The effects of a semi-rigid brace or taping on talocrural and subtalar kinematics in chronic ankle instability

Acute and Chronic Subtalar Joint Instability: Does It Really Exist?

Acute and chronic subtalar instability and commonly coexistent with other hindfoot pathology but can be difficult to diagnose. A high degree of clinical suspicion is required as most imaging modalities and clinical maneuvers are poor at detecting isolated subtalar instability. The initial treatment is similar to ankle instability, and a wide variety of operative interventions have been presented in the literature for persistent instability. Outcomes are variable and limited.

Reliability and validity of ultrasonographic automated length measurement system for assessing talofibular anterior instability in acute lateral ankle sprain

Ankle joint instability after acute lateral ankle sprain (LAS) is an important factor for deciding treatment strategies. Nevertheless, the degree of ankle joint mechanical instability as a criterion for making clinical decisions is unclear. This study examined the reliability and validity of an Automated Length Measurement System (ALMS) in ultrasonography for assessing real-time anterior talofibular distance. Using a phantom model, we tested whether ALMS could detect two points within a landmark following movement of the ultrasonographic probe. Furthermore, we examined whether ALMS was comparable with the manual measurement method for 21 patients with an acute LAS (42 ankles) during the reverse anterior drawer test. Using the phantom model, ALMS measurements showed excellent reliability, with errors below 0.4 mm and with a small variance. The ALMS measurement was comparable to manually measured values (ICC = 0.53-0.71, p < 0.001) and detected differences in talofibular joint distances between unaffected and affected ankles of 1.41 mm (p < 0.001). ALMS shortened the measurement time by one-thirteenth for one sample compared to the manual measurement (p < 0.001). ALMS could be used to standardize and simplify ultrasonographic measurement methods for dynamic joint movements without human error in clinical applications.

Mechanical and Sensorimotor Outcomes Associated With Talar Cartilage Deformation After Static Loading in Those With Chronic Ankle Instability

CONTEXT

Those with chronic ankle instability (CAI) demonstrate deleterious changes in talar cartilage composition, resulting in alterations of talar cartilage loading behavior. Common impairments associated with CAI may play a role in cartilage behavior in response to mechanical loading.

OBJECTIVE

To identify mechanical and sensorimotor outcomes that are linked with the magnitude of talar cartilage deformation after a static loading protocol in patients with and those without CAI.

DESIGN

Cross-sectional study.

SETTING

Laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Thirty individuals with CAI and 30 healthy individuals.

MAIN OUTCOME MEASURES(S)

After a 60-minute off-loading period, ultrasonographic images of the talar cartilage were acquired immediately before and after a 2-minute static loading protocol (single-legged stance). Talar cartilage images were obtained and manually segmented to enable calculation of medial, lateral, and overall average talar thickness. The percentage change, relative to the average baseline thickness, was used for further analysis. Mechanical (ankle joint laxity) and sensorimotor (static balance and Star Excursion Balance Test) outcomes were captured. Partial correlations were computed to determine associations between cartilage deformation magnitude and the mechanical and sensorimotor outcomes after accounting for body weight.

RESULTS

In the CAI group, greater inversion laxity was associated with greater overall (r = -0.42, P = .03) and medial (r = -0.48, P = .01) talar cartilage deformation after a 2-minute static loading protocol. Similarly, poorer medial-lateral static balance was linked with greater overall (r = 0.47, P = .01) and lateral (r = 0.50, P = .01) talar cartilage deformation. In the control group, shorter posterolateral Star Excursion Balance Test reach distance was associated with greater lateral cartilage deformation (r = 0.42, P = .03). No other significant associations were observed.

CONCLUSIONS

In those with CAI, inversion laxity and poor static postural control were moderately associated with greater talar cartilage deformation after a 2-minute static loading protocol. These results suggest that targeting mechanical instability and poor balance in those with CAI via intervention strategies may improve how the talar cartilage responds to static loading conditions.

Effect of Different Protection on Lateral Ankle during Landing: An Instantaneous Impact Analysis

Ankle sprain is the most common injury during parachute landing. The biomechanical behavior of the tissues can help us understand the injury mechanism of ankle inversion. To accurately describe the injury mechanism of tissues and assess the effect of ankle protection, a stable time of landing was obtained through the dynamic stability test. It was used for the boundary condition of the foot finite element (FE). The FE model was provided a static load equal to half of the bodyweight applied at the distal tibia and fibula; a foot-boot-brace FE model was established to simulate the landing of subjects on an inversion inclined platform of 0-20°, including non-, external, and elastic ankle braces. Compared with the non-ankle brace, both the external and elastic ankle braces decreased the peak strains of the cal-fibular, anterior Ta-fibular, and posterior Ta-fibular ligaments (15.2-33.0%), and of the peak stress of the fibula (15.2-24.5%). For the strain decrement of the aforementioned ligaments, the elastic brace performed better than the external ankle brace under the inversion of the 10° condition. The peak stress of the fibula (15.6 MPa) decreased up to 24.5% with an elastic brace and 5.6-10.3% with an external brace. The findings suggested that the behaviors of lateral ankle ligaments and fibula were meaningful for the functional ability of the ankle. This provides some suggestions regarding the optimal design of ankle protection.

Current Concepts on Subtalar Instability

Subtalar instability remains a topic of debate, and its precise cause is still unknown. The mechanism of injury and clinical symptoms of ankle and subtalar instabilities largely overlap, resulting in many cases of isolated or combined subtalar instability that are often misdiagnosed. Neglecting the subtalar instability may lead to failure of conservative or surgical treatment and result in chronic ankle instability. Understanding the accurate anatomy and biomechanics of the subtalar joint, their interplay, and the contributions of the different subtalar soft tissue structures is fundamental to correctly diagnose and manage subtalar instability. An accurate diagnosis is crucial to correctly identify those patients with instability who may require conservative or surgical treatment. Many different nonsurgical and surgical approaches have been proposed to manage combined or isolated subtalar instability, and the clinician should be aware of available treatment options to make an informed decision. In this current concepts narrative review, we provide a comprehensive overview of the current knowledge on the anatomy, biomechanics, clinical and imaging diagnosis, nonsurgical and surgical treatment options, and outcomes after subtalar instability treatment.

Assignment of local coordinate systems and methods to calculate tibiotalar and subtalar kinematics: A systematic review

The introduction of biplane fluoroscopy has created the ability to evaluate in vivo motion, enabling six degree-of-freedom measurement of the tibiotalar and subtalar joints. Although the International Society of Biomechanics defines a standard method of assigning local coordinate systems for the ankle joint complex, standards for the tibiotalar and subtalar joints are lacking. The objective of this systematic review was to summarize and appraise the existing literature that (1) defined coordinate systems for the tibia, talus, and/or calcaneus or (2) assigned kinematic definitions for the tibiotalar and/or subtalar joints. A systematic literature search was developed with search results limited to English Language from 2006 through 2020. Articles were screened by two independent reviewers based on title and abstract. Methodological quality was evaluated using a modified assessment tool. Following screening, 52 articles were identified as having met inclusion criteria. Methodological assessment of these articles varied in quality from 61 to 97. Included articles adopted primary methods for defining coordinate systems that included: (1) anatomical coordinate system (ACS) based on individual bone landmarks and/or geometric shapes, (2) orthogonal principal axes, and (3) interactive closest point (ICP) registration. Common methods for calculating kinematics included: (1) joint coordinate system (JCS) to calculate rotation and translation, (2) Cardan/Euler sequences, and (3) inclination and deviation angles for helical angles. The methods each have strengths and weaknesses. This summarized knowledge should provide the basis for the foot and ankle biomechanics community to create an accepted standard for calculating and reporting tibiotalar and subtalar kinematics.

People with chronic ankle instability benefit from brace application in highly dynamic change of direction movements

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.

Effects of an ankle brace on the in vivo kinematics of patients with chronic ankle instability during walking on an inversion platform

BACKGROUND

As in vivo tibiotalar and subtalar joint kinematics are not currently known following the application of an ankle brace, an investigation of these kinematics may provide insight into the mechanisms of ankle braces.

RESEARCH QUESTION

This study aimed to determine the effect of an ankle brace on in vivo kinematics of patients with chronic ankle instability.

METHODS

Eleven patients with chronic ankle instability were recruited in this study. A dual fluoroscopic imaging system and a solid modeling software were utilized to calculate the joint positions of the participants as they walked barefooted on a level platform, walked barefooted on a 15° inversion platform, and walked with an ankle brace on a 15° inversion platform. The joint positions during the three walking conditions were compared.

RESULTS

Tibiotalar joints were more inverted (pose 2, p = .004), and subtalar joints were more anteriorly translated (pose 2-6, p = .003), more plantarflexed (pose 2, p = .008; pose 3, p = .013; pose 5, p = .008; pose 6, p = .016) and more inverted (pose 1-5, p = .003; pose 6, p = .013) during barefooted walking on the inversion platform than during walking on the level platform. The inversion of subtalar joints was decreased after the brace application (pose 2-4, p = .003; pose 5, p = .004; pose 7, p = .016).

SIGNIFICANCE

Brace application reduced the increased subtalar inversion induced by the inversion platform. Nevertheless, increased subtalar anterior translation and plantarflexion persisted after brace application. The ankle brace might be beneficial for clinical populations with increased subtalar inversion.

Effect of a Semirigid Ankle Brace on the In Vivo Kinematics of Patients with Functional Ankle Instability during the Stance Phase of Walking

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.

Nonelastic and Kinesio Tex Tapes Improve Perceived Stability But Not Postural Control in Participants With Chronic Ankle Instability

The development of chronic ankle instability (CAI) is common following a lateral ankle sprain. Taping using nonelastic and Kinesio Tex (KT) tapes remain popular treatment strategies. The purpose of this investigation was to determine if KT tape improves static and dynamic postural control relative to nonelastic tape and a control condition. Twenty-four participants completed all three conditions. No immediate improvements in postural control were noted in either taping condition. Both nonelastic and KT tape improved perceived stability relative to the control condition. In conclusion, nonelastic and KT tape should not be used to immediately improve postural control in CAI participants.

Update on Subtalar Joint Instability

Subtalar joint stability is ensured by the osseous geometry of the talocalcaneal joint and the complex array of the ligaments at the medial and lateral aspect of the ankle joint, the sinus and canalis tarsi, and the talocalcaneonavicular joint, respectively. There is still a substantial lack of knowledge about the interaction of the ankle and subtalar joint complex. Subtalar joint instability appears to be more frequent than is generally assumed. The diagnosis of chronic subtalar joint instability makes the application of a comprehensive algorithm necessary. There is ongoing debate about the preferable techniques for restoration of subtalar joint stability.

Foot and ankle kinematics in chronic ankle instability subjects using a midfoot strike pattern when running, including influence of taping

BACKGROUND

Investigate differences in multi-segment foot kinematics between controls and participants with chronic ankle instability during running with a midfoot striking pattern and to evaluate the effect of Low-Dye and High-Dye taping.

METHODS

Three-dimensional multi-segment foot kinematics of 12 controls and 15 participants with chronic ankle instability were collected while running barefoot, and in both taping conditions. Ranges of motion occurring at each joint, each sub phase of stance, were compared between groups and between taping conditions (0-dimensional inference). Kinematic data were also compared using one-dimensional statistical parametric mapping.

FINDINGS

The symptomatic group demonstrated while barefoot running a significantly decreased rearfoot dorsiflexion range of motion during the peak impact phase as well as a less dorsiflexed position from 6 to 12% of the running cycle. During the absorption and generation phase, the symptomatic group also showed a significantly increased rearfoot dorsiflexion and adduction motion as well as an increased midfoot inversion motion. In the peak impact phase of both taping conditions, a decreased midfoot inversion motion was found. The High-Dye taping resulted in a decreased rearfoot plantarflexion motion whereas the Low-Dye caused a decreased midfoot inversion motion.

INTERPRETATION

Persons with chronic ankle instability seem to have altered rearfoot and midfoot kinematics while running with a midfoot striking index. High-Dye taping seems to have better therapeutic features than Low-Dye taping.

Subtalar joint instability

PURPOSE

Subtalar joint instability may frequently be overlooked and erroneously be integrated under the diagnosis of ankle joint instability. It was the scope of this review to characterize the present state-of-art with regard to the adequate diagnosis and treatment.

METHODS

While the clinical picture is mostly inconclusive for subtalar joint instability, a high degree of suspicion for this diagnosis is needed to employ weight-bearing x-rays, standardized stress radiography, CT scanning and MRI to further elucidate the etiopathology

RESULTS

Geometrical reasons as hindfoot deformities, isolated or combined injuries or instabilities in conjunction with the ankle ligament complex do exist which should be differentiated in detail and classified to indicate the adequate treatment. Treatment of acute lesions is simple and effective. A certain percentage of the patients with chronic subtalar instability is incorrectly labeled with the diagnosis of a sinus tarsi syndrome.

CONCLUSION

Subtalar joint arthroscopy for reconfirmation of the correct diagnosis conjoined with restoration of physiological hindfoot alignment and a preferably anatomical ligamentous reconstruction provide the basis for a good functional recovery.