Influence of ankle functional instability on the ankle electromyography during landing after volleyball blocking

Neuromuscular Electrical Stimulation Improves Frontal Ankle Motor Control in Individuals With Chronic Ankle Instability During Drop Landing

OBJECTIVE

This study investigated the effect of neuromuscular electrical stimulation on the frontal ankle motor control in individuals with chronic ankle instability during drop landing.

DESIGN

This was a randomized, controlled, double-blind trial. Thirty-six individuals with chronic ankle instability were randomly assigned to each group. Participants received 6-wk neuromuscular electrical stimulation intervention and sham stimulation in the neuromuscular electrical stimulation and control groups, respectively. Data were collected at week 0 and week 6 . A mixed-effects model and analysis of covariance were employed to investigate the between-group differences in continuous and discrete outcome variables at week 6 , with the outcome variables at week 0 as covariates.

RESULTS

Compared to control group, neuromuscular electrical stimulation group exhibited a 2.66° (2.45, 2.86) reduction in frontal ankle inversion angle, a 47.41°/sec (-16.05, -78.77) decrease in peak ankle inversion angular velocity, and a 0.43 Nm/kg (0.18, 0.68) increase in peak ankle eversion moment during drop landing at week 6 .

CONCLUSIONS

Applying 6-wk neuromuscular electrical stimulation to the fibularis longus resulted in decreased ankle inversion angle and ankle inversion angular velocity and increased peak ankle eversion moment during drop landing. Consequently, neuromuscular electrical stimulation could be considered an effective modality for individuals with chronic ankle instability to enhance the frontal ankle movement patterns and overall ankle motor control.

The influence of unstable surfaces on ankle muscle activation during functional exercises

BACKGROUND

The study aims to compare how 3 balance platform designs affect ankle muscle activation during various functional exercises, all performed on the dominant limb.

METHODS

Fifteen healthy, active participants performed single-leg stance, single-leg squat, and forward lunge on BOSU® Ball, wobble board, stability trainer, and flat ground. Surface electromyography was used to measure Peroneus Longus, Tibialis Anterior, Gastrocnemius, and Soleus activation during these exercises on different platforms and flat ground. Repeated measures ANOVA with two factors (exercise and platform) were used for analysis.

RESULTS

There was a significant interaction between balance platforms and exercises (p < 0.05). Soleus displayed the highest activation amplitudes during the single leg stance and single leg squat on BOSU®, and peroneus longus displayed the greatest activation amplitudes during the forward lunge on BOSU® (p < 0.05).

CONCLUSIONS

The present study findings indicated that exercises conducted on a flexible platform resulted in greater muscle activation levels when compared to those executed on both a rigid platform and flat ground. Based on the level of ankle muscle activation in the current study, exercises for the ankle would progress from exercises on to a flat ground to on a BOSU® in order to achieve progressively greater ankle muscle activation.

LEVEL OF EVIDENCE

Level III.

The effect of perturbation training with and without applying the dry needling on leg muscles in patients with chronic ankle sprain

INTRODUCTION

Ankle sprain is a common musculoskeletal injury that leads to recurrent instability. Repeated ankle sprain can be a mechanism for creating trigger point. Proper treatment of trigger points, in addition to preventing recurrence of sprains, may reduce pain and improve muscle function. This improvement can be the result of preserving the surrounding tissues from excessive pressure.

OBJECTIVE

Investigate the added value of dry needling into perturbation training protocol for chronic ankle sprain.

DESIGN

Randomized clinical trial; assessor-blind; before and after comparison.

SETTING

Treatment of patients referred to the institutional rehabilitation clinics.

MAIN OUTCOME MEASURE(S)

Functional assessment with FAAM questionnaire score, Pain with NPRS scale, ankle instability severity with Cumberland tool.

METHODS

Twenty-four patients with chronic ankle instability participated in this clinical trial and were randomly divided into two groups. Intervention was 12 sessions in which one group received only perturbation training and the other group received perturbation training along with dry needling. Repeated measures ANOVA was used to investigate the effect of treatment.

RESULTS

Data Analysis showed significant difference in NPRS and FAAM and Cumberland score before and after treatment in each group (P < 0.001). Comparison of the results between the groups did not show any significant difference (P > 0.05).

CONCLUSION

The findings showed that adding dry needling technique to the perturbation training does not have greater effects on the pain and function of patients with chronic ankle instability.

Ankle strategies for step-aside movement during quiet standing

The mediolateral ankle strategy plays a crucial role in providing ankle stability in ground obstacle-avoidance behavior. This is achieved by changing basic walking patterns according to the characteristics of the obstacle. In daily life, it is more common to use step-aside movement (i.e., dodging step) for collision avoidance rather than side-stepping (i.e., widening standing base) when encountering an approaching pedestrian or bicycle. While studies have been conducted on the mediolateral ankle strategy contribution in obstacle avoidance using side-stepping, knowledge of step-aside movement is still inadequate. Therefore, we conducted an electromyography (EMG) analysis on the tibialis anterior (TA), peroneus longus (PL), and soleus (SOL) muscles, as well as measured center of pressure (CoP) displacement, and vertical ground reaction force (vGRF) of the standing leg, in order to understand the role of ankle muscles in step-aside movement during quiet standing. Fifteen healthy young men repeated twelve step-aside movements in both left and right directions. A Bayesian one-sample t-test was used to determine the sufficient step and participant counts. Multiple linear regression analysis was used to investigate the correlation between the muscle activity and CoP displacement or vGRF. The regression coefficients (β) of the left push phase and the right loading phase were tested against zero using a Bayesian one-sample t-test to identify the correlation between independent and dependent variables. We used the one-dimensional statistical parametric mapping (SPM1d) method to analyze the differences between and within the groups of EMG data based on the continuous time series. The results showed that the PL displayed a substantial contribution to the mediolateral ankle strategy during the push phase of step-aside movement, and also contributed to maintaining ankle stability during the loading phase. This suggested that screening for PL weakness and providing appropriate interventions and/or training approaches is especially critical for populations with walking stability problems.

Influence of Landing in Neuromuscular Control and Ground Reaction Force with Ankle Instability: A Narrative Review

Ankle sprains are generally the most common injuries that are frequently experienced by competitive athletes. Ankle sprains, which are the main cause of ankle instability, can impair long-term sports performance and cause chronic ankle instability (CAI). Thus, a comprehensive understanding of the key factors involved in repeated ankle strains is necessary. During jumping and landing, adaptation to the landing force and control of neuromuscular activation is crucial in maintaining ankle stability. Ankle mobility provides a buffer during landing, and peroneus longus activation inhibits ankle inversion; together, they can effectively minimize the risk of ankle inversion injuries. Accordingly, this study recommends that ankle mobility should be enhanced through active and passive stretching and muscle recruitment training of the peroneus longus muscles for landing strategies should be performed to improve proprioception, which would in turn prevent ankle sprain and injury to neighboring joints.

Effect of Combined Balance Exercises and Kinesio Taping on Balance, Postural Stability, and Severity of Ankle Instability in Female Athletes with Functional Ankle Instability

Ankle sprain is a common musculoskeletal injury, and recurrent ankle sprains often lead to ankle instability. This study aimed to examine whether a 6-week balance training on a wobble board (WB) combined with kinesio taping (KT) is effective in improving balance, postural stability, and ankle stability among female athletes with functional ankle instability (FAI). Twenty-four female athletes with FAI were randomly assigned to study (SG) or control groups (CG). SG attended a 6-week training protocol of combined balance training on the wobble board with KT applied to ankles during exercise. CG only went through a 6-week balance training procedure that was the same as the SG. Before and after the training program, balance and postural stability and the severity of ankle instability were assessed by single-leg Biodex Balance system and Cumberland Ankle Instability Tool (CAIT), respectively. The analysis revealed that the scores of balance and postural stability decreased after the 6-week training for CG (p = 0.002) and SG (p = 0.001), which indicates an improvement for these variables, and the score of CAIT increased, which means the severity of instability reduced (p = 0.001 for both groups). Significant between-group differences were found for balance and postural stability (t = 2.79, p = 0.011, g = −1.99) and the severity of instability (t = 2.082, p = 0.049, g = 1.36), favoring SG compared with CG. This study showed that the addition of KT to balance training is more effective than balance training alone in improving balance, postural stability, and severity of ankle instability in female athletes with FAI. Our findings could provide a preliminary reference for designing combined balance and KT programs for delivering health benefits to females with FAI.

Electromiographic activity during single leg jump in adolescent athletes with chronic ankle instability: A pilot study

Chronic ankle instability (CAI) is a common condition in athletes, which can alter the muscular activity of lower limb during jump. The objective of the study was to verify the magnitude of activation, onset timing and order of recruitment of the proximal and local muscles to the ankle of young athletes with CAI during a single leg vertical jump. Thirty-seven athletes were selected and divided into: 1) CAI group and 2) control group. An electromyographic evaluation was performed during the jump on force plate. The muscles evaluated were the proximal muscles - gluteus medius (GMed), rectus femoris (RF) and local ankle muscles - tibialis anterior (TA), peroneus longus (PL) and lateral gastrocnemius (LG). In propulsion, the CAI group showed early activation of all evaluated muscles, when compared to control group (p = 0.05). No diferences were found between groups concerning magnitude of electromyographic signal and order of muscle recruitment. During landing, an increase in magnitude of the electromyographic signal of TA in the CAI group was observed and no diferences were found between groups for onset activation and order of muscle recruitment. The results can be applied to athletes' rehabilitation through specific neuromuscular control exercises, such as reaction time and local and proximal joint stabilization to optimize muscle performance and injury incidence. Therefore, in the single leg vertical jump athletes with CAI presented higher activation of the TA in the landing and an early activation of the GMed, RF, TA, PL and LG in propulsion in relation to control group.

Muscle activations during functional tasks in individuals with chronic ankle instability: a systematic review of electromyographical studies

BACKGROUND

It has been reported that individuals with chronic ankle instability (CAI) show motor control abnormalities. The study of muscle activations by means of surface electromyography (sEMG) plays a key role in understanding some of the features of movement abnormalities.

RESEARCH QUESTION

Do common sEMG activation abnormalities and strategies exists across different functional movements?

METHODS

Literature review was conducted on PubMed, Web-of-Science and Cochrane databases. Studies published between 2000 and 2020 that assessed muscle activations by means of sEMG during any type of functional task in individuals with CAI, and used healthy individuals as controls, were included. Methodological quality was assessed using the modified Downs&Black checklist. Since the methodologies of different studies were heterogeneous, no meta-analysis was conducted.

RESULTS

A total of 63 articles investigating muscle activations during gait, running, responses to perturbations, landing and hopping, cutting and turning; single-limb stance, star excursion balance task, forward lunges, ball-kicking, y-balance test and single-limb squatting were considered. Individuals with CAI showed a delayed activation of the peroneus longus in response to sudden inversion perturbations, in transitions between double- and single-limb stance, and in landing on unstable surfaces. Apparently, while walking on ground there are no differences between CAI and controls, walking on a treadmill increases the variability of muscles activations, probably as a "safety strategy" to avoid ankle inversion. An abnormal activation of the tibialis anterior was observed during a number of tasks. Finally, hip/spine muscles were activated before ankle muscles in CAI compared to controls.

CONCLUSION

Though the methodology of the studies herein considered is heterogeneous, this review shows that the peroneal and tibialis anterior muscles have an abnormal activation in CAI individuals. These individuals also show a proximal muscle activation strategy during the performance of balance challenging tasks. Future studies should investigate whole-body muscle activation abnormalities in CAI individuals.

Examining the Use of Kinesiology Tape During Weight Bearing Exercises on Proprioception in Participants With Functional Ankle Instability

The aim of this study was to examine the effect of tape worn during weight bearing exercises on proprioception (i.e., ankle angle repositioning error) in participants with functional ankle instability. We employed a randomized, controlled clinical study in a laboratory setting, with 56 participants with functional ankle instability. Participants were randomly assigned to three groups: (a) weight bearing exercises without tape (n = 18), (b) weight bearing exercises with tape (n = 19) and controls not engaged in weight bearing exercises (n = 19). Weight bearing exercises included six weeks of bilateral squats in partial form with up to 45 degrees of knee flexion, and unilateral partial squats with full heel raise, and with full toe raise. In the taped condition, participants wore tape for six weeks with up to three tape replacements per week. Proprioception was measured as ankle repositioning error. Results showed that the mean angle repositioning error among participants in the active weight bearing groups was decreased by the taping intervention, relative to the control group's performance (p = 0.042). There were no significant differences between weight bearing exercise groups and control groups. The addition of kinesiology tape in weight bearing exercises can improve proprioception in active conditions.

Effects of Plyometric and Balance Training on Neuromuscular Control of Recreational Athletes with Functional Ankle Instability: A Randomized Controlled Laboratory Study

Plyometric exercise has been suggested for knee injury prevention in sports participation, but studies on ankle plyometric training are limited. This study aims to investigate the change of joint position sense and neuromuscular activity of the unstable ankle after six-week integrated balance/plyometric training and six-week plyometric training. Thirty recreational athletes with functional ankle instability were allocated into three groups: plyometric group (P) vs. plyometric integrated with balance training group (BP) vs. control group (C). Ankle joint position sense, integrated electromyography (EMG), and balance adjusting time during medial single-leg drop-landing tasks were measured before and after the training period. Following the six-week period, both training groups exhibited a lower absolute error in plantar flexion (P group: pre: 3.79° ± 1.98°, post: 2.20° ± 1.31°, p = 0.016; BP group: pre: 4.10° ± 1.87°, post: 2.94° ± 1.01°, p = 0.045), and the integrated group showed a lower absolute error in inversion angles (pre 2.24° ± 1.44° and post 1.48° ± 0.93°, p = 0.022), and an increased integrated EMG of ankle plantar flexors before landing. The plyometric group exhibited a higher integrated EMG of the tibialis anterior before and after landing (pre: 102.88 ± 20.93, post: 119.29 ± 38.33, p = 0.009 in post-landing) and a shorter adjusting time of the plantar flexor following landing as compared to the pre-training condition (pre: 2.85 ± 1.15 s, post: 1.87 ± 0.97 s, p = 0.006). In conclusion, both programs improved ankle joint position sense and muscle activation of the ankle plantar flexors during single-leg drop landing. The plyometric group showed a reduced adjusting time of the ankle plantar flexor following the impact from drop landing.

Ankle Instability Patients Exhibit Altered Muscle Activation of Lower Extremity and Ground Reaction Force during Landing: A Systematic Review and Meta-Analysis

This review aimed to investigate characteristics of muscle activation and ground reaction force (GRF) patterns in patients with ankle instability (AI). Relevant studies were sourced from PubMed, CINAHL, SPORTDiscus, and Web of Science through December 2019 for case-control study in any laboratory setting. Inclusion criteria for study selection were (1) subjects with chronic, functional, or mechanical instability or recurrent ankle sprains; (2) primary outcomes consisted of muscle activation of the lower extremity and GRF during landing; and (3) peer-reviewed articles with full text available, including mean, standard deviation, and sample size, to enable data reanalysis. We evaluated four variables related to landing task: (1) muscle activation of the lower extremity before landing, (2) muscle activation of the lower extremity during landing, (3) magnitude of GRF, and (4) time to peak GRF. The effect size using standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for these variables to make comparisons across studies. Patients with AI had a lower activation of peroneal muscles before landing (SMD = -0.63, p < 0.001, CI = -0.95 to -0.31), greater peak vertical GRF (SMD = 0.21, p = 0.03, CI = 0.01 to 0.40), and shorter time to peak vertical GRF (SMD = -0.51, p < 0.001, CI = -0.72 to -0.29) than those of normal subjects during landing. There was no significant difference in other muscle activation and GRF components between the patients with AI and normal subjects (p > 0.05). Altered muscle activation and GRF before and during landing in AI cases may contribute to both recurrent ankle and ACL injuries and degenerative change of articular.

Individuals with chronic ankle instability exhibit altered ankle kinematics and neuromuscular control compared to copers during inversion single-leg landing

OBJECTIVES

This study compares the ankle kinematics and muscle activities of the individuals with chronic ankle instability (CAI), coper, and control groups in normal and inversion single-leg landings.

DESIGN

cross-sectional study; SETTING: Biomechanics laboratory.

PARTICIPANTS

Physically active adults with CAI (N = 12); and coper (N = 12) and control (N = 12) groups.

MAIN OUTCOME MEASURES

The participants performed normal and inversion single-leg landing. The muscle activity 200 ms before and after landing of the tibialis anterior, the medial gastrocnemius, and the fibularis longus (FL) were recorded. The FL latency, sagittal and frontal co-contraction indexes (CCI), ankle inversion angle at the initial contact, and the maximum inversion angle were recorded.

RESULTS

Significantly longer FL latency, decreased FL muscle activity, frontal CCI, and an increased maximum inversion angle at post-landing were discovered during inversion single-leg landing in the CAI group compared to the coper and control groups. However, no significant difference was observed among the CAI and coper groups during normal single-leg landing.

CONCLUSION

These results suggest prolonged FL latency and altered ankle kinematics suggest an increased risk of recurrent lateral ankle sprains in CAI with inversion single-leg landing.

Copers adopt an altered movement pattern compared to individuals with chronic ankle instability and control groups in unexpected single-leg landing and cutting task

Individuals with chronic ankle instability (CAI) demonstrate altered ankle kinematics during landing compared to uninjured individuals. However, if copers may have adopted unique movement strategy to prevent repeated ankle sprains is unclear. The purpose of this study compares the lower-extremity joint kinematics and muscle activities of CAI (N = 8), coper (COP) (N = 8), and control (CON) (N = 8) groups in unexpected single-leg landing and cutting. Performance time (from initial contact to toe-off), number of mistakes in the jumping direction, low-extremity joint angle are assessed. Muscle activities were recorded from the tibialis anterior, medial gastrocnemius, and peroneus longus (PL), and mean muscle activity, co-contraction index (CI), and PL latency were analyzed. Results of performance time and CI are not significant. Significantly less number of mistakes in the jumping direction and a shorter PL latency were discovered in the COP and CON compared with the CAI group (P < 0.05). The peak hip joint flexion angle is significantly smaller in the COP than in the CON (P = 0.04). In dynamic tasks requiring quick judgments of ankle inclination, the COP may be able to accurately sense the inclination of the foot. Additionally, movement strategies differed between the COP and CON groups in an unexpected single-leg landing and cutting.

Neuromuscular control of the ankle during pre-landing in athletes with chronic ankle instability: Insights from statistical parametric mapping and muscle co-contraction analysis

OBJECTIVE

The present study aimed to compare the neuromuscular control of the muscles around the ankle between athletes with CAI and without history of any ankle sprain (Non-CAI) by using statistic parametric mapping (SPM) and co-contraction analyses.

DESIGN

Cross-sectional study; Setting: Laboratory; Participants: 40 athletes (20 CAI, 20 Non-CAI) were pair-matched for age and gender.

MAIN OUTCOME MEASURES

Neuromuscular control was examined using surface electromyography (EMG) amplitude and muscle co-contraction 200 ms before foot-contact with the ground during a jump-landing task.

RESULTS

The EMG amplitude of tibialis anterior, peroneus longus, and gastrocnemius medialis were analyzed using statistic parametric mapping. The CAI group exhibited decreased EMG amplitude of peroneus longus during preparation for foot-contact. There were no significant co-contraction differences between groups.

CONCLUSIONS

Our findings demonstrate that SPM combined with the co-contraction provides a comprehensive EMG analysis to detect the differences of neuromuscular control between athletes with and without chronic ankle instability. Additionally, this finding indicates that CAI contributed to altered neuromuscular control during the pre-landing phase, which may contribute to re-injury mechanisms.

Lower-Extremity Kinematics During Ankle Inversion Perturbations: A Novel Experimental Protocol That Simulates an Unexpected Lateral Ankle Sprain Mechanism

Context: Lateral ankle sprains are a common injury in which the mechanics of injury have been extensively studied. However, the anticipatory mechanisms to ankle inversion perturbations are not well understood. Objective: To examine lower-extremity kinematics, including spatial and temporal variables of maximum inversion displacement and maximum inversion velocity, during landings on a tilted surface using a new experimental protocol to replicate a lateral ankle sprain. Setting: Three-dimensional motion analysis laboratory. Participants: A total of 23 healthy adults. Interventions: Participants completed unexpected (UE) and expected (EXP) unilateral landings onto a tilted surface rotated 25° in the frontal plane from a height of 30 cm. Main Outcome Measures: Ankle, knee, and hip kinematics at each discrete time point from 150 ms pre-initial contact (IC) to 150 ms post-IC, in addition to maximum ankle inversion and maximum inversion velocity, were compared between UE and EXP landings. Results: The UE landing produced significantly greater maximum inversion displacement (P < .01) and maximum inversion velocity (P = .02) than the EXP landing. Significantly less ankle inversion and internal rotation were found during pre-IC, whereas during post-IC, significantly greater ankle inversion, ankle internal rotation, knee flexion, and knee abduction were observed for the UE landing (P < .05). In addition, significantly less hip flexion and hip adduction were observed for the UE landing during pre-IC and post-IC (P < .05). Conclusions: Differences in the UE and EXP landings indicate the experimental protocol presented a UE inversion perturbation that approximates the mechanism of a lateral ankle sprain. Furthermore, knowledge of the inversion perturbation elicited a hip-dominant strategy, which may be utilized to assist with ankle joint stabilization during landing to further protect the lateral ankle from injury.

Description and Intrarater Test-Retest Reliability of a Reverse-Action Method to Assess Ankle Evertor Muscle Performance: The I-to-V Test

Purpose: Reverse action (RA) of the ankle evertor muscle is when the proximal attachment moves toward the distal attachment, moving the lower leg in the frontal plane when the foot and ankle are fixed on the ground and inducing ankle eversion. The purpose of this study was to describe an RA method for measuring ankle evertor muscle performance. Method: Eighteen healthy individuals were recruited for this study. To assess the RA of their ankle evertors, the participants sat with their knees together and their feet firmly planted on the floor, then spread their knees as far apart as possible. A tester used a measuring tape to measured the distance (in cm) between the medial tibial tuberosity of the tested side and that of the non-tested side. In the end range position of the RA, ankle evertor electromyographic activity was recorded simultaneously. The intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were calculated to establish the intrarater test-retest reliability. The correlation between each performance value and muscle activity was assessed using a linear correlation model. Results: The proposed method of assessing RA performance was highly reliable (ICC=0.95) and had a low SEM (1.63 cm); in addition, the performance value showed a strong positive correlation with ankle evertor muscle activity (ρ=0.90; 95% CI: 0.79, 0.95; p=0.01). Conclusions: The proposed RA method of assessing the ankle evertor muscles can be used as a simple, reliable, economical performance test. It can also be used as an alternate method of testing the peroneal muscles rather than selectively measuring ankle evertor performance because hip external rotation occurs when performing RA.

Does chronic ankle instability influence lower extremity muscle activation of females during landing?

Much remains unclear about how chronic ankle instability (CAI) could affect knee muscle activations and interact with knee biomechanics. Therefore, the purpose of this study was to assess the influence of CAI on the lower extremity muscle activation at the ankle and knee joints during landings on a tilted surface. A surface electromyography system and two force plates were used to collect lower extremity muscle activation of 21 young female individuals with CAI and 21 pair-matched controls during a double-leg landing with test limb landing on the tilted surface. In the pre-landing phase, compared to controls, CAI participants displayed a reduced ankle evertor activation that could place CAI at a high risk of giving way or sprain injury. In the landing phase, an increased tibialis anterior activation of CAI led to increased co-contraction of ankle muscles in the sagittal and frontal plane. A greater ankle muscle co-contraction could increase the ankle stability during landings but may adversely influence the knee muscle activations (e.g., a greater co-contraction ratio of quadriceps to hamstrings). Relevant training programs (e.g., increasing pre-landing peroneal activation, and optimizing activation ratio of quadriceps to hamstrings) may help individuals with CAI improving ankle stability and reduce atypical knee loading during landings.

Rehabilitation after anatomical ankle ligament repair or reconstruction

The selection, implementation of and adherence to a post-operative regimen are all essential in order to achieve the best outcomes after ankle ligament surgery. The purpose of this paper is to present a best-evidence approach to this, with grounding in basic science and a consensus opinion from the members of the ESSKA-AFAS Ankle Instability Group. Basic science and clinical evidence surrounding tissue healing after surgical repair or reconstruction of the ligaments as well as around the re-establishment of sensorimotor control are reviewed. A consensus opinion based on this evidence as to the recommended rehabilitation protocol after ankle ligament surgery was then obtained from the members of the ESSKA-AFAS Ankle Instability Group. Rehabilitation recommendations are presented for the initial post-operative period, the early recovery phase and a goal-orientated late rehabilitation and return-to-sport phase. This paper presents practical, evidenced-based guidelines for rehabilitation and return to activity after lateral ankle ligament surgery.

Rehabilitation after anatomical ankle ligament repair or reconstruction

The selection, implementation of and adherence to a post-operative regimen are all essential in order to achieve the best outcomes after ankle ligament surgery. The purpose of this paper is to present a best-evidence approach to this, with grounding in basic science and a consensus opinion from the members of the ESSKA-AFAS Ankle Instability Group. Basic science and clinical evidence surrounding tissue healing after surgical repair or reconstruction of the ligaments as well as around the re-establishment of sensorimotor control are reviewed. A consensus opinion based on this evidence as to the recommended rehabilitation protocol after ankle ligament surgery was then obtained from the members of the ESSKA-AFAS Ankle Instability Group. Rehabilitation recommendations are presented for the initial post-operative period, the early recovery phase and a goal-orientated late rehabilitation and return-to-sport phase. This paper presents practical, evidenced-based guidelines for rehabilitation and return to activity after lateral ankle ligament surgery.

Postural control systems in two different functional movements: a comparison of subjects with and without chronic ankle instability

[Purpose] The aim of this study was to evaluate postural control during two different movements of the Functional Movement Screen in patients with chronic ankle instability compared with healthy subjects. [Subjects] This study was a cross-sectional survey of 50 participants comprised of 25 chronic ankle instability patients and 25 healthy subjects. [Methods] All subjects were subjected to measurement of the Foot and Ankle Disability Index and center of pressure and Functional Movement Screen testing. The deep squat and hurdle step were performed for the lower extremities in Functional Movement Screen testing. Then, the center of pressure was measured with balance assessment software using a Nintendo Wii Balance Board. The center of pressure path length, velocity, and area of the 95% confidence ellipse and Functional Movement Screen scores were evaluated for all subjects. [Results] The results showed significant differences in center of pressure path length, velocity, and area of the 95% confidence ellipse between the groups for the hurdle step with the non-affected limb. However, there were no significant differences between groups for the deep squat and hurdle step with the affected limb. [Conclusion] The results of this study showed that there was a difference in the hurdle step with the non-affected limb in chronic ankle instability patients compared with normal subjects.

Multi-segment foot landing kinematics in subjects with chronic ankle instability

BACKGROUND

Chronic ankle instability has been associated with altered joint kinematics at the ankle, knee and hip. However, no studies have investigated possible kinematic deviations at more distal segments of the foot. The purpose of this study was to evaluate if subjects with ankle instability and copers show altered foot and ankle kinematics and altered kinetics during a landing task when compared to controls.

METHODS

Ninety-six subjects (38 subjects with chronic ankle instability, 28 copers and 30 controls) performed a vertical drop and side jump task. Foot kinematics were obtained using the Ghent Foot Model and a single-segment foot model. Group differences were evaluated using statistical parametric mapping and analysis of variance.

RESULTS

Subjects with ankle instability had a more inverted midfoot position in relation to the rearfoot when compared to controls during the side jump. They also had a greater midfoot inversion/eversion range of motion than copers during the vertical drop. Copers exhibited less plantar flexion/dorsiflexion range of motion in the lateral and medial forefoot. Furthermore, the ankle instability and coper group exhibited less ankle plantar flexion at touchdown. Additionally, the ankle instability group demonstrated a decreased plantar flexion/dorsiflexion range of motion at the ankle compared to the control group. Analysis of ground reaction forces showed a higher vertical peak and loading rate during the vertical drop in subjects with ankle instability.

INTERPRETATION

Subjects with chronic ankle instability displayed an altered, stiffer kinematic landing strategy and related alterations in landing kinetics, which might predispose them for episodes of giving way and actual ankle sprains.

Cold-water immersion alters muscle recruitment and balance of basketball players during vertical jump landing

The purpose of this study was to evaluate the effects of cold-water immersion on the electromyographic (EMG) response of the lower limb and balance during unipodal jump landing. The evaluation comprised 40 individuals (20 basketball players and 20 non-athletes). The EMG response in the lateral gastrocnemius, tibialis anterior, fibular longus, rectus femoris, hamstring and gluteus medius; amplitude and mean speed of the centre of pressure, flight time and ground reaction force (GRF) were analysed. All volunteers remained for 20 min with their ankle immersed in cold-water, and were re-evaluated immediately post and after 10, 20 and 30 min of reheating. The Shapiro-Wilk test, Friedman test and Dunn's post test (P < 0.05) were used. The EMG response values decreased for the lateral gastrocnemius, tibialis anterior, fibular longus and rectus femoris of both athletes and non-athletes (P < 0.05). The comparison between the groups showed that the EMG response was lower for the athletes. Lower jump flight time and GRF, greater amplitude and mean speed of centre of pressure were predominant in the athletes. Cold-water immersion decreased the EMG activity of the lower limb, flight time and GRF and increased the amplitude and mean speed of centre of pressure.

Six-week combined vibration and wobble board training on balance and stability in footballers with functional ankle instability

OBJECTIVE

To compare the effectiveness of a combination of vibration and wobble board training against wobble board training alone in footballers suffering from functional ankle instability (FAI).

DESIGN

A 2 × 3 prefactorial-postfactorial design.

SETTING

University research laboratory.

PARTICIPANTS

Thirty-three male semiprofessional footballers with self-reported unilateral FAI were randomly assigned in 3 groups: vibration and wobble board (mean age 22.2 years), wobble board (mean age 22.7 years), and control (mean age 23.1 years).

INTERVENTIONS

Participants in each intervention group performed a 6-week progressive rehabilitation program using a wobble board, either with or without the addition of vibration stimulus.

MAIN OUTCOME MEASURES

Absolute center of mass (COM) distribution during single-leg stance, modified star excursion balance test (SEBT) reach distances, and single-leg triple hop for distance (SLTHD) were measured before and after 6-week intervention.

RESULTS

Combined vibration and wobble board training resulted in reduced COM distribution [P ≤ 0.001, effect size (ES) = 0.66], increased SEBT reach distances (P ≤ 0.01 and P ≤ 0.002, ES = 0.19 and 0.29, respectively), and increased SLTHD (P ≤ 0.001, ES = 0.33) compared with wobble board training alone during the course of the 6-week training intervention.

CONCLUSIONS

Combined vibration and wobble board training improves COM distribution, modified SEBT scores, and SLTHD among footballers suffering FAI compared with wobble board training alone.

Dynamic postural stability for double-leg drop landing

Dynamic postural stability has been widely studied for single-leg landing, but seldom considered for double-leg landing. This study aimed to evaluate the dynamic postural stability and the influence mechanism of muscle activities during double-leg drop landing. Eight recreationally active males and eight recreationally active females participated in this study and dropped individually from three heights (0.32 m, 0.52 m, and 0.72 m). Ground reaction force was recorded to calculate the time to stabilisation. Electromyographic activities were recorded for selected lower-extremity muscles. A multivariate analysis of variance was carried out and no significant influence was found in time to stabilisation between genders or limb laterals (P > 0.05). With increasing drop height, time to stabilisation decreased significantly in two horizontal directions and the lower-extremity muscle activities were enhanced. Vertical time to stabilisation was not significantly influenced by drop height. Dynamic postural stability improved by neuromuscular change more than that required due to the increase of drop height. Double-leg landing on level ground is a stable movement, and the body would often be injured before dynamic postural stability is impaired. It is understandable to protect tissues from mechanical injuries by the sacrifice of certain dynamic postural stability in the design of protective devices or athlete training.

Isokinetic testing of evertor and invertor muscles in patients with chronic ankle instability

Ankle sprains are among the most common sport-related injuries and can lead to chronic ankle instability. Impaired sensorimotor function of the ankle musculature is often suggested as a cause. The current study sought to assess and compare the isokinetic performance and electromyographic patterns of evertor and invertor muscles in patients with chronic ankle instability and in a control group. Twelve patients with chronic ankle instability and twelve healthy subjects were included. Isokinetic eccentric and concentric testing at various angular velocities was performed for eversion and inversion movements. The corresponding myoelectric activities of the fibularis longus and tibialis anterior muscles were quantified from surface electromyographic recordings by computing average root mean square values. Patients had lower myoelectric activity of the evertor and invertor muscles than controls did; this difference could account for the eccentric weakness associated with ankle instability. Functional strength ratios revealed a dynamic strength imbalance in unstable ankle patients and that may contribute to recurrent injury. Our findings suggest that rehabilitation programs for unstable ankle patients must be focused on the motor control of eccentric contractions of the ankle evertors and invertors, to boost these muscles' contribution to ankle stabilization.

Instrumentos de avaliação para limitações funcionais associadas à instabilidade crônica de tornozelo: uma revisão sistemática da literatura

A instabilidade de tornozelo é definida como a sua tendência para sofrer falseios e entorses de repetição após a ocorrência de entorse lateral. Como a presença de instabilidade é definida por meio das queixas relatadas pelo indivíduo, apresenta caráter subjetivo, sendo importante identificar o melhor instrumento de avaliação para a determinação de sua presença e/ou gravidade. O objetivo deste estudo foi revisar, de forma sistemática, instrumentos de avaliação concebidos para pacientes com instabilidade crônica de tornozelo. Foram realizadas pesquisas bibliográficas nas bases de dados PubMed, Embase, BVS, LILACS e SciELO para identificar os instrumentos elegíveis. No total, seis estudos foram incluídos e apresentaram cinco instrumentos diferentes - Foot and Ankle Disability Index (FADI), Ankle Joint Functional Assessment Tool (AJFAT), Foot and Ankle Ability Measure (FAAM), Ankle Joint Functional Assessment Tool (AII) e Cumberland Ankle Instability Tool (CAIT). Foram encontrados instrumentos com qualidade que detectam limitações funcionais em indivíduos com instabilidade crônica de tornozelo, não sendo instrumentos válidos para diagnóstico de instabilidade. O CAIT mostrou-se a ferramenta mais completa, mas não foi validada em uma população específica de indivíduos com condição de instabilidade do tornozelo. Observa-se a necessidade de mais estudos clinimétricamente válidos a fim de atestar a sua validade para se obter uma ferramenta eficaz e completa da instabilidade funcional do tornozelo.

Changes in biomechanics and muscle activation in injured ballet dancers during a jump-land task with turnout (Sissonne Fermée)

Large impact loading with abnormal muscle activity and motion patterns may contribute to lower extremity injuries in ballet dancers. Yet, few studies investigated the influence of injury on the ballet movement. The purpose of this study was to find the neuromuscular and biomechanical characteristics in dancers with and without ankle injury during a jump-landing Sissonne Fermée task. Twenty-two ballet dancers were recruited and divided into the injured group (n = 11) and the uninjured group (n = 11). They performed a ballet movement called "Sissonne Fermée" with reflective markers and electrodes attached to their lower extremities. Ground reaction force, joint kinematics, and muscle activity were measured. The injured dancers had greater peak ankle eversion but smaller hindfoot-to-tibial eversion angles. Also, the injured dancers had greater activity of the hamstring of the dominant leg and tibialis anterior of the non-dominant leg during the pre-landing phase. The injured dancers had greater tibialis anterior activity of the dominant leg but less muscle activity in the medial gastrocnemius of the non-dominant leg during the post-landing phase. The injured dancers had a greater co-contraction index in the non-dominant ankle and a lower loading rate. The higher co-contraction indices showed that the injured dancers required more muscle effort to control ankle stability. Furthermore, the injured dancers used a "load avoidance strategy" to protect themselves from re-injury. Neuromuscular control training of the ankle joint for ballet dancers to prevent injury is necessary.

Dynamic ankle control in athletes with ankle instability during sports maneuvers

BACKGROUND

Ankle sprain is a common sports injury. While the effects of static constraints in stabilizing the ankle joint are relatively well understood, those of dynamic constraints are less clear and require further investigation.

PURPOSE

This study was undertaken to evaluate the dynamic stability of the ankle joint during the landing phase of running and stop-jump maneuvers in athletes with and without chronic ankle instability (CAI).

STUDY DESIGN

Controlled laboratory study.

METHODS

Fifteen athletes with CAI and 15 age-matched athletes without CAI performed running and stop-jump landing tasks. The dynamic ankle joint stiffness, tibialis anterior (TA)/peroneus longus (PL) and TA/gastrocnemius lateralis (GL) co-contraction indices, ankle joint angle, and root-mean-square (RMS) of the TA, PL, and GL electromyographic signals were measured during each task.

RESULTS

During running, the CAI group exhibited a greater ankle inversion angle than the control group in the pre-landing phase (P = .012-.042) and a lower dynamic ankle joint stiffness in the post-landing phase (CAI: 0.109 ± 0.039 N·m/deg; control: 0.150 ± 0.068 N·m/deg; P = .048). In the stop-jump landing task, athletes with CAI had a significantly lower TA/PL co-contraction index during the pre-landing phase (CAI: 49.1 ± 19; control: 64.8 ± 16; P = .009). In addition, the CAI group exhibited a greater ankle inversion (P = .049), a lower peak eversion (P = .04), and a smaller RMS of the PL electromyographic signal in the post-landing phase (CAI: 0.73 ± 0.32; control: 0.51 ± 0.22; P = .04).

CONCLUSION

Athletes with CAI had a relatively inverted ankle, reduced muscle co-contraction, and a lower dynamic stiffness in the ankle joint during the landing phase of sports maneuvers and this may jeopardize the stability of the ankle.

CLINICAL RELEVANCE

Sports training or rehabilitation programs should differentiate between the pre-landing and post-landing phases of sports maneuvers, and should educate athletes to land with an appropriate ankle position and muscle recruitment.

Kinematics, kinetics, and electromyogram of ankle during drop landing: a comparison between dominant and non-dominant limb

The biomechanical difference between the dominant and non-dominant limb has seldom been studied during double-leg landing. The objective of this study was to evaluate the effectiveness of limb laterality on the ankle kinematics, kinetics and electromyogram (EMG) during drop landing. Sixteen healthy adults were recruited and dropped individually from platforms with three different heights (0.32 m, 0.52 m, and 0.72 m). The ground reaction force, ankle joint kinematics, and surface EMG of tibialis anterior (TA) and lateral gastrocnemius (LG) were measured in both lower extremities. Two-way analysis of variance was used to analyze the effects of laterality and dropping height. The peak angular velocities in dorsiflexion and abduction were significantly higher in the dominant ankle, whereas the pre- and post-landing EMG amplitudes of the TA were significantly higher in the non-dominant limb. Compared with the dominant side, the non-dominant ankle has a more effective protective mechanism in that excessive joint motion is restrained by greater ankle flexor activity. Compared with the non-dominant side, the dominant ankle joint is in greater injury risk during drop landing, and data measured in the dominant limb may produce more conservative conclusions for injury protection or prediction.

Altered leg muscle activity in volleyball players with functional ankle instability during a sideward lateral cutting movement

OBJECTIVES

To study the activation patterns of tibialis anterior, peroneus longus and gastrocnemius lateralis muscles during a lateral shuffle maneuver in volleyball players with functional instability of the ankle joint.

DESIGN

Observational case-control study.

SETTING

Research laboratory.

PARTICIPANTS

Sixteen players with functional instability and 18 matched controls.

MAIN OUTCOME MEASURES

RMS values of tibialis anterior, peroneus longus and gastrocnemius lateralis muscles for the 50 ms before initial ground contact, timing of onset of muscle activity and linear envelopes for the period of ground contact were calculated.

RESULTS

Onset values showed similar patterns of activation for both groups. In healthy subjects, gastrocnemius lateralis activated earlier, followed by peroneus longus and tibialis anterior. In the unstable subjects, gastrocnemius lateralis and peroneus longus activated at the same time, followed by tibialis anterior. Unstable subjects also presented lower peroneus longus activity during the 50 ms before initial ground impact, a lower peroneus longus peak magnitude and a higher gastrocnemius lateralis peak magnitude.

CONCLUSIONS

Volleyball players with ankle functional instability showed decreased peroneus longus activity before ground impact that may predispose them to repetitive sprains and explain their "giving way" sensation, since peroneus longus is the main ankle evertor and an important stabilizer against sudden and excessive inversion.

Effects of muscular activation patterns on the ankle joint stabilization: An investigation under different Degrees of Freedom

Altered biomechanical demands of a stabilization task lead to specific changes in coordination patterns among the involved muscles. The objective of this work was to investigate the effects of increased Degrees of Freedom (DoF) of an external object on the stabilization process of the ankle joint in a voluntary force production task. Four muscles (vastus medialis, VM; tibialis anterior, TA; peroneus longus, PL; gastrocnemius medialis, GM) were recorded using surface electromyography and synchronized to dynamometric data. The subject's task was to exert force against the external object by performing a knee extension under 0, 1 or 3 DoF. Forces were measured using three dimensional force transducers and temporal coordination was assessed using the cross-correlation function (CCF). While the force decreased with increasing DoF the muscles showed a selective gain scaling in order to stabilize the ankle joint. Muscles fulfilling mainly stabilizing functions (TA and PL) tended to increase their activities, while the muscles with motor functions either decreased (GM) or increased (VM). The CCF revealed different intermuscular coordination strategies depending on the environmental condition, showing an advanced phasing in the ankle stabilizing PL in unstable environmental conditions (3 DoF). Nevertheless, the overall sequence of muscle activation was preserved. It is concluded that the process of joint stabilization is controlled in dependency of the status of the external system. The associated neuromuscular system adjustments underline the role of movement coordination in the stabilization process.

Chronic ankle instability alters central organization of movement

BACKGROUND

Chronic ankle instability alters spinal level sensorimotor function and is hypothesized to alter supraspinal motor control mechanisms. Gait initiation is a functional task modulated by supraspinal pathways, but the effect of chronic ankle instability, a peripheral musculoskeletal impairment, on gait initiation and thus supraspinal motor control mechanisms remains unknown.

PURPOSE

This study was conducted to determine if supraspinal aspects of motor control are altered in subjects with chronic ankle instability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Subjects with chronic ankle instability (5 males, 15 females; age, 20.5 +/- 1.0 years; height, 169.8 +/- 9.8 cm; weight, 74.2 +/- 20.2 kg) and uninjured controls (4 males, 16 females; age, 20.85 +/- 1.6 years; height, 164.3 +/- 7.9 cm; weight, 64.2 +/- 10.62 kg) completed 5 gait initiation trials for each leg at a self-selected pace. The resulting trajectory of the center of pressure trace was investigated and peak center of pressure excursions in the anteroposterior and mediolateral directions, peak resultant center of pressure excursions, and average direction-specific velocities were calculated.

RESULTS

Significant group x limb interactions were noted during the first (resultant center of pressure displacement [F(1,37) = 4.60, P = .04]) and second (mediolateral center of pressure displacement [F(1,37) = 3.82, P = .05]) period of gait initiation. Center of pressure displacement was reduced (impaired) in the involved limb of the chronic ankle instability group (resultant, 0.29 +/- 0.02; mediolateral, 0.72 +/- 0.02) relative to the uninvolved limb of the chronic ankle instability group (resultant, 0.32 +/- 0.02; mediolateral, 0.76 +/- 0.02) and both limbs of the control group (resultant, 0.32 +/- 0.02; mediolateral, 0.74 +/- 0.02) when the involved limb of the chronic ankle instability group served as the initial stance limb.

CONCLUSION

These interactions suggest that supraspinal motor control mechanisms are altered in subjects with chronic ankle instability to place a greater emphasis on reducing the postural demands on the involved limb.

CLINICAL RELEVANCE

These changes suggest that supraspinal adaptations to motor control may be an important contributor to the underlying neurophysiologic mechanism of chronic ankle instability. The presence of supraspinal adaptations in subjects with chronic ankle instability also indicates that health care providers and rehabilitation specialists treat chronic ankle instability as a global/central and not just a local/peripheral injury.