Comparison of custom-moulded ankle orthosis with hinged joints and off-the-shelf ankle braces in preventing ankle sprain in lateral cutting movements

The effect of two types of ankle orthoses on the repetitive rebound jump performance

Background

Ankle orthotics decreases the maximal vertical jump height. It is essential to maximize jump height and minimize ground contact time during athletic performance. However, the effect of ankle orthotics on athletic performance has not been reported. We aimed to investigate the effect of ankle orthotics on squat jump (SJ), countermovement jump (CMJ), and repetitive rebound jump (RJ) performance.

Methods

Twenty healthy volunteers performed SJ, CMJ, repetitive RJ under no-orthosis and two orthotic conditions (orthosis 1 and orthosis 2). During SJ and CMJ, we measured the vertical ground reaction force and calculated the following parameters: jump height, peak vertical ground reaction force, rate of force development, net vertical impulse, and peak power. During repetitive RJ, the jump height, contact time, and RJ index were measured. A two-dimensional motion analysis was used to quantify the ankle range of motion in the sagittal plane during SJ, CMJ, and repetitive RJ.

Results

Multivariate analysis of variance and the post hoc test showed orthosis 2 significantly decreased in the vertical jump height (p = 0.003), peak power (p = 0.007), and maximum plantarflexion and dorsiflexion angles (p < 0.001) during SJ Ankle orthoses 1 and 2 did not influence to the RJ performance compared to those using the no-orthosis condition. Additionally, orthosis 2 significantly decreased the jump height at the end of repetitive RJ (p = 0.046).

Conclusions

These results suggest that ankle orthosis do not affect average RJ performance but should be considered when performing repetitive jumps frequently.

Comparison of the Effect of the Combined Mechanism Ankle Support on Static and Dynamic Postural Control of Chronic Ankle Instability Patients

BACKGROUND

Chronic ankle instability (CAI) is associated with postural control impairment. Orthotic devices are routinely used to improve postural control of CAI patients and prevent recurrence of ankle sprain. This study aimed to evaluate and compare the effect of combined mechanism ankle support (CMAS) with soft ankle support (SAS) and custom-molded foot orthosis (CFO) on static and dynamic postural control in patients with CAI.

METHODS

Twenty-two patients with CAI and 22 matched healthy subjects were recruited. The participants were evaluated in four orthotic conditions (without orthosis and with the CMAS, SAS, and CFO). Static balance was investigated in single-limb stance on the force platform, and dynamic balance was assessed using the Star Excursion Balance Test (SEBT).

RESULTS

Statistically significant differences were found for the main effects of the groups in all center of pressure (COP) parameters and reach distances in medial (M), anteromedial (AM), and posteromedial (PM) directions of the SEBT ( P < .05). The main effect of the orthotics for all evaluated parameters, except reach distance in the PM direction, was statistically different. All COP parameters were significantly lower with the CMAS compared with other orthotic conditions in CAI patients. Also, the higher reach distances with the CMAS were obtained in the AM and M directions of the SEBT.

CONCLUSION

The CMAS improved impaired postural control in static and dynamic stability tests, but no similar effect was found for SAS and CFO. This result may have implications for the best bracing for CAI.

LEVEL OF EVIDENCE

Level II, comparative study.

Effect of simulated joint instability and bracing on ankle and subtalar joint flexibility

It is clinically challenging to distinguish between ankle and subtalar joints instability in vivo. Understanding the changes in load-displacement at the ankle and subtalar joints after ligament injuries may detect specific changes in joint characteristics that cannot be detected by investigating changes in range of motion alone. The effect of restricting joints end range of motion with ankle braces was already established, but little is known about the effect of an ankle brace on the flexibility of the injured ankle and subtalar joints. Therefore, the purposes of this study were to (1) understand how flexibility is affected at the ankle and subtalar joints after sectioning lateral and intrinsic ligaments during combined sagittal foot position and inversion and during internal rotation and (2) investigate the effect of a semi-rigid ankle brace on the ankle and subtalar joint flexibility. Kinematics and kinetics were collected from nine cadaver feet during inversion through the range of ankle flexion and during internal rotation. Motion was applied with and without a brace on an intact foot and after sequentially sectioning the calcaneofibular ligament (CFL) and the intrinsic ligaments. Segmental flexibility was defined as the slope of the angle-moment curve for each 1 Nm interval. Early flexibility significantly increased at the ankle and subtalar joint after CFL sectioning during inversion. The semi-rigid ankle brace significantly decreased early flexibility at the subtalar joint during inversion and internal rotation for all ligament conditions and at the ankle joint after all ligaments were cut.

The Mechanical Functionality of the EXO-L Ankle Brace: Assessment With a 3-Dimensional Computed Tomography Stress Test

BACKGROUND

A new type of ankle brace (EXO-L) has recently been introduced. It is designed to limit the motion of most sprains without limiting other motions and to overcome problems such as skin irritation associated with taping or poor fit in the sports shoe.

PURPOSE

To evaluate the claimed functionality of the new ankle brace in limiting only the motion of combined inversion and plantar flexion.

STUDY DESIGN

Controlled laboratory study.

METHODS

In 12 patients who received and used the new ankle brace, the mobility of the joints was measured with a highly accurate and objective in vivo 3-dimensional computed tomography (3D CT) stress test. Primary outcomes were the ranges of motion as expressed by helical axis rotations without and with the ankle brace between the following extreme positions: dorsiflexion to plantar flexion, and combined eversion and dorsiflexion to combined inversion and plantar flexion. Rotations were acquired for both talocrural and subtalar joints. A paired Student t test was performed to test the significance of the differences between the 2 conditions (P ≤ .05).

RESULTS

The use of the ankle brace significantly restricted the rotation of motion from combined eversion and dorsiflexion to combined inversion and plantar flexion in both the talocrural (P = .004) and subtalar joints (P < .001). No significant differences were found in both joints for the motion from dorsiflexion to plantar flexion.

CONCLUSION

The 3D CT stress test confirmed that under static and passive testing conditions, the new ankle brace limits the inversion-plantar flexion motion that is responsible for most ankle sprains without limiting plantar flexion or dorsiflexion.

CLINICAL RELEVANCE

This test demonstrated its use in the objective evaluation of braces.

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

BACKGROUND

A semi-rigid brace or taping is often used to prevent giving-ways in the joint with chronic ankle instability (CAI). However, it remains unknown whether the application of a semi-rigid brace or taping modifies abnormal kinematics in CAI joints. The objective of this study was to determine if the application of a semi-rigid brace or taping of the ankle normalizes abnormal weight-bearing kinematics in CAI joints during ankle internal rotation in plantar flexion.

METHODS

A total of 14 male patients with unilateral CAI (mean age 21.1 ± 2.5 years) were enrolled. Three-dimensional bone models created from the computed tomography images were matched to the fluoroscopic images to compute the 6 degrees-of-freedom talocrural, subtalar, and ankle joint complex (AJC) kinematics for the healthy and contralateral CAI joints, as well as for CAI joints with a brace or taping. Selected outcome measures were talocrural anterior translation, talocrural internal rotation, and subtalar internal rotation.

RESULTS

There was no significant difference in talocrural anterior translation and internal rotation induced by applying either a semi-rigid brace or taping (P > .05). For subtalar internal rotation, there was a tendency toward restoration of normal kinematics in CAI joints after applying a semi-rigid brace or taping. However, the difference was not significant (P > .05).

DISCUSSION

Application of a semi-rigid brace or taping had limited effects on the CAI joint during weight-bearing ankle internal rotation in plantar flexion. Further studies using a variety of testing conditions should be conducted in the future.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Cross-Sectional Case Series.

Differences in proprioception, muscle force control and comfort between conventional and new-generation knee and ankle orthoses

The aim of this study was to compare muscle force control and proprioception between conventional and new-generation experimental orthoses. Sixteen healthy subjects participated in a single-blind controlled trial in which two different types of orthosis were applied to the dominant knee or ankle, while the following variables were evaluated: muscle force control (accuracy), joint position sense, kinesthesia, static balance as well as subjective outcomes. The use of experimental orthoses resulted in better force accuracy during isometric knee extensions compared to conventional orthoses (P=0.005). Moreover, the use of experimental orthoses resulted in better force accuracy during concentric (P=0.010) and eccentric (P=0.014) ankle plantar flexions and better knee joint kinesthesia in the flexed position (P=0.004) compared to conventional orthoses. Subjective comfort (P<0.001) and preference scores were higher with experimental orthoses compared to conventional ones. In conclusion, orthosis type affected static and dynamic muscle force control, kinesthesia, and perceived comfort in healthy subjects. New-generation experimental knee and ankle orthoses may thus be recommended for prophylactic joint bracing during physical activity and to improve the compliance for orthosis use, particularly in patients who require long-term bracing.

The effects of a semi-rigid ankle brace on a simulated isolated subtalar joint instability

Subtalar joint instability is hypothesized to occur after injuries to the calcaneofibular ligament (CFL) in isolation or in combination with the cervical and the talocalcaneal interosseous ligaments. A common treatment for hindfoot instability is the application of an ankle brace. However, the ability of an ankle brace to promote subtalar joint stability is not well established. We assessed the kinematics of the subtalar joint, ankle, and hindfoot in the presence of isolated subtalar instability, investigated the effect of bracing in a CFL deficient foot and with a total rupture of the intrinsic ligaments, and evaluated how maximum inversion range of motion is affected by the position of the ankle in the sagittal plane. Kinematics from nine cadaveric feet were collected with the foot placed in neutral, dorsiflexion, and plantar flexion. Motion was applied with and without a brace on an intact foot and after sequentially sectioning the CFL and the intrinsic ligaments. Isolated CFL sectioning increased ankle joint inversion, while sectioning the CFL and intrinsic ligaments affected subtalar joint stability. The brace limited inversion at the subtalar and ankle joints. Additionally, examining the foot in dorsiflexion reduced ankle and subtalar joint motion.