Exploring the Role of Sprint Biomechanics in Hamstring Strain Injuries: A Current Opinion on Existing Concepts and Evidence

Hamstring strain injuries are one of the most common injuries in sprint-based sports with the mechanism of injury considered the result of an interaction between applied mechanical strain and the capacity of the muscle to tolerate strain. To date, injury prevention and rehabilitation strategies have frequently focused on enhancing the capacity of the hamstrings to tolerate strain, with little consideration of factors directly influencing mechanical strain. Sprint running biomechanics are one factor proposed to influence the mechanical strain applied to the hamstrings that may be modified (towards reduced strain) within rehabilitation and injury prevention programs. This article aims to explore the theoretical mechanistic link between sprint running mechanics and hamstring strain injury, along with the available supporting evidence. In doing so, it hopes to provide practitioners with an understanding of mechanical parameters that may influence hamstring strain injury whilst also identifying areas for further research exploration.

E-health intervention for preventing recurrent ankle sprains: a randomised controlled trial in general practice

BACKGROUND

Ankle sprains are frequent injuries in general practice. However, no effective treatment is available yet.

AIM

To examine the effectiveness of an unsupervised e-health-supported neuromuscular training programme in combination with usual care compared with usual care alone in patients with acute lateral ankle sprains in general practice.

DESIGN AND SETTING

Randomised controlled trial with 1-year follow-up among patients (14-65 years) who visited the GP with an acute lateral ankle sprain within 3 weeks of injury.

METHOD

The intervention group received, in addition to usual care, an unsupervised e-health-supported neuromuscular training programme and the control group received usual care alone. The primary outcome was self-reported re-sprains during 52 weeks of follow-up. Secondary outcomes were ankle function, pain in rest and during activity, subjective recovery, and return to the same type and level of sport.

RESULTS

In total, 165 participants (mean age 38.3 years and 69 [41.8%] male) were included. No statistically significant difference in the occurrence of a re-sprain were found between the intervention 20.7% (17/82) and control group 24.1% (20/83) (hazard ratio 1.14, 95% confidence interval = 0.59 to 2.21). Also, no statistically significant differences in secondary outcomes were found between groups. The adherence rate to the programme was low (6.1%, 5/82).

CONCLUSION

The rate of re-sprains was relatively high and an unsupervised e-health-supported neuromuscular training programme does not yield meaningful effects and does not encourage adherence in preventing re-sprains in patients in general practice. More research is necessary to indicate the best treatment modality and way of delivery for these patients.

Obstacle Course Events: Hazards and Prevention Measures

This article reviews hazards associated with obstacle course events (OCEs) like the Spartan Race and Tough Mudder, which are becoming increasingly popular, and provides strategies to mitigate these hazards. In seven studies, the overall weighted incidence of participants seeking medical care during OCEs was only 1.4% with ~6% of these requiring higher level medical care at a hospital. Nonetheless, 27% of participants self-reported =1 extremity injury. Common OCE medical problems included sprains/strains and dermatological injuries (abrasions/laceration/blisters); the ankle and knee were common injury locations. There are reports microorganism infections during OCEs, associated with ingestion of contaminated water and mud. On military obstacle courses, ~5% were injured, but this activity has the highest injury rate (injuries/hour of training) of all major testing or training activities. Ankle sprain risk can be reduced with proprioceptive training and prophylactic ankle bracing. Knee injury risk can be reduced with exercise-based programs that incorporate various components of proprioceptive training, plyometrics, resistance exercises, stretching, and shuttle/bounding running. Reducing abrasions and lacerations involve wearing low friction clothing, gloves, and prophylactic covering of skin areas prone to abrasions/lacerations with specific protective materials. Reducing blister likelihood involves use of antiperspirants without emollients, specialized sock systems, and covering areas prone to blisters with paper tape. Reducing infections from microorganism can be accomplished by protective covering open wounds, rinsing off mud post-race, and avoiding ingestion of food and drink contaminated with mud. These chiefly evidence-based injury and illness prevention measures should minimize the risks associated with OCEs.

Strength Conditioning Program to Prevent Adductor Muscle Strains in Football: Does it Really Help Professional Football Players?

Coaches at the professional level are often concerned about negative side effects from testing and intensive resistance training periods, and they are not willing to base their training prescriptions on data obtained from semiprofessional or amateur football players. Consequently, the purpose of this study was to analyze the reliability and effectiveness of two adductor injury active prevention programs using the adductor/abductor ratio and deficit between legs, on the basis of adduction-abduction power output during the exercises proposed, in professional football players. Forty-eight professional football players undertook complementary strength training for the adductor and abductor muscles in their dominant and non-dominant legs, once or twice a week throughout the playing season. The volume of the session was determined by the adductor/abductor ratio and the deficit between legs in the last session training measured. The number and severity of muscle injuries per 1000 h of exposure were recorded. Both prevention programs showed a very low rate of adductor injury (0.27 and 0.07 injuries/1000 h) with mild-to-moderate severity, maintaining a balance in percentage asymmetry between dominant and non-dominant legs for adductor (10.37%) and in the adductor/abductor ratio (0.92) in top professional football players throughout the season. The strength conditioning program proposed can help to prevent adductor muscle injuries in top professional football players.

A syringe adapter for reduced muscular strain and fatigue

Workers in hospitals, clinics, and contract research organizations who repetitively use syringes have an increased risk for musculoskeletal disorders. This study developed and tested a novel syringe adapter designed to reduce muscle strain associated with repetitive fluid draws. Three syringe plunger extension methods (ring-finger, middle-finger, and syringe adapter) were studied across twenty participants. Electromyogram signals for the flexor digitorum superficialis and extensor digitorum muscles were recorded. The syringe adapter required 31% of the 90th percentile flexor muscle activity as compared to the ring-finger syringe extension method, and 45% the 90th percentile flexor muscle activity as compared to the middle-finger method (p < 0.001). The greatest differences were observed when the syringe was near full extension. Although the syringe adapter took more time than the other syringe extension methods (1.5 times greater), it greatly helped reduce physical stress associated with repetitive, awkward syringe procedures.

Content Validity of Level Two of the Royal Air Force Aircrew Conditioning Programme

INTRODUCTION

The prevalence of flight-related neck pain in all Royal Air Force (RAF) aircrew is 66% and 70% in UK fast-jet aircrew. The RAF Aircrew Conditioning Programme (ACP) has been designed to enhance pilot performance through reducing fatigue and strain injuries, particularly to the neck. Content validity of the ACP was assessed to determine the appropriateness for delivery to aircrew.

METHODS

Six international medical experts reviewed level two of the ACP, which is delivered to student aircrew who have completed basic instruction in cervical spine stability, core stability and initial technique instruction for strength training. Content validity on overall exercise approach (5 items) and specific exercise session (24 items) was rated on a 4-point Likert-type ordinal scale for Relevance and Simplicity. Four reviewers had experience of delivering an exercise program to aircrew. The item-content validity index (I-CVI) was the proportion of experts rating an item/exercise as acceptable (score 3-4) while protocol-CVI was the average I-CVI across items.

RESULTS

Of the suggested exercise sessions, 20 reached an excellent I-CVI (1.00) for Relevance (4 reached acceptable I-CVI (0.83)), and 21 reached an excellent I-CVI (1.00) for Simplicity (3 reached acceptable I-CVI (0.83)). Protocol-CVI for the ACP was excellent for Relevance (0.90) and good for Simplicity (0.83). The need for sufficient supervision during the exercises was recommended for safe exercise execution and to maintain adherence.

CONCLUSION

The ACP demonstrated excellent relevance for the target population. The aircrew require additional supervision with the more complex neck exercises to enhance simplicity with the ACP.Slungaard E, Green NDC, Newham DJ, Harridge SDR. Content validity of level two of the Royal Air Force Aircrew Conditioning Program. Aerosp Med Hum Perform. 2018; 89(10):896-904.

The effect of sensory-targeted ankle rehabilitation strategies on single-leg center of pressure elements in those with chronic ankle instability: A randomized clinical trial

OBJECTIVES

To determine the effects of sensory-targeted ankle rehabilitation strategies on laboratory-oriented measures of single-leg balance in those with chronic ankle instability.

DESIGN

Non-inferiority randomized controlled trial.

METHODS

Seventy-seven participants with self-reported chronic ankle instability were randomized into 4 treatment groups: Ankle joint mobilization, plantar massage, triceps surae stretching, and a control group. All participants performed 3 trials of single-leg balance on a force plate with eyes open and closed at 3 time points (baseline, immediately after the first treatment, and following 6 treatments over 2 weeks). The spatial (standard deviation), temporal (velocity), and spatiotemporal (time-to-boundary) elements of center of pressure excursions in single-leg balance were evaluated with eyes open and eyes closed at each time point. Immediate and final change scores were calculated for each group from the baseline values on these variables.

RESULTS

Joint mobilization produced immediate improvements in the temporal elements with eyes open and closed that exceeded the minimum detectable changes for these measures. Plantar massage and triceps surae stretching also enhanced the temporal element after a single treatment, but only with eyes closed. No substantial benefit of any of the interventions were found after 2-weeks of treatment, regardless of treatment group.

CONCLUSIONS

Sensory-targeted ankle rehabilitation strategies substantially improve single-leg postural control after one treatment, but these changes are short-lived. Future research is needed to determine whether combinations of sensory-targeted ankle rehabilitation strategies with other therapeutic interventions potentially improve single-leg balance stability in those with CAI compared to use in isolation.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01541657.

The effectiveness of proprioceptive and neuromuscular training compared to bracing in reducing the recurrence rate of ankle sprains in athletes: A systematic review and meta-analysis

BACKGROUND

Ankle sprains are common musculoskeletal injuries in which the ligaments of the ankle partially or completely tear due to sudden stretching.

OBJECTIVES

To critically appraise, evaluate and establish the best available evidence to determine the effectiveness of proprioceptive and neuromuscular training (PNT) compared to bracing in reducing the recurrence rate of ankle sprains in athletes.

METHODOLOGY

The following seven databases were searched in June 2017: PubMed, Cochrane Library, PEDro, ScienceDirect, Scopus, SPORTDiscus, EBSCO Host: CINAHL. The main search terms used were "ankle sprains", "proprioceptive training", "neuromuscular training" and "bracing". The quality of the trials were critically appraised according to the PEDro scale. The RevMan 5© software was used to pool results.

RESULTS

Three studies met the inclusion criteria and the quality according to the PEDro scale ranged from 4/10-7/10. The pooled data showed no difference between PNT and bracing in reducing the recurrence rate of ankle sprains in athletes at 12 months after initiation of the study.

CONCLUSION

This systematic review of the overall effect suggested that current evidence (Level II) does not favour the use of PNT over bracing in reducing the recurrence rate of ankle sprains. Physiotherapists are advised to use either PNT or bracing according to the patients preference and their own expertise.

Improvement of Functional Ankle Properties Following Supplementation with Specific Collagen Peptides in Athletes with Chronic Ankle Instability

Following an initial ankle sprain it is not unlikely that chronic ankle instability (CAI) will develop. CAI is associated with impaired perceived functional and mechanical properties of the ligaments. Nutritional supplementation with collagen peptides has been shown to improve the functional and mechanical properties of the connective tissue. The purpose of this study was to investigate the effectiveness of specific collagen peptide supplementation (SCP) to improve ankle stability in athletes with CAI. 50 male and female athletes with CAI completed a randomized, double-blinded and placebo-controlled study with a daily oral administration of either 5 g SCP or 5 g placebo (Maltodextrin) over a period of six months. Both, the Cumberland Ankle Instability Tool (CAIT) and the German version of the Foot and Ankle Ability Measure (FAAM-G) were used to measure the subjective perceived function of the ankle. Additionally, the mechanical stability was determined by measuring the ankle stiffness by an ankle arthrometer. Finally, a three-month follow-up was performed. ANOVA analysis indicated that the subjective ankle stability was improved in both the CAIT (p < 0.001) and the FAAM-G (p < 0.001) following SCP supplementation compared with placebo. No significant changes between the groups were detected in the results of the ankle arthrometer. After six month the subjective report of the ankle stability function significantly improved and the three month follow-up revealed a significant decline in the number of ankle joint injuries (p < 0.05). These data support the concept that specific collagen peptide supplementation in athletes with chronic ankle instability results in significant improvements in subjective perceived ankle stability. The reduction in the re-injury rate of ankle sprains in the follow-up period suggests that these findings have clinical relevance.

Experimental evaluation of a novel robotic hospital bed mover with omni-directional mobility

Bed pushing during patient transfer is one of the most physically demanding and yet common tasks in the hospital setting. Powered bed movers have been increasingly introduced to hospitals to reduce physiological strains on the users. This study introduces and quantifies the manpower efficiency and health benefits of a novel robotic-assisted omni-directional hospital bed transporter (SESTO Bed Mover) in comparison with a conventional manual transport stretcher (Stryker Trauma Stretcher 1037) and a powered transport stretcher (HOSPIMEK HMPT 740), which has a fifth powered wheel providing power assistance only in the forward direction. A total of 14 subjects were recruited (7 porters and 7 students) and were tasked to complete a course within a controlled lab environment. It is concluded that the robotic bed mover is able to halve the required manpower to push hospital beds as compared to conventional bed pushing without any additional physiological strain, potentially improving efficiency by two-fold. Electromyography (EMG) patterns showed that users relied on the shoulder and back muscles in a fashion similar to conventional pushing, further confirming the intuitive drive of the robotic bed mover. Overall, the robotic bed mover shows reduced physical demands, less manpower required for patient transport and reduced back muscle activities, which strongly suggest health benefits for workers in the hospital.

The physiological effect of a 'climb assist' device on vertical ladder climbing

'Climb assist' claims to reduce strain when climbing ladders; however, no research has yet substantiated this. The purpose of this study was to assess the physiological and psychophysical effects of climb assist on 30 m ladder climbing at a minimum acceptable speed. Eight participants (six male and two female) climbed a 30 m ladder at 24 rungs per minute with and without climb assist, and were monitored for heart rate (HR), [Formula: see text]O₂ and rate of perceived exertion (RPE). All three variables decreased significantly (p < 0.05) with climb assist with [Formula: see text]O₂ decreasing by 22.5%, HR by 14.8% and RPE decreasing by a mean of 2.3 units on the 10-point Borg scale. When descending the ladder [Formula: see text]O₂ decreased by a mean of 42% compared to that ascending. At the minimal acceptable climbing speed climb assist decreases the physiological strain on climbers, as demonstrated by reduced [Formula: see text]O₂, HR and perceived exertion. Practitioner Summary: 'Climb assist' systems claim to reduce strain when climbing, however; no research has yet been published to substantiate this. A crossover study compared [Formula: see text]O₂, HR and RPE at a minimal acceptable climbing speed with and without climb assist. Climb assist significantly reduced all variables confirming it reduces strain when climbing.

Proprioceptive Training and Injury Prevention in a Professional Men's Basketball Team: A Six-Year Prospective Study

Single limb stance instability is a risk factor for lower extremity injuries. Therefore, the development of proprioception may play an important role in injury prevention. This investigation considered a professional basketball team for 6 years, integrating systematic proprioceptive activity in the training routine. The purpose was to assess the effectiveness of proprioceptive training programs based on quantifiable instability, to reduce ankle sprains, knee sprains, and low back pain through developing refined and long-lasting proprioceptive control. Fifty-five subjects were studied. In the first biennium (2004-2006), the preventive program consisted of classic proprioceptive exercises. In the second biennium (2006-2008), the proprioceptive training became quantifiable and interactive by means of electronic proprioceptive stations. In the third biennium (2008-2010), the intensity and the training volume increased while the session duration became shorter. Analysis of variance was used to analyze the differences in proprioceptive control between groups, years, and bienniums. Injury rates and rate ratios of injury during practices and games were estimated. The results showed a statistically significant reduction in the occurrence of ankle sprains by 81% from the first to the third biennium (p < 0.001). Low back pain showed similar results with a reduction of 77.8% (p < 0.005). The reduction in knee sprains was 64.5% (not significant). Comparing the third biennium with the level of all new entry players, proprioceptive control improved significantly by 72.2% (p < 0.001). These findings indicate that improvements in proprioceptive control in single stance may be a key factor for an effective reduction in ankle sprains, knee sprains, and low back pain.

Evaluating a prototype device designed to alleviate night vision goggle induced neck strain among military personnel

The purpose of this study was verify the design of a novel Helmet System Support Device (HSSD) that can be used by military aircrew to help intervene on and reduce the high prevalence of neck trouble. Twelve healthy participants repeated simulated helicopter aircrew tasks on 3 separate days. On each day they wore a different helmet configuration, where measures of performance, perceived demand/preference and muscular demand were recorded. The results showed that vigilance tasks were performed over 10% faster with the HSSD configuration compared to wearing the normal helmet configuration. Participants were able to maintain static (endurance) postures for 28% longer, and use of the HSSD helped to prevent neck muscle fatigue in the most demanding task. The results of this design verification study indicate that the HSSD may be a realistic, feasible near-term solution to intervene on the high prevalence of neck trouble among rotary-wing aircrew. Practitioner Summary: This paper verifies the effectiveness of the Helmet System Support Device (HSSD) as an on-body personal protective device to help control exposures associated with aircrew neck trouble. The HSSD reduced perceived demand, reduced cumulative muscle activity in select muscles and provided improved fatigue resistance, meeting its desired design objectives.

Sports and health: equivalence or contrariety

Playing sports is a widely known method of health promotion. Balanced exercise and diet are keys to healthy life. However, sports activities can cause different injuries, from joint to head injuries. Although head injuries cause a variety of acute and chronic disorders, they are often undertreated. There are 1.6 million injured people examined at emergency departments throughout Europe every year. In sports like boxing, football, soccer, hockey, handball, basketball and bicycling, head injuries occur at a frequency of 4% to 22%. Particularly significant are chronic difficulties that occur after recurrent head injuries, i.e. cognitive deficits and changes in electroencephalogram. Qualifications of professional personnel are insufficient for professional evaluation and treatment of head injuries. The best way for sports to become an important link in health and disease prevention is to go back to sports basics while using acquired scientific knowledge.

Effectiveness of powered hospital bed movers for reducing physiological strain and back muscle activation

Battery powered bed movers are becoming increasingly common within the hospital setting. The use of powered bed movers is believed to result in reduced physical efforts required by health care workers, which may be associated with a decreased risk of occupation related injuries. However, little work has been conducted assessing how powered bed movers impact on levels of physiological strain and muscle activation for the user. The muscular efforts associated with moving hospital beds using three different methods; powered StaminaLift Bed Mover (PBM1), powered Gzunda Bed Mover (PBM2) and manual pushing were measured on six male subjects. Fourteen muscles were assessed moving a weighted hospital bed along a standardized route in an Australian hospital environment. Trunk inclination and upper spine acceleration were also quantified. Powered bed movers exhibited significantly lower muscle activation levels than manual pushing for the majority of muscles. When using the PBM1, users adopted a more upright posture which was maintained while performing different tasks (e.g. turning a corner, entering a lift), while trunk inclination varied considerably for manual pushing and the PBM2. The reduction in lower back muscular activation levels may result in lower incidence of lower back injury.

[Study on effect of backrest thickness to lumbar muscle fatigue during computer work]

OBJECTIVE

To investigate the relationship between backrest thickness and lumbar muscle fatigue so as to confirm the fitting backrest thickness.

METHOD

Twenty subjects coming from university seated at a computer workstation in three backrest thicknesses: 4, 7 and 10 cm. The time that the subjects reported the lumbar muscle fatigue was collected during each trial and subjective appraise was collected at the end of the entire protocol.

RESULTS

The MF value decreased and lumbar muscle felt fatigue in all three backrest thickness. Subject could feel fatigue more late [(45.0 +/- 10.8) min] and subject felt more comfort at 7 cm thickness.

CONCLUSION

It is better to relive computer worker lumbar muscle fatigue when the backrest thickness was kept on 7 cm. Work break was needed because one hour work could cause muscle fatigue.

The impact of adherence on sports injury prevention effect estimates in randomised controlled trials: looking beyond the CONSORT statement

OBJECTIVE

To investigate estimated outcome effects of a sports injury prevention intervention when analysed by means of a per protocol (PP) analysis approach.

DESIGN

Randomised controlled trial (RCT) involving 522 athletes who sustained a lateral ankle sprain allocated to either an intervention (received a preventive programme in addition to usual care) or control group who were followed prospectively for one year.

METHODS

Secondary analysis of data relating to registered ankle sprain recurrences, exposure and adherence to the allocated intervention using a PP analysis approach.

RESULTS

Twenty-three percent of the RCT intervention group indicated to have fully adhered with the neuromuscular training programme. A per protocol analysis only considering fully adherent athletes and control athletes, showed a Hazard Ratio of 0.18 (95% CI: 0.07-0.43). Significantly fewer recurrent ankle sprains were found in the fully adherent group compared to the group that was not adherent (relative risk = 0.63; 95% CI: 0.43-0.99).

CONCLUSIONS

A PP analysis on fully adherent athletes versus control group athletes showed that the established intervention effect was over threefold higher compared to an earlier intention-to-treat based analysis approach. This shows that outcomes of intervention studies are heavily biased by adherence to the allocated intervention.

Assessing attitudes, beliefs and readiness for musculoskeletal injury prevention in the construction industry

The objectives are to determine attitudes and beliefs among construction workers and supervisors related to taking action to reduce musculoskeletal injuries (MSIs). "Action" stage of change was confirmed if workers in the last 6 months are continuing to take steps to reduce MSIs. Surveys (520 workers; 35% and 171 supervisors; 67%) revealed that more workers are concerned about MSIs (p<0.05) and are taking action to reduce MSIs (p<0.05) than supervisors. Workers taking action tended to be younger and less experienced than other workers (p=0.00). The final multivariate model showed those workers taking action were more likely to be mechanics and general laborers, to have experienced pain within the last week, to be involved in health and safety, to feel that changes aimed at reducing MSIs would be effective, and that injuries are due to adverse work conditions rather than with characteristics of individual workers. This information can be used to target ergonomics interventions in this industry.

[Latest standards of muscle injury prophylactic activities, treatment and rehabilitation]

Muscle injury represents the highest proportion of sport-linked contusions. Experimental and clinical studies aim at increasingly detailed recognition of muscle physiology and pathophysiology. It would allow to set up functional standards and permit to minimize risk of contusions associated with sport activities. In cases of such contusions it would restrict its sequele and would abbreviate the duration of treatment. In the study elements of prophylaxis, treatment and rehabilitation of injured muscles will be discussed, based on current scientific results. Review study includes data from studies investigating prophylactic activities, types of teratment and the effects of different rehabilitation strategy. Latest standards from First European Congress of Football Medicine, Munich 2004, were also taken into account. The prophylactic activities should focus on education attempting to popularize the knowledge of the role of warm-up activities which precede proper physical effort, muscle stretching and activities augmenting muscle strength. The treatment of muscle injury is related to the extent of their damage. First actions should be focused on the RICE principle (Rest, Ice, Compression, Elevation). In case of torn tissues, local injections of anesthetics, anti-inflammatory agents and regeneration-promoting agents used to be applied. Application of NSAIDs and anti-thrombotic prophylaxis is sound but due to their side effects it is recommended as frequently as it is counterindicated by physicians. A threshold in the therapy, not always noted by therapeutists, involves rapid mobilization of the injured tissue. This involves mobility exercises starting at 3-5 days post-trauma, with no load at the beginning, but starting at days 4 to 6 asssociated with appropriate loading. The recently conducted studies aim at stimulation of rapid muscle regeneration, inhibition of scar formation in the site of injury and elimination of already existing scars. The latter seems most difficult due to the high risk of the repeated muscle injury in the same site. The rehabilitation following trauma with particular attention paid to proprioceptive training is equally important. The risk of another contusion cannot be reduced to minimum until the pre-contusion proprioception level is achieved in the contused extremity.

Neck and back muscle loading in pilots flying high G(z) sorties with and without lumbar support

INTRODUCTION

Fighter pilots frequently encounter neck and back pain and injuries due to high G(z) loading. A lumbar support could diminish muscle strain in the lower back under G(z) loading and might also have a positive effect on cervical muscle strain, due to a more ergonomic sitting posture. The aim of this study was to determine the effects of individually adjusted lumbar supports on fighter pilots' neck and back muscle loadings.

METHODS

There were 11 Finnish Air Force pilots who acted as test subjects. They flew two basic air combat maneuvering sorties with and without the LS. The EMG activity of the sternocleidomastoid (SCM), cervical (CES), thoracic (TES), and lumbar erector spinae muscles (LES) were measured during these sorties, and the number and duration of EMG gaps was analyzed. Subjective experiences about the lumbar support were evaluated using a questionnaire.

RESULTS

In all measured muscles, mean percent maximal voluntary contraction (%MVC) was lower when the LS was used, yet these changes were not statistically significant. Individual differences in %MVC between flights diminished in the CES (9%), TES (7%), and LES (8%) with LS in use. There was also a tendency toward increased number of gaps in EMG activity when flying with the LS. According to questionnaire responses, the LS seems to relieve in-flight symptoms and reduce the fatigue in the lower back muscles. Not all subjects benefited from the LS, however.

CONCLUSION

There seems to be a tendency toward a lower muscle strain with the LS, but there are considerable individual differences.

The 2BFit study: is an unsupervised proprioceptive balance board training programme, given in addition to usual care, effective in preventing ankle sprain recurrences? Design of a randomized controlled trial

BACKGROUND

There is strong evidence that athletes have a twofold risk for re-injury after a previous ankle sprain, especially during the first year post-injury. These ankle sprain recurrences could result in disability and lead to chronic pain or instability in 20 to 50% of these cases. When looking at the high rate of ankle sprain recurrences and the associated chronic results, ankle sprain recurrence prevention is important.

OBJECTIVE

To evaluate the effect of a proprioceptive balance board training programme on ankle sprain recurrences, that was applied to individual athletes after rehabilitation and treatment by usual care.

METHODS/DESIGN

This study was designed as a randomized controlled trial with a follow-up of one year. Healthy individuals between 12 and 70 years of age, who were actively participating in sports and who had sustained a lateral ankle sprain up to two months prior to inclusion, were eligible for inclusion in the study. The intervention programme was compared to usual care. The intervention programme consisted of an eight-week proprioceptive training, which started after finishing usual care and from the moment that sports participation was again possible. Outcomes were assessed at baseline and every month for 12 months. The primary outcome of this study was the incidence of recurrent ankle injuries in both groups within one year after the initial sprain. Secondary outcomes were severity and etiology of re-injury and medical care. Cost-effectiveness was evaluated from a societal perspective. A process evaluation was conducted for the intervention programme.

DISCUSSION

The 2BFit trial is the first randomized controlled trial to study the effect of a non-supervised home-based proprioceptive balance board training programme in addition to usual care, on the recurrence of ankle sprains in sports. Results of this study could possibly lead to changes in practical guidelines on the treatment of ankle sprains. Results will become available in 2009.

TRIAL REGISTRATION

ISTRCN34177180.

The effectiveness of a balance training intervention in reducing the incidence of noncontact ankle sprains in high school football players

BACKGROUND

A high body mass index and previous ankle sprains have been shown to increase the risk of sustaining noncontact inversion ankle sprains in high school football players.

HYPOTHESIS

Stability pad balance training reduces the incidence of noncontact inversion ankle sprains in football players with increased risk.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Height, body mass, history of previous ankle sprains, and current ankle brace/tape use were documented at the beginning of preseason training in 2 high school varsity football teams for 3 consecutive years (175 player-seasons). Players were categorized as minimal risk, low risk, moderate risk, and high risk based on the history of previous ankle sprain and body mass index. Players in the low-, moderate-, and high-risk groups (ie, any player with a high body mass index and/or a previous ankle sprain) were placed on a balance training intervention on a foam stability pad. Players balanced for 5 minutes on each leg, 5 days per week, for 4 weeks in preseason and twice per week during the season. Postintervention injury incidence was compared with preintervention incidence (107 players-seasons) for players with increased risk.

RESULTS

Injury incidence for players with increased risk was 2.2 injuries per 1000 exposures (95% confidence interval, 1.1-3.8) before the intervention and 0.5 (95% confidence interval, 0.2-1.3) after the intervention (P < .01). This represents a 77% reduction in injury incidence (95% confidence interval, 31%-92%).

CONCLUSION

The increased risk of a noncontact inversion ankle sprain associated with a high body mass index and a previous ankle sprain was eliminated by the balance training intervention.

The placebo effect of ankle taping in ankle instability

PURPOSE

Recurrence of ankle sprains is common among athletes. Although ankle taping reduces the risk of injury, the mechanism underlying its effectiveness remains unclear. Anecdotal reports suggest a role of the belief among athletes that taping will protect them from injury. That is, taping may have a placebo effect. The purpose of the present study was to determine whether there was a placebo effect with ankle taping in individuals with ankle instability.

METHODS

Thirty participants with ankle instability completed a hopping test and a modified star excursion balance test under three conditions: (i) real tape, (ii) placebo tape, and (iii) control (no tape). Participants were blinded to the purpose of the study and were informed that the study aimed to compare two methods of ankle taping referred to as mechanical (real) and proprioceptive (placebo). The order of testing the three conditions and the two functional tests was randomized.

RESULTS

There was no significant difference in performance among the three conditions for the hopping test (P = 0.865) or the modified star excursion balance test (P = 0.491). However, a secondary exploratory analysis revealed that participants' perceptions of stability, confidence, and reassurance increased with both real and placebo ankle taping when performing the functional tasks.

CONCLUSION

The role of the placebo effect of ankle taping in individuals with ankle instability remains unclear. Clinicians should, therefore, continue to use ankle-taping techniques of known efficacy. They should, however, focus on maximizing patients' beliefs in the efficacy of ankle taping, because its application reassured participants and improved their perceived stability and confidence. The effect of ankle taping on participants' perceptions may contribute to its effectiveness in preventing injury.

Ankle sprain injuries: a 2-year prospective cohort study in female Greek professional basketball players

CONTEXT

Ankle sprains are a common basketball injury. Therefore, examination of risk factors for injury in female professional basketball players is worthwhile.

OBJECTIVE

To examine rates of ankle sprains, associated time missed from participation, and risk factors for injury during 2 consecutive seasons.

DESIGN

Prospective cohort study.

SETTING

Eighteen professional basketball facilities.

PATIENTS OR OTHER PARTICIPANTS

We observed 204 players from 18 female professional basketball teams for 2 consecutive seasons during a 2-year period.

MAIN OUTCOME MEASURE(S)

Using questionnaires, we recorded the incidence of ankle sprains, participation time missed, and mechanisms of injury in games and practice sessions. Potential risk factors, such as age, body mass, height, training experience, and history of ankle sprain, were examined using multivariate logistic regression.

RESULTS

Fifty of the 204 participants sustained ankle injuries; injuries included 32 ankle sprains, which translated to an ankle sprain rate of 1.12 per 1000 hours of exposure to injury. The 32 players missed 224.4 training and game sessions and an average of 7.01 sessions per injury. Most injuries occurred in the key area of the basketball court and were the result of contact. Injury rates during games were higher than injury rates during practice sessions. Centers, followed by guards and forwards, had the highest rate of injury. Players who did not wear an external ankle support had an odds ratio of 2.481 for sustaining an ankle sprain.

CONCLUSIONS

Female professional basketball athletes who did not wear an external ankle support, who played in the key area, or who functioned as centers had a higher risk for ankle sprain than did other players.

Comparison of 3 preventive methods to reduce the recurrence of ankle inversion sprains in male soccer players

BACKGROUND

Ankle sprains are frequent injuries in soccer. Several strategies can be used to prevent further ankle sprains in athletes: the most common are proprioceptive training, strength training, and orthoses.

OBJECTIVE

To investigate which of these 3 interventions is the most effective in preventing ankle sprains in athletes with previous ankle inversion sprain.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS AND MEASURES

Eighty male soccer players (age, 24.6 +/- 2.63 years; height, 175.60 +/- 4.36 cm; weight, 64.26 +/- 8.37 kg) in the first division of a men's league who had experienced previous ankle inversion sprain were randomly selected from an original population of 120 players. The subjects were individually and randomly assigned to 4 study groups: group 1 (n = 20) followed the proprioceptive program, group 2 (n = 20) followed the strength program, group 3 (n = 20) used orthoses, and group 4 (n = 20) was the control group. Data on the frequency of ankle sprain reinjury were collected at the end of the session.

RESULTS

There were no significant differences among the groups in the number of exposures. The incidence of ankle sprains in players in the proprioception training group was significantly lower than in the control group (relative risk of injury, 0.13; 95% confidence interval, 0.003-0.93; P = .02). The findings with respect to the strength and orthotic groups in comparison with the control group were not significant (relative risk of injury, 0.5; 95% confidence interval, 0.11-1.87; P = .27 for strength; relative risk of injury, 0.25; 95% confidence interval, 0.03-1.25; P = .06 for orthotic group).

CONCLUSION

Proprioceptive training, compared with no intervention, was an effective strategy to reduce the rate of ankle sprains among male soccer players who suffered ankle sprain.

Unloading reaction to electrical stimulation at neutral and supinated ankle positions

An unloading reaction has been characterized as a modified flexor reflex (FR), in which the standing subjects decrease the load on the stimulated foot and increase the load on the contralateral side, but, without withdrawal of the stimulated foot. Different behavioral circumstances have been shown to modulate this reflex. It is not known whether unloading reactions can be modulated with a loaded supinated ankle position, which, in excess, may result in an ankle sprain injury. Since ankle sprain depends on the load applied to a supinated foot, our premise is that unloading reactions may protect the ankle from a sprain injury. Therefore, this study investigated how the unloading reactions were modulated during a loaded supinated ankle condition. We delivered non-nociceptive and nociceptive electrical stimulations on the lateral aspect of the ankle in standing subjects with the foot in neutral and in a supinated position. The magnitude and latencies of reflex responses were registered using kinetic and kinematic analyses and subsequently compared among the conditions. The analysis demonstrated greater reactions for the supinated ankle condition. The individuals also moved their whole body downwards and shifted the body weight to the non-stimulated foot. Therefore, this study suggested that a modified type of the classic flexion reflex, i.e., unloading reaction, may be used as a strategy to unload a supinated ankle and potentially minimize the risk of ankle sprain injuries.

The effect of 2 Hz and 100 Hz electrical stimulation of acupoint on ankle sprain in rats

The electrical stimulation of acupoint (ESA) releases several endogenous neuropeptides, which play important roles in management of pain and inflammation. ESA with low and high frequencies has been shown to release different neuropepides, suggesting its various therapeutic effects. Pain and edema are major problems for ankle sprain. However, there have been few reports on the effects of ESA for ankle sprain. We aimed to investigate that ESA can reduce pain and edema resulting from ankle sprain, and whether there is a difference in therapeutic effects between low and high frequency ESA. To induce ankle sprain in Sprague-Dawley rats, the ankle of right hindpaw was overextended in direction of simultaneous inversion and plantar flexion. Stepping force and edema in the paw of the sprained ankle were measured by electronic balance and plethysmometer, respectively. In both 2 and 100 Hz ESA groups, stepping force was increased significantly in similar degrees (p<0.05). Only 2 Hz ESA produced the significant rapid decrease in ankle edema. This study demonstrates that ESA of 2 Hz and 100 Hz shows comparable analgesic effects, but only 2 Hz ESA can facilitate the reduction of edema caused by ankle sprain.

Prevention of hamstring strains in elite soccer: an intervention study

The purpose was to test the effect of eccentric strength training and flexibility training on the incidence of hamstring strains in soccer. Hamstring strains and player exposure were registered prospectively during four consecutive soccer seasons (1999-2002) for 17-30 elite soccer teams from Iceland and Norway. The first two seasons were used as baseline, while intervention programs consisting of warm-up stretching, flexibility and/or eccentric strength training were introduced during the 2001 and 2002 seasons. During the intervention seasons, 48% of the teams selected to use the intervention programs. There was no difference in the incidence of hamstring strains between teams that used the flexibility training program and those who did not [relative risk (RR)=1.53, P=0.22], nor was there a difference compared with the baseline data (RR=0.89, P=0.75). The incidence of hamstring strains was lower in teams who used the eccentric training program compared with teams that did not use the program (RR=0.43, P=0.01), as well as compared with baseline data for the same intervention teams (RR=0.42, P=0.009). Eccentric strength training with Nordic hamstring lowers combined with warm-up stretching appears to reduce the risk of hamstring strains, while no effect was detected from flexibility training alone. These results should be verified in randomized clinical trials.

Rubber bands reduce the cost of carrying loads

Vertical movement of the hip during locomotion causes a loaded backpack to be accelerated with each step, which imposes large peak forces on the wearer. Here we show that using bungee cords to suspend the load from a backpack frame reduces not only its vertical movement, and hence its vertical force on the carrier, but also the energetic cost of walking with the pack. This permits larger loads to be carried while moving rapidly, and at the same time reduces the risk of orthopaedic and muscular injury.

Acute ankle sprain: an update

Acute ankle injury, a common musculoskeletal injury, can cause ankle sprains. Some evidence suggests that previous injuries or limited joint flexibility may contribute to ankle sprains. The initial assessment of an acute ankle injury should include questions about the timing and mechanism of the injury. The Ottawa Ankle and Foot Rules provide clinical guidelines for excluding a fracture in adults and children and determining if radiography is indicated at the time of injury. Reexamination three to five days after injury, when pain and swelling have improved, may help with the diagnosis. Therapy for ankle sprains focuses on controlling pain and swelling. PRICE (Protection, Rest, Ice, Compression, and Elevation) is a well-established protocol for the treatment of ankle injury. There is some evidence that applying ice and using nonsteroidal antiinflammatory drugs improves healing and speeds recovery. Functional rehabilitation (e.g., motion restoration and strengthening exercises) is preferred over immobilization. Superiority of surgical repair versus functional rehabilitation for severe lateral ligament rupture is controversial. Treatment using semirigid supports is superior to using elastic bandages. Support devices provide some protection against future ankle sprains, particularly in persons with a history of recurrent sprains. Ankle disk or proprioceptive neuromuscular facilitation exercise regimens also may be helpful, although the literature supporting this is limited.

Prophylactic bracing versus taping for the prevention of ankle sprains in high school athletes: a prospective, randomized trial

Prophylactic ankle taping has been considered the mainstay of ankle injury prevention and has been used at all levels of competitive football. An alternative to taping is a semirigid ankle orthosis. This study prospectively compared the incidence of ankle sprains in high school football players during a single season, after randomization to either prophylactic bracing or taping of both ankles. Of 83 athletes followed up for an entire season, 6 ankle sprains occurred, 3 in each treatment group; and there was no statistically significant difference in the incidence of ankle sprains between the 2 groups. The time required to tape an athlete averaged 67 seconds per ankle, resulting in a total of 97 minutes per ankle during an entire season, and the average cost to tape each ankle during an entire season was greater than the cost of the commercially available brace. The projected cost savings for an athletic program using prophylactic bracing could be substantial when compared with the use of prophylactic taping of the ankle.

Ground reaction force in basketball cutting maneuvers with and without ankle bracing and taping

CONTEXT AND OBJECTIVE

In basketball, the most common injuries are ankle sprains. For this reason, players frequently use external ankle devices or taping as prophylactic and rehabilitation measures. The purpose of this study was to evaluate ground reaction force (GRF) responses in basketball players while performing typical cutting maneuvers with and without ankle bracing and ankle taping.

DESIGN AND SETTING

Comparative study with experimental design of single-group repeated measurements, at Medical Rehabilitation Division, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo.

METHODS

Vertical (Fy) and medial-lateral (Fz) GRF measurements were made under three conditions (taping, Aircast-type orthosis and basketball shoes alone), with analysis of peak forces at foot contact (Fymax1, Fzmax1, Fymax2 and Fzmax2), growth gradient (peak/time) (GG Fymax1, GG Fzmax1, GG Fymax2 and GG Fzmax2) and impulse after foot contact.

RESULTS

Bracing significantly reduced Fymax2 and GG Fymax2. GG Fzmax1 was significantly higher for the sport shoe condition than for the taping condition. Taping increased Fy in relation to the sport shoe at foot contact, but over a longer time interval, without increasing excessive ankle loading. Fz reached a peak in less time, which might generate greater inversion/eversion loading on a player's foot. The Aircast exerted better shock-absorbing effect than did the other two conditions, since it generated less vertical force over longer time intervals and smaller medial-lateral forces in relation to taping.

CONCLUSIONS

Ankle bracing and ankle taping action mechanisms are still unclear and therefore should be carefully prescribed. More studies are needed to clarify taping and bracing effects on sporting activities.

The role of fibular tape in the prevention of ankle injury in basketball: A pilot study

STUDY DESIGN

Prospective nonrandomized controlled trial.

OBJECTIVES

To determine the effect of fibular repositioning tape (FRT) on incidence and severity of ankle injury.

BACKGROUND

Pain and functional disability is common following ankle sprain and a major problem in sport. A novel method of taping, FRT, which has been described to prevent ankle sprain, requires less tape than traditional methods and is easier to apply. The objective of this study was to determine the effect of FRT on the incidence and severity of ankle injury in basketball.

METHODS AND MEASURES

One hundred twenty-five male basketball players were assigned at time of play to either the control (209 exposures) or FRT (224 exposures) condition in a manner of convenience. Control participants had the choice on the use and type of prophylaxis, excluding FRT. FRT participants were taped using the method described by Mulligan. Ankle injury data were collected after each exposure. Injury severity was determined by functional limitation, pain levels, and days to return to play.

RESULTS

Four hundred forty-three measured basketball exposures resulted in 11 ankle injuries. All injuries occurred in subjects with a history of previous ankle sprain. Significantly less ankle injuries were sustained by members of the FRT condition (n = 2), compared to members of the control condition (n = 9) (Fisher exact test, P = .03). The odds ratio of sustaining an ankle injury was 0.20 (P = .04; 95% confidence interval [CI]: 0.04, 0.93) when taped with FRT and the number needed to treat was 22 (95% CI, 12-312).

CONCLUSIONS

This study provides preliminary data regarding the prophylactic effects of FRT on ankle injury in male basketball players.

Do voluntary strength, proprioception, range of motion, or postural sway predict occurrence of lateral ankle sprain?

Prevention of ankle sprain, the most common sporting injury, is only possible once risk factors have been identified. Voluntary strength, proprioception, postural sway, and range of motion are possible risk factors. A systematic review was carried out to investigate these possibilities. Eligible studies were those with longitudinal design investigating ankle sprain in subjects aged > or = 15 years. The studies had to have measured range of motion, voluntary strength, proprioception, or postural sway before monitoring incidence of lateral ankle sprain. Dorsiflexion range strongly predicted risk of ankle sprain. Postural sway and possibly proprioception were also predictors. Therefore the preliminary evidence suggests that people with reduced ankle dorsiflexion range may be at increased risk of ankle sprain.

Why are older Australian football players at greater risk of hamstring injury?

INTRODUCTION

Increasing age is a commonly identified predictor of hamstring injury but is not modifiable to reduce injury risk. Why increasing age is a risk factor for hamstring injuries in athletes has not been studied to date. This study aimed to identify potentially modifiable age-related changes that predict hamstring injury in a population of Australian football players.

METHODS

One hundred and one young (< or =20 years), and 73 older (> or =25 years), Australian football players, without a history of hamstring injury in the past 12 months were studied prospectively. Players underwent screening of anthropometric, flexibility and lower extremity range of movement tests during the pre-season period and were followed-up for a full season with respect to injury and match participation. Comparisons of the age groups were performed to identify differences related to age. Logistic regression analysis was undertaken to determine whether the observed differences were predictors of hamstring injury.

RESULTS

There were significant differences between the age groups with respect to body weight, body mass index, hip flexor flexibility, hip internal rotation and ankle dorsiflexion range of movement. Body weight and hip flexor flexibility were significant independent predictors of hamstring injury in players aged > or =25 years. None of the observed differences were predictors of injury in the younger age group.

CONCLUSIONS

There are age-related changes that are potentially modifiable to reduce injury risk in older athletes and these factors should be considered in the development of hamstring injury prevention programs for this high risk group.

Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union

BACKGROUND

The incidence of hamstring muscle injuries in professional rugby union is high, but evidence-based information on risk factors and injury-prevention strategies in this sport is limited.

PURPOSE

To define the incidence, severity, and risk factors associated with hamstring muscle injuries in professional rugby union and to determine whether the use of hamstring strengthening and stretching exercises reduces the incidence and severity of these injuries.

STUDY DESIGN

Cohort study (prevention); Level of evidence, 3.

METHODS

Team clinicians reported all hamstring muscle injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury; loss of time from training and match play was used as the definition of an injury. Players' match and training exposures were recorded on a weekly basis.

RESULTS

The incidence of hamstring muscle injuries was 0.27 per 1000 player training hours and 5.6 per 1000 player match hours. Injuries, on average, resulted in 17 days of lost time, with recurrent injuries (23%) significantly more severe (25 days lost) than new injuries (14 days lost). Second-row forwards sustained the fewest (2.4 injuries/1000 player hours) and the least severe (7 days lost) match injuries. Running activities accounted for 68% of hamstring muscle injuries, but injuries resulting from kicking were the most severe (36 days lost). Players undertaking Nordic hamstring exercises in addition to conventional stretching and strengthening exercises had lower incidences and severities of injury during training and competition.

CONCLUSION

The Nordic hamstring strengthening exercise may reduce the incidence and severity of hamstring muscle injuries sustained during training and competition.

Strategies for the prevention of volleyball related injuries

Although the overall injury rate in volleyball and beach volleyball is relatively low compared with other team sports, injuries do occur in a discipline specific pattern. Epidemiological research has revealed that volleyball athletes are, in general, at greatest risk of acute ankle injuries and overuse conditions of the knee and shoulder. This structured review discusses both the known and suspected risk factors and potential strategies for preventing the most common volleyball related injuries: ankle sprains, patellar tendinopathy, and shoulder overuse.

The effect of a balance training program on the risk of ankle sprains in high school athletes

BACKGROUND

Ankle sprains are the most common musculoskeletal injuries that occur in athletes, and they have a profound impact on health care costs and resources.

HYPOTHESIS

A balance training program can reduce the risk of ankle sprains in high school athletes.

STUDY DESIGN

Randomized controlled clinical trial; Level of evidence, 1.

METHODS

Seven hundred and sixty-five high school soccer and basketball players (523 girls and 242 boys) were randomly assigned to either an intervention group (27 teams, 373 subjects) that participated in a balance training program or to a control group (28 teams, 392 subjects) that performed only standard conditioning exercises. On-site athletic trainers recorded athlete exposures and sprains.

RESULTS

The rate of ankle sprains was significantly lower for subjects in the intervention group (6.1%, 1.13 of 1000 exposures vs 9.9%, 1.87 of 1000 exposures; P = .04). Athletes with a history of an ankle sprain had a 2-fold increased risk of sustaining a sprain (risk ratio, 2.14), whereas athletes who performed the intervention program decreased their risk of a sprain by one half (risk ratio, 0.56). The ankle sprain rate for athletes without previous sprains was 4.3% in the intervention group and 7.7% in the control group, but this difference was not significant (P = .059).

CONCLUSION

A balance training program will significantly reduce the risk of ankle sprains in high school soccer and basketball players.

Single leg balance test to identify risk of ankle sprains

BACKGROUND

Ankle sprains are a common and potentially disabling injury. Successful prediction of susceptibility to ankle sprain injury with a simple test could allow ankle sprain prevention protocols to be initiated and help prevent disability in the athletic population.

OBJECTIVE

To investigate the ability of the single leg balance (SLB) test, carried out at preseason physical examination, to predict an ankle sprain during the autumn sports season.

DESIGN

Prospective cohort study

SETTING

High school varsity athletics and intercollegiate athletics.

MAIN OUTCOME MEASURE

Ankle sprains in athletes with positive SLB tests.

RESULTS

The association between a positive SLB test and future ankle sprains was significant. Controlling for confounding variables, the relative risk for an ankle sprain with a positive SLB test was 2.54 (95% confidence interval, 1.02 to 6.03). Athletes with a positive SLB test who did not tape their ankles had an increased likelihood of developing ankle sprains. The relative risk for ankle sprain for a positive SLB test and negative taping was 8.82 (1.07 to 72.70). A history of previous ankle injury was not associated with future ankle sprains in this study. The kappa value for interrater reliability for the SLB test was 0.898 (p<0.001).

CONCLUSIONS

An association was demonstrated between a positive SLB test and ankle sprain. In athletes with a positive SLB test, not taping the ankle imposed an increased risk of sprain. The SLB test is a reliable and valid test for predicting ankle sprains.