Brain Regulation of Muscle Tone in Healthy and Functionally Unstable Ankles

2013 ◽  
Vol 22 (3) ◽  
pp. 202-211 ◽  
Author(s):  
Alan R. Needle ◽  
Jacqueline A. Palmer ◽  
Trisha M. Kesar ◽  
Stuart A. Binder-Macleod ◽  
C. Buz Swanik
Keyword(s):  
Cortical Excitability ◽  
Ankle Instability ◽  
Silent Period ◽  
Lower Leg ◽  
Joint Laxity ◽  
Ligamentous Injury ◽  
Functional Ankle Instability ◽  
Cortical Silent Period ◽  
Leg Muscles ◽  
History Of

Context:Current research into the etiology of joint instability has yielded inconsistent results, limiting our understanding of how to prevent and treat ligamentous injury effectively. Recently, cortical reorganization was demonstrated in patients with ligamentous injury; however, these neural changes have not been assessed relative to joint laxity.Objective:The purpose of the current study was to determine if changes in cortical excitability and inhibition occur in subjects with functional ankle instability, as well as to investigate the relationship between these measures and joint laxity.Design:Posttest only with control group.Setting:University laboratory.Subjects:12 subjects with no history of ankle sprain (CON) and 12 subjects with a history of unilateral functional ankle instability (UNS).Interventions:Subjects were tested for joint laxity using an instrumented ankle arthrometer. Cortical excitability and inhibition were assessed using transcranial magnetic stimulation (TMS) to obtain motor-evoked potentials and the cortical silent period from the lower leg muscles.Main Outcome Measures:Joint laxity was quantified as peak anterior displacement and inversion rotation. Active motor threshold, slope, and intensity at 50% of peak slope of TMS-derived recruitment curves were used to quantify cortical excitability from lower leg muscles, while the cortical silent period from the peroneus longus was used to represent intracortical inhibition.Results:No significant differences were observed between groups for laxity or cortical measures. CON demonstrated a significant relationship between laxity and tibialis anterior excitability, as well as laxity and silent period, while UNS ankles demonstrated significant relationships between peroneal and soleus excitability and laxity measures.Conclusion:Our results support relationships between laxity and measures of excitability and inhibition that differ between healthy and unstable subjects. Future research should further investigate the mechanisms behind these findings and consider cortical influences when investigating altered joint laxity.

scholarly journals Eccentric Plantar-Flexor Torque Deficits in Participants With Functional Ankle Instability

2008 ◽  
Vol 43 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Jason Fox ◽  
Carrie L. Docherty ◽  
John Schrader ◽  
Trent Applegate
Keyword(s):  
Athletic Training ◽  
Ankle Instability ◽  
Plantar Flexion ◽  
Control Group ◽  
Prior History ◽  
Ankle Sprains ◽  
Plantar Flexors ◽  
Functional Ankle Instability ◽  
Significant Difference ◽  
History Of

Abstract Context: Inversion ankle sprains can lead to a chronic condition called functional ankle instability (FAI). Limited research has been reported regarding isokinetic measures for the plantar flexors and dorsiflexors of the ankle. Objective: To examine the isokinetic eccentric torque measures of the ankle musculature in participants with stable ankles and participants with functionally unstable ankles during inversion, eversion, plantar flexion, and dorsiflexion. Design: Case-control study. Setting: Athletic training research laboratory. Patients or Other Participants: Twenty participants with a history of “giving way” were included in the FAI group. Inclusion criteria for the FAI group included a history of at least 1 ankle sprain and repeated episodes of giving way. Twenty participants with no prior history of ankle injury were included in the control group. Intervention(s): Isokinetic eccentric torque was assessed in each participant. Main Outcome Measure(s): Isokinetic eccentric testing was conducted for inversion-eversion and plantar-flexion–dorsiflexion movements. Peak torque values were standardized to each participant's body weight. The average of the 3 trials for each direction was used for statistical analysis. Results: A significant side-by-group interaction was noted for eccentric plantar flexion torque (P < .01). Follow-up t tests revealed a significant difference between the FAI limb in the FAI group and the matched limb in the control group. Additionally, a significant difference was seen between the sides of the control group (P = .03). No significant interactions were identified for eccentric inversion, eversion, or dorsiflexion torques (P > .05). Conclusions: A deficit in plantar flexion torque was identified in the functionally unstable ankles. No deficits were identified for inversion, eversion, or dorsiflexion torque. Therefore, eccentric plantar flexion strength may be an important contributing factor to functional ankle instability.

Fear Avoidance Beliefs in College Athletes with a History of Ankle Sprain

2020 ◽  
Vol 41 (02) ◽  
pp. 128-133
Author(s):  
Mako Fukano ◽  
Shinshiro Mineta ◽  
Norikazu Hirose
Keyword(s):  
Ankle Joint ◽  
Ankle Sprain ◽  
Female Athletes ◽  
Ankle Instability ◽  
Joint Laxity ◽  
Ankle Sprains ◽  
Fear Avoidance ◽  
Functional Ankle Instability ◽  
Fear Avoidance Beliefs ◽  
Fear Of Movement

AbstractAnkle sprains are the most prevalent injuries, and elevated fear avoidance beliefs after ankle sprain episodes could inhibit athletic performance and contribute to residual symptoms, such as functional and/or mechanical instability. However, it remains unclear how fear avoidance beliefs differ according to conditions of posttraumatic sequelae. The purpose of this study was to determine whether fear of movement/reinjury differed between individuals with and without functional ankle instability (FI, NFI) and healthy controls (CON) and to examine the relationship between fear and ankle joint laxity by sex. Participants (115 male athletes, 105 female athletes) completed the Identification of Functional Ankle Instability, Athlete Fear Avoidance Questionnaire (AFAQ), Tampa Scale for Kinesiophobia (TSK), and ankle joint laxity test. Total 168 athletes (79 males, 89 females) data were eligible for analysis. The results demonstrated that fear of movement/reinjury was lower in individuals in the absence of functional ankle instability although they experienced ankle sprain (FI; TSK=38.6±4.5, AFAQ=27.4±6.2, NFI; TSK=35.7±5.6, AFAQ=24.5±6.6). The fear of movement/reinjury had correlation with ankle joint laxity only in female athletes (TSK; r=0.285, p=0.013, AFAQ; r 0=0.322, p=0.045).

Ankle Strength Deficits in a Cohort of College Athletes With Chronic Ankle Instability

2019 ◽  
Vol 28 (7) ◽  
pp. 752-757 ◽  
Author(s):  
Bethany Wisthoff ◽  
Shannon Matheny ◽  
Aaron Struminger ◽  
Geoffrey Gustavsen ◽  
Joseph Glutting ◽  
...  
Keyword(s):  
Athletic Training ◽  
College Athletes ◽  
Ankle Instability ◽  
Plantar Flexion ◽  
Chronic Ankle Instability ◽  
Ankle Sprains ◽  
Functional Ankle Instability ◽  
History Of ◽  
Ankle Strength ◽  
And Inversion

Context: Lateral ankle sprains commonly occur in an athletic population and can lead to chronic ankle instability. Objective: To compare ankle strength measurements in athletes who have mechanical laxity and report functional instability after a history of unilateral ankle sprains. Design: Retrospective cohort. Setting: Athletic Training Research Lab. Participants: A total of 165 National Collegiate Athletic Association Division I athletes, 97 males and 68 females, with history of unilateral ankle sprains participated. Main Outcome Measures: Functional ankle instability was determined by Cumberland Ankle Instability Tool scores and mechanical ankle instability by the participant having both anterior and inversion/eversion laxity. Peak torque strength measures, concentric and eccentric, in 2 velocities were measured. Results: Of the 165 participants, 24 subjects had both anterior and inversion/eversion laxity and 74 self-reported functional ankle instability on their injured ankle. The mechanical ankle instability group presented with significantly lower plantar flexion concentric strength at 30°/s (139.7 [43.7] N·m) (P = .01) and eversion concentric strength at 120°/s (14.8 [5.3] N·m) (P = .03) than the contralateral, uninjured ankle (166.3 [56.8] N·m, 17.4 [6.2] N·m, respectively). Conclusion: College athletes who present with mechanical laxity on a previously injured ankle exhibit plantar flexion and eversion strength deficits between ankles.

scholarly journals Clinical Examination Results in Individuals With Functional Ankle Instability and Ankle-Sprain Copers

2013 ◽  
Vol 48 (5) ◽  
pp. 581-589 ◽  
Author(s):  
Cynthia J. Wright ◽  
Brent L. Arnold ◽  
Scott E. Ross ◽  
Jessica Ketchum ◽  
Jeffrey Ericksen ◽  
...  
Keyword(s):  
Activities Of Daily Living ◽  
Clinical Examination ◽  
Ankle Sprain ◽  
Daily Living ◽  
Ankle Instability ◽  
Ankle Sprains ◽  
Foot And Ankle ◽  
Functional Ankle Instability ◽  
History Of ◽  
Ability Measure

Context: Why some individuals with ankle sprains develop functional ankle instability and others do not (ie, copers) is unknown. Current understanding of the clinical profile of copers is limited. Objective: To contrast individuals with functional ankle instability (FAI), copers, and uninjured individuals on both self-reported variables and clinical examination findings. Design: Cross-sectional study. Setting: Sports medicine research laboratory. Patients or Other Participants: Participants consisted of 23 individuals with a history of 1 or more ankle sprains and at least 2 episodes of giving way in the past year (FAI: Cumberland Ankle Instability Tool [CAIT] score = 20.52 ± 2.94, episodes of giving way = 5.8 ± 8.4 per month), 23 individuals with a history of a single ankle sprain and no subsequent episodes of instability (copers: CAIT score = 27.74 ± 1.69), and 23 individuals with no history of ankle sprain and no instability (uninjured: CAIT score = 28.78 ± 1.78). Intervention(s): Self-reported disability was recorded using the CAIT and Foot and Ankle Ability Measure for Activities of Daily Living and for Sports. On clinical examination, ligamentous laxity and tenderness, range of motion (ROM), and pain at end ROM were recorded. Main Outcome Measure(s): Questionnaire scores for the CAIT, Foot and Ankle Ability Measure for Activities of Daily Living and for Sports, ankle inversion and anterior drawer laxity scores, pain with palpation of the lateral ligaments, ankle ROM, and pain at end ROM. Results: Individuals with FAI had greater self-reported disability for all measures (P < .05). On clinical examination, individuals with FAI were more likely to have greater talar tilt laxity, pain with inversion, and limited sagittal-plane ROM than copers (P < .05). Conclusions: Differences in both self-reported disability and clinical examination variables distinguished individuals with FAI from copers at least 1 year after injury. Whether the deficits could be detected immediately postinjury to prospectively identify potential copers is unknown.

Cortical inhibition at rest and under a focused attention challenge in adults with migraine with and without aura

Cephalalgia ◽  
2011 ◽  
Vol 31 (8) ◽  
pp. 914-924 ◽  
Author(s):  
Joachim Maier ◽  
Imke Sebastian ◽  
Matthias Weisbrod ◽  
Christine M Freitag ◽  
Franz Resch ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Migraine With Aura ◽  
Contingent Negative Variation ◽  
Magnetic Stimulation ◽  
Migraine Without Aura ◽  
Cortical Excitability ◽  
Silent Period ◽  
Cortical Inhibition ◽  
Focused Attention ◽  
Cortical Silent Period

Objectives: We aimed to further elucidate the functional and attentional regulation of cortical excitability in migraine patients. Methods: We investigated the cortical silent period (CSP) after transcranial magnetic stimulation as a measure of cortical inhibition under three conditions: resting condition, cortical preactivation during reaction preparation, and during the post-processing of a motor response using a visual contingent negative variation paradigm in adults with migraine with aura, migraine without aura and healthy controls. Results: CSP was reduced in individuals with migraine with aura and unaffected in those with migraine without aura under resting conditions. Along with the intensity of transcranial magnetic stimulation, CSP increased equally in all groups (equal slopes). Furthermore, the functional challenge by a contingent negative variation task requiring focused sustained attention led to a comparable reduction of CSP duration in all groups. Discussion: Our data provide further hints towards the conclusion that a specific cortical inhibition deficit in migraine with aura but not migraine without aura is due to a tonic imbalance and not related to increased reactions to phasic stressors. Given that CSP at rest is related to GABA-ergic inhibition whereas the CSP reduction during late contingent negative variation is thought to be related to dopaminergic disinhibition in the basal ganglia, our results point towards reduced GABA-ergic cortical inhibition related to dysfunctional thalamo-cortical loops, especially in migraine with aura.

scholarly journals Altered Kinematics and Time to Stabilization During Drop-Jump Landings in Individuals With or Without Functional Ankle Instability

2016 ◽  
Vol 51 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Cynthia J. Wright ◽  
Brent L. Arnold ◽  
Scott E. Ross
Keyword(s):  
Ankle Sprain ◽  
Sagittal Plane ◽  
Ankle Instability ◽  
Control Group ◽  
Initial Contact ◽  
Functional Ankle Instability ◽  
Jump Landing ◽  
Time To Stabilization ◽  
History Of ◽  
Jump Landings

Context It has been proposed that altered dynamic-control strategies during functional activity such as jump landings may partially explain recurrent instability in individuals with functional ankle instability (FAI). Objective To capture jump-landing time to stabilization (TTS) and ankle motion using a multisegment foot model among FAI, coper, and healthy control individuals. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants Participants were 23 individuals with a history of at least 1 ankle sprain and at least 2 episodes of giving way in the past year (FAI), 23 individuals with a history of a single ankle sprain and no subsequent episodes of instability (copers), and 23 individuals with no history of ankle sprain or instability in their lifetime (controls). Participants were matched for age, height, and weight (age = 23.3 ± 3.8 years, height = 1.71 ± 0.09 m, weight = 69.0 ± 13.7 kg). Intervention(s) Ten single-legged drop jumps were recorded using a 12-camera Vicon MX motion-capture system and a strain-gauge force plate. Main Outcome Measures Mediolateral (ML) and anteroposterior (AP) TTS in seconds, as well as forefoot and hindfoot sagittal- and frontal-plane angles at jump-landing initial contact and at the point of maximum vertical ground reaction force were calculated. Results For the forefoot and hindfoot in the sagittal plane, group differences were present at initial contact (forefoot: P = .043, hindfoot: P = .004). At the hindfoot, individuals with FAI displayed more dorsiflexion than the control and coper groups. Time to stabilization differed among groups (AP TTS: P < .001; ML TTS: P = .040). Anteroposterior TTS was longer in the coper group than in the FAI or control groups, and ML TTS was longer in the FAI group than in the control group. Conclusions During jump landings, copers showed differences in sagittal-plane control, including less plantar flexion at initial contact and increased AP sway during stabilization, which may contribute to increased dynamic stability.

The Role of Ankle Strength in Functional Ankle Instability

1997 ◽  
Vol 6 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Cynthia M. McKnight ◽  
Charles W. Armstrong
Keyword(s):  
Range Of Motion ◽  
Ankle Instability ◽  
Plantar Flexion ◽  
Normative Values ◽  
Functional Ankle Instability ◽  
Full Activity ◽  
History Of ◽  
Ankle Strength

The purpose of this study was to determine if there were any differences in ankle range of motion, strength, or work between persons with normal ankles (Normal,n= 14), those with functional ankle instability (FAI,n= 15), and those with a history of FAI who have been through formal proprioceptive rehabilitation (Rehab,n= 14). A second puipose was to determine normative values for ankle strength and work measurements using the Biodex® isokinetic system. There were no significant differences between groups for ankle range of motion or for any strength or work measurements. The overall strength/work averages were 11.75/3.42 for plantar flexion, 339/1.48 for dorsiflexion, 3.30/2.40 for inversion, and 2.62/1.79 for eversion. Dorsiflexion torque overall was 31.43% of plantar flexion, and the evertors produced 75.42% of the torque produced by the invertors. It is recommended that clinicians continue to rehabilitate ankles with strength and proprioceptive exercises but do not rely on ankle strength/work testing as the only criteria for determining an athlete's readiness to return to full activity.

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