Sex Effects on Ankle Biomechanics During Sports-Relevant Tasks and Peroneal Muscle Parameters

Introduction: Ankle sprains from excessive inversion are the most frequent sports- related injury. Common ankle prophylactics are designed to prevent injury by limiting excessive ankle inversion, yet may restrict other ankle motions leading to repeated re-injury. Females are twice as likely as males to suffer an ankle sprain, however, it is unknown if a sex dimorphism in ankle biomechanics exists when wearing ankle prophylactics, and whether differences in the peroneal musculature exist between sexes. Purpose: To quantify the ability of ankle prophylactics (Ankle Roll Guard (ARG), Brace, Control, and Tape) to prevent excessive ankle inversion during a sudden inversion event, and determine whether the effectiveness of the ankle prophylactics and in vivo peroneal muscle parameters differ between sexes. Methods: Thirty-two (16 male and 16 female) participants had dominant limb (i.e., braced) frontal and sagittal plane ankle biomechanics, including peak inversion and plantarflexion angle and range of motion (ROM), and time to peak inversion, quantified during the sudden inversion event with four prophylactic conditions (ARG, Brace, Control, and Tape) and peroneal muscle parameters recorded. With each prophylactic, participants performed five successful trials of the sudden inversion event. Peroneal muscle parameters, including physiological cross-sectional area (PCSA) and stiffness, were quantified in vivo using ultrasound shear-wave elastography, while peroneal strength was measured with an isokinetic dynamometer. Statistical Analysis: All kinematic variables were submitted to a RM ANOVA to test for main effect and interaction of brace (ARG, Brace, Control, and Tape) and sex (male and female). Peroneal muscle parameters were also submitted to independent samples t-test to test the effect of sex. Results: A prophylactic by sex interaction (p = 0.010), revealed females exhibit greater ankle inversion ROM with Control and ARG (p = 0.001, p = 0.010) compared to males. Females also exhibited greater ankle inversion ROM with ARG compared to Brace (p = 0.001), and Control compared to Brace and Tape (p \u3c 0.001, p \u3c 0.001), while males exhibited no significant difference between any prophylactic condition (p \u3e 0.05). Ankle prophylactic impacted ankle inversion ROM (p \u3c 0.001), time to peak inversion (p \u3c 0.001), and peak plantarflexion angle (p \u3c 0.001) and ROM (p \u3c 0.001). Females exhibited smaller peroneal PCSA (p = 0.002) and dorsiflexion strength (p = 0.047), but sex had no significant effect on peroneal strength (p =0.142) or stiffness (p \u3e 0.05). Conclusion: The protective benefits of ankle prophylactics may depend on the specific device and sex of the user. With the lace-up brace and tape, participants decreased ankle biomechanics associated with injury, but this protective benefit was only evident for females. Females exhibited a sex dimorphism in ankle biomechanics during the sudden inversion event, and smaller and weaker peroneals that may contribute to the sex disparity in injury rate

Effectiveness of Novel Ankle Prophylactic Compared with Lace-Up Brace or Tape

Context: Conventional ankle prophylactics restrict harmful ankle inversion motions that lead to injury. But these existing prophylactics also limit other ankle motions, potentially leading to detriments in functional joint capacity. The ankle roll guard (ARG) may alleviate the prevailing issues of existing ankle prophylactics and prevent harmful ankle inversion, while allowing other joint motions. Objective: This technical report sought to compare the ARG’s ability to prevent ankle inversion, but not restrict other ankle motions with existing prophylactics. Design: Repeated-measures study. Setting: Motion capture laboratory. Participants: Thirty participants. Intervention: Each participant had dominant limb ankle kinematics recorded during 5 successful trials of a sudden inversion event and 30-cm drop landing task with each of 4 conditions (ARG, ASO ankle stabilizer [brace], closed-basket weave athletic tape [tape], and unbraced [control]). Main Outcome Measures: Peak ankle inversion angle, range of inversion motion (ROM), and time to peak inversion during the sudden inversion event, and ankle plantar- and dorsiflexion ROM during the drop landing were submitted to a 1-way repeated-measures analysis of variance to test the main effect of prophylaxis. Results: Participants exhibited greater inversion ROM with control compared with tape (P = .001), and greater plantar- and dorsiflexion ROM with ARG and control compared with brace (P = .02, P = .001) and tape (P = .02, P \u3c .001). It took significantly longer to reach peak ankle inversion with brace and tape compared with ARG (P \u3c .001, P = .001) and control (P = .01, P = .01). No significant difference in peak ankle inversion was observed between any condition (P \u3e .05). Conclusion: The ARG may prevent ankle inversion angles where injury is thought to occur (reportedly \u3e41°), but is less restrictive than existing prophylactics. The less restrictive ARG may make its use ideal during rehabilitation as it allows ankle plantar- and dorsiflexion motions, while preventing inversion related to injury

Dataset for Evaluation of the Ankle Roll Guard’s Effectiveness to Improve Clinical Benefit

Ankle Roll Guard is a new, patent protected orthopedic product. The Ankle Roll Guard Armor1 provides an individual protection from “rolling” or spraining their ankle via a lightweight buttress on the lateral aspect of their shoe. This design prevents the ankle from rolling or inverting past 30 degrees, postures where injury is reported to occur, without placing mechanical restriction on the joint. This key innovation allows the user a natural, unrestricted ankle range of motion without compromising the product’s injury protection. Existing prophylactic products, however, provide ankle stability via mechanical restriction to the joint. While these prophylactic products are somewhat effective at preventing injury, the mechanical restriction impairs joint motion, often leading to the development of long-term ankle ailments. The Ankle Roll Guard, however, provides a critical solution to this issue. The product’s design allows the user protection from injury without the mechanical restriction of existing prophylactic products. Yet, because the Ankle Roll Guard is completely new, data regarding the product’s effectiveness is limited to anecdotal evidence provided by users. To target new consumers and stimulate company growth, Ankle Roll Guard needs independent scientific testing to validate the product’s effectiveness. With that in mind, researchers in Boise State University’s Center for Orthopaedic and Biomechanics sought to quantify and improve the Ankle Roll Guard’s effectiveness. Specifically, this effort quantified the effectiveness of the Ankle Roll Guard to prevent ankle inversion and compare its effectiveness with existing prophylactic products, including external brace, athletic tape and unbraced, control ankle, during a sudden inversion event and a battery of functional tasks. The experimental outcomes provided herein by Boise State researchers demonstrate the Ankle Roll Guard may prevent excessive ankle inversion, but not as effectively as “more” restrictive ankle prophylactics (in particular, Brace and Tape). Yet the Ankle Roll Guard’s design may provide mechanical stability necessary to prevent ankle sprain, without the deleterious impact on the user’s knee joint and functional performance routinely seen when wearing the more restrictive ankle prophylactics

Effect of Sex and Ankle Brace Design on Knee Biomechanics During a Single-Leg Cut

Background: Despite success at preventing ankle sprain, prophylactics that restrict ankle plantarflexion motion may produce deleterious knee biomechanics and increase injury risk. Purpose: To determine if ankle prophylactics that restrict plantar- and dorsiflexion motion produce changes in knee biomechanics during a single-leg cut and whether those changes differ between sexes. Study Design: Controlled laboratory study. Methods: A total of 17 male and 17 female participants performed a single-leg cut with 4 conditions: Ankle Roll Guard (ARG), lace-up brace, nonelastic tape, and an unbraced control. Peak stance knee flexion, abduction, and internal rotation joint angle and moment; total knee reaction moment (TKM) and its components (sagittal, frontal, and transverse); and ankle plantarflexion and inversion range of motion (ROM) and peak stance joint moments were tested with a repeated measures analysis of variance to determine the main effect and interaction of condition and sex. Results: Brace and tape restricted plantarflexion ROM as compared with ARG and control (all P \u3c .001). With the brace, women had increased peak knee abduction angle versus ARG (P = .012) and control (P = .009), and men had decreased peak knee internal rotation moment as compared with ARG (P = .032), control (P = .006), and tape (P = .003). Although the restrictive tape decreased inversion ROM when compared with ARG (P = .004) and brace (P = .017), it did not change knee biomechanics. Neither brace nor tape produced significant changes in TKM or components, yet sagittal TKM increased with ARG versus control (P = .016). Women exhibited less ankle inversion ROM (P = .003) and moment (P = .049) than men, while men exhibited significantly greater frontal TKM (P = .022) and knee internal rotation moment with the ARG (P = .029), control (P = .007), and tape (P = .016). Conclusion: Prophylactics that restrict ankle plantarflexion motion may elicit knee biomechanical changes during a single-leg cut, but these changes may depend on prophylactic design and user’s sex and may increase women’s injury risk. Clinical Relevance: Sex-specific ankle prophylactic designs may be warranted to reduce knee injury during sports

Impact of Sex and Lace-Up Ankle Brace on Knee Biomechanics During a Single-Leg Cut

Ankle braces effectively limit harmful ankle motions, but may produce hazardous alterations in knee biomechanics. This study determined how four ankle braces (ankle roll guard (ARG), lace-up brace, non-elastic tape, control) impact knee biomechanics during a single-leg cut, and whether the impact differs between sexes. With the lace-up brace, females increased peak abduction angle 2.5º compared to control (p=0.008), whereas, males decreased peak internal rotation moment compared to control (p=0.006) and tape (p=0.002) conditions. During the cut, males exhibited greater knee internal rotation compared to females (p=0.010), but only with ARG (p=0.009), tape (p=0.005), and control (p=0.002) conditions

Relationship Between Peroneal Muscle Architecture and Dynamic Ankle Function for Individuals with Chronic Ankle Instability

Peroneal architecture may predispose individuals to the impaired ankle function that leads to chronic ankle instability (CAI). But, it is unclear if CAI individuals exhibit different peroneal and ankle function than healthy controls. This study determined peroneal muscle architecture and dynamic ankle function for 30 (12 CAI, 18 CON) participants. Each participant had peroneal architecture (physiological cross-sectional area (PCSA), volume, stiffness), ankle strength (both maximum dorsiflexion and eversion), and ankle biomechanics (peak plantarflexion and negative ankle work during a 30 cm drop landing) quantified. Each variable was submitted to independent t-tests to determine group differences and linear discriminant analysis to determine whether peroneal architecture and dynamic ankle function could accurately identify CAI status. CAI individuals exhibited weaker dorsiflexors (p=0.049), but no differences in peroneal architecture (PCSA p=0.546, volume p=0.488, stiffness p=0.653) or ankle function (negative work p=0.383, peak plantarflexion rotation p=0.958). Yet, 75% (9/12) of CAI and 66.7% (12/18) of CON participants were accurately identified from peroneal muscle architecture and dynamic ankle function. Considering 75% of CAI individuals were accurately identified, specific peroneal and ankle function measures may predispose individuals to CAI

Stiffness of Peroneal Musculature Relates to Ankle Inversion

Adequate stiffness of the peroneal musculature may prevent excessive ankle inversion that leads to injury. Thus, this study determined the relation between peroneal stiffness and ankle inversion. Ten (9 male and 1 female) participants (ht: 1.7 0.1 m, wt: 73.3 9.8 kg) had ankle inversion (including range of inversion and time to peak inversion) quantified during a sudden inversion event. Resting and contracted peroneal muscle stiffness was also quantified with an ultrasound using shear wave elastography. Correlations examined linear relationship between ankle inversion and muscle stiffness. Resting muscle stiffness exhibited a positive relationship with the range of ankle inversion (r = 0.508) and contracted muscle stiffness exhibited a negative relationship with time to peak inversion (r = -0.538), but neither was significant (p = 0.067 and p = 0.054). Both resting and contracted stiffness of the peroneals were related to ankle inversion. But, more work is needed to determine the stiffness necessary to prevent the excessive inversion that leads to injury