The contributions of proprioceptive deficits, muscle function, and anatomic laxity to functional instability of the ankle

Deficits in proprioception and strength may contribute to the impaired postural stability among individuals with functional ankle instability

Purpose: The correlations of postural stability with proprioception and strength may explain the recurrent sprains among individuals with functional ankle instability (FAI). This study aimed to compare anterior-posterior (AP) and medial-lateral (ML) postural stability, along with ankle proprioception and strength between individuals with and without FAI and investigated their correlations. Methods: Forty participants with FAI and another 40 without FAI were recruited. Their postural stability, represented by time to stabilization (TTS) in the AP (TTSAP) and ML (TTSML) directions, was calculated by the ground reaction force during jumping onto a force plate. Their ankle proprioception and strength during plantarflexion/dorsiflexion and inversion/eversion were measured using a proprioception device and a strength testing system, separately. Results: Individuals with FAI had longer TTSAP (p = 0.015) and TTSML (p = 0.006), larger ankle proprioception thresholds (p = 0.000-0.001), and less strength (p = 0.001-0.017) than those without FAI. Correlations between strength and TTSAP were detected among individuals with (ankle plantarflexion, r = -0.409, p = 0.009) and without FAI (ankle plantarflexion, r = -0.348, p = 0.028; ankle dorsiflexion, r = -0.473, p = 0.002). Correlations of proprioception (ankle inversion, r = 0.327, p = 0.040; ankle eversion, r = 0.354, p = 0.025) and strength (ankle eversion, r = -0.479, p = 0.002) with TTSML were detected among individuals without FAI but not among those with FAI. Conclusion: Individuals with FAI have worse postural stability and proprioception and less strength. Their proprioception and strength decreased to a point where they could not provide sufficient functional assistance to the ML postural stability. Improvements in proprioception and strength may be keys to prevent recurrent ankle sprains among individuals with FAI.

Contralateral thalamocortical connectivity is related to postural control in the uninvolved limb of older adults with history of ankle sprain

BACKGROUND

Sensorimotor brain connectivity is often overlooked when determining relationships between postural control and motor performance following musculoskeletal injury. Thalamocortical brain connectivity is of particular interest as it represents the temporal synchrony of functionally and anatomically linked brain regions. Importantly, adults over the age of 60 are especially vulnerable to musculoskeletal injury due to age-related declines in postural control and brain connectivity.

RESEARCH QUESTION

Is there a relationship between thalamocortical connectivity and static postural control in older adults with a history of LAS?

METHODS

Data were analyzed from twenty older adults (mean age = 67.0 ± 4.3 yrs; 13 females) with a history of LAS. The sensorimotor network (SMN) was identified from resting-state MRI data, and a priori thalamic and postcentral gyri regions of interest were selected in order to determine left and right hemisphere thalamocortical connectivity. Balance was assessed for the involved and non-involved limbs via center of pressure velocity (COPV) in the medial-lateral (ML) and anterior-posterior (AP) directions.

RESULTS

Contralateral thalamocortical connectivity was significantly associated with COPV_ML COPV_ML (r = -0.474, P = 0.05) and COPV_AP (r = -0.622, P = 0.008) in the non-involved limb. No significant association was observed between involved limb balance and contralateral thalamocortical connectivity (COPV_ML: r = -0.08, P = 0.77; COPV_AP: r = 0.12, P = 0.63).

SIGNIFICANCE

A significant relationship between thalamocortical connectivity and static postural control was observed in the non-involved, but not the involved limb in older adults with a history of LAS. Findings suggest that thalamocortical connectivity may lead to or be the product of LAS.

Evaluation of dynamic postural control during single-leg landing tasks using initial impact force, landing leg stiffness and time to stabilisation

Time to stabilisation (TTS) provides limited information to evaluate the dynamic postural control for individuals with functional ankle instability in single-leg landing task. More information is needed to understand TTS and evaluate the dynamic postural control better. The purpose is to develop a method estimating TTS, initial impact force (IIF) and landing leg stiffness (LLS) through fitting ground reaction force (GRF) decay in single leg landing with exponential vibration decay function (EVDF), and investigate effects of landing directions and GRF components on these parameters. Thirty-nine healthy participants were recruited. EVDF was used to fit GRF decays in different single-leg landings. TTS, IIF, and LLS were compared across landing directions and GRF components. The mean regression determinants of fitting GRF decays with EVDF were greater than 0.50. TTS was sensitive to GRF components (P = 0.041 females, P = 0.028 males). IIF was sensitive to GRF components (P = 0.001) for both genders. LLS was sensitive to GRF components (P = 0.023) for males. This method showed a moderate to strong feasibility for reporting GRF decay during landing, and provided movement characteristic information for better understanding of dynamic postural control together with TTS during landing.

Ankle Joint Microinstability: You Might Have Never Seen It but It Has Definitely Seen You

Ankle microinstability results from the superior fascicle of anterior talofibular ligament (ATFL) injury and is a potential cause of chronic pain and disability after an ankle sprain. Ankle microinstability is usually asymptomatic. When symptoms appear, patients describe a subjective ankle instability feeling, recurrent symptomatic ankle sprains, anterolateral pain, or a combination of them. A subtle anterior drawer test can usually be observed, with no talar tilt. Ankle microinstability should be initially treated conservatively. If this fails, and because superior fascicle of ATFL is an intra-articular ligament, an arthroscopic procedure is recommended to address.

The Relationship Between Health-Related Quality of Life and Lower-Extremity Visuomotor Reaction Time in Young Adult Women Following Ankle Sprain

CONTEXT

Many individuals who sustain a lateral ankle sprain (LAS) fail to return to prior activity due to residual symptoms; and report elevated levels of injury-related fear, decreased function, and decreased health-related quality of life (HRQOL). Additionally, individuals with history of LAS exhibit deficits in neurocognitive functional measures like visuomotor reaction time (VMRT), which contributes to worse patient-reported outcome scores. The aim of this study was to examine the relationship between HRQOL and lower-extremity (LE) VMRT in individuals with LAS history.

DESIGN

Cross-sectional.

METHODS

Young adult female volunteers with history of LAS (n = 22; age = 24 [3.5] y; height = 163.1 [9.8] cm; mass = 65.1 [11.5] kg; and time since last LAS = 67.8 [50.5] mo) completed HRQOL outcomes including the following: (1) Tampa Scale of Kinesiophobia-11, (2) Fear-Avoidance Beliefs Questionnaire, (3) Penn State Worry Questionnaire, (4) modified Disablement in the Physically Active Scale, and (5) Foot and Ankle Disability Index (FADI). Additionally, participants completed a LE-VMRT task by responding to a visual stimulus using their foot to deactivate light sensors. Participants completed trials bilaterally. Separate Spearman rho correlations were performed to assess the relationship between patient-reported outcomes assessing constructs of HRQOL and LE-VRMT bilaterally. Significance was set at P < .05.

RESULTS

There was a strong, significant negative correlation between FADI-Activities of Daily Living (ρ = -.68; P = .002) and FADI-Sport (ρ = -.76; P = .001) scores and injured limb LE-VMRT; moderate, significant negative correlations between the uninjured limb LE-VMRT and FADI-Activities of Daily Living (ρ = -.60; P = .01) and FADI-Sport (ρ = -.60; P = .01) scores; and moderate, significant positive correlations between the injured limb LE-VMRT and modified Disablement in the Physically Active Scale-Physical Summary Component (ρ = .52; P = .01) and modified Disablement in the Physically Active Scale-Total (ρ = .54; P = .02) scores. All other correlations were not statistically significant.

CONCLUSIONS

Young adult women with history of LAS demonstrated an association between self-reported constructs of HRQOL and LE-VMRT. As LE-VMRT is a modifiable injury risk factor, future studies should examine the effectiveness of interventions designed to improve LE-VMRT and the impact on self-reported HRQOL.

Morphologic evaluation of injured and contralateral uninjured ankles in patients with unilateral chronic ankle instability

OBJECTIVE

To compare the morphological anatomy and abnormalities of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) in unilateral chronic ankle instability (CAI).

METHODS

22 patients (men: women, 13:9; mean age, 28.95 ± 8.127 years) with unilateral CAI and 18 healthy volunteers (men: women, 9:9, mean age, 28.33 ± 3.678 years) were recruited. MRI scans were divided into Group 1 (22 injured ankles), Group 2 (22 contralateral uninjured ankles), and Group 3 (36 healthy volunteer ankles). The morphologic variables, MRI signal intensity (SI) values were evaluated.

RESULTS

The ATFL proximal, intermediate, and distal sites and the CFL proximal and distal sites in Group 3 were narrower than those in Group 1 (P ＜0.05). Both ATFL and CFL in Group 1 were thicker than those in Group 3 (P ＜0.01). The proximal and intermediate sites of the ATFL and the proximal site of the CFL in Group 3 were narrower than those in Group 2 (P ＜0.01). The intermediate site of the ATFL and the proximal and distal sites of the CFL in Group 2 were thicker than those in Group 3 (P ＜0.01). The mean SI values of the ATFL in Group 1 were higher than those in Groups 2 and 3 (P ＜0.01). The ATFL and CFL SI values were higher in Group 2 than those in Group 3 (P ＜0.05).

CONCLUSION

Both the injured and contralateral uninjured ankles had wider ATFL and CFL, more thickness, and higher SI values compared with those of healthy volunteer ankles.

ADVANCES IN KNOWLEDGE

High-resolution three-dimensional MRI provides a potential tool assisting clinical decision on the treatment and rehabilitation therapy of patients with unilateral CAI.

Effect of Application of Repeated Downhill Walking Bouts on Ankle Isokinetic Parameters in Children with Obesity

BACKGROUND

Obesity among children became of high concern. Obesity can affect many health aspects including muscular strength. Downhill walking is a useful intervention to enhance muscular strength, especially in older adults.

OBJECTIVE

The current study's purpose was to investigate the effect of repeated bouts of downhill walking on ankle isokinetic parameters in children with obesity.

METHODS

32 obese male children aged from 8 to 12 years engaged in the study. The children were divided into two groups: the level walking group (LWG) (n = 16) and the downhill walking group (DWG) (n = 16). Participants in both groups walked 20 minutes on the treadmill, two sessions per week for 6 weeks, with a speed of 5 km/h, and the treadmill slope used for the DWG was set at -20%. Isokinetic dynamometry (Cybex 6000) was used to analyze the normalized eccentric and concentric torque of both ankle dorsiflexors and plantar flexors of the dominant leg in all participants.

RESULTS

The normalized peak torques for eccentric plantar flexion, concentric plantar flexion, eccentric dorsiflexion, and concentric dorsiflexion significantly increased by 38.66%, 23.87%, 38.58%, and 15.51%, respectively, after repeated bouts of downhill walking. Level walking resulted in nonsignificant improvement in the muscular torques.

CONCLUSION

Downhill walking is a beneficial intervention in improving ankle muscular torques of obese children.

Ankle-Injury Patients Perform More Microadjustments during Walking: Evidence from Velocity Profiles in Gait Analysis

Introduction

We evaluated the velocity profiles of patients with lateral collateral ligament (LCL) injuries of the ankle with a goal of understanding the control mechanism involved in walking.

Methods

We tracked motions of patients' legs and feet in 30 gait cycles recorded from patients with LCL injuries of the ankle and compared them to 50 gait cycles taken from normal control subjects. Seventeen markers were placed on the foot following the Heidelberg foot measurement model. Velocity profiles and microadjustments of the knee, ankle, and foot were calculated during different gait phases and compared between the patient and control groups.

Results

Patients had a smaller first rocker percentage and larger second rocker percentage in the gait cycle compared to controls. Patients also displayed shorter stride length and slower strides and performed more microadjustments in the second rocker phase than in other rocker/swing phases. Patients' mean velocities of the knee, ankle, and foot in the second rocker phase were also significantly higher than that in control subjects. Discussion. Evidence from velocity profiles suggested that patients with ligament injury necessitated more musculoskeletal microadjustments to maintain body balance, but these may also be due to secondary injury. Precise descriptions of the spatiotemporal gait characteristics are therefore crucial for our understanding of movement control during locomotion.

Location of Talar Osteochondral Defects in Chronic Lateral Ankle Instability in an Asian Population

Osteochondral defect of the talus is traditionally described to involve the anterolateral and posteromedial portion of the talar dome in patients with chronic lateral ankle instability. Recent studies challenged this notion with advances in preoperative imaging and arthroscopy. Since Asian patients are more prone to ligamentous laxity, we postulate that the morphology and severity of osteochondral defects may be different in this population. Intraoperative records of 272 patients undergoing modified Broström-Gould procedure were reviewed for arthroscopic evidence of osteochondral defects. We characterized the morphology according to an anatomical 9-grid classification. Talar osteochondral defects were seen in 52 (19.1%) patients with a double lesion present in 1 patient. Medial-sided lesions account for nearly 3-quarters (n = 38, 73.1%) of all lesions and tend to be larger (79.4 ± 55.7 mm² vs 51.0 ± 28.6 mm², p =.08). There was no osteochondral defect seen in the central zones. There was no significant gender or age differences between patients with medial and lateral lesions. The most commonly performed procedure was microfracture. Osteochondral defects are commonly encountered in our Asian patients undergoing surgery for chronic lateral ankle instability. Contrary to published data, medial lesions are prevalent with no central lesions seen.

Chronic ankle instability is associated with proprioception deficits: A systematic review and meta-analysis

BACKGROUND

Acute ankle injury causes damage to joint mechanoreceptors and deafferentation and contributes to proprioception deficits in patients with chronic ankle instability (CAI). We aimed to explore whether deficits of proprioception, including kinesthesia and joint position sense (JPS), exist in patients with CAI when compared with the uninjured contralateral side and healthy people. We hypothesized that proprioception deficits did exist in patients with CAI and that the deficits varied by test methodologies.

METHODS

The study was a systematic review and meta-analysis. We identified studies that compared kinesthesia or JPS in patients with CAI with the uninjured contralateral side or with healthy controls. Meta-analyses were conducted for the studies with similar test procedures, and narrative syntheses were undertaken for the rest.

RESULTS

A total of 7731 studies were identified, of which 30 were included for review. A total of 21 studies were eligible for meta-analysis. Compared with the contralateral side, patients with CAI had ankle kinesthesia deficits in inversion and plantarflexion, with a standardized mean difference (SMD) of 0.41 and 0.92, respectively, and active and passive JPS deficits in inversion (SMD = 0.92 and 0.72, respectively). Compared with healthy people, patients with CAI had ankle kinesthesia deficits in inversion and eversion (SMD = 0.64 and 0.76, respectively), and active JPS deficits in inversion and eversion (SMD = 1.00 and 4.82, respectively). Proprioception deficits in the knee and shoulder of patients with CAI were not statistically significant.

CONCLUSION

Proprioception, including both kinesthesia and JPS, of the injured ankle of patients with CAI was impaired, compared with the uninjured contralateral limbs and healthy people. Proprioception varied depending on different movement directions and test methodologies. The use of more detailed measurements of proprioception and interventions for restoring the deficits are recommended in the clinical management of CAI.

Change in dynamic postural control after a training program in collegiate soccer players with unilateral chronic ankle instability

BACKGROUND

Improving dynamic postural stability after lateral ankle sprain due to chronic ankle instability helps prevent recurrence, and changes in dynamic postural stability can be assessed with the Star Excursion Balance Test. To date, no studies have examined the change in Star Excursion Balance Test score after the end of a balance training program or whether chronic ankle instability affects the rate of change. To examine the effect of chronic ankle instability on changes in Star Excursion Balance Test. score over time after a balance training program.

METHODS

Fifteen collegiate soccer players with chronic ankle instability selected with the Cumberland Ankle Instability Tool and ultrasonography. Participants completed a 6-week balance training program. We assessed the Star Excursion Balance Test 5 times (before and immediately after the program and 2, 4, and 6 weeks later) and examined differences in the duration of training effects by a 2-way analysis of variance, with Bonferroni correction for post hoc comparisons to explain any significant interactions. The significance level for all analyses was set at P < .05. We performed statistical analyses with SPSS version 25.

RESULTS

Analysis of the posterolateral and posteromedial scores in Star Excursion Balance Test showed a significant effect of time. Post hoc analysis of the posterolateral score showed that for each leg, participants reached significantly farther after the program than before (P = .012). The posterolateral scores at 2, 4, and 6 weeks after the training program did not differ from before the program, but the posteromedial score was significantly improved immediately after the program (P = .008) and also 2 (P = .004) and 4 weeks later (P = .006).

CONCLUSIONS

A 6-week balance training program to improve dynamic postural control can improve posterolateral and posteromedial scores in people with chronic ankle instability, and the improvements in posteromedial are still present 4 weeks after program completion.

Biomechanical and viscoelastic properties of the ankle muscles in men with previous history of ankle sprain

In this study, we aimed to explore the impact of previous history of lateral ankle sprain on the mechanical and viscoelastic properties of the tibialis anterior (TA), peroneus longus (PL) and gastrocnemius lateralis (GL) and medialis (GM) in asymptomatic men. For this purpose, a group of 26 men with previous history of lateral ankle sprain (ASG) and a control group (CG) of 29 healthy counter-parts participated in this study. Tone, stiffness, elasticity and mechanical stress relaxation time were measured using a myotonometer in a single session. Higher tone was noted for TA and GL in ASG as compared to CG (effect size of Cohen's d = 0.57 [p = 0.04] and 0.59 [p = 0.04], respectively). Further, stiffness was higher in ASG than in CG for TA (d = 0.56; p = 0.04), PL (d = 0.58; p = 0.04) and GL (d = 0.63; p = 0.02). Stress relaxation time was also lower for the ASG compared to the CG for TA (d = 0.61; p = 0.03), PL (d = 0.55; p = 0.04) and GL (d = 0.68; p = 0.02). There were no significant differences between groups in elasticity (p > 0.05). GM experienced no significant changes after ankle sprain in any of the variables (p > 0.05). To conclude, previous history of lateral ankle sprain results in higher TA and GL muscle tone. Likewise, these muscles in addition to PL exhibit less deformation against resistance due to their increased stiffness, thus needing a shorter time to restore to their original shape after deformation.

Electromyographic Activity of Hip Musculature During Functional Exercises in Participants With and Without Chronic Ankle Instability

Objective

The main objective of the present study was to investigate the electromyographic (EMG) activity of gluteus medius (Gmed) and gluteus maximus (Gmax) muscles during functional exercises in subjects with chronic ankle instability (CAI) vs healthy controls.

Methods

Seventeen subjects (age, 24.4 ± 2.03 years) with CAI and 17 healthy controls (age, 24.6 ± 2.57 years) were recruited for the present study. For all participants, after testing maximum voluntary isometric contraction of the Gmed and Gmax muscle, EMG activity of these muscles was recorded during functional exercises, such as the Y Balance Test and the single-leg squat with and without Swiss ball.

Results

EMG activity of Gmed and Gmax was found to be significantly (P < .05) reduced during all functional exercises in subjects with CAI when compared with healthy controls. No significant differences (P > .05) were observed in the EMG activity of both muscles across different functional exercises.

Conclusion

Our findings indicate that EMG activity of hip muscles is significantly reduced in CAI subjects, which might give an indication regarding the inclusion of hip muscle strengthening (Gmax and Gmed) in the rehabilitation of CAI. Moreover, Gmed and Gmax muscle activity did not vary during the different functional exercises within each group, which might indicate that activation pattern of these muscles are not sensitive to the type of functional task.

Does the Spraino low-friction shoe patch prevent lateral ankle sprain injury in indoor sports? A pilot randomised controlled trial with 510 participants with previous ankle injuries

Background

Lateral ankle sprains are common in indoor sports. High shoe–surface friction is considered a risk factor for non-contact lateral ankle sprains. Spraino is a novel low-friction patch that can be attached to the outside of sports shoes to minimise friction at the lateral edge, which could mitigate the risk of such injury. We aimed to determine preliminary effectiveness (incidence rate and severity) and safety (harms) of Spraino to prevent lateral ankle sprains among indoor sport athletes.

Methods

In this exploratory, parallel-group, two-arm pilot randomised controlled trial, 510 subelite indoor sport athletes with a previous lateral ankle sprain were randomly allocated (1:1) to Spraino or ‘do-as-usual’. Allocation was concealed and the trial was outcome assessor blinded. Match and training exposure, number of injuries and associated time loss were captured weekly via text messages. Information on harms, fear-of-injury and ankle pain was also documented.

Results

480 participants completed the trial. They reported a total of 151 lateral ankle sprains, of which 96 were categorised as non-contact, and 50 as severe. All outcomes favoured Spraino with incidence rate ratios of 0.87 (95% CI 0.62 to 1.23) for all lateral ankle sprains; 0.64 (95% CI 0.42 to 0.98) for non-contact lateral ankle sprains; and 0.47 (95% CI 0.25 to 0.88) for severe lateral ankle sprains. Time loss per injury was also lower in the Spraino group (1.8 vs 2.8 weeks, p=0.014). Six participants reported minor harms because of Spraino.

Conclusion

Compared with usual care, athletes allocated to Spraino had a lower risk of lateral ankle sprains and less time loss, with only few reported minor harms.

Trial registration number

NCT03311490.

Center of pressure excursion and muscle activation during gait initiation in individuals with and without chronic ankle instability

The aim of the current study was to determine differences in center of pressure (COP)excursion and muscle activation during gait initiation (GI) in those with and without chronic ankle instability (CAI). Thirty-four participants, 17 per group, volunteered to participate. Participants were asked to stand barefoot on a force plate before initiating gait upon hearing an auditory cue. Reaction time, anticipatory postural adjustment phase time, as well as normalized peak COP excursion during the anticipatory postural adjustment phase was calculated. Response time of Soleus and Tibialis Anterior muscles were concurrently recorded via electromyography. The results demonstrate a longer reaction time and shorter anticipatory postural adjustment phase time in the CAI group (p < 0.05). No significant between group differences in peak normalized COP excursion were noted (p > 0.05). Muscle onset patterns differed between groups as those with CAI demonstrated earlier Soleus activation compared to the control group (p < 0.05). The results suggest that those with CAI have an altered GI motor control strategy as evidenced by reduced or absent Soleus muscle inhibition during APA phase of GI relative to controls. The APA phase is controlled by the secondary motor area, therefore, the presence of motor control alterations in CAI patients may be due to a supra-spinal alterations.

Effects of lateral ankle sprain on range of motion, strength and postural balance in competitive basketball players: a cross-sectional study

BACKGROUND

Lateral ankle sprain is the most common injury in basketball, and many of these sprains resulted in residual functional deficits. This study aimed to compare ankle strength and range of motion, and postural balance between competitive basketball players with and without lateral ankle sprain.

METHODS

This was a cross-sectional study involving 42 male competitive basketball players. Subjects were divided into the injured and uninjured groups based on self-reported questionnaires. Ankle range of motion (ROM) was measured using a goniometer, ankle isokinetic strength testing performed using Biodex System 4 PRO, and single-leg stability tests performed using Biodex Balance System SD.

RESULTS

Between the injured and uninjured ankles, there was a decrease in plantarflexion ROM (44.89±6.85 vs. 50.75±9.31, P<0.05) and an increase in eversion ROM (14.50±5.63 vs. 11.74±4.53, P<0.05). There was a reduction in inversion and plantarflexion strength at 30°/s peak torque and 120 °/s peak torque (P<0.05). However, no significant difference observed in the postural stability indexes between the two groups.

CONCLUSIONS

This study proves that there are residual ROM and strength deficits after an ankle sprain, however, these deficits do not affect their balance ability.

Relationship Between Isokinetic Muscle Strength and Functional Tests in Chronic Ankle Instability

Isokinetic muscle strength measurements and functional tests are usually performed to evaluate ankle condition in chronic ankle instability (CAI), yet there is no clear demonstration of the relationship between isokinetic muscle strength and functional tests. The objective of this study was to evaluate the relationship between isokinetic muscle strength and functional tests in CAI. Between April 2014 and August 2016, 103 patients with unilateral CAI were studied. Single-leg balance, single-heel raise, and single-leg squat tests were performed for static balancing assessment. Single-leg hop, double-leg jump, and sidestep tests were performed for dynamic balancing assessment. The isokinetic muscle strength of both ankles was measured using a dynamometer. The involved ankle showed lower muscle strength in inversion than the uninvolved ankle, while eversion, dorsiflexion, and plantarflexion muscle strength had no significant differences between ankles. There were significant correlations between the isokinetic muscle strength of inversion and the single-leg balance test, single-heel raise test, and sidestep test (Pearson's r; 0.246, 0.514, and 0.229 at 30°/second; 0.288, 0.473, and 0.239 at 180°/second, respectively). The single leg balance, single heel raise, and sidestep tests are useful to assess not only ankle functional performance but also isokinetic muscle strength. Among these tests, the single heel raise test was the most reliable test to reflect muscle strength deficiency in CAI.

An examination of muscle force control in individuals with a functionally unstable ankle

Previous studies suggest that functional ankle instability (FAI) may be associated with deficits in the ability to sense muscle forces. We tested individuals with FAI to determine if they have reduced ability to control ankle muscle forces, which is a function of force sense. Our test was performed isometrically to minimize the involvement of joint position sense and kinesthesia. A FAI group and a control group were recruited to perform an ankle force control task using a platform-based ankle robot. They were asked to move a cursor to hit 24 targets as accurately and as fast as possible in a virtual maze. The cursor movement was based on the direction and magnitude of the forces applied to the robot. Participants underwent three conditions: pre-test (baseline), practice (skill acquisition), and post-test (post skill acquisition). The force control ability was quantified based on the accuracy performance during the task. The accuracy performance was negatively associated with the collision count of the cursor with the maze wall. The FAI group showed reduced ability to control ankle muscle forces compared to the control group in the pre-test condition, but the difference became non-significant in the post-test condition after practice. The change in performance before and after practice may be due to different degrees of reliance on force sense.

Effect of Impairment-Based Rehabilitation on Lower Leg Muscle Volumes and Strength in Patients With Chronic Ankle Instability: A Preliminary Study

Context: Patients with chronic ankle instability (CAI) have demonstrated atrophy of foot and ankle musculature and deficits in ankle strength. The effect of rehabilitation on muscle morphology and ankle strength has not previously been investigated in patients with CAI. Objective: Our objective was to analyze the effect of impairment-based rehabilitation on intrinsic and extrinsic foot and ankle muscle volumes and strength in patients with CAI. Design: Controlled laboratory study. Setting: Laboratory. Patients: Five young adults with CAI. Intervention: Twelve sessions of supervised impairment-based rehabilitation that included range of motion, strength, balance, and functional exercises. Main Outcome Measures: Measures of extrinsic and intrinsic foot muscle volume and ankle strength measured before and after 4 weeks of supervised rehabilitation. Novel fast-acquisition magnetic resonance imaging was used to scan from above the femoral condyles through the entire foot. The perimeter of each muscle was outlined on each axial slice and then the 2-dimensional area was multiplied by the slice thickness (5 mm) to calculate muscle volume. Plantar flexion, dorsiflexion, inversion, and eversion isometric strength were measured using a hand-held dynamometer. Results: Rehabilitation resulted in hypertrophy of all extrinsic foot muscles except for the flexor hallucis longus and peroneals. Large improvements were seen in inversion, eversion, and plantar flexion strength following rehabilitation. Effect sizes for significant differences following rehabilitation were all large and ranged from 1.54 to 3.35. No significant differences were identified for intrinsic foot muscle volumes. Conclusion: Preliminary results suggest that impairment-based rehabilitation for CAI can induce hypertrophy of extrinsic foot and ankle musculature with corresponding increases in ankle strength.

Factors Contributing to Chronic Ankle Instability: A Systematic Review and Meta-Analysis of Systematic Reviews

BACKGROUND

Many factors are thought to contribute to chronic ankle instability (CAI). Multiple systematic reviews have synthesised the available evidence to identify the primary contributing factors. However, readers are now faced with several systematic reviews that present conflicting findings.

OBJECTIVE

The aim of this systematic review and meta-analysis was to establish the statistical significance and effect size of primary factors contributing to CAI and to identify likely reasons for inconsistencies in the literature.

METHODS

Relevant health databases were searched: CINAHL, MEDLINE, PubMed, Scopus and SPORTDiscus. Systematic reviews were included if they answered a focused research question, clearly defined the search strategy criteria and study selection/inclusion and completed a comprehensive search of the literature. Included reviews needed to be published in a peer-reviewed journal and needed to review observational studies of factors and/or characteristics of persons with CAI, with or without meta-analysis. There was no language restriction. Studies using a non-systematic review methodology (e.g. primary studies and narrative reviews) were excluded. Methodological quality of systematic reviews was assessed using the modified R-AMSTAR tool. Meta-analysis on included primary studies was performed.

RESULTS

Only 17% of primary studies measured a clearly defined CAI population. There is strong evidence to support the contribution of dynamic balance, peroneal reaction time and eversion strength deficits and moderate evidence for proprioception and static balance deficits to non-specific ankle instability.

CONCLUSIONS

Evidence from previous systematic reviews does not accurately reflect the CAI population. For treatment of non-specific ankle instability, clinicians should focus on dynamic balance, reaction time and strength deficits; however, these findings may not be translated to the CAI population. Research should be updated with an adequately controlled CAI population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016, CRD42016032592.

Changes in the Ground Reaction Force, Lower-Limb Muscle Activity, and Joint Angles in Athletes with Unilateral Ankle Dorsiflexion Restriction During A Rebound-Jump Task

BACKGROUND

This study compared differences between a control group and a group with unilateral ankle dorsiflexion restriction in the ground reaction force (GRF), angles of the lower limbs joints, and muscular activity during a rebound-jump task in athletes who continue to perform sports activities with unilateral ankle dorsiflexion restriction.

METHODS

The athletes were divided into the following two groups: The dorsiflexion group included those with a difference of ≥7° between bilateral ankle dorsiflexion angles (DF), and the control group included those with a difference of <7° between the two ankles (C). An ankle foot orthosis was attached to subjects in group C to apply a restriction on the right-angle dorsiflexion angle. The percentage of maximum voluntary contraction (%MVC) of the legs musculature, components of the GRF, and the hip and knee joint angles during the rebound-jump task were compared between groups DF and C.

RESULTS

Group DF showed increased %MVC of the quadriceps muscle, decreased upward component of the GRF, decreased hip flexion, and increased knee eversion angles.

CONCLUSIONS

This study highlighted that athletes with ankle dorsiflexion restriction had significantly larger knee eversion angles in the rebound-jump task. The reduced hip flexion was likely caused by the restricted ankle dorsiflexion and compensated by the observed increase in quadriceps muscle activation when performing the jump.

The efficacy of virtual reality assisted versus traditional rehabilitation intervention on individuals with functional ankle instability: a pilot randomized controlled trial

PURPOSE

Virtual reality (VR) training, a virtual environment commonly generated by computer systems, may enhance the therapeutic efficacy of functional rehabilitation programmes. The aim of this study was to investigate the efficacy of a VR assisted intervention (VRAI) versus traditional rehabilitation intervention (TRI) on functional ankle instability (FAI).

METHODS

A single-blind randomized controlled study was conducted with 10 subjects for each group. The VRAI was conducted with the Nintendo Wii Fit Plus, whilst the TRI was conducted with a series of exercises with theraband. The muscle strength change of the two groups and the difference between pre and post interventions for each group were compared.

RESULTS

The VRAI group had less improvement in the muscle strength of all ankle motions than did the TRI group (p > .05). The VRAI group had a greater improvement in muscle strength of plantar flexion than other motions, whilst the TRI group had an improvement in muscle strength of all ankle motions (p < .05).

CONCLUSIONS

The effects of VR training for the condition of FAI were not comparable to conventional training. However, VR training may be added to the conventional training programme as an optional for the condition of FAI. Implications for Rehabilitation Functional ankle instability (FAI) is subjective feelings of ankle instability resulting from proprioceptive and neuromuscular deficits in which individuals may experience "giving way" condition of the ankle. Therapeutic applications of virtual reality (VR) may be comparable to traditional rehabilitation interventions (TRI) in the rehabilitation of individuals with FAI. However, there is no definitive evidence for the issue. Integrating low-cost VR into functional rehabilitation programme can provide insight into an issue of whether it can be replaced with traditional therapeutic approaches. Although, the efficacy of VR application on strengthening muscles is unable to compare to traditional strengthening programmes, it may be considered an optional treatment based on the proprioceptive improvements.

The effect of ankle tape on joint position sense after local muscle fatigue: a randomized controlled trial

Background

Ankle tape is widely used by athletes to prevent ankle sprain. Although there is growing evidence that ankle tape improve joint position sense, but yet it is not clear even if tape improve joint position sense after muscle fatigue, because fatigue impair joint position sense and raise the risk of ankle sprain. The aim of this study is to examine the effect of ankle tape on joint position sense after local muscle fatigue.

Method

This trial is a randomized controlled trial. 34 healthy subjects participated in this trial. Subjects were randomized distributed into two groups: with tape and without tape. Active and passive absolute error and variable error mean values for two target positions of the ankle joint (15° inversions and inversion minus 5°) before and after fatigue protocol consisted of 30 consecutive maximal concentric/concentric contractions of the ankle evertors and invertors. In this trail joint position sense for all subjects was assessed using The Biodex System isokinetic dynamometer 3, this system is used also for fatigue protocol.

Results

For the variable error (VE), significant mean effect was found for active joint position sense in 15° of inversion after muscle fatigue (P < 0, 05). It was a significant decrease in the work in the last third of inversion detected (P < 0, 05). There was no significant main effect found for fatigue index of eversion.

Conclusion

Ankle tape can improve joint position sense at the fatigue session when joint position sense becomes worse. As a result, ankle tape may be useful to prevent ankle sprain during playing sports. We suggest athletes and individuals at risk of ankle sprain to apply taping before high-load activity.

Trial registration

The study was retrospectively registered on the ISRCTN registry with study ID ISRCTN30042335 on 12th December 2017.

Ankle sprain as a work-related accident: status of proprioception after 2 weeks

Purpose

This study aims at verifying whether proprioception is abnormal or not, two weeks after a grade 1 and 2 ankle sprain in the scope of work-related accident.

Methods

A descriptive, observation and transversal study was designed to compare speed, movement and oscilation of centre of pressure in employees of companies signed up to a mutual company. Participants’ healthy feet comprised the control group, and feet that had undergone an ankle sprain due to a work-related accident comprised the cases group. The following stability tests were undertaken to both the healthy and injuried feet using a force plate: Monopodal Romberg test with eyes open, Monopodal Romberg test with eyes open on a 30 mm thick foam rubber, Monopodal Romberg test with eyes closed, and Romberg test as monopodal support with eyes closed on a 30 mm thick foam rubber. A multiple logistic regression analysis was performed. From the results of this regression model the COR curve test was performed.

Results

71.7% accuracy in the predictions was attained. The equation was as follows: Condition (injured or healthy) = 0.052⋅% RGC AP Movement − 0.81⋅MREO AP Movement. The variable MREO antero-posterior movement was used in the COR curve methodology. The area under the curve was greater than 0.65 and at a 95% confidence interval the 0.75 value was included, which in our case was the injured subject condition. Values for sensitivity, specificity, positive predictive value and negative predictive value were 0.667, 0.633, 64.5%, and 65.5%, respectively.

Conclusion

The participants in this study showed a diminished capacity for postural control in an ankle two weeks after an ankle sprain.

The immediate effect of talocrural joint manipulation on functional performance of 15-40 years old athletes with chronic ankle instability: A double-blind randomized clinical trial

OBJECTIVE

To evaluate the immediate effect of talocrural joint manipulation (TCJM) on functional performance of athletes with chronic ankle instability (CAI).

PARTICIPANTS

Forty athletes (18males, 22females) with CAI divided into TCJM group (n = 20) and sham manipulation group (n = 20).

INTERVENTION

TCJM was performed as a quick thrust on the involved talus, in the posterior direction. Sham manipulation was maintaining the same position, without any thrust.

MAIN OUTCOME MEASURES

Functional performance of athletes was assessed with single leg hop; speed and Y balance tests, before and after the interventions.

RESULTS

All functional tests evaluated in this study improved significantly after TCJM (p-value<0.05). These findings were not seen in the control group. Between-group comparisons also showed significant changes for all the measurements after the interventions (p < 0.05).

CONCLUSIONS

TCJM can significantly increase the functional performance of athletes with CIA and can be an effective supplementary treatment for these subjects. However, this was a pre-post study and future studies with long-term follow-ups may provide more reliable results about the long-term effectiveness of this type of treatment.

Deficits in subtalar pronation and supination proprioception in subjects with chronic ankle instability

Deficits in joint position sense (JPS) and force sense (FS) are two functional insufficiencies contributing to chronic ankle instability (CAI). To date, JPS and FS have been only investigated in the sagittal and transverse movement planes but not in the functional movement plane of the pronators and supinators defined by the axis of the subtalar joint (STJ). The purpose of this study was to investigate subtalar JPS as well as pronator and supinator FS in supinated and pronated joint angle in subjects with CAI. Using a force transducer and a goniometer integrated in an apparatus with a movement axis corresponding to Inman's STJ axis, JPS and FS were examined in 20 sport students with CAI and 20 age- and sex-matched controls. Compared to uninjured subjects, CAI leads to reduced pronator (p<0.01) and supinator FS (p<0.01) as well as JPS (p<0.05). A significant main effect for 'angle' was found for JPS (P<0.0001). JPS is affected by a significant 'group'×'angle' interaction (p<0.05) indicating reduced JPS in the 24° supinated angle however not in the 8° pronated angle. The angle-specific JPS deficits indicate that the anatomical STJ axis has to be considered when assessing pronation and supination proprioception in subjects with CAI.

Peroneal electromechanical delay and fatigue in patients with chronic ankle instability

PURPOSE

The purpose of this study was to investigate the effect of chronic ankle instability (CAI) on electromechanical delay times (EMD) before and after fatigue. Understanding the mechanisms that contribute to CAI is essential for the development of effective rehabilitation programmes. It was hypothesized that patients with CAI will demonstrate prolonged EMD times compared to healthy subjects and that fatigue will cause greater increases in EMD times in the CAI group.

METHODS

Twenty-one male volunteers participated in the study providing data on 16 ankles with CAI and 26 with no history of ankle injury. EMD was measured on an isokinetic dynamometer. Measurements were taken with the ankle in neutral (0°) and at 30° of inversion. All subjects followed an isokinetic fatigue protocol until eversion torque fell below 50 % of initial torque for three consecutive repetitions. A 2 × 2 × 2 ANOVA was used to calculate the effect of ankle status (CAI vs. healthy), fatigue, angle (0° vs. 30°) and their interactions on EMD.

RESULTS

Fatigue caused a significant increase on EMD [non-fatigued: 122(29)ms vs. fatigue 155(54)ms; p < 0.001]. EMD times were shorter at 30° of inversion compared to neutral [neutral: 145(39)ms vs. 30° of inversion: 132(40)ms, p = 0.015]. An interaction effect for ankle status and angle was found (p = 0.026) with CAI ankles demonstrating longer EMD [CAI: 156(45)ms vs. healthy: 133(40)ms] in neutral but not at 30° of inversion [CAI: 133(46)ms vs. 132(33)ms].

CONCLUSIONS

Patients with CAI had longer EMD times in neutral, but not when the ankle was placed in inversion. This suggests that rehabilitation programmes may be more effective when retraining occurs with the ankle in neutral position. It is likely that low EMD times prevent ankle acceleration at the beginning of the mechanism of injury, but they are less important when the ankle has already inverted at 30°. Both CAI and healthy subjects demonstrated longer EMD after fatigue, emphasizing the importance of proper conditioning in the prevention of delayed peroneal response and subsequent ankle injury. Improving resistance to fatigue of the peroneals may prove to be an effective prevention tool of ankle sprain recurrence in patients with CAI.

LEVEL OF EVIDENCE

III.

Bilateral Proprioceptive Evaluation in Individuals With Unilateral Chronic Ankle Instability

CONTEXT

  Despite extensive research on chronic ankle instability, the findings regarding proprioception have been conflicting and focused only on the injured limb. Also, the different components of proprioception have been evaluated in isolation.

OBJECTIVE

  To evaluate bilateral ankle proprioception in individuals with unilateral ankle instability.

DESIGN

  Cohort study.

SETTING

  Research laboratory center in a university.

PATIENTS OR OTHER PARTICIPANTS

  Twenty-four individuals with a history of unilateral ankle sprain and chronic ankle instability (mechanical ankle instability group, n = 10; functional ankle instability [FAI] group, n = 14) and 20 controls.

MAIN OUTCOME MEASURE(S)

  Ankle active and passive joint position sense, kinesthesia, and force sense.

RESULTS

  We observed a significant interaction between the effects of limb and group for kinesthesia (F = 3.27, P = .049). Increased error values were observed in the injured limb of the FAI group compared with the control group (P = .031, Cohen d = 0.47). Differences were also evident for force sense (F = 9.31, P < .001): the FAI group demonstrated increased error versus the control group (injured limb: P < .001, Cohen d = 1.28; uninjured limb: P = .009, Cohen d = 0.89) and the mechanical ankle instability group (uninjured limb: P = .023, Cohen d = 0.76).

CONCLUSIONS

  Individuals with unilateral FAI had increased error ipsilaterally (injured limb) for inversion movement detection (kinesthesia) and evertor force sense and increased error contralaterally (uninjured limb) for evertor force sense.

Effects of the application of ankle functional rehabilitation exercise on the ankle joint functional movement screen and isokinetic muscular function in patients with chronic ankle sprain

[Purpose] This study was conducted to investigate the effects of ankle functional rehabilitation exercise on ankle joint functional movement screen results and isokinetic muscular function in patients with chronic ankle sprain patients. [Subjects and Methods] In this study, 16 patients with chronic ankle sprain were randomized to an ankle functional rehabilitation exercise group (n=8) and a control group (n=8). The ankle functional rehabilitation exercise centered on a proprioceptive sense exercise program, which was applied 12 times for 2 weeks. To verify changes after the application, ankle joint functional movement screen scores and isokinetic muscular function were measured and analyzed. [Results] The ankle functional rehabilitation exercise group showed significant improvements in all items of the ankle joint functional movement screen and in isokinetic muscular function after the exercise, whereas the control group showed no difference after the application. [Conclusion] The ankle functional rehabilitation exercise program can be effectively applied in patients with chronic ankle sprain for the improvement of ankle joint functional movement screen score and isokinetic muscular function.

Therapeutic interventions for improving self-reported function in patients with chronic ankle instability: a systematic review

OBJECTIVE

To identify which therapeutic intervention may be most effective for improving self-reported function in patients with chronic ankle instability (CAI).

DESIGN

Systematic literature review. Articles were appraised using the Downs and Black Checklist by 3 reviewers.

DATA SOURCES

PubMed along with CINAHL, MEDLINE and SPORTDiscus within EBSCOhost for pertinent articles from their inception through August 2016.

ELIGIBILITY CRITERIA FOR SELECTED STUDIES

Articles included were required to (1) be written in English, (2) report adequate data to calculate effect sizes, (3) identify patients with CAI, (4) use some form of therapeutic intervention and (5) use a self-reported questionnaire as a main outcome measurement.

RESULTS

A broad spectrum of therapeutic interventions were identified related to balance training, multimodal rehabilitation, joint mobilisation, resistive training, soft-tissue mobilisation, passive calf stretching and orthotics. All of the articles included in the balance training category had moderate-to-strong Hedges g with none of the 95% CIs crossing 0. Hedges g effect sizes ranged from -0.67 to -2.31 and -0.51 to -1.43 for activities of daily living and physical activity, respectively. The multimodal rehabilitation category also produced moderate-to-strong Hedges g effect sizes but with large CIs crossing 0. Hedges g effect sizes ranged from -0.47 to -9.29 and -0.62 to -24.29 for activities of daily living and physical activity, respectively.

CONCLUSIONS

The main findings from this systematic review were balance training provided the most consistent improvements in self-reported function for patients with CAI.

Four Weeks of Balance Training does not Affect Ankle Joint Stiffness in Subjects with Unilateral Chronic Ankle Instability

Background

Balance training has been shown to be effective in preventing ankle sprain recurrences in subjects with chronic ankle instability (CAI) but the biomechanical pathways underlying the clinical outcomes are still unknown. This study was conducted to determine if a 4-week balance training intervention can alter the mechanical characteristics in ankles with CAI.

Methods

Twenty-two recreationally active subjects with unilateral CAI were randomized to either a control (n = 11, 35.1 ± 9.3 years) or intervention (n = 11, 33.5 ± 6.6 years) group. Subjects in the intervention group were trained on the affected limb with static and dynamic components using a Biodex balance stability system for 4-weeks. The ankle joint stiffness and neutral zone in inversion and eversion directions on the involved and uninvolved limbs was measured at baseline and post-intervention using a dynamometer.

Results

At baseline, the mean values of the inversion stiffness (0.69 ± 0.37 Nm/degree) in the involved ankle was significantly lower (p < 0.011, 95% CI [0.563, 0.544]) than that of uninvolved contralateral ankle (0.99 ± 0.41 Nm/degree). With the available sample size, the eversion stiffness, inversion neutral zone, and eversion neutral zone were not found to be significantly different between the involved and uninvolved contralateral ankles. The 4-week balance training intervention failed to show any significant effect on the passive ankle stiffness and neutral zones in inversion and eversion.

Conclusion

Decreased inversion stiffness in the involved chronic unstable ankle was found that of uninvolved contralateral ankle. The 4-week balance training program intervention was ineffective in altering the mechanical characteristics of ankles with CAI.

Level of evidence

Randomized controlled clinical trial; Level of evidence, 1.

Feedback and Feedforward Control During Walking in Individuals With Chronic Ankle Instability

Study Design Controlled laboratory study. Background Recurrent ankle sprains associated with chronic ankle instability (CAI) occur not only in challenging sports but also in daily walking. Understanding whether and how CAI alters feedback and feedforward controls during walking may be important for developing interventions for CAI prevention or treatment. Objective To understand whether CAI is associated with changes in feedback and feedforward control when individuals with CAI are subjected to experimental perturbation during walking. Methods Twelve subjects with CAI and 12 control subjects walked on a treadmill while adapting to external loading that generated inversion perturbation at the ankle joint. Ankle kinematics around heel contact during and after the adaptation were compared between the 2 groups. Results Both healthy and CAI groups showed an increase in eversion around heel contact in early adaptation to the external loading. However, the CAI group adapted back toward the baseline, while the healthy controls showed further increase in eversion in late adaptation. When the external loading was removed in the postadaptation period, healthy controls showed an aftereffect consisting of an increase in eversion around heel contact, but the CAI group showed no aftereffect. Conclusion The results provide preliminary evidence that CAI may alter individuals' feedback and feedforward control during walking. J Orthop Sports Phys Ther 2016;46(9):775-783. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6403.

Changes in ground reaction force during a rebound-jump task after hip strength training for single-sided ankle dorsiflexion restriction

[Purpose] Lateral ankle sprains are common injuries suffered while playing sports, and abnormal forward- and inward-directed ground reaction force occurs during a jumping task. However, the influence of hip muscle strength training on jumping performance after ankle injuries has not been fully examined. This study thus examined changes in ground reaction force during a rebound-jump task after training to strengthen hip muscles. [Subjects and Methods] Ten of 30 female high school basketball players were assigned as subjects who showed a difference of 7 or more degrees in dorsiflexion ranges between the bilateral ankles. The subjects underwent 12 weeks of training to strengthen hip abductors and external rotators. Comparisons between before and after training were made regarding ground reaction force components, hip and knee joint angles, percentage of maximum voluntary contraction in leg muscles, and muscle strength of hip muscles during the rebound-jump task. [Results] After training, the subjects showed increased strength of external rotator muscles, increased percentage of maximum voluntary contraction in the gluteus medius muscle, decreased inward ground reaction force, and increased flexion angles of the hip and knee joints. [Conclusion] This study suggests that training to strengthen hip muscles may ameliorate the inward ground reaction force in athletes with ankle dorsiflexion restriction.

Postural control systems in two different functional movements: a comparison of subjects with and without chronic ankle instability

[Purpose] The aim of this study was to evaluate postural control during two different movements of the Functional Movement Screen in patients with chronic ankle instability compared with healthy subjects. [Subjects] This study was a cross-sectional survey of 50 participants comprised of 25 chronic ankle instability patients and 25 healthy subjects. [Methods] All subjects were subjected to measurement of the Foot and Ankle Disability Index and center of pressure and Functional Movement Screen testing. The deep squat and hurdle step were performed for the lower extremities in Functional Movement Screen testing. Then, the center of pressure was measured with balance assessment software using a Nintendo Wii Balance Board. The center of pressure path length, velocity, and area of the 95% confidence ellipse and Functional Movement Screen scores were evaluated for all subjects. [Results] The results showed significant differences in center of pressure path length, velocity, and area of the 95% confidence ellipse between the groups for the hurdle step with the non-affected limb. However, there were no significant differences between groups for the deep squat and hurdle step with the affected limb. [Conclusion] The results of this study showed that there was a difference in the hurdle step with the non-affected limb in chronic ankle instability patients compared with normal subjects.

Effects of Ankle Kinesio Taping on Postural Control in Stroke Patients

BACKGROUND

To investigate the effects of kinesio taping on postural control in stroke patients.

MATERIALS AND METHODS

Forty stroke patients aged 30 to 60 years were randomly divided into an experimental and a control group. In the experimental group, kinesio tape (KT) was applied directly on the skin over the affected ankle in the direction of dorsiflexion and eversion to correct the equinovarus deformity. The tape was kept on the ankle for 1 day. The results were measured with the forward reach test, lateral reach test, Berg Balance Scale (BBS), and timed up and go test. Center of pressure (COP) displacement and velocity were also measured while the patients stood on a force plate. All variables were measured on the first day immediately after taping and 24 hours later in the KT group, and on the first day and also 24 hours later in the control group.

RESULTS

There was a statistically significant difference in BBS between the first day and 24 hours later in the KT group (P = .01). The forward reach test and mediolateral displacement of the COP differed significantly after taping in the experimental group compared to the control group (P = .04). Immediately after taping, BBS improved significantly in the KT group (P = .02).

CONCLUSIONS

The application of KT improved forward reach test results and displacement of the COP in stroke patients.

Anatomic Reconstruction With a Semitendinosus Allograft for Chronic Lateral Ankle Instability

BACKGROUND

The modified Broström procedure has been successful for most patients with chronic lateral ankle instability (CLAI); however, a subset of patients has had unsatisfactory outcomes. For those at risk of failure, anatomic reconstruction of the lateral ankle ligaments using a semitendinosus allograft to augment the modified Broström procedure is available.

PURPOSE

To report the results of anatomic reconstruction of the lateral ankle with a semitendinosus allograft for the treatment of CLAI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This is a retrospective review of a single surgeon's experience from 2003 to 2011 in performing anatomic lateral ankle ligament reconstruction with a semitendinosus allograft for the treatment of CLAI. Of 38 patients (40 ankles), 31 (33 ankles; 82% of patients) returned for final follow-up and constituted the study group. Preoperatively, all patients completed the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score (AHS) and a visual analog scale (VAS) for pain and underwent plain and stress talar tilt radiographs. At the most recent follow-up, patients were evaluated by an independent surgeon and completed the postoperative AHS, Foot-Function Index (FFI), VAS for pain, Tegner activity score, and a satisfaction survey. Patients were evaluated with plain and stress talar tilt and anterior drawer radiographs.

RESULTS

At a mean follow-up of 38 ± 30 months (range, 24-107 months), 100% of patients were completely satisfied with the procedure. AHS values significantly improved from a mean of 60.3 ± 14.4 to 87.5 ± 9.3 (P < .0001). VAS pain scores significantly decreased from 7.3 ± 1.3 to 1.9 ± 1.8 (P < .0001). Twenty-two of 31 patients (71%) either returned to or were 1 level below their previous preoperative or preinjury Tegner activity level. No patients developed arthritic changes beyond grade I on plain radiographs. On stress radiographs, the mean talar tilt decreased from 14.3° ± 5.4° to 3.1° ± 2.4°. The mean postoperative anterior tibiotalar translation was 1.8 ± 1.1 mm, with no patients having greater than 5 mm of translation.

CONCLUSION

Anatomic lateral ankle ligament reconstruction with a semitendinosus allograft for the treatment of CLAI leads to high patient satisfaction, decreased pain, a stable ankle without arthritic changes, and significantly improved function.

H-index is important for postural control for people with impaired foot sole sensation

INTRODUCTION

People with Peripheral Neuropathy (PN), especially those with impaired sensory inputs through the small-afferent fiber (type II afferent fibers) reflex loop (SAF), might depend more on the large-afferent fiber (type I afferent fibers) reflex loop (LAF) for postural control.

PURPOSE

To examine whether the function of the LAF reflex loop, reflected by the H-reflex and ankle joint proprioception, influences postural control when the SAF reflex loop is impaired, as indicated by reduced foot sole cutaneous sensation.

METHODS

Thirteen participants (8 women, 5 men) diagnosed with PN and 12 age-matched controls (7 women, 5 men) completed the testing protocol. Measures of interest included the H-index, active (AAP) and passive (PAP) ankle proprioception, plantar pressure sensitivity (PPS), average sway velocity (VAVG) and area (A95) during 30 seconds eyes-closed standing, 6-minute walk distance (6MWD) and timed up-and-go duration (TUG).

RESULTS

Statistically significant group-dependent regression was observed between VAVG and H-index. Compared to the control group, the PN group demonstrated reduced PPS (2.0 ± 1.9 vs. 4.2 ± 1.2, P < .05) and H-index (63.6 ± 10.9 vs. 76.4 ± 16.0, P < .05), greater VAVG (3.5 ± 2.1 vs. 1.6 ± 0.6 cm/s, P < .05) and A95 (10.0 ± 10.1 vs. 2.5 ± 1.5 cm2, P < .05), shorter 6MWD (442.2 ± 93.0 vs. 525.3 ± 68.2 m, P < .05), and longer TUG (9.4 ± 1.6 vs. 6.5 ± 1.3 s, P < .05). Within the PN group, but not the control group, the H-index was correlated with VAVG (r = -.56, P < .05). Moreover, within the PN group only, PAP scores were correlated with 6MWD (r = -.68, P < .05) and TUG (r = -.59, P < .05) performance. No other statistically significant group difference, correlation or group-dependent regression was observed.

CONCLUSION

VAVG, 6MWD, and TUG correlated with LAF reflex loop function observed among those with impaired functioning of the SAF reflex loop. This observation suggests that the LAF reflex loop may be critical to the control of balance in those individuals suffering from small-fiber PN.

Deviations in gait metrics in patients with chronic ankle instability: a case control study

Background

Gait metric alterations have been previously reported in patients suffering from chronic ankle instability (CAI). Previous studies of gait in this population have been comprised of relatively small cohorts, and the findings of these studies are not uniform. The objective of the present study was to examine spatiotemporal gait metrics in patients with CAI and examine the relationship between self-reported disease severity and the magnitude of gait abnormalities.

Methods

Forty-four patients with CAI were identified and compared to 53 healthy controls. Patients were evaluated with spatiotemporal gait analysis via a computerized mat and with the Short Form (SF) - 36 health survey.

Results

Patients with CAI were found to walk with approximately 16% slower walking velocity, 9% lower cadence and approximately 7% lower step length. Furthermore, the base of support, during walking, in the CAI group was approximately 43% wider, and the single limb support phase was 3.5% shorter compared to the control group.

All of the SF-36 8-subscales, as well as the SF-36 physical component summary and SF-36 mental component summary, were significantly lower in patients with CAI compared to the control group. Finally, significant correlations were found between most of the objective gait measures and the SF-36 mental component summary and SF-36 physical component summary.

Conclusions

The results outline a gait profile for patients suffering from CAI. Significant differences were found in most spatiotemporal gait metrics. An important finding was a significantly wider base of support. It may be speculated that these gait alterations may reflect a strategy to deal with imbalance and pain. These findings suggest the usefulness of gait metrics, alongside with the use of self-evaluation questionnaires, in assessing disease severity of patients with CAI.