Prophylactic ankle bracing reduces rearfoot motion during sudden inversion

Gait and muscle activity measures after biomechanical device therapy in subjects with ankle instability: A systematic review

INTRODUCTION

Health specialists suggest a conservative approach comprising non-pharmacological interventions as the initial course of action for individuals with repetitive ankle sprain due to ankle instability. This systematic review aimed to assess the effectiveness of biomechanical devices (Foot Orthoses, Ankle Orthoses, and Taping) on gait and muscle activity in individuals with ankle instability.

METHODS

A systematic search was performed on electronic databases, including PubMed, EMBASE, Clinical Trials.gov, Web of Science, and Scopus. The PEDro scoring system was used to evaluate the quality of the included studies. We extracted data from population, intervention, and outcome measures.

RESULTS

In the initial search, we found 247 articles. After following the steps of the PRISMA flowchart, only 22 reports met the inclusion criteria of this study. The results show that biomechanical device therapy may increase swing time, stance time, and step. Additionally, studies suggest that these devices can reduce plantar flexion, inversion, and motion variability during gait. Biomechanical devices have the potential to optimize the subtalar valgus moment, push-off, and braking forces exerted during walking, as well as enhance the activity of specific muscles including the peroneus longus, peroneus brevis, tibialis anterior, gluteus medius, lateral gastrocnemius, rectus femoris, and soleus.

CONCLUSION

Biomechanical devices affect gait (spatiotemporal, kinetic, and kinematic variables) and lower limb muscle activity (root mean square, reaction time, amplitude, reflex, and wave) in subjects with ankle instability.

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.

The Effect of Ankle Bracing on Kinematics in Simulated Sprain and Drop Landings: A Double-Blind, Placebo-Controlled Study

BACKGROUND

The efficacy of external ankle braces to protect against sudden inversion sprain has yet to be determined while taking into account the possible placebo effect of brace application.

PURPOSE

To assess the protective effect of an external ankle brace on ankle kinematics during simulated inversion sprain and single-legged drop landings among individuals with a history of unilateral lateral ankle sprain.

HYPOTHESIS

The primary hypothesis was that active and placebo external braces would reduce inversion angle during simulated inversion sprain.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen participants with ankle instability and previous sprain performed single-legged drop landings and sudden inversion tilt perturbations. Kinematics of the affected limb were assessed in 3 conditions (active bracing, passive placebo bracing, and unbraced) across 2 measurement days. Participators and investigators were blinded to the brace type tested. The effect of bracing on kinematics was assessed with repeated measures analysis of variance with statistical parametric mapping, with post hoc tests performed for significant interactions.

RESULTS

Only active bracing reduced inversion angles during a sudden ankle inversion when compared with the unbraced condition. This reduction was apparent between 65 and 140 milliseconds after the initial fall. No significant differences in inversion angle were found between the passive placebo brace and unbraced conditions during sudden ankle inversion. Furthermore, no significant differences were found among all tested conditions in the sagittal plane kinematics at the knee and ankle.

CONCLUSION

During an inversion sprain, only the actively protecting ankle brace limited inversion angles among participants. These results do not indicate a placebo effect of external bracing for patients with ankle instability and a history of unilateral ankle sprain. Furthermore, sagittal plane knee kinematics appear to remain unaffected by bracing during single-legged landing, owing to the limited effects of bracing on sagittal ankle kinematics. These results highlight the role of brace design on biomechanical function during sports-related and injury-prone movements.

CLINICAL RELEVANCE

Athletes prone to reinjury after lateral ankle sprain may benefit from brace designs that allow for full sagittal range of motion but restrict only frontal plane motion.

Biomechanical comparison of 3 ankle braces with and without free rotation in the sagittal plane

CONTEXT

Various designs of braces including hinged and nonhinged models are used to provide external support of the ankle. Hinged ankle braces supposedly allow almost free dorsiflexion and plantar flexion of the foot in the sagittal plane. It is unclear, however, whether this additional degree of freedom affects the stabilizing effect of the brace in the other planes of motion.

OBJECTIVE

To investigate the dynamic and passive stabilizing effects of 3 ankle braces, 2 hinged models that provide free plantar flexion-dorsiflexion in the sagittal plane and 1 ankle brace without a hinge.

DESIGN

Crossover study.

SETTING

University Movement Analysis Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Seventeen healthy volunteers (5 women, 12 men; age = 25.4 ± 4.8 years; height = 180.3 ± 6.5 cm; body mass = 75.5 ± 10.4 kg).

INTERVENTION(S)

We dynamically induced foot inversion on a tilting platform and passively induced foot movements in 6 directions via a custom-built apparatus in 3 brace conditions and a control condition (no brace).

MAIN OUTCOME MEASURE(S)

Maximum inversion was determined dynamically using an in-shoe electrogoniometer. Passively induced maximal joint angles were measured using a torque and angle sensor. We analyzed differences among the 4 ankle-brace conditions (3 braces, 1 control) for each of the dependent variables with Friedman and post hoc tests (P < .05).

RESULTS

Each ankle brace restricted dynamic foot-inversion movements on the tilting platform as compared with the control condition, whereas only the 2 hinged ankle braces differed from each other, with greater movement restriction caused by the Ankle X model. Passive foot inversion was reduced with all ankle braces. Passive plantar flexion was greater in the hinged models as compared with the nonhinged brace.

CONCLUSIONS

All ankle braces showed stabilizing effects against dynamic and passive foot inversion. Differences between the hinged braces and the nonhinged brace did not appear to be clinically relevant.

The effect of lace-up ankle braces on injury rates in high school football players

BACKGROUND

Although ankle injuries occur frequently in high school football players, no prospective studies have been performed to determine if wearing lace-up ankle braces will reduce the incidence and severity of ankle and other lower extremity injuries in these athletes.

PURPOSE

This study was conducted to determine if lace-up ankle braces reduce the incidence and severity of lower extremity injuries sustained by high school football players.

DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 2081 players from 50 high schools were randomly assigned to a braced or control group. Braced group players wore lace-up ankle braces during the 2010 football season. Athletic trainers recorded brace compliance, athlete-exposures, and injuries. Cox proportional hazards models were utilized to compare injury rates between groups. Injury severity (days lost) was tested with Wilcoxon rank sum.

RESULTS

The rate of acute ankle injury (per 1000 exposures) was 0.48 in the braced group compared with 1.12 in the control group (Cox hazard ratio [HR] = 0.39; 95% confidence interval [CI], 0.24-0.65; P < .001). The severity (median days lost) of acute ankle injuries was the same (5 days) in both groups (P = .985). The rate of acute knee injury was 0.70 in the braced group compared with 0.69 in the control group (HR = 0.92; 95% CI, 0.57-1.47; P = .721). There was no difference (P = .242) in the severity of knee injuries between the groups (controls = 11.5 days, braced = 17 days). The rate of other lower extremity injuries was 0.95 in the braced group and 1.32 in the control group (HR = 0.72; 95% CI, 0.48-1.09; P = .117), while the severity was similar in both groups (6 days vs 7 days; P = .295).

CONCLUSION

Players who used lace-up ankle braces had a lower incidence of acute ankle injuries but no difference in the incidence of acute knee or other lower extremity injuries. Braces did not reduce the severity of ankle, knee, or other lower extremity injuries.

The effect of lace-up ankle braces on injury rates in high school basketball players

BACKGROUND

Ankle injuries are the most common injury in basketball players. However, no prospective studies have been performed to determine if wearing lace-up ankle braces will reduce the incidence of ankle injuries in high school athletes.

PURPOSE

This trial was undertaken to determine if lace-up ankle braces reduce the incidence and severity of acute first-time and recurrent ankle injuries sustained by high school basketball players.

DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 1460 male and female basketball players from 46 high schools were randomly assigned to a braced or control group. The braced group players wore lace-up ankle braces during the 2009-2010 basketball season. Athletic trainers recorded brace compliance, athlete exposures, and injuries. Cox proportional hazards models (adjusted for demographic covariates), accounting for intracluster correlation, were utilized to compare time to first acute ankle injury between groups. Injury severity (days lost) was tested with the Wilcoxon rank-sum test.

RESULTS

The rate of acute ankle injury (per 1000 exposures) was 0.47 in the braced group and 1.41 in the control group (Cox hazard ratio [HR] 0.32; 95% confidence interval [CI] 0.20, 0.52; P < .001). The median severity of acute ankle injuries was similar (P = .23) in the braced (6 days) and control group (7 days). For players with a previous ankle injury, the incidence of acute ankle injury was 0.83 in the braced group and 1.79 in the control group (Cox HR 0.39; 95% CI 0.17, 0.90; P = .028). For players who did not report a previous ankle injury, the incidence of acute ankle injury was 0.40 in the braced group and 1.35 in the control group (Cox HR 0.30; 95% CI 0.17, 0.52, P < .001).

CONCLUSION

Use of lace-up ankle braces reduced the incidence but not the severity of acute ankle injuries in male and female high school basketball athletes both with and without a previous history of an ankle injury.