A systematic review on ankle injury and ankle sprain in sports

Individuals with chronic ankle instability exhibit decreased postural sway while kicking in a single-leg stance

Individuals with chronic ankle instability (CAI) usually experience deficits in balance control, which increase displacement in the body's center of pressure (COP) when they balance on a single leg. Little is known, however, about whether or not these individuals use the strategies of postural adjustment properly, especially during functional tasks that may predispose them to ankle sprain. The aim of this study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments in individuals with and without CAI as they kick a ball while standing in a single-leg stance with their ankle in neutral and supinated positions. COP displacements were calculated and their magnitudes (range) analyzed during APA and CPA intervals and over the duration of the whole task, represented by the COP area of sway and mean velocity. The CAI group exhibited a significant decrease in CPA and area of sway over the whole task, relative to controls. These results suggest that the decreased balance sway could be caused by the need for further stabilization of the ankle in more unstable postures to prevent recurrent sprain. Our findings could help clinicians to better understand the strategies of postural adjustments in individuals with CAI, and may assist and motivate new investigations into balance control interventions in such individuals, as well as proactively address recurrent ankle sprain conditions.

Health care consumption and costs due to foot and ankle injuries in the Netherlands, 1986-2010

Background

Foot and ankle injuries account for a large proportion of Emergency Department attendance. The aim of this study was to assess population-based trends in attendances due to foot and ankle injuries in the Netherlands since 1986, and to provide a detailed analysis of health care costs in these patients.

Methods

Age- and gender-standardized emergency attendance rates and incidence rates for hospital admission were calculated for each year of the study. Injury cases and hospital length of stay were extracted from the National Injury Surveillance System (non-hospitalized patients) and the National Medical Registration (hospitalized patients). Data were grouped into osseous and ligamentous injuries for foot and ankle separately. An incidence-based cost model was applied to calculate associated direct health care costs.

Results

Since 1986 the overall emergency attendance rate decreased from 858 to 640 per 100,000 person years. In non-admitted patients (90% of cases), ligamentous injuries approximately halved, whereas osseous injuries increased by 28% (foot) and 25% (ankle). The incidence rate for hospital admission increased by 35%, mainly due to an almost doubling of osseous injuries. Attendance rates showed a peak in adolescents and adults until ~45 years of age in males and (less pronounced) in females. The total number of hospital days decreased to 58,708 days in 2010. Hospital length of stay (HLOS) increased with age and was highest for osseous injuries. HLOS was unaffected by gender, apart for longer stay in elderly females with an osseous ankle injury. Health care costs per case were highest for osseous injuries of the ankle (€ 3,461). Costs were higher for females and increased with age to € 6,023 in elderly males and € 10,949 in elderly females. Main cost determinants were in-hospital care (56% of total costs), rehabilitation/nursing care (15%), and physical therapy (12%).

Conclusions

Since 1986, the emergency attendance rate of foot and ankle injuries in the Netherlands decreased by 25%. Throughout the years, the attendance rate of (relatively simple) ligamentous injuries strongly reduced, whereas osseous injuries nearly doubled. Attendance rates and health care costs were gender- and age-related. Main cost determinants were in-hospital care, rehabilitation/nursing care, and physical therapy.

Postural Control Characteristics during Single Leg Standing of Individuals with a History of Ankle Sprain: Measurements Obtained Using a Gravicorder and Head and Foot Accelerometry

[Purpose] This study aimed to validate the postural control characteristics of individuals with a history of ankle sprain during single leg standing by using a gravicorder and head and foot accelerometry. [Subjects] Twenty subjects with and 23 subjects without a history of ankle sprain (sprain and control groups, respectively) participated. [Methods] The anteroposterior, mediolateral, and total path lengths, as well as root mean square (RMS) of each length, were calculated using the gravicorder. The anteroposterior, mediolateral, and resultant acceleration of the head and foot were measured using accelerometers and were evaluated as the ratio of the acceleration of the head to the foot. [Results] There was no significant difference between the two groups in path length or RMS acceleration of the head and foot. However, the ratios of the mediolateral and resultant components were significantly higher in the sprain group than in the control group. [Conclusion] Our findings suggest that individuals with a history of ankle sprain have a higher head-to-foot acceleration ratio and different postural control characteristics than those of control subjects.

Arthroscopic synovectomy in the treatment of functional ankle instability: outcomes and gait analysis

BACKGROUND

Natural consequence of repetitive ankle sprains is the chronic ankle instability. Objective of this study was to clarify the gait patterns of functional ankle instability (FAI) patients after arthroscopic synovectomy, but also assessment of postoperative recovery.

PATIENTS AND METHODS

Arthroscopic synovectomy was performed to 14 FAI patients with history of unilateral repetitive ankle sprains, pain, and subjective sensation of instability. At a mean 54 months of follow-up (27-84), clinical assessment was conducted with respect to pain, number of ankle sprains, and American Orthopaedics Foot and Ankle Society (AOFAS) scores. Gait analysis was conducted to determine the temporospatial, kinetic and kinematic parameters at the last follow-up.

RESULTS

Mean AOFAS scores increased from 68 (range 55-75) to 89 (range 77-100) points (P < 0.01). Mean ankle sprains was 13 in a period of 23 (range 14-48) months (0.58 per month) and decreased to three sprains in a mean time period of 54 months (0.053 per month) (P < 0.01). Mean preoperative and postoperative VAS scores were 8.0 and 2.9, respectively (P < 0.01). During gait analysis, no significant differences were found in ankle joint, including foot progression angles, ankle dorsi-plantar flexion degrees and ground reaction forces (P > 0.01). Among temporospatial parameters, only double support time showed a significant difference (P < 0.01). All patients were satisfied from the procedure and returned to their previous activity level.

CONCLUSION

Improved long-term clinical results and scores were obtained in our patient group when compared with the preoperative scores. Also, three-dimensional gait analysis showed that the involved ankles demonstrate similar gait patterns to the uninvolved ankles in patients with FAI.

Ankle position affects dorsalis pedis artery exposure in anterior ankle arthroscopy

BACKGROUND

In anterior ankle arthroscopy, the anterior working area (AWA) is restricted by the presence of the dorsalis pedis artery (DPA) and tendons. Pseudoaneurysms caused by iatrogenic damage to the DPA are difficult to identify intraoperatively. In knee arthroscopy, risk of popliteal artery damage is reduced in the flexed position [1]. This study investigates how DPA movement is affected by dorsiflexion and plantarflexion with the aim of identifying the positions providing the greatest AWA.

METHODS

Twelve cadaveric ankles were dissected to access the DPA. While distracted, ankles were progressively dorsiflexed at 5° intervals from maximum plantarflexion. DPA and tibialis anterior tendon (TA) movement at each 5° interval was measured by their respective distances from the inferior border of the medial malleolus.

RESULTS

Mean ankle dorsiflexion was 24.58±1.30° with all specimens showing anterior DPA and TA movement as dorsiflexion increased. Mean DPA and TA movement at maximum dorsiflexion was 3.58±0.29mm and 2.92±0.34mm respectively. A ratio of 1:1.23 relates TA and DPA movement (inmm), and a ratio of 10:1.46 relates dorsiflexion angle to DPA movement (inmm).

CONCLUSION

Anterior movement of the dorsalis pedis artery during dorsiflexion increases the AWA for anterior arthroscopy. Increasing the AWA with maximal dorsiflexion may prove to be a valuable method for lowering the risk of iatrogenic DPA damage. Additionally, increased AWA may allow the use of larger diameter surgical instruments allowing greater control and a reduction in operation time.

Neuromuscular control during stepping down in continuous gait in individuals with and without ankle instability

Ankle sprains are a common injury and those affected are at a risk of developing chronic ankle instability (CAI). Complications of an acute sprain include increased risk of re-injury and persistent disability; however, the exact link between ankle sprains and chronic instability has yet to be elucidated. The purpose of this study was to investigate neuromuscular control (including kinematics, kinetics and EMG) during stepping down from a curb, a common yet challenging daily activity, in persons with ankle instability (n = 11), those with a history of ankle sprain without persistent instability, called ankle sprain "copers" (CPRs) (n = 9) and uninjured controls (CTLs) (n = 13). A significant group difference was noted as the CPR group demonstrated increased tibialis anterior activity in both the preparatory (pre-touchdown) and reactive (post-touchdown) phases when compared to healthy and unstable groups (P < 0.05). It follows that the CPR group also demonstrated a significantly less plantar-flexed position at touchdown than the other two groups (P < 0.05). This is a more stable position to load the ankle and this strategy differed from that used by participants with CAI and uninjured CTLs. These findings provide insight into the neuromuscular control strategies of CPRs, which may allow them to more appropriately control ankle stability following sprains.

Eccentric/concentric training of ankle evertor and dorsiflexors in recreational athletes: muscle latency and strength

The aim of this study was to investigate the effects of a combined eccentric-concentric exercise program of the ankle evertors and dorsiflexors on the latency time of the peroneus longus and tibialis anterior muscles. Twenty-four healthy male recreational athletes were admitted to this study and were randomly assigned to either the exercise group (n = 12) or the control group (n = 12). Subjects in the exercise group performed an isokinetic exercise program of the ankle evertors and dorsiflexors in a combined eccentric-concentric mode for 3 days per week for 6 weeks. Before and after the exercise program, muscle reaction times of the peroneus longus and tibialis anterior muscles to sudden supinating maneuvers on a tilting platform, and isokinetic strength of the ankle joint musculature were evaluated. The peroneus longus and tibialis anterior reaction times showed significant (P < 0.01-0.05) reductions following six weeks of intervention in the exercise group. Additionally, eccentric peak torques for the ankle evertor and dorsiflexors represented significant (P < 0.05) increases in the exercise group compared with the control group. The results of this study suggest that it is possible to reduce peroneal and anterior tibial reaction times following a six week eccentric/concentric isokinetic training program in healthy ankles.

In vivo kinematics of the talocrural and subtalar joints during weightbearing ankle rotation in chronic ankle instability

BACKGROUND

Chronic ankle instability (CAI) results in abnormal ankle kinematics, but there exists limited quantitative data characterizing these alterations. This study was undertaken to investigate kinematic alterations of the talocrural and subtalar joints in CAI.

METHODS

A total of 14 male patients with unilateral CAI (mean age = 21.1 ± 2.5 years) were enrolled. Computed tomography and fluoroscopic imaging of both lower extremities during weightbearing passive ankle joint complex (AJC) rotation were obtained. Three-dimensional bone models created from the computed tomography images were matched with the fluoroscopic images to compute the 6 degrees-of-freedom talocrural, subtalar, and AJC kinematics.

RESULTS

In 20° plantarflexion, ankles with CAI demonstrated significantly increased anterior translation of the talocrural joint during AJC internal rotation from 5° to 7° and significantly decreased talocrural internal rotation within an AJC arc of motion from -1° to 5°. CAI joints demonstrated significantly increased internal rotation of the subtalar joint within an AJC arc of motion from -1° to 3°.

DISCUSSION

In CAI, altered subtalar internal rotation occurs with increased talocrural anterior translation and reduced talocrural internal rotation during weightbearing ankle internal rotation in plantarflexion. These results suggest that altered subtalar mechanics may contribute to CAI symptoms.

Exercise and ankle sprain injuries: a comprehensive review

Ankle sprains are common in team sports and sports played on courts, and often result in structural and functional alterations that lead to a greater reinjury risk. Specific exercises are often used to promote neuromuscular improvements in the prevention and rehabilitation of ankle injuries. This literature review summarizes the neuromuscular characteristics of common ankle sprains and the effectiveness of exercise as an intervention for improving neuromuscular function and preventing reinjury. Our review found that appropriate exercise prescription can increase static and dynamic balance and decrease injury recurrence. In particular, the addition of dynamic activities in the exercise program can be beneficial because of the anticipatory postural adjustments identified as a key factor in the injury mechanism.

Prevalence of chronic ankle instability in high school and division I athletes

OBJECTIVE

The purpose of this study was to determine the prevalence of chronic ankle instability among high school and collegiate athletes.

DESIGN

Descriptive epidemiological survey.

METHODS

Athletes from four high schools and a division I university were contacted to participate. For collegiate athletes, a questionnaire packet was distributed during preparticipation physicals. For high school athletes, parental consent was obtained and then questionnaires were distributed during preparticipation physicals, parent meetings, or individual team meetings. All athletes completed the Cumberland Ankle Instability Tool for both their left and right ankles. Subjects also provided general demographic data and completed the Ankle Instability Instrument regarding history of lateral ankle sprains and giving way. Athletes were identified as having chronic ankle instability if they scored less than 24 on the Cumberland Ankle Instability Tool.

RESULTS

Of the 512 athletes who completed and returned surveys, 23.4% were identified as having chronic ankle instability. High school athletes were more likely to have chronic ankle instability than their collegiate counterparts (P < .001). Chronic ankle instability was more prevalent among women than among men in both high school (P = .01) and collegiate settings (P = .01).

CONCLUSIONS

Findings of this study revealed differences in the distribution of chronic ankle instability that warrant further study.

Implementation of an app-based neuromuscular training programme to prevent ankle sprains: a process evaluation using the RE-AIM Framework

BACKGROUND/AIM

The contemporary electronic media is regarded as a practical tool in the dissemination of preventive measures and interventions. For this purpose an App (free of charge) was developed including an efficacious programme for the prevention of ankle sprain recurrences. This study evaluated the implementation effectiveness of this 'Versterk je Enkel' App.

METHODS

The App was evaluated within its practical context using the Reach Effectiveness Adoption Implementation Maintenance (RE-AIM) Framework. The launch of the App was accompanied by a press release, website banners, as well as online and offline advertisements. Data for the evaluation of the App were objectively registered through Google analytics. Data were obtained in February 2013 based on 25,781 users resulting in follow-ups of 18 months (iOS version) and 15 months (Android version), respectively. Users questionnaires provided a qualitative view of the objectively assessed measures (n=82) to gain insight into the demographics of users, reasons to download, user experience and how the information was used.

RESULTS

The App reached only 2.6% of the projected target population. User ratings for the App's relevancy, clarity, usefulness, appeal, information and reliability were high. App usage indicates that compliance with the embedded programme was low.

CONCLUSIONS

Although the App was well received by the users, targeted efforts are required to ensure proper uptake and usage of the App by the target population. This also holds true for eHealth and mHealth efforts aimed at athlete care and injury prevention in general.

Ankle kinematics and muscle activity in functional ankle instability

OBJECTIVE

Following an ankle injury, many patients have functional ankle instability (FAI) with an increased predisposition to reinjury. The purpose of this study was to assess the effects of FAI on ankle kinematics and muscle activity during a lateral hop movement.

DESIGN

Cross-sectional and observational study; all data collection for each subject was performed on 1 day.

SETTING

Clinical biomechanics laboratory.

PATIENTS

Two groups were studied: (1) Control group-no ankle injury (n = 12), and (2) FAI group (n = 12).

INTERVENTIONS

The lateral hop movement consisted of multiple lateral and medial 1-legged hops over an obstacle (width, 72.5 cm; depth, 25.5 cm; height, 14.3 cm) onto adjacent force platforms. Each subject was instructed to perform as many lateral hops as possible during the 6-second trial. Means, SDs, 95% confidence intervals of the differences, and P-values were calculated.

MAIN OUTCOME MEASURES

Ankle kinematics and muscle activity throughout the lateral hop movement.

RESULTS

Significant differences existed between groups for mean (SD) dorsiflexion ankle positions--FAI 82.4 degrees (6.4) versus normal 75.2 degrees (10.1) and tibialis anterior normalized muscle activity--FAI 0.27 (0.21) versus normal 0.16 (0.13) at ground contact.

CONCLUSIONS

The FAI group revealed greater tibialis anterior muscle activity and dorsiflexion ankle position at contact moving in the lateral direction. These differences between groups may have been related to an inherent predisposition to ankle injuries, a preexisting difference in task performance, a consequence of injuries, or a compensatory adaptation to previous injuries.

Predictive factors for ankle syndesmosis injury in football players: a prospective study

OBJECTIVES

Up to 25% of all ankle injuries involve the ankle syndesmosis and factors that increase risk have yet to be investigated prospectively. This study aimed to identify predictors of ankle syndesmosis injury in football players.

DESIGN

A prospective study.

METHODS

Rugby Union and Australian Football League players were recruited during 2010. Rugby League and different Rugby Union players were recruited during 2011. Baseline data collection included: age, body size, flexibility, strength and balance. Bivariate correlations were performed between all predictors. Variables with r ≥ 0.7 had only one variable entered in further analysis. Remaining predictor variables were analysed for association with the presence/absence of ankle syndesmosis injury. Variables with non-significant association with injury (p>0.2) were included in a backward step-wise Cox regression model.

RESULTS

202 male participants aged 21 ± 3.3 years (mean ± SD) were recruited of whom 12 (5.9%) sustained an ankle syndesmosis injury. The overall incidence rate was 0.59/1000 h sport participation for Rugby Union and Rugby League. Australian Football League training data was not available. No significant predictors were identified; however, participants who sustained an injury during the season performed a higher vertical jump (63.6 ± 8.2 cm) and greater Star Excursion Balance Test reach (80.5 ± 5.3 cm), than participants who did not sustain an injury: 59.1 ± 7.8 cm for Vertical Jump and 77.9 ± 6.1 cm for Star Excursion Balance Test. This was normalised for height.

CONCLUSIONS

Variables such as age, body size, foot posture, flexibility and muscle strength did not increase risk of ankle syndesmosis injury. Jump height and balance performance may play a role in predicting ankle syndesmosis sprains.

A Comparison of the Foot and Ankle Condition between Elite Athletes and Non-athletes

[Purpose] The purpose of this study was to compare the foot and ankle condition between elite athletes and non-athletes. [Subjects] The elite athletes group included 85 subjects (28 males and 57 females) and the non-athletes group included 85 subjects (38 males and 47 females). [Methods] All subjects were evaluated for pain (visual analogue scale, VAS) and foot and ankle condition (The Foot and Ankle Disability Index, FADI, and The Foot and Ankle Outcome Score, FAOS). [Results] The elite athlete group showed significant differences from the non-athletes group in VAS, FADI (FADI, FADI-Sports), and FAOS (FAOS-symptoms, FAOS-pain, FAOS-ADL, FAOS-sports, FAOS-QoL). In addition, a meaningful difference in VAS, FADI-Sports, and FAOS-symptoms was observed between gymnasts and wrestlers. [Conclusion] The results of this study suggest the necessity prevention of injury to the foot and ankle of elite athletes, and for the development of exercise for the rehabilitation of foot and ankle injuries, because there is a difference in foot and ankle condition between elite athletes and non-athletes.

Relationship between stress ankle radiographs and injured ligaments on MRI

OBJECTIVE

This study was performed to investigate the relationship between the injured lateral ankle ligaments on MRI and stress ankle radiographs.

MATERIALS AND METHODS

Two hundred and twenty-nine consecutive patients (mean age 35.5 years, SD 14.6 years; 136 males and 93 females) that underwent ankle stress radiographs and MRI for lateral ankle instability were included. Tibiotalar tilt angle and anterior translation of talus were measured on stress ankle radiographs. Degree of lateral ligaments (anterior talofibular, calcaneofibular, and posterior talofibular) and deltoid ligament injuries were evaluated and scored as intact (0), partial injury (1), and complete injury (2) on MR images. Effusion of ankle joint was also recorded. The effects of gender, age, injuries of ligaments, and ankle joint effusion on stress radiographs were statistically analyzed.

RESULTS

Gender (p = 0.010), age (p = 0.020), and anterior talofibular ligament (ATFL) injury (p < 0.001) were the factors significantly affecting tibiotalar tilt angle. Posterior talofibular ligament (PTFL) injury (p = 0.014) was found to be the only significant factor affecting the anterior translation on the anterior drawer radiographs.

CONCLUSIONS

ATFL injury and PTFL injury on MRI significantly affected tibiotalar tilt angle and anterior drawer on stress radiographs. Other factors, such as age and gender, need to be considered in evaluating radiographic lateral ankle instability.

Measuring Ankle Instability in Pediatric Charcot-Marie-Tooth Disease

Children with Charcot-Marie-Tooth disease frequently suffer ankle sprain and experience chronic ankle instability; however, no pediatric self-reported measures of chronic ankle instability exist. The aim was to modify and validate the most reliable measure of chronic ankle instability in adults: the Cumberland Ankle Instability Tool. The Cumberland Ankle Instability Tool-Youth was tested for reliability, construct validity, and sensitivity to discriminate between 104 children aged 8 to 16 years: 31 children with Charcot-Marie-Tooth disease, 31 unaffected children with a history of ankle sprains, and 42 controls. Children with Charcot-Marie-Tooth disease had lower scores compared to unaffected children with a history of sprains (χ2 = 15.10; P < .001) and controls (χ2 = 33.69; P < .001). Scores moderately correlated to visual analog scale scores of ankle steadiness (r s = 0.684; P < .001), and "good" test-retest reliability was identified (ICC2,1 = 0.73). The Cumberland Ankle Instability Tool-Youth demonstrated excellent sensitivity and construct validity, identifying chronic ankle instability as a common problem for children with Charcot-Marie-Tooth disease.

Design and Kinematic Analysis of Parallel Robot for Ankle Rehabilitation

Ankle injury is one of the most common injuries in sports or domestic related accidents. This injury can usually be treated via a number of rehabilitation exercises. However, currently rehabilitation of ankle injury directly depends of physiotherapy session administered by experts; which is tedious and expensive in nature. In this paper, we proposed a concept based on parallel mechanism to assist patients undergoing ankle rehabilitation procedures. This is due to a number of advantages of parallel mechanism as compared to serial mechanism higher payload-to-weight ratio, structure rigidity, accuracy and relatively simple solution. We reported our design process; including the concept generation and selection according to a number of relevant design parameters. After which, followed by embodiment design involving kinematic analysis of the proposed mechanism. The findings, in terms of conceptual design and kinematic analysis should be able to provide an insight for ankle rehabilitation based on suitable parallel mechanism.

Aquatic training for ankle instability

The aim of the present study was to evaluate balance deficits after an ankle sprain in collegiate students and to examine the effectiveness of 2 different balance rehabilitation programs on balance ability. Thirty collegiate students with functional ankle instability were randomly divided into 2 groups. Both groups followed an intervention balance program for 6 weeks, 3 times per week, 20 minutes per session, using balance boards. One of the 2 training groups performed the exercises on the ground-the "Land" group (n = 15), and the other in a swimming pool-the "Aquatic" group (n = 15). Balance ability was assessed before and after the 6-week intervention program. Balance assessments included static (stability indices: total, anterior-posterior, medial-lateral) and dynamic (dynamic moving the cursor) stability tests on the Biodex Stability System (Biodex, Inc, Shirley, NY). The results showed that in both training groups balance ability of the injured leg was significantly improved after the training period. In the final measurements, no statistically significant differences between the injured and healthy limb were found. The present study indicates that the performance of balance exercises in or out of water by collegiate students with functional ankle instability improves their balance ability.

LEVEL OF EVIDENCE

Therapeutic, Level 1.

Traumeel vs. diclofenac for reducing pain and improving ankle mobility after acute ankle sprain: a multicentre, randomised, blinded, controlled and non-inferiority trial

BACKGROUND

Acute ankle sprains are common and activity limiting injuries, and topical diclofenac gel has proven efficacy in alleviating pain and restoring function. This trial aimed to compare a topical natural agent, Traumeel with topical diclofenac gel (1%) in the management of acute ankle sprain.

METHODS

This prospective, multicentre, randomised, blinded, active-control and non-inferiority study involved 449 physically active adults sustaining unilateral grade 1 or 2 ankle sprain within the past 24 h. Participants were randomised to receive 2 g of Traumeel ointment (T-O) (n = 152) or Traumeel gel (T-G) (n = 150) or diclofenac gel (D-G) (n = 147), administered topically to the ankle three times a day for 14 days, with 6-weeks follow up.

RESULTS

Day 7 median percentage reductions in Visual Analogue Scale pain score were 60.6%, 71.1% and 68.9% for the T-O, T-G and D-G groups, respectively. Total pain relief was reported by 12 (8.5%), 7 (5.0%) and 8 (5.9%) participants in each group, respectively. Median improvements in Foot and Ankle Ability Measure Activities of Daily Living subscale score were 26.2, 26.2 and 25.0 points for T-O, T-G and D-G groups, respectively. Mann-Whitney effect sizes and lower bound confidence intervals demonstrated non-inferiority of Traumeel vs. diclofenac for reducing pain and functional improvement. At 6 weeks, participants reported total pain relief and normal functioning. Adverse events (n = 43) were reported by 31/447 participants (6.9%). Treatments were equally well tolerated.

CONCLUSIONS

T-O and T-G decreased pain and improved joint function to the same extent as D-G in acute ankle sprain, and were well tolerated.

Joint mobilization acutely improves landing kinematics in chronic ankle instability

PURPOSE

The objective of this study is to examine the acute effect of ankle joint mobilizations akin to those performed in everyday clinical practice on sagittal plane ankle joint kinematics during a single-leg drop landing in participants with chronic ankle instability (CAI).

METHODS

Fifteen participants with self-reported CAI (defined as <24 on the Cumberland Ankle Instability Tool) performed three single-leg drop landings under two different conditions: 1) premobilization and, 2) immediately, postmobilization. The mobilizations performed included Mulligan talocrural joint dorsiflexion mobilization with movement, Mulligan inferior tibiofibular joint mobilization, and Maitland anteroposterior talocrural joint mobilization. Three CODA cx1 units (Charnwood Dynamics Ltd., Leicestershire, UK) were used to provide information on ankle joint sagittal plane angular displacement. The dependent variable under investigation was the angle of ankle joint plantarflexion at the point of initial contact during the drop landing.

RESULTS

There was a statistically significant acute decrease in the angle of ankle joint plantarflexion from premobilization (34.89° ± 4.18°) to postmobilization (31.90° ± 5.89°), t(14) = 2.62, P < 0.05 (two-tailed). The mean decrease in the angle of ankle joint plantarflexion as a result of the ankle joint mobilization was 2.98° with a 95% confidence interval ranging from 0.54 to 5.43. The eta squared statistic (0.32) indicated a large effect size.

CONCLUSION

These results indicate that mobilization acted to acutely reduce the angle of ankle joint plantarflexion at initial contact during a single-leg drop landing. Mobilization applied to participants with CAI has a mechanical effect on the ankle joint, thus facilitating a more favorable positioning of the ankle joint when landing from a jump.

Eminence-based medicine versus evidence-based medicine: when can the athlete with a sprained ankle return to play?

When can the athlete with a sprained ankle to return to play? The medical literature provides no definitive answer to this question, so we surveyed 500 experts in sports medicine, and asked them if they agree with the following statement: "For patients with an acute ankle injury, the ability to hop on the sidelines is sufficient evidence to allow the athlete to return to the field." Overall, the experts did not endorse this statement. Further, a review of the medical literature failed to lend support for the statement. Taken together, some level V (expert opinion) evidence emerges, namely, that a patient's ability to successfully complete the hop test is not necessarily sufficient evidence to allow a return to play. That finding does not mean that a physician must shun the test; rather, the conclusion is that it cannot be relied on in isolation. The hop test, used in context with other findings, along with a consideration of the risks and benefits of continued play, may help the physician on the field reach a reasonable conclusion. To date, however, there is no single, easily applied test that can correctly determine whether an athlete is safe to return to the field.

How much does the human medial gastrocnemius muscle contribute to ankle torques outside the sagittal plane?

Ankle movements in the frontal plane are less prominent though not less relevant than movements in the plantar or dorsal flexion direction. Walking on uneven terrains and standing on narrow stances are examples of circumstances likely imposing marked demands on the ankle medio-lateral stabilization. Following our previous evidence associating lateral bodily sways in quiet standing to activation of the medial gastrocnemius (MG) muscle, in this study we ask: how large is the MG contribution to ankle torque in the frontal plane? By arranging stimulation electrodes in a selective configuration, current pulses were applied primarily to the MG nerve branch of ten subjects. The contribution of populations of MG motor units of progressively smaller recruitment threshold to ankle torque was evaluated by increasing the stimulation amplitude by fixed amounts. From smallest intensities (12–32 mA) leading to the firstly observable MG twitches in force-plate recordings, current pulses reached intensities (56–90 mA) below which twitches in other muscles could not be observed from the skin. Key results showed a substantial MG torque contribution tending to rotate upward the foot medial aspect (ankle inversion). Nerve stimulation further revealed a linear relationship between the peak torque of ankle plantar flexion and inversion, across participants (Pearson R > .81, p < .01). Specifically, regardless of the current intensity applied, the peak torque of ankle inversion amounted to about 13% of plantar flexion peak torque. Physiologically, these results provide experimental evidence that MG activation may contribute to stabilize the body in the frontal plane, especially under situations of challenged stability.

The efficacy of manual joint mobilisation/manipulation in treatment of lateral ankle sprains: a systematic review

BACKGROUND

Lateral ankle sprains are common and can have detrimental consequences to the athlete. Joint mobilisation/manipulation may limit these outcomes.

OBJECTIVE

Systematically summarise the effectiveness of manual joint techniques in treatment of lateral ankle sprains.

METHODS

This review employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A computer-assisted literature search of MEDLINE, CINHAL, EMBASE, OVID and Physiotherapy Evidence Database (PEDro) (January 1966 to March 2013) was used with the following keywords alone and in combination 'ankle', 'sprain', 'injuries', 'lateral', 'manual therapy', and 'joint mobilisation'. The methodological quality of individual studies was assessed using the PEDro scale.

RESULTS

After screening of titles, abstracts and full articles, eight articles were kept for examination. Three articles achieved a score of 10 of 11 total points; one achieved a score of 9; two articles scored 8; one article scored a 7 and the remaining article scored a 5. Three articles examined joint techniques for acute sprains and the remainder examined subacute/chronic ankle sprains. Outcome measures included were pain level, ankle range of motion, swelling, functional score, stabilometry and gait parameters. The majority of the articles only assessed these outcome measures immediately after treatment. No detrimental effects from the joint techniques were revealed in any of the studies reviewed.

CONCLUSIONS

For acute ankle sprains, manual joint mobilisation diminished pain and increased dorsiflexion range of motion. For treatment of subacute/chronic lateral ankle sprains, these techniques improved ankle range-of-motion, decreased pain and improved function.

Exercise intensity progression for exercises performed on unstable and stable platforms based on ankle muscle activation

Ankle sprains are a common sports injury. The literature focuses on the application of neuromuscular training for the improvement of balance, injury prevention and rehabilitation. However, there is a dearth of knowledge about the appropriate prescription of exercises using unstable platforms and surfaces. The purpose of this study was to devise an ankle rehabilitation or training program with exercise progression based on the extent of muscle activation, employing platforms with different levels of stability and additional resistance. A descriptive study of electromyography (EMG) during ankle exercises was performed with a convenience sample of healthy subjects. Forty-four subjects completed 12 exercises performed in a random order. Exercises were performed unipedally or bipedally with or without elastic tubing as resistance on various unstable (uncontrolled multiaxial and uniaxial movement) and stable surfaces. Surface EMG from the tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) were collected to quantify the amount of muscle activity. Significant differences were found between exercise conditions for PL (p<.001), TA (p=.011), and SOL (p<.001). The greatest EMG activity for all muscles occurred with an upright unipedal stance on a soft stability surface with resistance. The least EMG activity for the TA and SOL were in a seated position and for the PL in an erect bipedal position without resistance. Based on the level of ankle muscle activation, exercises for the ankle should progress from bilateral exercises on exercise balls (lowest intensity), to a unipedal position on a soft surface in combination with elastic tubing (highest intensity) in order to achieve progressively greater ankle muscle activation.

Differences in lateral drop jumps from an unknown height among individuals with functional ankle instability

CONTEXT

Functional ankle instability (FAI) is a debilitating condition that has been reported to occur after 20% to 50% of all ankle sprains. Landing from a jump is one common mechanism of ankle injury, yet few researchers have explored the role of visual cues and anticipatory muscle contractions, which may influence ankle stability, in lateral jumping maneuvers.

OBJECTIVE

To examine muscle-activation strategies between FAI and stable ankles under a lateral load and to evaluate the differences in muscle activation in participants with FAI and participants with stable ankles when they were unable to anticipate the onset of lateral loads during eyes-open versus eyes-closed conditions.

DESIGN

Case-control study.

SETTING

Controlled laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

A total of 40 people participated: 20 with FAI and 20 healthy, uninjured, sex- and age-matched persons (control group).

INTERVENTION(S)

Participants performed a 2-legged lateral jump off a platform onto a force plate set to heights of 35 cm or 50 cm and then immediately jumped for maximal height. They performed jumps in 2 conditions (eyes open, eyes closed) and were unaware of the jump height when their eyes were closed.

MAIN OUTCOME MEASURE(S)

Amplitude normalized electromyographic (EMG) area (%), peak (%), and time to peak in the tibialis anterior (TA), peroneus longus (PL), and lateral gastrocnemius (LG) muscles were measured.

RESULTS

Regardless of the eyes-open or eyes-closed condition, participants with FAI had less preparatory TA (t158 = 2.22, P = .03) and PL (t158 = 2.09, P = .04) EMG area and TA (t158 = 2.45, P = .02) and PL (t158 = 2.17, P = .03) peak EMG than control-group participants.

CONCLUSIONS

By removing visual cues, unanticipated lateral joint loads occurred simultaneously with decreased muscle activity, which may reduce dynamic restraint capabilities in persons with FAI. Regardless of visual impairment and jump height, participants with FAI exhibited PL and TA inhibition, which may limit talonavicular stability and intensify lateral joint surface compression and pain.

Lateral ankle instability in high-demand athletes: reconstruction with fibular periosteal flap

PURPOSE

Fibular periosteal flaps have been used to address chronic lateral ankle instability, but there are no studies in the literature reporting functional outcomes after this particular procedure in high-demand athletes. We postulated that for chronic instability, nonanatomical reconstruction of the lateral ankle ligament with a fibular periosteal flap will return high-demand athletes to their previous levels of activity.

METHODS

Forty patients who had grade III ankle sprain and experienced no success after a course of supervised conservative management lasting at least six months and who had a preinjury Tegner score of ≥ 6 underwent a lateral compartment reconstruction with a fibular periosteal flap. Each patient was given the Tegner and Karlsson questionnaire and was evaluated by the Zwipp method, Foot and Ankle Outcome Score (FAOS) and the American Orthopaedic Foot and Ankle Society (AOFAS) score at the six-month, one, two and three-year time points. Range of motion (ROM) of the affected ankle was assessed, and stress X-rays were performed. Mean patient age was 24.5 (range17-30) years, and no patient was lost to follow-up.

RESULTS

Mean follow-up was 36 (minimum 18) months, mean Tegner scores at the one, two and three-year time points were 8.8, 8.9 and 8.9, respectively, and mean Karlsson scores were 93 ± 5.2, 95 ± 3.1 and 94.9, respectively. AOFAS and FAOS scores improved from a mean of 69.4 and 71.4, respectively, in the preoperative group to a mean of 97.2 and 94.4, respectively, at the last follow-up. The ROM was equal to the contralateral ankle in all but two patients at the two-year follow-up. No major complications were found.

CONCLUSION

Nonanatomical ligament reconstruction with a fibular periosteal flap for chronic lateral ankle instability was effective in returning high-demand athletes to their preinjury functional levels.

Therapeutic interventions for increasing ankle dorsiflexion after ankle sprain: a systematic review

CONTEXT

Clinicians perform therapeutic interventions, such as stretching, manual therapy, electrotherapy, ultrasound, and exercises, to increase ankle dorsiflexion. However, authors of previous studies have not determined which intervention or combination of interventions is most effective.

OBJECTIVE

To determine the magnitude of therapeutic intervention effects on and the most effective therapeutic interventions for restoring normal ankle dorsiflexion after ankle sprain.

DATA SOURCES

We performed a comprehensive literature search in Web of Science and EBSCO HOST from 1965 to May 29, 2011, with 19 search terms related to ankle sprain, dorsiflexion, and intervention and by cross-referencing pertinent articles.

STUDY SELECTION

Eligible studies had to be written in English and include the means and standard deviations of both pretreatment and posttreatment in patients with acute, subacute, or chronic ankle sprains. Outcomes of interest included various joint mobilizations, stretching, local vibration, hyperbaric oxygen therapy, electrical stimulation, and mental-relaxation interventions.

DATA EXTRACTION

We extracted data on dorsiflexion improvements among various therapeutic applications by calculating Cohen d effect sizes with associated 95% confidence intervals (CIs) and evaluated the methodologic quality using the Physiotherapy Evidence Database (PEDro) scale.

DATA SYNTHESIS

In total, 9 studies (PEDro score = 5.22 ± 1.92) met the inclusion criteria. Static-stretching interventions with a home exercise program had the strongest effects on increasing dorsiflexion in patients 2 weeks after acute ankle sprains (Cohen d = 1.06; 95% CI = 0.12, 2.42). The range of effect sizes for movement with mobilization on ankle dorsiflexion among individuals with recurrent ankle sprains was small (Cohen d range = 0.14 to 0.39).

CONCLUSIONS

Static-stretching intervention as a part of standardized care yielded the strongest effects on dorsiflexion after acute ankle sprains. The existing evidence suggests that clinicians need to consider what may be the limiting factor of ankle dorsiflexion to select the most appropriate treatments and interventions. Investigators should examine the relationship between improvements in dorsiflexion and patient progress using measures of patient self-reported functional outcome after therapeutic interventions to determine the most appropriate forms of therapeutic interventions to address ankle-dorsiflexion limitation.

Effects of fatiguing treadmill running on sensorimotor control in athletes with and without functional ankle instability

BACKGROUND

Sensorimotor control is permanently impaired following functional ankle instability and temporarily decreased following fatigue. Little is known on potential interactions between both conditions. The purpose was to investigate the effect of fatiguing exercise on sensorimotor control in athletes with and without (coper, controls) functional ankle instability.

METHODS

19 individuals with functional ankle instability, 19 ankle sprain copers, and 19 non-injured controls participated in this cohort study. Maximum reach distance in the star excursion balance test, unilateral jump landing stabilization time, center of pressure sway velocity in single-leg-stance, and passive ankle joint position sense were assessed before and immediately after fatiguing treadmill running. A three factorial linear mixed model was specified for each outcome to evaluate the effects of group, exhausting exercise (fatigue) and their interactions (group by fatigue). Effect sizes were calculated as Cohen's d.

FINDINGS

Maximum reach distance in the star excursion balance test, jump stabilization time and sway velocity, but not joint position sense, were negatively affected by fatigue in all groups. Effect sizes were moderate, ranging from 0.27 to 0.68. No significant group by fatigue interactions were found except for one measure. Copers showed significantly larger prefatigue to postfatigue reductions in anterior reach direction (P≤0.001; d=-0.55) compared to the ankle instability (P=0.007) and control group (P=0.052).

INTERPRETATION

Fatiguing exercise negatively affected postural control but not proprioception. Ankle status did not appear to have an effect on fatigue-induced sensorimotor control impairments.

Comparison of bone tunnel and suture anchor techniques in the modified Broström procedure for chronic lateral ankle instability

BACKGROUND

The modified Broström procedure is frequently used to treat chronic lateral ankle instability. There are 2 common methods of the modified Broström procedure, which are the bone tunnel and suture anchor techniques.

PURPOSE

To compare the clinical outcomes of the modified Broström procedure using the bone tunnel and suture anchor techniques.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Eighty-one patients (81 ankles) treated with the modified Broström procedure for chronic lateral ankle instability constituted the study cohort. The 81 ankles were divided into 2 groups, namely, a bone tunnel technique (BT group; 40 ankles) and a suture anchor technique (SA group; 41 ankles). The Karlsson score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, anterior talar translation, and talar tilt angle were used to evaluate clinical and radiographic outcomes. The BT group consisted of 32 men and 8 women with a mean age of 34.8 years at surgery and a mean follow-up duration of 34.2 months. The SA group consisted of 33 men and 8 women with a mean age of 33.3 years at surgery and a mean follow-up duration of 32.8 months.

RESULTS

Mean Karlsson scores improved significantly from 57.0 points preoperatively to 94.9 points at final follow-up in the BT group and from 59.9 points preoperatively to 96.4 points at final follow-up in the SA group. Mean AOFAS scores also improved from 64.2 points preoperatively to 97.8 points at final follow-up in the BT group and from 70.3 points preoperatively to 97.4 points at final follow-up in the SA group. Mean anterior talar translations in the BT group and SA group improved from 9.0 mm and 9.2 mm preoperatively to 6.5 mm and 6.8 mm at final follow-up, respectively. Mean talar tilt angles were 12.0° in the BT group and 12.5° in the SA group preoperatively and 8.8° at final follow-up for both groups. No significant differences were found between the 2 groups in terms of the Karlsson score, AOFAS score, anterior talar translation, and talar tilt angle.

CONCLUSION

The bone tunnel and suture anchor techniques of the modified Broström procedure showed similar good functional and radiographic outcomes. Both techniques appear to be effective and reliable methods for the treatment of chronic lateral ankle instability.

Comparative analysis of inter- and intraligamentous distribution of sensory nerve endings in ankle ligaments: a cadaver study

BACKGROUND

The aim of this study was to analyze the inter-, intraligamentous, and side-related patterns of sensory nerve endings in ankle ligaments.

METHODS

A total of 140 ligaments from 10 cadaver feet were harvested. Lateral: calcaneofibular, anterior-, posterior talofibular; sinus tarsi: lateral- (IERL), intermediate-, medial-roots inferior extensor retinaculum, talocalcaneal oblique and canalis tarsi (CTL); medial: tibionavicular (TNL), tibiocalcaneal (TCL), superficial tibiotalar, anterior/posterior tibiotalar portions; syndesmosis: anterior tibiofibular. Following immunohistochemical staining, the innervation and vascularity was analyzed between ligaments of each anatomical complex, left/right feet, and within the 5 levels of each ligament.

RESULTS

Significantly more free nerve endings were seen in all ligaments as compared to Ruffini, Pacini, Golgi-like, and unclassifiable corpuscles (P ≤ .005). The IERL had significantly more free nerve endings and blood vessels than the CTL (P ≤ .001). No significant differences were seen in the side-related distribution, except for Ruffini endings in right TCL (P = .016) and unclassifiable corpuscles in left TNL (P = .008). The intraligamentous analysis in general revealed no significant differences in mechanoreceptor distribution.

CONCLUSIONS

The IERL at the entrance of the sinus tarsi contained more free nerve endings and blood vessels, as compared to the deeper situated CTL. Despite different biomechanical functions in the medial and lateral ligaments, the interligamentous distribution of sensory nerve endings was equal.

CLINICAL RELEVANCE

The intrinsic innervation patterns of the ankle ligaments provides an understanding of their innate healing capacities following injury as well as the proprioception properties in postoperative rehabilitation.

National Athletic Trainers' Association position statement: conservative management and prevention of ankle sprains in athletes

OBJECTIVE

To present recommendations for athletic trainers and other allied health care professionals in the conservative management and prevention of ankle sprains in athletes.

BACKGROUND

Because ankle sprains are a common and often disabling injury in athletes, athletic trainers and other sports health care professionals must be able to implement the most current and evidence-supported treatment strategies to ensure safe and rapid return to play. Equally important is initiating preventive measures to mitigate both first-time sprains and the chance of reinjury. Therefore, considerations for appropriate preventive measures (including taping and bracing), initial assessment, both short- and long-term management strategies, return-to-play guidelines, and recommendations for syndesmotic ankle sprains and chronic ankle instability are presented.

RECOMMENDATIONS

The recommendations included in this position statement are intended to provide athletic trainers and other sports health care professionals with guidelines and criteria to deliver the best health care possible for the prevention and management of ankle sprains. An endorsement as to best practice is made whenever evidence supporting the recommendation is available.

Efficacy and safety of diclofenac diethylamine 2.32% gel in acute ankle sprain

BACKGROUND

Topical diclofenac diethylamine (DDEA) 2.32% gel achieves lasting efficacy in localized pain with two applications per day, while maintaining the favorable safety profile of topical diclofenac and potentially improving convenience and patient compliance.

METHODS

This randomized double-blind controlled study enrolled patients with acute ankle sprain treated with DDEA 2.32% gel two times per day (bid) (n = 80) or three times per day (tid) (n = 80) or placebo (n = 82). Efficacy (including pain and swelling) and local tolerability were evaluated during 8 ± 1 d.

RESULTS

By day 5, the reduction in pain on movement (POM) (primary efficacy variable) with DDEA bid and tid (49.1 and 49.7 mm, respectively; 100-mm visual analog scale) was almost double that with placebo (25.4 mm) (P < 0.0001). In patients with severe baseline POM (≥ 80 mm), mean change in POM from baseline to day 5 with DDEA bid or tid was 30-40 mm greater than that with placebo, which was double the difference (15-20 mm) in patients with mild-moderate baseline POM (<80 mm). More than 70% of all DDEA patients experienced ≥ 50% reduction in POM between days 1 and 5 versus 21% of placebo patients (P < 0.0001). By study end (day 8), ankle swelling in patients treated with DDEA (0.3 cm) was one-third that in those treated with placebo (0.9 cm) (P < 0.0001), which had still not achieved the level of ankle joint function seen with DDEA on day 5 (P < 0.0001). At day 5, treatment satisfaction was "good" to "excellent" in almost 90% of DDEA patients but only "good" or "very good" in 23% of placebo patients (P < 0.0001). DDEA 2.32% gel was well tolerated.

CONCLUSIONS

DDEA 2.32% gel twice daily (applied in the morning and evening) was well tolerated and provided lasting relief from pain, improved function, and reduced symptomatic healing time in uncomplicated ankle sprain.

Management of acute lateral ankle ligament injury in the athlete

PURPOSE

Inversion injuries involve about 25 % of all injuries of the musculoskeletal system and about 50 % of these injuries are sport-related. This article reviews the acute lateral ankle injuries with special emphasis on a rationale for treatment of these injuries in athletes.

METHODS

A narrative review was performed using Pubmed/Medline, Ovid and Embase using key words: ankle ligaments, injury, lateral ligament, ankle sprain and athlete. Articles related to the topic were included and reviewed.

RESULTS

It is estimated that one inversion injury of the ankle occurs for every 10,000 people each day. Ankle sprains constitute 7-10 % of all admissions to hospital emergency departments. Inversion injuries involve about 25 % of all injuries of the musculoskeletal system, and about 50 % of these injuries are sport-related. The lateral ankle ligament complex consists of three ligaments: the anterior talofibular ligament, the calcaneofibular ligament and the posterior talofibular ligament. The most common trauma mechanism is supination and adduction (inversion) of the plantar-flexed foot.

CONCLUSION

Delayed physical examination provides a more accurate diagnosis. Ultrasound and MRI can be useful in diagnosing associated injury and are routine investigations in professional athletes. Successful treatment of grade II and III acute lateral ankle ligament injuries can be achieved with individualized aggressive, non-operative measures. RICE therapy is the treatment of choice for the first 4-5 days to reduce pain and swelling. Initially, 10-14 days of immobilization in a below the knee cast/brace is beneficial followed by a period in a lace-up brace or functional taping reduces the risk of recurrent injury. Acute repair of the lateral ankle ligaments in grade III injuries in professional athletes may give better results.

In vivo kinematics of the talocrural and subtalar joints with functional ankle instability during weight-bearing ankle internal rotation: a pilot study

Functional ankle instability (FAI) may involve abnormal kinematics. However, reliable quantitative data for kinematics of FAI have not been reported. The objective of this study was to determine if the abnormal kinematics exist in the talocrural and subtalar joints in patients with FAI. Five male subjects with unilateral FAI (a mean age of 33.4 ± 13.2 years) were enrolled. All subjects were examined with stress radiography and found to have no mechanical ankle instability (MAI). Lateral radiography at weight-bearing ankle internal rotation of 0° and 20° was taken with the ankle at 30° dorsiflexion and 30° plantar flexion. Patients underwent computed tomography scan at 1.0 mm slice pitch spanning distal one third of the lower leg and the distal end of the calcaneus. Three-dimensional (3D) kinematics of the talocrural and subtalar joints as well as the ankle joint complex (AJC) were determined using a 3D-to-2D registration technique using a 3D-to-2D registration technique with 3D bone models and plain radiography. FAI joints in ankle dorsiflexion demonstrated significantly greater subtalar internal rotation from 0° to 20° internal rotation. No statistical differences in plantar flexion were detected in talocrural, subtalar or ankle joint complex kinematics between the FAI and contralateral healthy joints. During ankle internal rotation in dorsiflexion, FAI joints demonstrated greater subtalar internal rotation. The FAI joints without mechanical instability presented abnormal kinematics. This suggests that abnormal kinematics of the FAI joints may contribute to chronic instability. FAI joints may involve unrecognized abnormal subtalar kinematics during internal rotation in ankle dorsiflexion which may contribute to chronic instability and frequent feelings of instability.

Epidemiology of U.S. high school sports-related ligamentous ankle injuries, 2005/06-2010/11

OBJECTIVE

Describe ankle injury epidemiology among US high school athletes in 20 sports.

DESIGN

Descriptive prospective epidemiology study.

SETTING

Sports injury data for the 2005/06 to 2010/11 academic years were collected using an Internet-based injury surveillance system, Reporting Information Online.

PARTICIPANTS

A nationwide convenience sample of US high schools.

ASSESSMENT OF RISK FACTORS

Injuries sustained as a function of sport and gender.

MAIN OUTCOME MEASURES

Ankle sprain rates and patterns, outcomes, and mechanisms.

RESULTS

From 2005/06 to 2010/11, certified athletic trainers reported 5373 ankle sprains in 17,172,376 athlete exposures (AEs), for a rate of 3.13 ankle sprains per 10,000 AEs. Rates were higher for girls than for boys (rate ratio [RR], 1.25; 95% confidence interval [CI], 1.17-1.34) in gender-comparable sports and higher in competition than practice for boys (RR, 3.42; 95% CI, 3.20-3.66) and girls (RR, 2.71; 95% CI, 2.48-2.95). The anterior talofibular ligament was most commonly injured (involved in 85.3% of sprains). Overall, 49.7% of sprains resulted in loss of participation from 1 to 6 days. Although 0.5% of all ankle sprains required surgery, 6.6% of those involving the deltoid ligament also required surgery. The athletes were wearing ankle braces in 10.6% of all the sprains. The most common injury mechanism was contact with another person (42.4% of all ankle sprains).

CONCLUSIONS

Ankle sprains are a serious problem in high school sports, with high rates of recurrent injury and loss of participation from sport.

Myoelectric stimulation on peroneal muscles with electrodes of the muscle belly size attached to the upper shank gives the best effect in resisting simulated ankle sprain motion

Ankle sprain is a common sports related injury that may be caused by incorrect positioning of the foot prior to and at initial contact during landing from a jump or gait. Furthermore a delayed reaction of the peroneal muscle may also contribute to the injury mechanism. A recent study demonstrated that myoelectric stimulation of the peroneal muscles within 15 ms of a simulated inversion event would significantly resist an ankle spraining motion. This study further investigated its effect with three different electrode sizes and three different lateral shank attachment positions. Twelve male subjects with healthy ankles performed simulated ankle supination spraining motion on a pair of mechanical sprain simulators. A pair of electrodes of one of the three sizes (large, medium, small) was attached to one of the three positions (upper 1/4, middle, lower 1/4) along the lateral shank to deliver an electrical signal of 130 V for 0.5s when the sprain simulator started. Ankle kinematics data were collected by a tri-axial gyroscope motion sensor and the peak inward heel tilting velocity was obtained to represent the effect in resisting the simulated ankle spraining motion. Repeated measures one-way analysis of variance was performed and showed a significant drop from 273.3 (control, no stimulation) to 215.8 deg/s (21%) when small electrodes were attached to the upper 1/4 position. Decrease was found in all other conditions but the drops (11-18%) were not statistically significant. The small electrodes used in this study fitted the width of the peroneal muscle belly at the upper 1/4 position, so the electrical current may have well flowed to the motor points of the muscles to initiate quick contraction.

Does Wearing a Prophylactic Ankle Brace During Drop Landings Affect Lower Extremity Kinematics and Ground Reaction Forces?

The objective of the study was to determine if prophylactic ankle bracing worn by females during landings produces abnormal lower extremity mechanics. Angular kinematic and ground reaction force (GRF) data were obtained for 16 athletically experienced females who performed brace and no-brace drop landings. The brace condition displayed reduced in/external rotation and flexion displacements about the ankle and knee joints and increased vertical and mediolateral GRF peak magnitudes and rate of vertical GRF application (pairedttest,P< .05). The ankle and knee joints landed in a less plantar flexed and more flexed position, respectively. No significant ab/adduction outcomes may have occurred due to interparticipant variability and/or a lack of brace restriction. Conclusion: During typical landings, this lace-up brace increases vertical GRF, decreases ankle and knee joint displacements of flexion and int/external rotation, but minimally affects ab/adduction displacements.

Reliability and consistency of plantarflexor stretch-shortening cycle function using an adapted force sledge apparatus

There are various limitations to existing methods of studying plantarflexor stretch-shortening cycle (SSC) function and muscle-tendon unit (MTU) mechanics, predominantly related to measurement validity and reliability. This study utilizes an innovative adaptation to a force sledge which isolates the plantarflexors and ankle for analysis. The aim of this study was to determine the sledge loading protocol to be used, most appropriate method of data analysis and measurement reliability in a group of healthy, non-injured subjects. Twenty subjects (11 males, 9 females; age: 23.5 ±2.3 years; height: 1.73 ±0.08 m; mass: 74.2 ±11.3 kg) completed 11 impacts at five different loadings rated on a scale of perceived exertion from 1 to 5, where 5 is a loading that the subject could only complete the 11 impacts using the adapted sledge. Analysis of impacts 4-8 or 5-7 using loading 2 provided consistent results that were highly reliable (single intra-class correlation, ICC > 0.85, average ICC > 0.95) and replicated kinematics found in hopping and running. Results support use of an adapted force sledge apparatus as an ecologically valid, reliable method of investigating plantarflexor SSC function and MTU mechanics in a dynamic controlled environment.