Comparison of Anterior Ankle Translation With and Without Ankle Braces

BACKGROUND

Lateral ankle sprains are a common musculoskeletal injury. Ankle braces are frequently used to prevent ankle injuries.

AIM

The purpose of this study was to examine the anterior translation of the talocrural joint of 2 ankle braces relative to a control.

METHODS

Ankle mobility was assessed with the Mobil-Aider arthrometer in 3 conditions: TayCo ankle brace, Aircast ankle brace, and control. Three measures were recorded for each condition.

RESULTS

Thirty participants (9 male and 21 female patients) participated. Friedman's analysis of variance found significant between-group differences for the trial with the largest translation. Wilcoxon signed-ranks post hoc testing found significant between-group differences between the control and TayCo (P < .001) and the control and Aircast conditions (P < .001). Post hoc power analysis revealed a Kendall's W of 0.804.

CLINICAL APPLICATION

The TayCo brace is unique in that it is worn on the outside of the athletic shoe, whereas the Aircast is composed of lateral constraints worn inside the shoe. Both braces provided significant constraint over anterior talus translation when compared to control. The TayCo brace (51%-52% of control) was also significantly better than the Aircast (58%-59% of control) with less anterior translation permitted. This may be instrumental in preventing ankle injuries.

LEVEL OF EVIDENCE

2b.

Effect of Braces on Performance in the Context of Chronic Ankle Instability

Ankle braces are commonly recommended for prevention of ankle sprains, especially secondary sprains, rehabilitation, and return to normal activity or sport after injury. One common resistance to use is the feeling that braces will impede functional performance. For people with chronic ankle instability, the limited research indicates that the use of semirigid, lace-up, or soft-shell braces will not affect, and in some cases, may enhance performance. Activities that could be enhanced are jumping, hopping, and dynamic balance.

Ankle Sprain Bracing Solutions and Future Design Consideration for Civilian and Military Use

INTRODUCTION

Ankle sprains are common injuries within the civilian and military populations, with lingering symptoms that include pain, swelling, giving-way, and a high likelihood for recurrence. Numerous bracing systems are available to stabilize the ankle joint following sprains, with new design iterations frequently entering the market. Currently available braces generally include sleeve, lace-up, and stirrup designs. Sleeves provide mild compression and warmth but limited stability for the ankle, while lace-ups and stirrups appear to be more effective at preventing and treating lateral ankle sprains.

AREAS COVERED

This review summarizes the use of various brace options in practice. Their major clinical benefits, and limitations are highlighted, followed by an overview of emerging concepts in brace design. Current advancements in biomechanical simulation, multifunctional material fabrication, and wearable, field-deployed devices for human injury surveillance are discussed, providing possibilities for conceiving new design concepts for next-generation smart ankle braces.

EXPERT OPINION

Performance of the commercially available braces are limited by their current design concepts. Suggestions on future brace design include: (1) incorporating high-performance materials suitable for extreme environments, (2) leveraging modeling and simulation techniques to predict mechanical support requirements, and (3) implementing adaptive, customizable componentry material to meet the needs of each unique patient.

Effects of elastic ankle support on running ankle kinematics in individuals with chronic ankle instability and healthy controls

BACKGROUND

Individuals with chronic ankle instability (CAI) have an increased risk for recurrent injuries. The preventive effects of external ankle supports are not fully understood. This study aimed to examine the effect of elastic ankle support on running ankle kinematics.

METHODS

3D running gait analysis of individuals with and without CAI was conducted at three-minute-running trials at 2.78 m/s with and without elastic ankle support in a randomised order. Ankle kinematics and intra-individual standard deviations (variability) were calculated at each percent of the running gait cycle. Group and ankle support effects were calculated using statistical parameter mapping.

RESULTS

Twenty-seven individuals were analysed (CAI: n = 14, controls: n = 13). When wearing ankle support, CAI individuals showed significantly decreased plantarflexion angles at 43-47 % (p = 0.033) and 49-51 % (p = 0.043) of the running gait cycle compared to normal running. In healthy controls, no differences in ankle angles between both conditions were found. Comparisons between CAI individuals and healthy controls showed statistically significant differences in the plantar-/dorsiflexion angles at 38-41 % (p = 0.044) with ankle support and at 34-46 % (p = 0.004) without ankle support. Significant ankle angle variability differences were found for ankle in-/eversion between CAI individuals and healthy controls (p = 0.041) at 32-33 % of the running gait cycle.

CONCLUSIONS

Elastic ankle support reduces the range of sagittal plane running ankle kinematics of CAI individuals but not of healthy controls. Further research is needed to evaluate the association between ankle support effects and the risk for recurrent ankle sprains.

The Effect of Ankle Brace Use on a 3-Step Volleyball Spike Jump Height

Purpose

The purpose of this study was to determine whether ankle brace use in university-level varsity volleyball athletes affected their 3-step spike jump height and whether certain types of ankle braces have a greater effect on jump height.

Methods

Nine male university-level varsity volleyball athletes participated in a repeated-measures design study in which each athlete performed three 3-step volleyball spike jumps in 3 ankle brace conditions (soft, rigid, and no brace). Vertical jump height was measured by the Vertec device and video motion analysis at a university biomechanics research laboratory.

Results

Vertical jump heights were significantly lower in both brace conditions (soft, 2.3 cm, standard deviation [SD] 1.2 cm, P < .001; rigid, 1.7 cm, SD 0.9 cm, P < .003) compared with the no-brace condition, and no differences in vertical jump height were observed between the brace conditions (0.6 cm, SD 0.3, P = .3). There was a negative correlation between body fat percentage and vertical jump height (r = –0.075, P = .02). The Vertec device reliably measured vertical jump in all 3 conditions. The no-brace vertical ground reaction forces during the loading phase were significantly greater than brace conditions. Ankle range of motion was greatest in the no-brace condition.

Conclusions

Results from this study suggests that high-performance athletes wearing ankle braces experience a significant decrease in vertical jump height independent of the type of ankle brace worn.

Clinical Relevance

Sports physicians and health care providers caring for high-level athletes should counsel athletes on the trade-offs of wearing protective equipment in sport, as potential decreases in sports performance can lead to increased injury prevention.

Level of Evidence

III.

Ankle bracing's effects during a modified agility task: analysis of sEMG, impulse, and time to complete using a crossover, repeated measures design

This study explored the effects of no braces, softshell (AE), and semi-rigid (T1) ankle braces on time to complete a modified agility task, as well as lower extremity muscle activity and impulse during the change of direction component of the task. Thirty-nine healthy, active individuals completed a modified agility task under the three brace conditions. Time to complete the modified agility task, along with mean surface electromyographic activity (sEMG) and impulse during the deceleration and propulsive phases of the task were measured. There were no significant differences across conditions with respect to sEMG or impulse measures during the deceleration or propulsive phases. There was a significant change in time to complete the modified agility task, F(2,76) = 17.242, p< 0.001, ηp² = 0.312. Post-hoc analysis revealed a significant increase in time to complete the modified agility task when wearing the AE (0.16 (95% CI, 0.062 to 0.265) seconds, p< 0.001) and T1 (0.20 (95% CI, 0.113 to 0.286) seconds, p< 0.001) ankle braces compared to no braces. It appears that performance on a modified agility task may be diminished when wearing ankle braces, although sEMG activity and impulse are unaffected.

The Influence of Ankle Braces on Functional Performance Tests and Ankle Joint Range of Motion

CONTEXT

The lateral ankle sprain is one of the most common lower-extremity injuries in sports. Previous research has found that some prophylactic ankle supports reduce the risk of recurrent ankle sprains and provide extra support to the joint. However, there is a continued concern that these supports may negatively influence performance.

OBJECTIVE

To determine if wearing an ankle brace influences athlete performance and ankle kinematics during functional performance tests.

DESIGN

Repeated measures.

SETTING

University gymnasium.

OTHER PARTICIPANTS

Male and female recreational or competitive athletes (n = 20).

INTERVENTION

Participants performed 3 trials of a standing long jump, vertical jump, 40-yard sprint, and T-drill under each of the following 3 conditions: wearing traditional lace-up brace (brace 1), modified lace-up brace (brace 2), and no-brace.

MAIN OUTCOME MEASURES

A 2-dimensional motion capture camera was used to measure ankle range of motion (ROM) in the sagittal plane during the vertical and standing long jumps and in the frontal plane during the cutting phase of the T-drill. Performance of each test and ankle ROM were compared between each of the braced conditions.

RESULTS

Ankle braces did not influence performance in speed or agility functional performance tests (P > .05). Ankle braces negatively affected performance of the standing long jump (P = .01) and vertical jump (P = .01). There was no significant difference between brace or no-brace conditions in ankle inversion ROM during the T-drill (P > .05). Both brace conditions restricted ROM in the sagittal plane during the vertical and standing long jumps (P < .05).

CONCLUSIONS

Braced conditions restricted sagittal plane ROM during the vertical jump and long jump. This decrease in ROM explains the decline in functional performance also seen during these tests.

Ankle bracing's effects on lower extremity iEMG activity, force production, and jump height during a Vertical Jump Test: An exploratory study

OBJECTIVE

To determine if softshell (AE) and semi-rigid (T1) ankle braces affect lower extremity iEMG activity, force, and jump height during a Vertical Jump Test.

DESIGN

Repeated measures, crossover.

SETTING

Laboratory.

PARTICIPANTS

42 healthy, active individuals.

OUTCOME MEASURES

Vertical jump height, iEMG activity, peak vGRF.

RESULTS

There was significant change across conditions in lateral gastrocnemius (LG) iEMG activity, F(2,70) = 5.31, p = .007, ηp2 = 0.132, with T1 LG iEMG being significantly less (-2.08(99% CI, -3.98 to 0.18) %MVIC, p = .004) than no brace. Significant changes were seen in rectus femoris (RF) iEMG activity, F(2,68) = 6.36, p = .003, ηp2 = 0.158, with T1 RF iEMG activity being significantly less than AE RF iEMG activity (-2.78(99% CI, -5.36 to -0.19) %MVIC, p = .005). There was a significant change in vertical jump height across conditions, F(2,78) = 22.13, p < .0005, ηp2 = 0.362, with a significant decrease in the AE (-2.41(99% CI, -3.66 to -1.17) cm, p < .0005) and T1 conditions (-2.89(99% CI,-4.56 to -1.23) cm, p < .0005), compared to no brace.

CONCLUSION

Vertical jump height is significantly reduced when wearing ankle braces. Effects on lower extremity iEMG activity are dependent upon brace type.

The Comparative Effects of Ankle Bracing on Functional Performance

Ankle sprains represent a common musculoskeletal injury that clinicians are tasked with preventing and treating. Because of the prevalence of this injury, ankle braces have been designed to prophylactically protect the joint and reduce the incidence of repetitive sprains. Although an abundance of literature exists focusing on the efficacy of braces in preventing ankle sprains in young, healthy, and physically active populations, there is a scarcity of evidence specific to the impact of these apparatuses on functional performance; therefore, the purpose of this critically appraised topic (CAT) is to investigate the effects of ankle braces on functional performance measures in such individuals. The outcomes of this CAT will assist sport rehabilitation specialists with informed clinical decision making in managing young, healthy, and physically active populations using ankle braces. Do ankle braces hinder functional performance measures when compared with an unbraced condition in a young, healthy, and physically active population? A minimum of level II evidence research studies were surveyed for this CAT. For this CAT, 1 randomized controlled trial and 3 prospective cohort studies were selected. One study found a statistically significant main effect of increased agility run times while participants wore ankle braces. Another study demonstrated a statistically significant decrease in vertical jump height and ankle range of motion while wearing braces. No other statistically significant findings were reported among studies comparing unbraced with braced conditions. Current data indicate that young, healthy, and physically active individuals may experience varied performance effects when executing specific functional performance tasks while wearing ankle braces. In general, bracing does not appear to significantly impair performance on most functional tasks; however, decrements were noted to increases in agility run time and decreases in vertical jump height. Subsequent analysis indicated that a brace may result in decreased ankle plantarflexion, dorsiflexion, eversion, and inversion range of motion, which may underpin noted performance deficits.

The effect of ankle bracing on landing biomechanics in female netballers

OBJECTIVES

Investigate the impact of lace-up ankle braces on landing biomechanics.

DESIGN

Within-subject repeated measures. Participants completed a drop jump, drop land, and netball-specific task in braced and unbraced conditions.

SETTING

Biomechanical research laboratory.

PARTICIPANTS

Twenty female high school netballers.

MAIN OUTCOME MEASURES

Leg, knee, and ankle stiffness, knee/ankle stiffness ratio, knee and ankle sagittal excursion, peak vertical ground reaction force, time-to-peak vertical ground reaction force, and loading rate.

RESULTS

In the brace condition leg stiffness increased bilaterally during the drop land (ES = 0.21, 0.22), ankle stiffness increased bilaterally during the drop jump (ES = 0.37, 0.29) and drop land (ES = 0.40, 0.60), and knee/ankle stiffness ratio decreased in all three tasks (ES = -0.22 to -0.45). Ankle sagittal excursion decreased bilaterally during the drop jump (ES = -0.35, -0.53) and drop land (ES = -0.23, -0.46), and decreased in the lead limb during the netball jump (ES = -0.36). Knee excursion decreased bilaterally during the drop jump (ES = -0.36, -0.40) and in the lead limb during netball task (ES = -0.59). Lead limb TTP was greater during the netball jump (ES = 0.41).

CONCLUSIONS

Lace-up ankle braces may increase leg and joint stiffness and reduce joint excursion during landing but do not appear to affect landing forces. The observed effect on landing biomechanics may predispose young netballers to injury.

The effect of reduced ankle dorsiflexion on lower extremity mechanics during landing: A systematic review

OBJECTIVES

To examine the evidence for effect of restricted ankle dorsiflexion range of motion on lower-extremity landing mechanics.

DESIGN

Literature review.

METHODS

Systematic search of the literature. Articles critiqued by two reviewers.

RESULTS

Six studies were identified that investigated the effect of restricted DF ROM on landing mechanics. Overall, results suggest that landing mechanics are altered with restricted DF ROM, but studies disagree as to the particular mechanical variables affected.

CONCLUSIONS

There is evidence that restricted dorsiflexion range of motion may alter lower-extremity landing mechanics in a manner, which predisposes athletes to injury. Interpretation of results was made difficult by the variation in landing tasks investigated and the lack studies investigating sport-specific landing tasks. The focus of studies on specific mechanical variables rather than mechanical patterns and the analysis of pooled data in the presence of different compensation strategies between participants also made interpretation difficult. These areas require further research.