the effects of ankle bracing on biomechanical stability and influencing factors may provide important information regarding the neuromuscular effects of bracing.Context: To study the effects of 2 different ankle braces on the neuromuscular factors influencing ankle stiffness.Objective: Mixed-model repeated-measures design.Design: Research laboratory.Setting: Twenty-eight physically active participants composing 2 groups: 14 with unilateral functional ankle instability (age  =  26.19 ± 6.46 years, height  =  166.07 ± 12.90 cm, mass  =  69.90 ± 13.46 kg) and 14 with bilaterally stable ankles (age  =  23.76 ± 5.82 years, height  =  174.00 ± 11.67 cm, mass  =  68.60 ± 13.12 kg).Patients or Other Participants: Participants were fitted with surface electromyography electrodes over the peroneus longus, peroneus brevis, tibialis anterior, and soleus muscles. Each participant received transient motion oscillations to his or her ankle on a custom-built medial-lateral swaying cradle in each of 3 conditions: no ankle brace (NB), lace-up brace (LU), and semirigid brace (SR).Intervention(s): Ankle stiffness as measured by the cradle and preactivation levels (percentage of maximal voluntary isometric contraction) of the 4 test muscles.Main Outcome Measure(s): Stiffness levels increased across brace conditions (NB  =  24.79 ± 6.59 Nm/rad, LU  =  28.29 ± 7.05 Nm/rad, SR  =  33.22 ± 8.78 Nm/rad; F2,52  =  66.185, P < .001). No differences were found between groups for rotational stiffness (stable  =  27.36 ± 6.17 Nm/rad, unstable  =  30.18 ± 8.21 Nm/rad; F1,26  =  1.084, P  =  .307). Preactivation levels did not change for any of the tested muscles with the application of an ankle brace (F2,52  =  1.326, P  =  .275).Results: The increase in ankle rotational stiffness with the addition of an ankle brace and the lack of any demonstrable neuromuscular changes suggested ankle braces passively contributed to the stability of the system.Conclusions:

2012 ◽  
Vol 21 (2) ◽  
pp. 127-136 ◽  
Author(s):  
Cynthia J. Wright ◽  
Brent L. Arnold

Context:Force sense (FS), the proprioceptive ability to detect muscle-force generation, has been shown to be impaired in individuals with functional ankle instability (FAI). Fatigue can also impair FS in healthy individuals, but it is unknown how fatigue affects FS in individuals with FAI.Objective:To assess the effect of fatigue on ankle-eversion force-sense error in individuals with and without FAI. Design: Case control with repeated measures.Setting:Sports medicine research laboratory.Participants:32 individuals with FAI and 32 individuals with no ankle sprains or instability in their lifetime. FAI subjects had a history of ≥1 lateral ankle sprain and giving-way ≥1 episode per month.Interventions:Three eversion FS trials were captured per load (10% and 30% of maximal voluntary isometric contraction) using a load cell before and after a concentric eversion fatigue protocol.Main Outcome Measures:Trial error was the difference between the target and reproduction forces. Constant error (CE), absolute error (AE), and variable error (VE) were calculated from 3 trial errors. A Group × Fatigue × Load repeated-measures ANOVA was performed for each error.Results:There were no significant 3-way interactions or 2-way interactions involving group (all P > .05). CE and AE had a significant 2-way interaction between load and fatigue (CE: F1,62 = 8.704, P = .004; AE: F1,62 = 4.024, P = .049), and VE had a significant main effect for fatigue (F1,62 = 5.130, P = .027), all of which indicated increased FS error with fatigue at 10% load. However, at 30% load only VE increased with fatigue. The FAI group had greater error as measured by AE (F1,62 = 4.571, P = .036) but not CE or VE (P > .05).Conclusions:Greater AE indicates that FAI individuals are less accurate in their force production. Fatigue impaired force sense in all subjects equally. These deficits provide evidence of impaired proprioception with fatigue and in individuals with FAI.


2008 ◽  
Vol 29 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Tricia J. Hubbard

Background: Not all patients develop chronic ankle instability (CAI) after one or more lateral ankle sprains; some seem to heal or adjust to the ankle laxity after injury. Why do some patients develop CAI and others are able to cope and return to normal function? The purpose of this study was to examine ligament laxity between subjects with and without CAI. Materials and Methods: Sixteen subjects with unilateral CAI and 16 subjects without participated in the study. Ligament laxity was measured with an instrumented ankle arthrometer. The arthrometer measured ankle joint motion for anterior/posterior displacement (mm) during loading at 125 N and inversion/eversion rotation (degrees of ROM) during loading at 4000 N/mm. For each dependent variable a 2 × 2 mixed model ANOVA was run with the between factor being group (CAI, No CAI) and the within factor with repeated measures being side (involved, uninvolved). Results: A significant group by side interaction for anterior displacement (F1,30 = 370.085, p < 0.001), and inversion rotation (F1,30 = 7.455, p = 0.010) was found. There was significantly more anterior displacement and inversion rotation for the involved ankles of the CAI group than the involved ankles of the stable group and the uninvolved ankles of the CAI group. Conclusion: Based on the results of this study it appears that the increased anterior displacement and inversion rotation compared to patients without instability may be why subjects develop CAI. Although the patients without instability have a history of more than one lateral ankle sprain, they did not demonstrate increased laxity, which may be the reason why they do not complain of the functional impairment demonstrated in subjects with CAI.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Patrick Fuerst ◽  
Albert Gollhofer ◽  
Markus Wenning ◽  
Dominic Gehring

Abstract Background The application of ankle braces is an effective method for the prevention of recurrent ankle sprains. It has been proposed that the reduction of injury rates is based on the mechanical stiffness of the brace and on beneficial effects on proprioception and neuromuscular activation. Yet, how the neuromuscular system responds to the application of various types of ankle braces during highly dynamic injury-relevant movements is not well understood. Enhanced stability of the ankle joint seems especially important for people with chronic ankle instability. We therefore aimed to analyse the effects of a soft and a semi-rigid ankle brace on the execution of highly dynamic 180° turning movements in participants with and without chronic ankle instability. Methods Fifteen participants with functional ankle instability, 15 participants with functional and mechanical ankle instability and 15 healthy controls performed 180° turning movements in reaction to light signals in a cross-sectional descriptive laboratory study. Ankle joint kinematics and kinetics as well as neuromuscular activation of muscles surrounding the ankle joint were determined. Two-way repeated measures analyses of variance and post-hoc t-tests were calculated. Results Maximum ankle inversion angles and velocities were significantly reduced with the semi-rigid brace in comparison to the conditions without a brace and with the soft brace (p ≤ 0.006, d ≥ 0.303). Effect sizes of these reductions were larger in participants with chronic ankle instability than in healthy controls. Furthermore, peroneal activation levels decreased significantly with the semi-rigid brace in the 100 ms before and after ground contact. No statistically significant brace by group effects were found. Conclusions Based on these findings, we argue that people with ankle instability in particular seem to benefit from a semi-rigid ankle brace, which allows them to keep ankle inversion angles in a range that is comparable to values of healthy people. Lower ankle inversion angles and velocities with a semi-rigid brace may explain reduced injury incidences with brace application. The lack of effect of the soft brace indicates that the primary mechanism behind the reduction of inversion angles and velocities is the mechanical resistance of the brace in the frontal plane.


2021 ◽  
Vol 30 (1) ◽  
pp. 62-69
Author(s):  
Adam E. Jagodinsky ◽  
Christopher Wilburn ◽  
Nick Moore ◽  
John W. Fox ◽  
Wendi H. Weimar

Context: Ankle bracing is an effective form of injury prophylaxis implemented for individuals with and without chronic ankle instability, yet mechanisms surrounding bracing efficacy remain in question. Ankle bracing has been shown to invoke biomechanical and neuromotor alterations that could influence lower-extremity coordination strategies during locomotion and contribute to bracing efficacy. Objective: The purpose of this study was to investigate the effects of ankle bracing on lower-extremity coordination and coordination dynamics during walking in healthy individuals, ankle sprain copers, and individuals with chronic ankle instability. Design: Mixed factorial design. Setting: Laboratory setting. Participants: Forty-eight recreationally active individuals (16 per group) participated in this cross-sectional study. Intervention: Participants completed 15 trials of over ground walking with and without an ankle brace. Main Outcome Measures: Coordination and coordination variability of the foot–shank, shank–thigh, and foot–thigh were assessed during stance and swing phases of the gait cycle through analysis of segment relative phase and relative phase deviation, respectively. Results: Bracing elicited more synchronous, or locked, motion of the sagittal plane foot–shank coupling throughout swing phase and early stance phase, and more asynchronous motion of remaining foot–shank and foot–thigh couplings during early swing phase. Bracing also diminished coordination variability of foot–shank, foot–thigh, and shank–thigh couplings during swing phase of the gait cycle, indicating greater pattern stability. No group differences were observed. Conclusions: Greater stability of lower-extremity coordination patterns as well as spatiotemporal locking of the foot–shank coupling during terminal swing may work to guard against malalignment at foot contact and contribute to the efficacy of ankle bracing. Ankle bracing may also act antagonistically to interventions fostering functional variability.


2013 ◽  
Vol 48 (2) ◽  
pp. 192-202 ◽  
Author(s):  
Alan R. Needle ◽  
Swanik Charles B. (Buz) ◽  
William B. Farquhar ◽  
Stephen J. Thomas ◽  
William C. Rose ◽  
...  

Context: Ankle sprains are common in athletes, with functional ankle instability (FAI) developing in approximately half of cases. The relationship between laxity and FAI has been inconclusive, suggesting that instability may be caused by insufficient sensorimotor function and dynamic restraint. Research has suggested that deafferentation of peripheral mechanoreceptors potentially causes FAI; however, direct evidence confirming peripheral sensory deficits has been elusive because previous investigators relied upon subjective proprioceptive tests. Objective: To develop a method for simultaneously recording peripheral sensory traffic, joint forces, and laxity and to quantify differences between healthy ankles and those with reported instability. Design: Case-control study. Setting: University laboratory. Patients or Other Participants: A total of 29 participants (age = 20.9 ± 2.2 years, height = 173.1 ± 8.9 cm, mass = 74.5 ± 12.7 kg) stratified as having healthy (HA, n = 19) or unstable ankles (UA, n = 10). Intervention(s): Sensory traffic from muscle spindle afferents in the peroneal nerve was recorded with microneurography while anterior (AP) and inversion (IE) stress was applied to ligamentous structures using an ankle arthrometer under test and sham conditions. Main Outcome Measure(s): Laxity (millimeters or degrees) and amplitude of sensory traffic (percentage) were determined at 0, 30, 60, 90, and 125 N of AP force and at 0, 1, 2, 3, and 4 Nm of IE torque. Two-factor repeated-measures analyses of variance were used to determine differences between groups and conditions. Results: No differences in laxity were observed between groups (P &gt; .05). Afferent traffic increased with increased force and torque in test trials (P &lt; .001). The UA group displayed decreased afferent activity at 30 N of AP force compared with the HA group (HA: 30.2% ± 9.9%, UA: 17.1% ± 16.1%, P &lt; .05). Conclusions: The amplitude of sensory traffic increased simultaneously with greater ankle motion and loading, providing evidence of the integrated role of capsuloligamentous and musculotendinous mechanoreceptors in maintaining joint sensation. Unstable ankles demonstrated diminished afferent traffic at low levels of force, suggesting the early detection of joint loading may be compromised.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Gonghao Zhang ◽  
Shengxuan Cao ◽  
Chen Wang ◽  
Xin Ma ◽  
Xu Wang ◽  
...  

An ankle brace is commonly used by patients after they suffer from initial ankle sprains, reducing the incidents of recurrent sprain or limiting laxity in joints with functional ankle instability (FAI). However, whether the application of a semirigid ankle brace can improve the abnormal ankle gait kinematics of patients with FAI remains unknown. This study aimed to determine the effect of a semirigid ankle brace on the gait kinematics of ankle joints through 3D-2D fluoroscopy image registration. A total of 8 subjects with FAI (3 males and 5 females, 10 feet) as FAI group and 10 subjects without FAI (6 males and 4 females, 10 feet) as control group were enrolled in this study. Three-dimensional bone models created from computed tomography images were matched to fluoroscopic images to compute the 6 degrees of freedom (DOF) talocrural, subtalar, and ankle joints complex kinematics for control and FAI group with or without brace during the stance phase of walking. FAI patients had significantly less ROMs in inversion/eversion rotation of the talocrural and subtalar joint after wearing semirigid ankle brace. Laxity was observed in most of the displacements of the talocrural and subtalar joints in FAI group. The brace partly altered the ankle joints movement in opposite directions, especially joint rotation, and restricted the talocrural and subtalar joints in the dorsiflexion position during the touch down phase of walking.


2020 ◽  
Vol 29 (3) ◽  
pp. 391-403
Author(s):  
Dania Rishiq ◽  
Ashley Harkrider ◽  
Cary Springer ◽  
Mark Hedrick

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.


Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.


2019 ◽  
Vol 24 (2) ◽  
pp. 200-208
Author(s):  
Ravindra Arya ◽  
Francesco T. Mangano ◽  
Paul S. Horn ◽  
Sabrina K. Kaul ◽  
Serena K. Kaul ◽  
...  

OBJECTIVEThere is emerging data that adults with temporal lobe epilepsy (TLE) without a discrete lesion on brain MRI have surgical outcomes comparable to those with hippocampal sclerosis (HS). However, pediatric TLE is different from its adult counterpart. In this study, the authors investigated if the presence of a potentially epileptogenic lesion on presurgical brain MRI influences the long-term seizure outcomes after pediatric temporal lobectomy.METHODSChildren who underwent temporal lobectomy between 2007 and 2015 and had at least 1 year of seizure outcomes data were identified. These were classified into lesional and MRI-negative groups based on whether an epilepsy-protocol brain MRI showed a lesion sufficiently specific to guide surgical decisions. These patients were also categorized into pure TLE and temporal plus epilepsies based on the neurophysiological localization of the seizure-onset zone. Seizure outcomes at each follow-up visit were incorporated into a repeated-measures generalized linear mixed model (GLMM) with MRI status as a grouping variable. Clinical variables were incorporated into GLMM as covariates.RESULTSOne hundred nine patients (44 females) were included, aged 5 to 21 years, and were classified as lesional (73%), MRI negative (27%), pure TLE (56%), and temporal plus (44%). After a mean follow-up of 3.2 years (range 1.2–8.8 years), 66% of the patients were seizure free for ≥ 1 year at last follow-up. GLMM analysis revealed that lesional patients were more likely to be seizure free over the long term compared to MRI-negative patients for the overall cohort (OR 2.58, p < 0.0001) and for temporal plus epilepsies (OR 1.85, p = 0.0052). The effect of MRI lesion was not significant for pure TLE (OR 2.64, p = 0.0635). Concordance of ictal electroencephalography (OR 3.46, p < 0.0001), magnetoencephalography (OR 4.26, p < 0.0001), and later age of seizure onset (OR 1.05, p = 0.0091) were associated with a higher likelihood of seizure freedom. The most common histological findings included cortical dysplasia types 1B and 2A, HS (40% with dual pathology), and tuberous sclerosis.CONCLUSIONSA lesion on presurgical brain MRI is an important determinant of long-term seizure freedom after pediatric temporal lobectomy. Pediatric TLE is heterogeneous regarding etiologies and organization of seizure-onset zones with many patients qualifying for temporal plus nosology. The presence of an MRI lesion determined seizure outcomes in patients with temporal plus epilepsies. However, pure TLE had comparable surgical seizure outcomes for lesional and MRI-negative groups.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dulanji K. Kuruppu ◽  
Joshua Tobin ◽  
Yan Dong ◽  
Sheena K. Aurora ◽  
Laura Yunes-Medina ◽  
...  

Abstract Background Galcanezumab is a calcitonin gene-related peptide (CGRP) monoclonal antibody (mAb) indicated for the preventive treatment of migraine. While galcanezumab has demonstrated efficacy in patients who did not respond to prior preventive medications in general, its efficacy in patients who did not benefit from individual, commonly prescribed preventive treatments due to inadequate efficacy or safety/tolerability remains unknown. Methods CONQUER was a 3-month, randomized, double-blind, placebo-controlled, phase 3b study that enrolled patients with episodic or chronic migraine who had 2 to 4 migraine preventive medication category failures in the past 10 years. Patients were randomly assigned 1:1 to receive placebo (N = 230) or galcanezumab 120 mg/month (240 mg loading dose; N = 232). Post hoc analyses were conducted to determine the efficacy of galcanezumab in patients who had not benefited from six of the most commonly prescribed migraine preventive medications. The mean change from baseline in monthly migraine headache days and ≥ 50 % response rates were assessed over months 1–3. Improvement in Migraine-Specific Questionnaire Role Function-Restrictive (MSQ-RFR) scores were assessed at month 3. The endpoints were estimated via mixed model with repeated measures. Results The most common treatment failures due to inadequate efficacy or safety/tolerability, which at least 20 % of patients reported trying without benefit, included topiramate, amitriptyline, propranolol, valproate or divalproex, onabotulinum toxin A, and metoprolol. Patients who had not previously benefited from these treatments had a greater mean reduction in monthly migraine headache days across months 1–3 in the galcanezumab group compared to placebo (all p < 0.01). More patients treated with galcanezumab experienced a ≥ 50 % reduction from baseline in monthly migraine headache days across months 1–3 compared to placebo (all p < 0.05). Galcanezumab-treated patients had a greater improvement in mean MSQ-RFR scores at month 3 compared to placebo (all p < 0.01). Conclusions In this population, galcanezumab was effective in reducing monthly migraine headache days, improving response rates, and enhancing quality of life in patients who had not previously benefited from topiramate, amitriptyline, propranolol, valproate or divalproex, onabotulinum toxin A, and/or metoprolol due to inadequate efficacy or safety/tolerability. Trial registration ClinicalTrials.gov NCT03559257 (CONQUER).


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